Topic 1: Maintaining a Balance.

Most organisms are active in a limited temperature range. Organisms have to adapt to the extreme fluctuations of the external environment in order to

keep internal conditions within an extremely narrow range

Identify the role of enzymes in metabolism, describe their chemical composition and use a simple model to describe their specificity on substrates.

Enzymes are protein molecules present in cells that act as biological catalysts controlling all metabolic reactions (chain of amino acids- CHONPS)

Accelerate/ increase the rate of chemical reactions without being used up- can be reused Long chains of amino acids folded into a specific shape substrate specific Anabolic reactions build up large molecules from simpler substrates, endergonic Catabolic reactions break down complex molecules into simpler ones, exergonic Co-enzymes (organic)/ Cofactors (inorganic- vitamin/metal) binds with protein forming part

of active site essential for reactions to occur- some enzymes can function alone but others need to be enzyme-cofactor complex

Eg. Amylase (starch glucose), rennin (milk curdle- absorb protein- in stomachs of milk drinking calf’s), catalyse (H2O2 H2O + O2)

Intercellular enzymes (inside cells- catalyse) or extracellular enzymes (digestive enzymes)

Role in Metabolism: Speed/slow reactions w/o raising temperature (lower act. NRG) heat damages living tissue Lower act NRG: reduces amount needed eg cannot combine glucose and oxygen with heat

so enzymes lower activation energy so ATP can be produced

Factors affecting enzymes: Temperature: optimum 37 deg. efficiency decreases at high temperatures and loses

functioning above 60 as hydrogen bonds maintaining shape break and alters shape (aka it becomes denatured)- active site no longer fits substrate- cold temperatures mean that the shape is altered and the enzyme is unable to meet minimum activation energy

pH: functions in narrow range outside affects shape: usually optimum at neutral but enzymes such as pepsin or rennin function best at 2 (stomach)

Substrate concentration: activity will increase to a point as the substrate and enzyme have a high affinity to one another until saturation point where all enzyme molecules are being used and rate steady’s as at maximum turnover rate increase enzyme concentration

Models: Lock and key: active site rigid substrate reciprocally shaped to fit site= enzyme-substrate

complex reaction occur in close proximity Induced-fit model (new modification- based on the realisation that proteins are not rigid)

active site alters slightly to fit tightly around substrate (like a sock and foot)

Identify the pH as the way of describing the acidity of a substance

Scale measures acidity or alkalinity Measures the concentration of hydrogen ions in a solution makes more acidic 7 neutral further away= more acidic or more basic

Describe homeostasis as the process by which organisms maintain a relatively stable internal environment.

Maintenance by an organism of a constant or almost constant internal state, regardless of external environmental change

Continue to function effectively internally and combat environmental fluctuations

Explain why the maintenance of a constant internal environment is important for optimum metabolic efficiency.

Cells- cytoplasm and interstitial fluid- vulnerable to environmental change need to be maintained in a narrow range of conditions enzymes are sensitive to changes

Metabolic efficiency relies on optima range of temp and pH, concentration of reactants, water/salt conc. (osmotic pressure), absence of toxins which may inhibit enzyme function

Need reactants for reaction to occur eg levels of ATP affect the energy powering metabolism levels of glucose/oxygen affect amount of ATP produced ripple affect

Water required as a solvent – concentration of salts limit- affect osmotic balance Toxins may block active site or alter optimal environment CO2 lowers pH

Explain that homeostasis consists of two stages: detecting changes from the stable state and counteracting changes from the stable state.

1) receptors or sensory cells detect a stimulus eg. Chemical change in the body 2) effector organs produces a response that restores steady state Homeostasis maintains conditions in a narrow range if exceeds limited range the negative

feedback mechanism occurs to counteract the change and restore natural balance

Outline the role of the nervous system in detecting and responding to environmental changes Based on negative feedback system to combat environmental change Stimulus receptor (convert stimulus to impolses) sensory neurons (PNS) control

centre (CNS- brain/spine- hypothalamus)- process new info and trigger impulses motor neurons effectors response

Sense organs detect stimuli from external environment/ interceptors detect internal change Thermo receptors- detect heat/ chemoreceptors- detect chemical conc. Such as CO2 levels,

photoreceptors- detect light in eye/ mechanoreceptors- detect movement or vibrations ear CNS processes information by interconnecting nerve cells and initiate the response via PNS

Temperature Regulation: Heat gained through heat energy released from respiration, muscle function, ext. sun, food Heat lost through radiation of heat out of body, convection- wind, evaporation, ext. factors Detected by thermoreceptors outside (skin) and inside body- inside present in hypothalamus

monitoring blood temp and sensitive to small temperature changes Sent to hypothalamus to process stimulate a response

Warming body Cooling bodyRaise hairs (goose bumps)- trap an insulating Vasodilation- heat loss at surface due- radiation,

layer of air- reduce heat loss from radiation conduction, constriction- rednessVasoconstriction- prevent heat from reaching surface and direct toward centre of body- pale and blue appearance

Sweating- sweat glands activated by heat loss centre- body cooled as sweat evapourates- sweat not in all animals- kangaroos lick paws

Shivering- generate muscle movement- heat Decrease metabolism- less heat generate- tiredIncrease metabolism- thyroid- generate heat

Identify the broad range of temperatures over which life is found compared with the narrow limits for individual species.

