Life’s OrganizationUnit 2

Yes, it is time to move to your second divider labeled Unit 2

What makes something alive?

To be considered alive, an organism (living thing) must have certain characteristics.

1. Be made up of Cells Living things (Organisms) are made up of

small, contained units called cells. Cells are the smallest unit of an organism. Organisms can be unicellular or consist of one

cell. (We’ve seen these in the pond water lab) Many living things are multicellular which

means many cells. Plants and most animals are multicellular.

2. Living Things (Organisms) Reproduce

All organisms produce new organisms through the process of reproduction.

There are two types of reproduction sexual and asexual.

Sexual reproduction involves two different parents that each provide a

cell (gamete) to produce an offspring

Asexual reproduction involves one parent. Usually the offspring splits off from its parents. For example a cell splitting in two. The offspring has the exact same genetics as its parent.

3. Organisms are put together based on their Genetic Code

All organisms are based on a universal genetic code know as deoxyribonucleic acid also known as DNA.

In asexual reproduction, the offspring have the same exact genetic code. The offspring are clones of their parent.

In sexual reproduction, offspring share some characteristics of each parent. Offspring DNA is 50% from Mother and 50% from Father.

4. Organisms Grow & Develop All living things grow at some part of their lives.

Growth is an increase in cell size or cell number

Growth takes place when a fertilized egg cell divides many times

Cell differentiation results in some cells becoming specialized as bone cells, liver cells or brain cells

Development can also include periods of rapid change – in humans aka puberty!!

5. Organisms need materials & energy

Living Things need food for energy to grow, reproduce and survive.

Metabolism involves the chemical reactions that organisms do to break down and build materials needed to carry out life functions and stay alive.

The way living things get their energy varies. Autotrophs/Producers make their own food using the sun’s energy through photosynthesis.

Heterotrophs/Consumers get their energy by eating other organisms.

Herbivores -eat primarily plants

Carnivores eat primarily meat

Omnivores eat both meat & plants

Decomposers- are mostly fungi and bacterial

that consume dead plants & animals

6. Organisms Respond to their Environment

Living things are aware of and respond to stimuli in the environment.

A stimulus is a signal that an organism responds to.

External stimuli comes from the environment such as changes in light, temperature, noise, etc.

Internal stimuli comes from inside the organisms body. When your body’s blood glucose (sugar) falls too low, you become hungry.

7. Living Things maintain an Internal Balance

Homeostasis- involves processes that an organism uses to keep internal conditions (like temperature & water constant) stable & constant to survive.

Homeostasis involves internal feedback systems in our bodies. If our body temperature gets too hot when exercising, our skin sweats to help to cool us down. If our temperature gets too cold we shiver to produce heat in our body.

8. Living things excrete waste products

Excretion is the process by which waste products of metabolism and other non-useful materials are eliminated from an organism

Humans excrete urine which is concentrated in the kidneys

Fish and water organisms excrete Ammonia which is highly toxic and highly soluble in water

Movement- The ability to move is called locomotion. This is beneficial to an organism in allowing it to escape predators, move to where there is more food or to find mates.

Cilia

Flagella

Setae or hairs on an earthworm

Water Flea AKA Daphne

9. Some living things can move

10. Living Things conduct Synthesis

Synthesis-the process that organisms take simple building blocks and make something more complex

Plants synthesize glucose using sunlight, CO2 and water.

11. Living Things can Evolve Over time organisms change in response to

changes in the environment. The change may be gradual and take many generations.

Evolution is the change in a species over time responding to changes in their environment.

Structural Organization of Organisms

Organism-an individual with the ability to carry out the activities of life

  Organ Systems-A group of organs that work

together to perform a major task (i.e. digestive systems, reproductive system)

  Organs-a Structure made up of similar tissues

that work together to perform a task. Often part of a larger system. (i.e. stomach, eyes, kidneys

Tissues- A group of similar cells that work together to perform the same function (i.e. muscle tissue)

  Cells-Smallest living unit of an organism

Cells are the basic unit of structure in every living thing.

