21/04/23
REVISION 1REVISION 1 – –Use a Use a redred pen and start pen and start
responding to the markings responding to the markings in in greengreen
B4 The Processes of B4 The Processes of LifeLife
21/04/23B4.1 How do Chemical B4.1 How do Chemical Reactions take place in living Reactions take place in living
things?things?Task: Find all the information you are presented today in explanation 1. what these keywords are; 2. when and where they are involved in life processes.
CelluloseDenatureMitochondriaCatalystSubstrateProtein-SynthesisNitratesMagnesiumAmino Acid
21/04/23
Photosynthesis IntroductionPhotosynthesis IntroductionBasically, photosynthesis is the process through which a plant makes large food molecules using carbon dioxide and water and it happens in plants as well as some micro organisms: That’s a nice plant. I’m
going to put it in the sun and give it lots of water
and air…
CO2
H2O
21/04/23
Respiration IntroductionRespiration IntroductionI enjoy taking samples using quadrats.
In order to do this, I need energy. Where does this energy come from?
All living things, including plants, get their energy from respiration. Respiration is basically the process of breaking down the large food molecules that were probably originally made in plants.
21/04/23
Enzyme use in natureEnzyme use in nature
Cells use glucose to generate energy – this process is called “respiration”. Respiration happens in mitochondria and is catalysed by enzymes.
Photosynthesis is catalysed by enzymes in the cells.
Enzymes are proteins that speed up chemical uses. Here are two important natural uses for them:
21/04/23
EnzymesEnzymesEnzymes are biological catalysts. They help the
reactions that occur in our bodies by controlling the rate of reaction.
An enzyme is basically a protein molecule made up of long chains of amino acids. Cells make enzymes according to the instructions carried in their genes.
The enzyme’s shape helps another molecule “fit” into it:
This shape can be destroyed by high temperatures or the wrong pH:
Enzyme Substrate
21/04/23
The “Active Site”The “Active Site”
Enzyme Substrate
Active site
21/04/23
Enzymes are denatured
beyond 40OC
EnzymesEnzymesEnzymes work best in certain conditions:
Enzyme activity
Temp pH pH400C
Could be protease (found in the stomach)
Could be amylase (found in the intestine)
Enzymes are used in industry to bring about reactions at normal temperatures and pressures that would otherwise be expensive. However, most enzymes are denatured at high temperatures and can be costly to produce.
21/04/23B4.2 How do Plants make B4.2 How do Plants make food?food?
21/04/23
Travels up from the roots
WATER
CARBON DIOXIDEEnters the leaf through small holes on the underneath
SUNLIGHTGives the plant energy CHLOROPHY
LL The green stuff where the chemical reactions happen
Photosynthesis – the 4 things you Photosynthesis – the 4 things you needneed
21/04/23
Carbon dioxide + _____ glucose + _____
6CO2 + 6H20 C6H12O6 + 6O2
Sunlight
Chlorophyll
Sunlight
Chlorophyll
The GLUCOSE produced by photosynthesis is used by the plant for _______ (through ____________). It is stored in the plant as ___________.
Words – respiration, starch, water, oxygen, energy
Photosynthesis equationsPhotosynthesis equations
21/04/23What is the glucose used What is the glucose used for?for?
1) Glucose (sugar) can be used to make long chains of insoluble starch…
Glucose molecules
Starch molecule
2) Glucose can be used to make cellulose for cell walls…
3) Glucose can be combined with nitrates to make proteins (for growth)…
Glucose molecules
Glucose molecules
Cellulose
Proteins
Glucose can also be used for respiration, either by the plant or by what eats it!