Maintain constant temp- most organisms enzymes denature above 42 degrees- weak hydrogen bonds break as temperature increases- change shape of active site

Most living things live between 10 and 35 degrees/ plants between 5 and 40 degrees Organisms can survive as low as -70 (poles) and as high as 350 (in hot vents) Individual species can only live over a limited range of this staghorn coral Platypus:-8 to 34 degrees, silky oak: 0-38 degrees (alpine regions), pompei worm most heat

tolerant animal between 22 and up to 80 degrees insulated by bacterial cover, banksia withstand immense fire temperatures to regenerate , artic fox can live -70- shunting blood vessels

Can live over very limited ranges- Stag horn Coral- 4 degrees variationCompare responses of names Australian ectothermic and endothermic organisms to changes in the ambient temperature and explain how these responses assist temperature regulation:

Endothermic organisms rely on internal regulation of temperature such as metabolism whilst ectothermic organisms rely on the external environment for temperature regulation

Ambient temperature is the temperature of the environment in immediate surroundings Ectoderms body temperature influenced by ambient temperature but endotherms is not

and instead have behavioural adaptations to maintain constant internal state

Behavioural Structural physiologicalThorny devil Desert- central

AustraliaLies flattened against warm sand in morning- removes during day- shade/burrow

Fattened body with large scales9cm long

Eats ants/ makes use of dew by absorbing through skin

Mitchells Hopping Mouse

Desert On cold nights- fluffs out furBurrows from late morning to mid arvo and not active mid day

Small slim body/ small ears

Network of blood vessels and sweat glands in ears

Corroboree Frog Alpine- high altitude areas of South Australia

Stays in moss overnight basks in sun in the morningOnly active on warm days when feed to gain fat eating insects

Small, thin body covered with wet slimy skin- coloured black with yellow features

Late winter- sex organs develop so ready to mate when first active in spring

Mountain Pigmy Possum

Alpine- Eastern Australia above 1400m

Doubles in body weight between spring-autumn eating anthropoids/seeds, hibernates by curling body into ball during winter

Thick fur, round stocky body

Limited blood circulation in ears, slows down metabolic rate- conserve energy/ reduce heat produced

Advantages Ectothermic: don’t have to generate heat don’t need as much foodDisadvantage: if too cold enzymes unable to become active need to expose self (danger of predators) in order to warm upIdentify some responses of plants to temperature change:

Plants respond to changes in light, water availability and temperature

Responses to high temperatures: Above 40 degrees damages protiens/ above 75 degrees damages chlorophyll pigment Cannot move to avoid heat Evaporative cooing/ transpiration- heat/ light cause stoma to open- transpiration cools

plant- excessive heat cause stoma to close- threat overheating cause dehydration Turgor response: wilt (through water loss due to transpiration) to reduce SA exposed to

sun if not enough water to replenish plant may die eg hydrangea Leaf orientation: hang vertically downward only exposed to less intense rays of early/ late

and avoid exposure to midday sun eucalypts

Leaf falling: eucalypts drop some leaves in dry months to reduce SA exposed to sun- eucalypt

Reseeding: bottle brush resprout on the underside of leaf in epicormic buds which are protected by fire/ banksias pods open and release seeds after fire- regenerate

Responses to cold temperatures: Organic anti-freeze- ice forms between cells- risk of damage to plants produce anti-freeze

organic compounds reducing the temperature at which the cytoplasm freezes (Antarctic hairgrass plant)

Dormancy: deciduous trees loose their leaves in winter allowing them to survive low temps, water and light shortages (deciduous beech)

Vernalisation: flowering in response to low temperatures- tulip bulbs must be expsed to qt least 3 months extreme cold before flowering

Responses to temperature change due to changing light, temperature or chemical composition of plant

Adaptations- a feature that helps and organism exist in its environment

Structural- physical features of the body

Bilby has large ears with many blood vessels

Schlerophyll- hard leaves (don’t wilt when lots water lost)/ needle shaped- small SA/V reduce water loss

Behavioural Kangaroo licks forearms- evaporative cooling

Eucalypts- leaves hang vertically- no midday sun

Physiological Spinifex hopping mouse- concentrated urine-retain h20

Sacred lotus- alter its metabolic rate- constant temp

Adaptations to High Temperatures Adaptations to water lossThe Red Kangaroo Feed at dawn/dusk and rest in shade

in midday sunLick forearms for evaporative coolingLarge ears with man blood vessels for vasodilation

Produce small amounts concentrated urineEmbryonic diapause- withhold fertilised egg if lack water to support- lack stress of supporting joey and use water for self

Yellow Box Eucalyptus

Shiny leaves reflect sun raysLeaves hang vertically to prevent exposure to midday sunDrop old leaves in high temperature to reduce SA exposed to sun

Hard sclerophyll leaves to prevent damage when water lostWoody seed pod to prevent seeds from drying out

Plants and animals transport dissolved nutrients and gasses in a fluid medium.