New cells are formed from other existing cells

The cell is a fundamental unit of structure, function and organization in all living organisms.

Cell Theory –Developed during the mid 17th century was made possible by advances in microscopy.

Cells theory states that:

Many scientist do not classify viruses with living things

Viruses are not made of cells Viruses are made of proteins and genetic material

HIV Virus

Viruses cannot independently carry out all of the processes of life (can’t function outside of a living cell)

Virus must invade the cell of a living organism to reproduce

Some viruses are pathogens. Pathogens are anything that causes disease.

Virus also do not respond to antibiotics Different Viruses cause HIV, influenza,

warts and many other diseases

1. Prokaryote- cells that don’t have a nucleus or many organelles

Came first-were the first examples of life Simple compared to eukaryote cells Prokaryotes-Think of bacteria which can be killed using antibiotics.

There are two types of cells

2. Eukaryotes- are more complex and are what you are used to seeing and studying.

Have a nucleus that contains the genetic information

Have many specialized organelles

EUKARYOTE CELLS and CELL ORGANELLES

http://www.allaboutmammals.com/label/biology.shtml

Cytoplasm refers to the jelly-like material with organelles in it. AKA Cytosol

If the organelles were removed, the soluble part that would be left is called the cytosol. It consists mainly of water with dissolved substances such as amino acids in it.

Nucleus- The nucleus is the control center of the cell. It is the largest organelle in the cell and it contains the DNA of the cell.   DNA (Deoxyribonucleic Acid) contains all the information for cells to live, perform their functions and reproduce. 

Inside the nucleus is another organelle called the nucleolus. The nucleolus is responsible for making ribosomes.

Mitochondria

Mitochondria -Their main function is the conversion of the potential energy of food molecules into ATP.

There are more mitochondria in cells that have to

perform lots of work (leg muscle cells, heart muscle cells etc).

Mitochondria have their own DNA Mitochondrial DNA- You have an exact copy of

your mother’s mitochondrial DNA

Mitochondria have: an outer membrane that encloses the entire structure an inner membrane that encloses a fluid-filled matrix between the two is the intermembrane space

Cellular Respiration takes place in the Mitochondria

All living cells do cellular respiration

Endoplasmic reticulum (ER)- The rough endoplasmic reticulum is where most protein synthesis occurs in the cell. There are two types of ER.

Rough ER- When ribosomes are attached it Smooth ER when there are no ribosomes attached. 

                                                    

                                        

Golgi complex- It is organelle in the cell that is responsible for sorting and correctly shipping the proteins produced in the ER.  Just like our postal packages which should have a correct shipping address, the proteins produced in the ER, should be correctly sent to their respective address. 

In the cell, shipping and sorting done by the Golgi complex. It is a very important step in protein synthesis (Making of Proteins).

. 

Some ribosomes are found in the cytoplasm, but most are attached to the endoplasmic reticulum.

Ribosomes- Organelles that help in the synthesis of proteins.

The fluid mosaic model describes the structure of the plasma membrane

The Fluid-mosaic model- membrane is seen as a bilayer of phospholipids in which protein molecules are embedded.

                                             Channels/pores- A channel in the cell's plasma membrane. This channel is made up of certain proteins whose function is to control the movement of food and water into the cell. These channels are made up of certain proteins.

                      

Vesicles- This term literally means "small vessel". This organelle helps store and transport products produced by the cell.

The vesicles are the transport and delivery vehicles like our mail and  Federal Express trucks. Some vesicles deliver materials to parts of the cell and others transport materials outside the cell in a process called exocytosis

Lysosomes function as the cell's recycling compartment.

Lysosomes receive cellular and proteins and lipids that need digesting through the process of endocytosis. The metabolites that result are transported either by vesicles or directly across the membrane.