21/04/23
A Typical Plant Cell:A Typical Plant Cell:Cell wall – made of cellulose which strengthens the cell
Cell membrane – controls what comes in and out
Nucleus – controls what the cell does and stores genetic info for making proteins
Large vacuole – contains sap and helps support the cell Cytoplasm –
Chemical reactions happen here
Chloroplasts – contains chlorophyll and enzymes for photosynthesis reactions
21/04/23
2 common nutrients…2 common nutrients…
Nitrates: Used to make proteins Lack of it leads to stunted growth
Magnesium: Used to make chlorophyll Lack of it leads to yellow leaves
21/04/23
DiffusionDiffusionDiffusion is when something travels from an area of high concentration to an area of low concentration. For example, consider the scent from a hamburger…
The “scent particles” from this hamburger are in high
concentration here:
Eventually they will “diffuse” out into this
area of low concentration:
Carbon dioxide and oxygen pass in and out of leaves by diffusion.
21/04/23
Diffusion SummaryDiffusion SummaryDiffusion is when particles spread from an area of high concentration to an area of ___ concentration. The particles move along a “concentration _____” and this process takes no _____ (it’s a “passive” process”). Diffusion can be accelerated by increasing the _______ of the particles, which makes them move _______.
Words – faster, low, gradient, temperature, energy
21/04/23
OsmosisOsmosisOsmosis is a “special kind of ___________”. It’s when water diffuses from a __________ area to a less concentrated area through a partially permeable _________ (i.e. one that allows water to move through but not anything else):
Water Sugar solutionIn this example the water molecules will move from left to right (along the concentration ______) and gradually _____ the sugar solution. Plants use osmosis to take in water through their roots.
Words – membrane, concentrated, dilute, diffusion, gradient
21/04/23
Strong sugar
solution
Medium sugar
solution
Weak sugar
solution
Pota
to c
ells
21/04/23
Active TransportActive TransportIn diffusion substances moved along a concentration gradient. In active transport, substances move against this gradient:
Outside cell
Inside cell
This process takes ______ and this comes from ___________. It enables cells to take in substances even though there are in very small __________. Root hair cells take in ______ using active transport.
Cell membrane
Words – concentration, energy, respiration, nutrients
21/04/23
Carbon dioxide diffuses into the leaf through holes in the bottom surface.
Diffusion and Active Transport in Diffusion and Active Transport in plantsplants
More concentrated
Less concentrated
Mineral
…while plant nutrients are taken in by root hair cells using active transport.
21/04/23Encouraging Encouraging PhotosynthesisPhotosynthesis
Using knowledge of limiting factors, explain how plant growth is encouraged in a greenhouse:
21/04/23
Limiting PhotosynthesisLimiting Photosynthesis
1. Temperature – the best temperature is about 300C – anything above 400C will slow photosynthesis right down
2. CO2 – if there is more carbon dioxide photosynthesis will happen quicker
3. Light – if there is more light photosynthesis happens faster
What factors could limit the rate of photosynthesis?
21/04/23Drawing graphs of these Drawing graphs of these factorsfactors
1. Temperature
Photosynthesis is controlled by enzymes – these are destroyed at temperatures above 400C
2. Carbon dioxide
3. Light
Photosynthesis increases at first but is then limited by a lack of increase in temp or CO2
Photosynthesis increases at first but is then limited by a lack of increase in temp or light
21/04/2321/04/23
Fieldwork techniquesFieldwork techniques
Recording light levels
Using quadrats
Fieldwork techniques also involve using a key to identify plants.
21/04/23
B4.3 How do living organisms B4.3 How do living organisms obtain energy?obtain energy?
21/04/23Uses for energy from Uses for energy from respirationrespiration
Animals and plants have many uses for the energy they generate from respiration:
1) To perform the life processes, such as moving, _____ etc
2) To build up body _______
3) To maintain a constant body ___________ (warm-blooded mammals only)
4) To build up sugars, ________ and other nutrients in plants
5) Active __________Words – nitrates, tissue, proteins, transport, growing
21/04/23
SynthesisSynthesis
1) Glucose (sugar) can be used to make long chains of insoluble starch…
Glucose molecules
Starch molecule
“Synthesis” means “making large molecules out of small ones”. Two examples:
2) Glucose can be combined with nitrates to make proteins (for growth)…Glucose
molecules Proteins
21/04/23
Respiration IntroductionRespiration IntroductionI enjoy taking samples using quadrats.