Developed transport systems allow complex organisms to transport substances- diffusion not efficient enough due to SA/V

All transport systems: a transport medium, presence of vessels to carry, a driving mechanism Blood is a transport medium- plasma and red blood cells 45% cells and 55% plasma Distributes heat, maintains a pH of 7.35 carries nutrients required and wastes to be

excreted by the body

Red blood cells- transport oxygen- forms in bone marrow- no nucleus, just haemoglobin pigment Have diameter of 7 micrometres/ Biconcave

o Contain haemoglobin: a protein globin and iron combine with oxygen to form oxyhaemoglobin

White blood cells- protect infection- smaller with a nucleus Platelets- half size of red blood cells used in clotting of blood- stick to eachother and

blood fibres on site of the wound- release an enzyme to seal blood vessels and cause blood to clot

Plasma- 90% water/10% protiens- carries substances in dissolved or suspended form RBC:WBC:PLATELETS 600:1:45

Identify the form(s) in which each of the following is carried in the mammalian blood. Transport substances to maintain homeostasis chemical maintenance to metabolism

Substance FormCarbon Dioxide 70%transported dissolved as hydrogen carbonate ions

7% dissolved in plasma 23% combined with haemoglobin

Waste product of respiration diffuses from cells into blood stream produced carbonic acid in water lowers the pH of bloodTherefore either rapidly converted into hydrogen carbonate ions: CO2+H20H2CO3 HCO3- + H+

Oxygen 98.5% combines with haemoglobin- 4 oxygen’s to on haemoglobin molecule (oxyhaemoglobin)

1.5% dissolved in plasma Biconcave shape f red blood cell- SA/V for diffusion of oxygen

Water Carried as blood plasma which is 90% waterSalts Carried as ions in the plasma eg Na+ and Ca2+

Lipids Cannot be dissolved in plasma Lipids digested into fatty acids and glycerol packaged into spherical particles (micelles) absorbed into lacteals in villi of small intestine processed into micelles (chylomicrons) carried in blood as miscible

Nitrogeoeous waste Converted to urea as less toxic dissolved in the plasma with small amounts ammonia and uric acid

Other products of digestion

Disolved or suspended in the plasma amino acids/ glucose

Explain the adaptive advantage of haemoglobin: Protein: 4 polypeptide chains (globins), bonded to haem (iron containing group) Increases oxygen carrying capacity of blood able to bond to 4 molecules 250 million Hb molecules per RBC take up O2 in lungs which is released when too much

CO2 in the surroundings Ability to bind to oxygen increases after the first oxygen molecule binds changes shape

after binding making it easier to bind- a small increase of oxygen concentration in blood significant increase of oxygen saturation in blood

Capacity to release oxygen increases when CO2 present CO2 lowers pH of blood due to carbonic acid haemoglobin is less attracted to oxygen at lower pH due to changed shape releases oxygen able to combine and bind with carbon dioxide more easily

In a red blood cell does not affect osmotic balance in plasma Enables increased efficiency of oxygen absorption by cells and greater energy capacity in

respiration can occupy different environments/ more complex moement

Outline the need for oxygen in living cells and explain why the removal of CO2 from cells is essential

Oxygen needed for cellular respiration obtain energy growth repair, movement, excretion and reproduction enabled ATP from energy rich sources

Carbon dioxide is waste product of respiration- needs to be removed to prevent pH change forms carbonic acid with water lower pH denature enzymes metabolism

Compare the structure of arteries, capillaries and veins in relation to their function. Transport system in mammals transport blood and lymph Interstitial fluid (diffuse out of capillaries- carry nutrients)- returns to lymphatic vessels

forming lymph and is carried back toward the heart to the venous system to re-join blood

Describe the main changes in the chemical composition of the blood as it moves around the body and identify the tissues in which these changes occur.

Organ Change ExplanationLungs In: high CO2/ low O2

Out: low CO2/ high O2-CO2 conc. Higher in blood than alveoli and O2 conc higher in alveoli than blood- diffusion-Oxygen attaches to Hb in deoxy. blood to heart

Right side heart In: high CO2/ low O2Out: high CO2/ low O2

-Blood enter from vena cava deoxygenated blood carried to lungs via pulmonary artery

Left side of heart In: low CO2/ high O2Out: low CO2/ high O2

-enters from lungs via pulmonary vein oxygenated blood with O2 from lungs leaves for body tissues via aorta

Kidney In: Urea, some ammonia, saltsOut: nitrogenous wastes removed

-enters via renal artery-wastes, excess water and salts filtered by nephron in kidney-blood exits via renal vein

Liver In:, poisonous substances (alcohol), products of digestion high-amino acids/ glucoseOut: High Urea/ glucose increase or decrease

-Liver breaks down toxic products of digestion and converts ammonia to urea-If meal eaten insulin cause absorption/ storage of glucose in liver- removed= low-If blood glucose low glucagon trigger glucose release= high

Intestines In: low products of digestion (glucose/ amino acids)Out: high

-nutrients from digested food diffuse into blood capillaries ventricles/ veins carry to liver

Body tissues In: low CO2/ high O2Out: high CO2/ low O2

-O2 needed for cell respirationconcentration gradient triggers release of O2/ uptake CO2

Describe current theories about processes responsible for the movement of materials theough plants in xylem and phloem tissue.