A Centrosome is found in the nucleus and is made of a pair of small Organelles called the centrioles.Centrioles are made up of a ring of nine groups of microtubules.

During animal cell division, the centrosome divides and the centrioles replicate (make new copies). The two centrosomes move to opposite ends of the nucleus, and from each centrosome, microtubules grow into a "spindle" which is responsible for separating replicated chromosomes into the two daughter cells.

Plant cells have centrosomes that function much like animal cell centrosomes. However, unlike centrosomes in animal cells, Plant cells do not have centrioles. 

CENTROSOME

Vacuoles- can be used to store water, waste or food inside of a plant cell.

• Vacuoles and vesicles are storage organelles in cells. Vacuoles are larger than vesicles. Either structure may store water, waste products, food, and other cellular materials.

In plant cells, the vacuole may take up most of the cell's volume.

When a plant wilts it means that the vacuole has lost enough water so the “water balloon” deflates and no longer helps the cell wall hold the plant upright.

                      

Chloroplast- The cell organelle in which photosynthesis takes place. In this organelle the light energy of the sun is converted into chemical energy.

- Chloroplasts are found only in plant cells not animal cells.

-Chloroplasts contain tiny green pigments called chlorophylls- Chlorophylls are responsible for trapping the

light energy from the sun.

The chemical energy that is produced by chloroplasts is finally used to make  glucose and carbohydrates like starch

PHOTOSYNTHESIS

GLUCOSE

Organic (comes from something alive) molecules contain Carbon and Hydrogen

       Cell Wall- One of the most important distinguishing features of plant cells is the presence of a cell wall

• The cell wall protects the cellular contents gives rigidity to the plant structure

• The cell wall is a structure of great tensile strength, the cell wall is formed from fibrils of cellulose molecules

• Animal cells do not have a Cell wall.

Photosynthesis is the reverse reaction of Cellular Respiration

Chemical Composition All living things are made up of four main elements 

Carbon- CHydrogen- H

  Oxygen- O Many other elements in smaller amounts such as Iron (in hemoglobin), N, Calcium (bones/teeth)

Organic substances come from living things that are alive and also contain C and H

Identify which substances are organic:-H20inorganic does not contain C and H-C6H12O6 (Glucose)organic does contain both C and H-CH4 (Methane-Natural Gas)organic does contain both C and H

Organic Molecules  Structure molecules such as the cell wall  Enzymes-proteins that speed up chemical

reactions such as digestion  DNA, Proteins, and Fats  Carbohydrates such as glucose (C6H12O6)

Inorganic compounds DO NOT contain both CARBON and HYDROGEN

Salts –NaCl (Sodium Chloride- table salt) Minerals (Fe, N, P, K etc.) Most acids and bases  O2-Oxygen  CO2-Carbon Dioxide  H2O-Water

CLASSIFICATION Biologists found it necessary to classify living

organisms in a logical way.

Linnaeus came up with a system in the 1700s. -He used binomial nomenclature which means every organism can be identified by two names-Genus and Species

 

Taxonomy-the science of classifying organisms according to their shared traits Phylogeny-the study of evolutionary history and relationships

Tree of life

The concept of a tree of life is that a tree branches illustrate the idea that all life on earth is related

Carl Woese, introduced the three-domain system in 1990

The Tree of Life consists of three domains: - 1. Domain Archaea - (prokaryotes) are

a group of single-celled microorganisms. -live in most extreme environments such as hot springs and brine pools (salt)

=

2. Domain Bacteria (prokaryotes) –most are unicellular Under a microscope, they look like balls, rods or

spirals. They are so small that a line of 1,000 could fit

across a pencil eraser. Most bacteria won't hurt you - less than 1 percent

makes people sick.

Many bacteria are helpful

Some bacteria help to digest food, destroy disease-causing cells and give the body needed vitamins (vitamin K and B-12).

Bacteria are also used in making healthy foods like yogurt and cheese.