In order to do this, I need energy. Where does this energy come from?
Our energy comes from a process called respiration, which basically involves turning food and oxygen into energy and this reaction is controlled by enzymes.
21/04/23
(Aerobic) Respiration(Aerobic) Respiration
Words – breathing, energy, grow, respiration, food, mitochondria
All living organisms have to move, _____, reproduce etc. Each of these life processes needs ENERGY. ___________ is the process our bodies use to produce this energy:
Glucose + oxygen water + carbon dioxide + ENERGY
The glucose we need comes from ______ and the oxygen from _________. Water and carbon dioxide are breathed out. The MAIN product of this equation is _________. Respiration happens in _________ in cells.
21/04/23
Muscles and exerciseMuscles and exerciseWhen we exercise our muscles are supplied with more oxygen and glucose, increasing the rate of respiration.
Muscles store glucose as glycogen which can then be converted back into glucose during exercise.
21/04/23
Anaerobic respirationAnaerobic respirationUnlike aerobic respiration, anaerobic respiration is when energy is provided WITHOUT needing _________:
This happens when the body can’t provide oxygen quick enough for __________ respiration to take place.
Anaerobic respiration produces energy much _______ than aerobic respiration but only produces 1/20th as much.
Anaerobic respiration can also take place in other low-oxygen conditions, such as plant roots in _________ soil or bacteria in ________ wounds.
Words – oxygen, aerobic, quicker, puncture, waterlogged
Glucose lactic acid + a bit of energy
21/04/23
Making EthanolMaking EthanolEthanol is an important chemical. Many countries are increasing the amount of ethanol put into their petrol supplies:
Ethanol is another product of anaerobic respiration in plant cells and some micro organisms:
Ford Escape E85 – runs on 85% ethanol
Sugar ethanol + carbon dioxide + energy
21/04/23
BacteriaBacteriaConsider a bacteria cell in more detail:
Bacteria – containing cytoplasm and a membrane surrounded by a cell wall. The genes are NOT in a distinct nucleus.
The cell contains a number of features, including:
1) Chromosomal DNA, containing the genetic info of the cell
2) Plasmid DNA, containing extra information such as defence mechanisms
3) Flagella, which helps the cell move
21/04/23
The Structure of BacteriaThe Structure of Bacteria
Bacteria also have plasmids (circular strands of DNA) that can be copied and move between different bacteria. This means that resistance to antibiotics can be passed on without the need for reproduction.
21/04/23
4)
2)
Respiration in CellsRespiration in CellsNotice that plant and animal cells (and bacteria) have many features that help respiration:
Mitochondria – contain enzymes for respiration reactions
Cell Membrane – controls what comes in and out
Cytoplasm - where enzymes are made
Nucleus – carries genetic info for making enzymes
1)
3)
In bacteria cells, this job is done by circular DNA
21/04/2321/04/23Using Anaerobic Using Anaerobic RespirationRespiration
Anaerobic respiration in micro organisms is used to make fuels through:
1) Manure or other waste that can be used to release methane (biogas)
2) Corn or sugar cane that can be broken down in a fermenter to produce alcohols like bio-ethanol.
Anaerobic respiration is also used in fermentation to make bread and alcohol.
21/04/23
LET ME SEE YOUR ‘RESPIRATION’ HOMEWORK BEFORE WE GO!
AND COMPLETE THE ‘TRANSPORTATION OF MOLECUES’
HOMEWORK!
I WILL MARK THEM ALL ON TUESDAY AND A GRADE FOR EVERYONE ON
WEDNESDAY FOR REVIEW ON PROGRESS!