B8,B9 Flashcards
At night what is the limiting factor for photosynthesis?
Light intensity
Design an experiment to show how a plant is photosynthesising?
- Use water plant
- Collection chamber over plant
- Leave to collect oxygen
- Collect bubbles
- Use a glowing splint over gas collected
- Rich oxygen will relight splint
Examples of leaf adaptations which maximise the rate of photosynthesis?
- Most leaves are broad, giving them a big surface area for light to fall on
- most leaves are thin so diffusion distances for gases are short
- contain chlorophyll to absorb light
- They have air spaces that allow carbon dioxide to get to the cells and oxygen leave by diffusion
Formula for inverse square law?
Light intensity = 1 / distance^2
How can farmers use their knowledge of limiting factors to increase profits?
- They can control the temperature,light intensity and Co2 to acheive the fastest possible rate of photosynthesis leading to greater yeild
How can the presence of starch be detected in plants?
Use iodine solution should turn blue/black
How can you show the plant gives off oxygen during photosynthesis?
Using a water plant ,collect gas bubbles during photosynthesis. The gas will relight a glowing splint which contains oxygen
How does light intensiity affect rate of photosynthesis?
Increasing light intensity increases rate of photosynthesis until another factor becomes limiting
How does temperature affect The rate of photosynthesis?
The kinetic energy of the particles is increased. The rate decreases past a certain temperature as enzymes become denatured
How dooes the amount of chlorophyll affect photosynthesis?
Decreasing chlorophyll decreases photosynthesis as chlorophyll is required to absorb light energy
How does the amount of CO2 affect rate of photosynthesis?
Increasing co2 increases photosynthesis until another factor is limiting as Co2 is required to make glucose
An investigation of photosynthesis why did a student add sodium hydrogencarbonate to the water?
Because it’s a source of CO2
In winter what is the limiting factor for CO2?
Temperature
Is photosynthesis endothermic or exothermic?
Endothermic it needs energy from the enviroment
What is the energy source for photosynthesis?
Light
What are 5 uses of photosynthesis?
- Respiration
- Startch for storage
- Celluose for strength
- Amino acid and proteinsynthesis
- Lipids for energy storage
What are the main factors that affect photosynthesis?
- Temperature
- Light intensity
- Co2 Concentration
- Amount of chlorophyll
What is a limiting factor?
An enviromental factor which restricts photosynthesis
What is meant by the inverse square law?
The light intensity is inversley proportional to square of the distance
What is photosynthesis?
A chemical reaction that takes place inside a plant producing food for plant to survive
What is the compensation point?
The light intensity at which rate of photosynthesis is equal to the respiration of a plant
What products can glucose be converted into in plants?
- Starch
- celluose
- fats
- proteins
What substance absorbs the energy required for photosynthesis?
Chlorophyll. It is green so absorbs the red and blue parts
Where does photosynthesis take place?
Chloroplasts in leaf pallaside cells
What part of the em specturum is absorbed by chlorophyll?
Red and blue
Word equation for photosynthesis?
Co2 + water = glucose + oxygen
Aerobic respiration formula
glucose + oxygen = carbon dioxide + water
Aerobic respiration is endothermic or exothermic?
Exothermic
Chemical formula for aerobic respiration
C6H12O6 = 6CO2 + 6H2O
Common metabolic reactions
- the reactions of respiration
- the reactions of photosynthesis
- the conversion of glucose to starch and glycogen to starch
Differences between anaerboic and aerobic respiration
- Anaerobic produces lactic acid, aerobic doesn’t
- Anaerobic doesn’t produce CO2 aerobic does
- Anaerobic doesn’t produce water ,aerobic does
Give examples of the liver’s metabolic functions
- detoxifying poisonous substances such as ethanol from alcoholic drinks
- breaking old worn out blood cells and storing iron until it is needed to synthesise more blood cells
How do muscles store glucose?
As glycogen
How efficient is respiration?
40%
How is lactic acid transported away from the muscles?
Blood flow through the muscles transports lactic acid to the liver, where it is oxidised back into glucose
Name two things delivered in blood to muscles during periods of increased exercise?
Glucose and oxygen
What happens to your body when you exercise?
- Muscles contract more frequently so you need more energy. Comes from respiration
- You need nore oxygen to get to your cells
- Your breathing rate and heart rate increase to get oxygen around body quicker
What is aerobic respiration?
Respiration using oxygen to break down food molecules is called aerobic respiration
What is anaerobic respiration in yeast called?
Fermentation
What is metabolism?
Metabolism is the sum of all the reactions in a cell or the body
What is not broken down completely in anaerobic respiration?
Glucose, due to the lack of oxygen, as a result lactic acid is made
What is oxygen debt?
The amount of extra oxygen required by the body for recovery after intense exercise
What is produced when a plant respires anaerobically?
Alcohol and carbon dioxide
What is the breakdown product of amino acids in humans?
Urea
Where does aerobic respiration take place?
Aerobic respiration occurs in the mitochondria of cells. It is where the energy (ATP) is produced in the cell, and the process of cellular respiration is the way the cells form that energy.
Where does the process of anaerobic respiration occur?
In the cytoplasm of the cell
Where is the energy that is made from respiration used?
- Used for digestion
- Used to make muscles contract
- Used for cell division
- To maintain homeostasis
- Used for active transport
Which of these is NOT a product of anaerobic respiration in plants and yeast cells? (ethanol, lactic acid, carbon dioxide)
Lactic acid, it is only made in animal cells
Why can anaerobic respiration lead to muscle fatigue?
Lactic acid builds up in the muscles, causing less efficient muscle contraction
Why is anaerobic respiration less efficient than aerobic respiration?
Glucose is not completely broken down, so less energy is transferred
Why is fermentation important?
Used to produce bread and alcholic drinks
Why is lactic acid produced during exercise?
If insufficient oxygen is available to the muscles like during exercise, the heart and lungs are unable to supply sufficient oxygen.
Muscles begin to respire anaerobically.
Lactic acid is produced from glucose, instead of carbon dioxide and water.
Word equation for anaerboic respiration in humans
glucose = lactic acid
Word equation for anaerobic respiration in plants and other organisms
glucose = ethanol + carbon dioxide
Word equation for oxygen debt replacement
lactic acid + oxygen = carbon dioxide + water
Which two products are formed when lipids break down?
- Fatty acids
- Glycerol
Explain the lock key theory?
- Enzyme binds to substrate because substrate fits active site
- Substrate is broken down
- So products are released