XYLEM PHLOEMSubstances Water/ mineral ions Products of photosynthesis-

glucose, sucrose, amino acidsPassive/Active Water root= passive

Ions root = activeXylem leaf= passive (cohesion/ adhesion)

Source phloem = active/ water drawn from xylem via osmosis due to high sugar concentrationIn phloem= passive/ active- conc. Gradient and osmotic pressurePhloem sink= active/ osmosis

Direction of flow Root leavesOne direction

High sugar conc low sugar conc.Many directions

Mechanism Evaporation draw water upWater molecules adhesion/ cohesion

Osmotic pressure difference/ gradient between source/ sinkWater drawn in at any point

Xylem theory: Transpiration stream theory Water absorbed to root (osmosis) root pressure draws more water in push water up Transpiration stream evaporative pull replace water evaporated from leaves Adhesion/ cohesion forces prevent water from flowing back down

Evidence: High water conc. At centre of leaf/ low water conc. at surface of leaf 1893: Stratsburger cut tree trunks submerged in poising solution Poison rose in xylem

and only stopped rising when leaves died: did not need root pressure to obtain water transpiration pull was passive and only force leading to rise of water

Phloem theory: Pressure flow theory/ Source to sink theory Driven by osmotic pressure gradient (differences between sugar and water concentrations) Sugar actively loaded from source phloem (attracts water from xylem- osmotic pressure) As sugar enters osmotic pressure at source end high- draws water pressure flow drives

water toward where water exit and dissolved sugars toward low sugar conc. (sink) more sugar enters at source maintaining gradient Water can enter via osmosis at any point drawn toward where water exits phloem at sink Sugars offloaded into sink via active transport water drawn out low osmotic pressure

Evidence: Radioactive tracers (Carbon 14)- show movement of glucose in plants X-rays Amphids stuck proboscis (mouth part) on phloem tube cut body off sap kept flowing

show that pressure and hence sugar concentration head toward sink Movement in phloem too fast for diffusion/ too slow for active mix of both/ osmotic pres.

Analyse information from secondary sources to identify current technologies that allow measurement of oxygen saturation and carbon dioxide concentrations in blood and describe and explain the conditions under which these technologies are used.

Identify technologies: ABG (Arterial Blood Gas) measure how efficiently obtaining O2/ getting rid of CO2

measure partial pressure of O2 and CO2, O2 content/ saturation, bicarbonate content- highlight kidney function, pH (number of H+ ions- CO2)

Pulse oximeter monitor O2 saturation via a sensor using the absorption of light to indicate the uptake of O2 by Hb in comparison with oxygen carrying capacity

Conditions under which the technologies are used: ABG invasive – measured through direct blood sample drawn through an arterial probe:

o Assess/detect repertory diseases emphysema, pneumoniao Test how well kidneys and lungs are maintaining blood pH- detect kidney efficiency

Pulse oximeter non-invasive: used to constantly monitor blood gasses a sensor is attached to the person's finger, earlobe or toe. Detect colour of the blood (changes amount of oxygen that is dissolved in the blood) The sensor emits a light measures the amount of light absorbed as it passes through the tissue and blood, and transmits the information

o during heavy sedation or anesthesia provide constant monitoringo on a ventilator, artificial breathing machine, during stress testing, in sleep

laboratories, checking the body's response to different medications

Impact of advances in biology on technology: Biology allow understanding of vitality of oxygen/ toxic CO2 importance of functionality of

lungs, kidney development of technologies for early detection/ maintenance of disease New technologies research into smartphones to detect O2 levels from oximeters via

Bluetooth self evaluation and care save lives/ medical advancements and efficiency

Analyse information from secondary sources to identify the products extracted from donated blood and discuss the uses of these products

Used to treat patients with illnesses/ blood deficiencies (leukemia) replacing components of blood the most efficient treatment

Blood separated into 20 different fractions (centrifuging)- one donation treat many patients Whole blood only used when nooded lost more than 20% blood volume- injury/surgery

Component Blood Product FunctionRed Blood Cells Red cell concentrate Anaemia/after blood loss increase oxygen

carrying capacity to body tissuesPlasma Plasma Haemophilia treat people with clotting disorders/

adjust blood osmotic pressure/ balance salts/ increase blood volume after blood loss

White Blood Cells White cell concentrate Boost immune system treat life threatening infections when cell count low/ not working

Platelets Platelet concentrate Lymphoma/ leukaemia blood clotting capabilityCryoprecipitate Cryprecipitate AHF Fraction of plasma with blood clotting factors

treat sever haemorrhagingImmunoglobulin Immunogloulin Infection fighting component of blood plasma

treat inefficient immune systems eg AIDS

Impact on Biology Advances in technology, society and environment, future directions Understanding cross match blood groups, separation of blood more successful transfusion Increased blood shelf life adding chemicals Separation of blood less donors overcome lack of compatible donors- 3x more transfuse Development of blood screening to detect hepatitis and aids more successful transfuse New technologies: developing shelf life through freeze fractioning, improve blood screening

methods, artificial blood- overcome blood shortages when marrow cant manufacture blood