Bacteria that are Pathogens Examples of bacteria that cause infections

include: -Streptococus -(strep throat) -Staphylcocus-(staph infections) -E. Coli. -(food poisoning-wash your hands ) Antibiotics are powerful medicines that fight

bacterial infections If a virus is making you sick, taking antibiotics

may do more harm than good

3. Domain Eukarya (eukaryotes) The presence of a nucleus gives eukaryotes

their name, which comes from the Greek ευ (eu, "good") and κάρυον (karyon, "nut" or "kernel").

Group of organisms that share a common ancestor

Mneumonic that I learned:

Did King Philip Come Over From Germany Saturday

Mnemonics

Mnemonic Zoology termKing KingdomPenguins PhylumCongregate ClassOn OrderFrozen FamilyGround GenusSometimes Species

Current Classification of living organisms is based on:

Similarities in structure Evolutionary relationships Biochemical similarities (similar enzymes) Genetic similarities-(DNA and RNA

patterns)

Patterns in Embryological development

Fossil Evidence

Six Kingdoms

SIX KINGDOMS

1. Kingdom Eubacteria- Bacteria  2. Kingdom Archaebacteria-live in most

extreme environments such as hot springs and brine pools (salt)

3. Kingdom PROTISTA Protista-very diverse Kingdom that lives in water

Some protists are more like plants or fungi and others more like animals.

Some move (cilia, flagella, pseudopodia); others don't

Some are autotrophic; others are heterotrophic

Other examples - diatoms and paramecium

Single cell algae

Ameba

Euglena-chloroplasts but no cell wall

4. Kingdom Fungi- most are decomposers  

Decomposers feed on dead and decaying material. (Saprophytes)

Examples: are mushrooms, bracken fungus on trees and yeast

Plants are Autotrophs which means they can make their own food

Autotrophs make their own food through the process of photosynthesis.

All plants are Multicellular. Green algae do photosynthesis but are now grouped with the protists

5. Plantae- The plants

6. Animalia-Animals

All animals are multicellular All animals are heterotrophs Heterotrophs eat other plants and animals.

(AKA Consumers) Heterotrophs cannot make their own food. Animal cells do not contain a cell wall or

have chloroplasts

Genus and Species Two Word naming system called binomial

nomenclature Names are in Latin and used by all the scientists in

the world AKA- The Scientific Name of an organism Every species in the world can be identified by its

Genus and Species name. Genus and Species are written in Italics with the

Genus capitalized What is the scientific name for humans?

Homo sapiens

Domestic Dog- Canus familiaris Grey Wolf- Canus lupus

They both have the same Genus. What does that mean? They are very closely related If you are writing it by hand you underline the

Genus and SpeciesCommon Name Scientific NameBeaver Castor candadensisWhite tailed deer Odocoileus virginianus

Common Name: Right Whale Scientific Name: Eubalaena glacialis Description: The Right whale is a slow swimmer and has a gentle nature. This whale reaches about 50 feet in length and weighs about 70 tons. Habitat: Right Whales are distributed around the North Atlantic and the North Pacific Oceans.

Common Names VS Scientific Names Many organisms have different common names

and scientist have to know the exact species Skunks have different common names in

different parts of our country including civet cat and polecat

Both are called skunks, but only the one on the left is Mephitis mephitis.

The one on the right is Spilogale gracilis

FROM ATOMS TO CELLS- A. Everything on Earth is made of Matter   Matter has mass and takes up space   Matter is made up of ATOMS   Atoms are too small to be seen with an ordinary

microscope (100 million in a row would make a row 1 cm wide)

The smallest particle of an element that maintains its characteristics is an atom

  Atoms combine with other atoms to form

molecules using chemical bonds 

Research on the Atom in the 1900s Ernest Rutherford studied the nucleus and

determined: The nucleus was very dense and

contained protons and neutrons Electrons are distributed in the mostly

empty space surrounding the nucleus

Niels Bohr studied the electrons and determined:  Electrons moved around the nucleus in orbits