Analyse and present information from secondary sources to report on progress in the production of artificial blood and use available evidence to propose reasons why such research is needed

Progress in production: 1616- William Harvey described blood circulation scientists consider blood alternatives WWI/WWII/ Vietnam war treat soldiers who suffer blood loss/ transportation in hot Began experimenting by Dr Leland Clark in 1960’s oxygen carrying perfluorocarbons AIDS epidemic fear of transmission of infections

Why needed? Need blood oxygen transport/ maintaining fluid, water and salt volume Overcome issues including cross matching- reject transfusion Many countries do not have high quality storage facilities short shelf life Most development after HIV epidemic in the 80’s diseases prevent donation

Transfusions Artificial-42 days shelf life-Must be matched to blood type-needs refrigeration-contains clotting/ disease fighting components-May contain diseases need screening

-Lasts for over a year-Does not need to be matched-not need refrigeration-no clotting/ disease fighting components-no contaminants- no screening needed

Designed to increase plasma volume/ oxygen carrying capacity with a long shelf-life, production in large quantities, non-toxic and safe, continues to circulate in body

Types of Oxygen carrying artificial blood:

Perfluorocarbons: Carry oxygen in a dissolved form when more O2 needed works via passive diffusion Carry 5x more oxygen than blood can/ disease free/ stored indefinitely at room temp Broken down in kidney and liver breathed out by lungs Very small can flow through swollen tissue More research needed difficulty mixing with blood stream, need combination with other

substances research mixing with lipids to form an emulsion 5 products trailed in USA but non approved for medical use

Haemoglobin based oxygen carriers: eg Hemapure (used in South Africa) Made from steralised Hb from expired human blood, cow blood and placental blood Treated to be disease free/ not cause rejection or allergic reactions in patients, stored for

yeas at room temp, highly effective at releasing oxygen into tissues, no membrane- no matching of blood types

Current problems: don’t have enzyme preventing oxidisation stop from carrying oxygen, only stay in body for 1 day (increase bp), must be encapsulated in synthetic lipid

Future research: enclosing enzymes/ capsule of phospholipids to increase circulation period

Current research: Not cleared in Australia for use AIDS epidemic – drive approval of artificial blood in Africa Haemopure sterilised cattle Hb shelf life 36 months Polyheme awaiting clearance in US and Australia developed in SAus modified human

Hb delier oxygen 3x more efficient that RBC Both products have circulation time of 12-24 hours compared with 50 days in RBC’s

3. Plants and animals regulate the concentration of gases, water and waste products of metabolism in cells and in interstitial fluid

Need to remove wastes toxic to internal environment and interfere with metabolism Removed via excretion lungs (CO2), nitrogenous wastes (kidney), gills, stomata Removing metabolic wastes/ maintaining osmoregulation maintain blood pH and volume

Explain why the concentration of water in cells should be maintained within a narrow range for optimal function

Leads to changes of solute concentration in cells: water in cells determines osmotic pressure and gradient net movement of water determines conc. of solutes both inside and outside cells conc. of toxins depend on dilution (affect pH)

Provide a medium for chemical reactions: chemical reactions only when dissolved in water water and solute levels must be maintained so cellular reactions can take place

o Too much water- cause cell to burst/ dilute solutes slow metabolism cannot function effectively

o too little- cause to wilt cytoplasm too concentrated/ increase conc. of solutes lower pH/ osmotic pressure and pH must be maintained for enzyme function

High Specific heat capacity: absorbs/ releases large amounts of heat for small change in temperature impact enzyme function within cell

Explain why the removal of wastes is essential for continued metabolic activity: Need to maintain homeostasis toxic to cells If not continually removed accumulate alter internal environment Slow or inhibit enzyme function CO2 lowers pH denature enzymes Other wastes increase solute conc.--> alter reaction wastes, osmotic imbalance- alter

membrane functioning

Identify the role of the kidney in the excretory system of fish and mammals: Filter blood that enters and remove nitrogenous waste from breakdown of amino acids in

liver excrete Osmoregulation stable water balance in the body stable blood pressure/ volume/ pH filtration in nephron renal artery carried out of nephron via ureters bladder

urethra

Freshwater fish: Trout excrete excess water and nitrogenous wastes whilst conserving salts urinate frequent too much water in bodies habitat has little salt and lots of fresh water

excess water accumulate through osmosis across gills- high conc.- low conc. excrete excess water and ammonia no salt accumulation excess salt out gills large glomeruli for filtration of blood in large volumes active re-absorption of salt via gills and water diffuse in and ions out via conc. gradient in gills- need to conserve salts

Marine fish: Snapper kidneys conserve water whilst excreting excess salt and nitrogenous wastes urinate less water loss through osmosis across gills into high salt concentration in habitat small amount concentrated urine active secretion of salt from kidneys which diffuses out through gills drink lot of sea water use water and extract salt kidneys excrete salt and nitrogenous

wastes

water diffuse out via gill and salt diffuse in due to concentration gradient kidneys have small glomeruli with mechanism for removing salt

Mammals: excrete wastes/ conserve or excrete salts and water when required kidney can adjust reabsorption of wastes, water and salts through changing conc. of urine hot weather water lost in sweat from evaporative cooling and thus concentrated urine

produced whilst in cold weather less sweat and more urine is produced with more water adjustment to water and salt levels through hormone ADH and aldosterone make

adjustments to concentration of urine based on body needs

Explain why the processes of diffusion and osmosis are inadequate in removing dissolved nitrogenous waste:

active transport is quicker and more effective as removes wastes against conc. gradient control passage of salts and wastes in turn draw water maintain water balance kidney selectively reabsorbs useful materials

Diffusion: Rate of movement too slow: slow movement- allow wastes to accumulate Not all wastes removed: toxins would only move out of cells if more concentrated inside cell

and would stop at equilibrium not all waste removed accumulation change pH and other conditions in cells

Osmosis: Too much water lost in urine: if lots of nitrogenous waste lots of water drawn in to

equalise very dilute urine too much water lost needed for internal function Make too dilute for excretion by diffusion: fresh water environments osmosis from

surroundings dilute toxins lower conc. gradient slow excretion by diffusion

Distinguish between active and passive transport and relate these to processes occurring in the mammalian kidney

Kidney uses both active and passive transport to selectively excrete wastes, salt and water Ability to alter urine concentration homeostasis maintained 2 process: bloodstream kidney tubules/ reabsorption from urine to kidney tubules- blood

Passive Active-Diffusion and osmosis movement across concentration gradient based on Brownian motion-slow if gradient not steep-water movement once filtration has occurred in Bowman's capsule, water returns via the interstitial fluid from the tubule to the capillary in the process of osmosis along the length of the tubulebased on the salt balance which occurs by active transport-some wastes such as urea and ammonia move via diffusion

-moves sodium/hydrogen ions, glucose and amino acids across the wall of the nephron via carrier proteins-reabsorption or glucose and amino acids from urine-more wastes and hydrogen ions are added to urine in kidney tubules-conservation of salts: ‘sodium pump mechanism’ actively transports salts back into kidney tubules water conservation salts draw water across gradient via osmosis

Explain how the processes of filtration and reabsorption in the mammalian nephron regulate body fluid composition

Main functional unit of kidney is nephron bowman’s capsule, proximal convoluted tubule, loop of Henle, distal convoluted tubule, collecting duct

Glomerular filtrate fluid in nephron chemically altered in nephron become urine

Filtration: Renal artery small vessels network of capillaries (glomerulus) High pressure blood forced through glomerulus into bowman’s capsule- filter on size Filtration in Bowmans capsule Blood cells and proteins remain water with dissolved amino acids, glucose, ions,

nitrogenous wastes pass through become glomerular filtrate which is altered in nephron

Reabsorption: Active transport Filtrate contains molecules the body needs amino acids, glucose, some water and ions

99% filtrate reabsorbed whilst only 1% excreted as urine Back into interstitial fluid blood capillaries larger vessels renal vein Reabsorption based on bodies requirements at that time feedback from body Hormones control changes in membrane permeability control substances reabsorbed

o Proximal tubule: organic nutrients (glucose/amino acids),ions (K+, Na+, HCO3,Ca+, Mg+, NaCl (salts)) and water/ H+ and NH3 absorbed into nephron

o Loop of Henle: Descending: water/ Ascending: membrane impermeable to water but permeable to salts (disassociated into ions) ions reabsorbed (sodium mainly as a part of osmoregulation)

o Distal tubule: Salts, water, bicarbonate ions (HCO3-)/ k+ and H+ taken ino Collecting tubules: mainly water and some urea

Solutes reabsorbed accumulate in SALTY medulla draw water out by osmosis Specific to substances reabsorbed permeability of membrane/ specific carrier proteins Loop of henle vital to osmoregulation- longer- more space for water osmosis into medulla

Tubular Secretion: Removal of other toxic substances from blood with active secretion into nephron Metabolic wastes by diffusion and drugs (penicillin/morphine)/other by active Permeability of membrane to water controlled by ADHconserve water make permeable Aldosterone (adrenal glands) control transport of Na in ascending loop of Henle

Outline the role of the hormones, aldosterone and ADH (anti-diuretic hormone), in the regulation of water and salt levels in blood

Travel from endocrine glands to target cells via blood circulation Important role in osmoregulation regulate solute concentration regulate blood volume

and pressure through a large volume of dilute urine/ small volume concentrated urine

Aldosterone: For the conservation of salts within the body Adrenal gland- regulate passage of sodium and potassium ions Decrease in conc. Na+ decrease blood volume stimulate adrenal gland aldosterone Increase permeability to sodium especially ascending loop of Henle and Distal tubule salt

actively reabsorbed to kidney interstitial tissue Blood pressure and volume decreases detected by receptors in kidneyaldosterone

increase active transport of ions in ascending loop increase H2O reabsorbed—regulate bp and solute concentration increase blood pressure and blood volume