Electrons in the inner shell (closest to the nucleus) have the least energy

Current understanding of atoms

Protons and Neutrons are about the same mass

Protons have + charge and Neutrons carry no

charge (think neutral)

Electrons are negatively charged and are in

constant motion in an area called the cloud

Atoms contain equal numbers of electron and

protons, atoms are neutral in charge

Cloud Model of the Atom

The electron has a probability of being anywhere at any time and the cloud represents where it most likely is

Chemical Compounds Most elements are found combined with other

elements in compounds Compound-is a substance formed by chemical

combination of two or more elements in definite proportions

Water is an important inorganic compound- contains 2 atoms of Hydrogen

for every atom of Oxygen

Molecule-the smallest unit of a compound.  

Chemical Bonds

Ionic Bonds- form when one or more electrons are transferred from one atom to another. These pos or neg charged atoms are called ions

Covalent Bonds- form when electrons are shared between atoms

Major Elemental Components of the human body

Oxygen-64%Carbon-18%Hydrogen 10%Nitrogen-3%Phosphorus-1%Sulfur-.75%Trace Elements 3.25%

About 70% of the Human Body is composed of water

Organic Compounds-contain the elements Carbon and Hydrogen

1. Carbohydrates- Simple Sugars have six carbon atoms bonded together 

One sugar subunit is called a monosaccharideGlucose- C6H12O6

  Fructose- C6H12O12

 

Carbohydrates-Disaccharides

Two sugar subunits is called a disaccharide 

Lactose-milk sugar  Sucrose-C12H22O11 Table Sugar

Many sugar subunits are called a polysaccharides

 Glycogen-is stored in the liver and later used by the mitochondria in muscle cells to provide energy (ATP) to do work or exercise

Glucagon is a hormone, secreted by the pancreas, that raises blood glucose levels. Its effect is opposite that of insulin, which lowers blood glucose levels

Catabolism is the set of pathways that break down molecules (such as Glycogen) into smaller units (such as Glucose) and release energy

 

Energy Storage in Cells Starch-plants store energy as Starch.

 -Potato starch -Corn starch Starch is a very large molecule and can’t pass

through cells membranes

Starch must be broken down into smaller glucose molecules so that if can move across membranes within an organism.

Glycogen-Animals such as humans store energy in the liver to later be used by muscle cells to do work or exercise

2. Lipids- oils and fatsHigh energy bonds used for long term energy storageSaturated Fats-almost every Carbon position is bonded to a Hydrogen AtomSaturated Fats are solids at room temperatureSATURATED FATS CAUSE HEART DISEASE

2. Lipids-oils and fats Unsaturated Fats- are usually a liquid at room

temperature. Some Carbon positions are not bonded to a Hydrogen Atoms

Trans fat is considered by some doctors to be the worst of them all because of its double-barreled impact on your cholesterol levels.

-trans fat —both raises your "bad" (LDL) cholesterol and lowers your "good" (HDL) cholesterol-Restaurants like using trans fats to fry their foods because they’re easy to use,

inexpensive to produce and last a long time

Polyunsaturated Fats

Polyunsaturated-Many Carbon positions are not bonded to Hydrogen Atoms

Polyunsaturated vegetable oils are the safest fats

Canola oil, flax seed oil, soy oil, safflower oil and sunflower oil are healthier choices

3. Proteins

Amino Acids are the building blocks of proteins

20 different types of Amino Acids  Amino Acids put together in thousands of

various combinations DNA provides the instructions for putting

the amino acid sequences together

Proteins are the structural blocks of cellular systems and are formed by joining of amino acids by peptide bonds (polymerization) .

Proteins are made of Carbon, Hydrogen, Nitrogen and Oxygen

Each amino acid in turn consists of an amino group, a carboxyl group and side chains.