ADH: Anti-diuretic Hormone:

Dehydration blood volume drops detect by osmoreceptors in the hypothalamus stimulate pituitary ADH

Increase permeability of membranes of distal tubules and collecting ducts to water Water reabsorbed to kidney tissue bloodstream conservation of water Too much fluid detected by sensors in the heart- stop AHD-

Aldosterone ADH-Regulate blood volume-stimulate Adrenal Gland-Increase nephron permeability to sodium-Act on ascending loop of Henle/ distal tubule

-Regulate blood volume-Stimulated pituitary gland-increase nephron permeability to water-Act on distal/collecting tubule

Gather, process and analyse information from secondary sources to compare the process of renal dialysis with the function of the kidney

Renal dialysis process to carry out the function of a failed kidney filter blood efficiently Remove metabolic wastes that have build up in persons blood Some of the causes of kidney disease include: diabetes can cause kidney damage,

Hypertension – high blood pressure, Glomerulonephritis – swelling or inflammation of the tiny filtering units (nephrons), toxic medications, Sepsis, tumours or kidney stones obstructing the kidney/ ureter poorly handled diabetes/HBP or chronic glomerulonephritis cause chronic renal failure

Results in loss of kidney function: fatigue, dry skin and itching, headaches, weight loss, nausea and loss of appetite, dehydration

Dialysis artificially removes waste from your blood only needed when the kidneys fail.

Haemodialysis Peritoneal DialysisOutside the body- blood cleansed and returned to body via catheter

In peritoneal cavity outside the body. Tubes run dialysis fluid into abdominal cavity where diffusion occur- fluid drained and discarded

Move across semi permeable membrane into dialysis fluid

Moves across membrane (peritoneum) to dialysis fluid which is in abdominal cavity

Passive PassivePerformed in hospital Can be done at home

Haemodialysis: pumps blood through a system of coiled tubes with artificial semi-permeable membranes tubes submerged in dialysis fluid- flow in opposite direction to blood- maximise diffusion tubes are coiled to increase SA fluid (dialysate) has same concentration as blood plasma w/o metabolic wastes through

chemicals such as NaCl, Sodium bicarbonate CaCl, KCl and MgCl move through semi-permeable membrane via diffusion fluid constantly replaced

3-4 hours/ 2-3 times a week and cannot remove some wastes like sodium phosphate and K+ Dialysis fluid flows in different direction to blood passive diffusion May risk infection due it invasive technique/ lack of mobility- hospital

Dietary changes include reducing fluids, limiting dairy food, avoiding salty foods and controlling the amount of potassium you eat

Peritoneal Dialysis: occurs inside your body using the peritoneal membrane as a filter. The peritoneal membrane is a fine layer of tissue that lines your peritoneal cavity, which

contains your stomach, liver, spleen and intestines. It has a rich blood supply uses an access device called a catheter- remains in your body until no longer needed connected to a bag containing a special fluid. The catheter allows the fluid to enter and leave

your peritoneal cavity. Waste and extra fluid move from your blood into the special fluid, which is then drained from the body.

Kidneys Renal Dialysis

-Active and passive transport is used throughout the nephron.-Constantly- 150-180L filtered a day-internally monitored with hormones-Uses a series of membranes (nephrons) which are selectively permeable-continuous process; very efficient-Useful substances are reabsorbed actively by the kidney (Na, glucose and amino acids)-membranes-blood/ intertestual fluid-Nitrogenous wastes and water removed-controls blood pressure and pH balance

-Only passive transport is used-3-4 times a week for 3 hours-externally monitored with computers-Also uses membranes (but artificial) which are selectively permeable-Slow process, occurs a few times a week for patients-Useful substances diffuse into blood from dialysing fluid, no reabsorption-Artificial tubing-Dialysate fluid- Nitrogenous wastes and water removed-controls blood pressure and pH balance

Kidney active transport= faster/ reabsorbtion hormonal control exactly to body needs Two healthy kidneys filter the blood volume about once every half-hour. Dialysis is slower

and less efficient process but it is a lifesaver for those people with damaged kidneys

Present information to outline the general use of hormone replacement therapy in people who cannot secrete aldosterone

Hypoaldosteronism is a condition where people fail to secrete aldosterone due to failure of adrenal glands

Addison’s Disease high urine output low blood volume low bp heart failure body would not be able to reabsorb salt dehydration/ excessive potassium, Weakness

fatigue and weight loss imbalance of H+ due to low Na low blood pH/glucose Fludrocortisone(Florinef) : artificial hormone which can be used as a treatment for people

who cannot secrete aldosterone- treat Addison’s disease or low blood pressure careful monitoring must be maintained to avoid fluid retention and high blood pressure. Taken orally once or twice a day lead to side effects such as blurry vision, depression,

swelling, weight gain, pancreatitis, high blood pressure, low K+ (muscle weakness) Advantages: increase fluid retention, bp, danger of heart failure live normal life

Analyse information from secondary sources to compare and explain the differences in urine concentration of terrestrial mammals, marine fish and freshwater fish

Terrestrial Mammal Marine Fish Freshwater FishConcentration Varied urine-depend on

needs of bodySet concentrated urine Set dilute urine

Product Urea- least toxic Urea and ammonia (diluted by water)

Urea and ammonia

Reason Dry environment- water conserved by hormoneUrea as it is less toxic than ammonia- not need to be diluted

Ion conc. high in surroundings water lost by osmosisUrine is concentrated to remove water

Surrounding water dilute to fish cells water enters gill by osmosis—lots of dilute urine to rid excess H2O

Example Human- aldosterone and ADH- Kangaroo rat lives in desert off very little water-loop of Henle 3x length of humans-

Whiting Native Bass

conserve water

Use available evidence to explain the relationship between the conservation of water and the production and excretion of concentrated nitrogenous waste in a range of Australian insects and terrestrial mammals.

Waste from breakdown of protein produce ammonia Ammonia makes pH more alkaline- must be diluted with large amounts of water + excreted

directly—converted to dilute forms of urea or uric acid Ammonia require least energy to be made- only excreted where large amount of water

available (fish) Urea (humans) and uric acid can be excreted in a less dilute form- less water loss- more NRG Uric acid- non soluble in water – excreted as paste so more water can be conserved as least

toxic (pigeon and grass hopper) Regulating water content solved by varying type of nitrogenous waste excreted amount

of water needing to be reabsorbed and conserved effects the type and hence concentration of waste excreted

Define enantiostasis as the maintenance of metabolic and physiological functions in response to variations in the environment and discuss its importance to estuarine organisms in maintaining appropriate salt concentrations.

Enantiostasis: a type of homeostasis: the maintenance of metabolic and physiological in response to variations in the environment- by organisms that experience extreme fluctuations in conditions

Maintain internal salt concentrations protect enzyme activity due to the fact that homeostasis is hard to maintain in fluctuating environments

In a estuary- river meets ocean- salt and water conc. fluctuates due to tide high tide sea water flows so a higher concentration of salt in environment than cytoplasm and vice versa

Avoid or tolerate changes in environment to maintain metabolic activityo Osmoconformers: alter concentration of internal environment to match

environment (conform) body tolerates internal change o Osmoregulator: avoid changes to internal environment – regulate internal

conditions to keep levels optimal and constant regardless of environment

Osmoconformer Osmoregulator - MusselMetabolism- tolerate broad range salinityModify internal conc. to match surroundings

Maintain constant internal environmentMetabolism- limited range of conditions

Small organic molecules (eg non-essential amino acids) to vary internal solute conc.

In freshwater – water accumulates by osmosis produce more dilute urine to counteract

Internal and external conc. equal Higher osmotic pressure inside the bodyFiddler crab- in salt water accumulates excess salt in tissues to equalise salt concentration and pumps out excess salt via gills when freshwater

Mussels- close their valves when tide is in to maintain internal salt concentration the same as in salt water

Processes used by different plants for salt regulation in saline environments.

Grey Mangrove halophyte: Use leaf fall (accumulate salt in old leaves and drop)/ excrete salt through salt glands on leaf surface which is washed off by rain, Pneumatophores (long roots only let water in, excluding salt with a physical barrier in the cuticle)

Pneumatophores grow above low tide line- need sufficient oxygen for respiration Saltbush salt excluder actively transports excess Na and Cl to bladder cells on tip of

hairs on leaf surface which burst when bladder reaches capacity releases salts Put one mangrove in fresh water and other in salt- plastic bag-silver nitrate Halophyte (water plant), xerophyte (arid plant), mesophyte (average conditions)

Describe adaptations of a range of terrestrial Australian plants that assist in minimising water loss Water lost through transpiration Xerophytes are plants living in arid conditions adaptations to minimise water loss Stoma open in response to heat and light/ need CO2/ temperature regulation via evap.

cooling risk of dehydration, need lots of stoma for photosynthesis regulate opening

StructureShiny, waxy cuticle and white hairs

Reflect sunlight regulate internal temp less evaporative cooling

Banksia- thick cuticle and leathery leaves

Needle Leaves Reduce SA exposed to air- reduce no of stoma and water loss

Hakea

Cladodes Photosynthetic stems: reduce SA of leaves- less transpiration

She-Oaks (casurina)

Hairs on underside of leaf Increase humidity around stomata reduce conc. Gradient as more water in air less evapouration

Banksia/Hakea

Tough, dry (sclerophyll) leaves Protect cell from damage through wilting when water lost

Eucalyptus

Woody fruits Prevent seeds from drying out/ water lost when fruits fall

Banksia/ Hakea

Sunken Stomata Increase humidity around stomata- less evaporation

Hakea

Leaves hang vertically Prevent overheating through exposure to midday sun/ photosynthesis in morning and arvo so stoma can close during midday to prevent water loss

Eucalyptus

Curled leaves Increase humidity- keep stoma open for longer with less water loss

Porcupine grass

Shedding leaves Reduce no. of stomata River gum