4. Nucleic Acids- Nucleic Acids- Stores the genetic information of the cell and organism

DNA (Deoxyribonucleic Acid)

RNA (Ribonucleic Acid)

Diffusion Diffusion occurs when a system is not at equilibrium

(concentration same on both side of membrane)

Diffusion is the movement from a region of high concentration to a region of low concentration.

Diffusion can occur through a cell membrane.

The cell membrane allows small molecules like water (H2O), oxygen (O2), carbon dioxide (CO2), and others to pass through easily. It is said to be permeable to these molecules.

If a cell is floating in a water solution (like the ocean) that has some oxygen dissolved in it, the oxygen molecules will move into the cell.

If the cell uses some of the oxygen as it comes into the cell, more oxygen will move into the cell than out of the cell.

Same process appliesto O2 moving into a Muscle cell from the blood

If the starch (or some other large molecule like a protein) is in a cell, the water moves into the cell faster than it leaves, and the cell swells.

Osmosis-is special type ofDiffusion that involves the movement of water across a membrane

What’s going on when you eat salty popcorn?

What is happening to the cells that line your mouth?

Does that have anything to do with Diffusion/Osmosis?

Salt makes a person thirsty because it first dries out the tongue and mouth. After the digestion process has started, salt moves from the stomach and into the small intestine. The salt is then absorbed into the wall of the small intestine, and into the blood stream.

Concentration Gradient- The difference in concentration between the cell and its environment is called the concentration Gradient.

Passive Transport- Diffusion of substances through the membrane without the use of energy. Movement is from an area of higher concentration to lower concentration.

Active Transport- Requires energy and can move substances against the concentration gradient from an area of low concentration to and area of high concentration. Carrier proteins in the membrane help in the transport of materials. (show You tube video) 

Homeostasis

Glossary Homeostasis is all about keeping conditions at the right levels to

support life. You need to be comfortable with the related terms Maintain – keep up at the proper level (ie. Body temp) Constant or Steady State – the same. Internal – inside the body. Environment – surroundings of the body. Dynamic Equilibrium- example of a system in a steady state.

May change a small amount up or down. Feedback- A control system that allows for feedback and self-

correction to adjust according to differences between the actual level and the desired level.

What is Homeostasis?

Body cells work best if they have the correct Temperature Water levels Glucose concentration

Your body has mechanisms to keep the cells in a constant environment.

What is Homeostasis?

The maintenance of a constant environment in the body is called Homeostasis

Controlling body temperature

All mammals maintain a constant body temperature.

Human beings have a body temperature of about 37ºC. E.g. If your body is in a hot environment your

body temperature is 37ºC If your body is in a cold environment your

body temperature is still 37ºC

Controlling body temperature

Animals with a large surface area compared to their volume will lose heat faster than animals with a small surface area.

Volume = _______Surface area = ______Volume : Surface area ratio = ___________

Volume = _______Surface area = ______Volume : Surface area ratio = ___________

Controlling body temperature

Volume : Surface area ratio = 1:6

Volume : Surface area ratio = 1:5

For every 1 unit of heat made, heat is lost out of 6 sides

For every 1 unit of heat made, heat is lost out of 5 sides

Controlling body temperature

Volume : Surface area ratio = 1:6

Volume : Surface area ratio = 1:5

The bigger the Volume : Surface Area

ratio is, the faster heat will

be lost.

What mechanisms are there to cool the body down?

1. Sweating When your body is hot, sweat glands are

stimulated to release sweat. The liquid sweat turns into a gas (it

evaporates) To do this, it needs heat. It gets that heat from your skin. As your skin loses heat, it cools down.

Sweating

The skin

What mechanisms are there to cool the body down?

2. Vasodilation Your blood carries most of the heat energy

around your body. There are capillaries underneath your skin that

can be filled with blood if you get too hot. This brings the blood closer to the surface of

the skin so more heat can be lost. This is why you look red when you are hot!

If the temperature rises, the blood vessel dilates (gets bigger).

This means more heat is lost from the surface of the skin

What mechanisms are there to warm the body up?

1. Vasoconstriction This is the opposite of vasodilation The capillaries underneath your skin get

constricted (shut off). This takes the blood away from the

surface of the skin so less heat can be lost.

If the temperature falls, the blood vessel constricts (gets shut off).

This means less heat is lost from the surface of the skin

What mechanisms are there to warm the body up?

Piloerection This is when the hairs on your skin

“stand up” . It is sometimes called “goose bumps” or

“chicken skin”! The hairs trap a layer of air next to the

skin which is then warmed by the body heat

The air becomes an insulating layer.

Controlling Glucose levels Your cells also need an exact level of

glucose in the blood. Excess glucose gets turned into glycogen

in the liver This is regulated by 2 hormones

(chemicals) from the pancreas called:

InsulinGlucagon

Shivering

When you shiver, the muscles are producing heat

Muscles use ATP produced in the Mitochondria which releases

CO2 and heat.

If there is too much glucose in the blood, Insulin converts some of it to glycogen

Glycogen

Insulin

Glucose in the blood

If there is not enough glucose in the blood, Glucagon converts some glycogen into glucose.

Glycogen

Glucagon

Glucose in the blood

Diabetes

Some people do not produce enough insulin.

When they eat food, the glucose levels in their blood cannot be reduced.

This condition is known as DIABETES. Diabetics sometimes have to inject insulin

into their blood. They have to be careful of their diet.

Time

Glucose Concentration

Meal eaten

Insulin is produced and glucose levels fall to normal again.

Glucose levels rise after a meal.

Normal

Time

Glucose Concentration

Meal eaten

Insulin is not produced so glucose levels stay high

Glucose levels rise after a meal. Diabetic

The glucose in the blood increases.

Glycogen

Insulin

Glucose in the blood

. But there is no insulin to convert it into glycogen

Glucose concentration rises to dangerous levels.

Controlling water levels

The control of water levels is carried out by the KIDNEYS.

It is closely linked to the excretion of urea. Urea is a waste product that is made when

the LIVER breaks down proteins that are not needed by the body.

Urea contains the element Nitrogen.

The kidneysThe kidneys “clean” the blood of waste products and control how much water is kept in the body. The waste products and water make up urine which is excreted via the ureter.

“Dirty” blood enters the kidney through the renal artery. Then, several things happen to clean the blood...

Blood enters the tubule area in a capillary.The capillary forms a small “knot” near the kidney tubule.The blood is filtered so all the small particles go into the tubule.

The capillary then carries on to run next to the tubule.

1. Filtration

The kidney tubule now contains lots of blood components including:

Glucose:Ions:Water:Urea:

Draw in the blood components on your kidney tubule on your notes. Make your own key and symbols

2. Reabsorb sugar

The body needs to have sugar in the blood for cells to use in respiration. So all the sugar is reabsorbed back into the capillary.

2. Reabsorb sugar

The body needs to have sugar in the blood for cells to use during cellular respiration. So all the sugar is reabsorbed back into the capillary.

3. Reabsorb water

Water and ions are the next to be absorbed. It depends on how much is needed by the body.

3. Reabsorb water

Water and ions are the next to be absorbed. It depends on how much is needed by the body.

Reabsorbing water

If you have too little water in your blood, you will produce very concentrated urine.

(very little water in it)

If you have too much water in your blood, you will produce very dilute urine.

(lots of water in it)

5. Excrete the waste

Everything that is left in the kidney tubule is waste:

• All the urea• Excess water

This waste is called urine. It is excreted via the ureter and is stored in the bladder.

The “clean” blood leaves the kidney in the renal vein.

Renal vein

Ureter

Summary of urine production

Urea is a waste product made in the LIVER Water content of the body is controlled in

the KIDNEYS Urea, water and other waste makes up

URINE. Urine travels down the URETER and is

stored in the BLADDER Urine is excreted through the URETHRA.

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