Topic 4- Bioenergetics Flashcards
What is aerobic respiration?
Exothermic reaction- glucose reacts with oxygen to release energy used by cells
State the word equation for photosynthesis
Carbon dioxide + water -> glucose + oxygen
Is photosynthesis exothermic or endothermic?
Endothermic- energy transferred from environment to chloroplasts by light
What are 3 leaf adaptations which maximise photosynthesis rate?
Broad leaves- maximise surface area
Chlorophyll present- trap light energy
Guard cells- control opening of stomata for gas exchange
What are the 4 main factors that affect the rate of photosynthesis?
- Temperature
- Light intensity
- CO2 concentration
- Amount of chlorophyll
How does temp affect rate of photosynthesis?
Increasing temp increases rate
Kinetic energy of particles is increased
Rate decreases past certain temp as enzymes become denatured
How does light intensity affect the rate of photosynthesis?
Increasing light - increases rate
Until another factor becomes limiting
How does CO2 concentration affect the rate of photosynthesis?
Increasing CO2- increases rate
Until another factor becomes limiting
As CO2 is required to make glucose
How does amount of chlorophyll affect the rate of photosynthesis?
Decreasing chlorophyll- decreases rate
It is required to absorb light energy
What is a limiting factor?
Environmental factor that can restrict the rate of photosynthesis
What are 3 different uses of the glucose produced during photosynthesis?
Respiration
Cellulose (strength)
Lipids (energy storage)
What is the word equation for aerobic respiration?
Glucose + oxygen -> CO2 + water
Where does aerobic respiration take place?
Mitochondria
Why do orangisms require energy produced by respiration?
Synthesis of larger molecules
Muscle contraction
Active transport
What is anaerobic respiration?
Exothermic reaction
Glucose broke down to release energy in the absence of oxygen
What is the equation for anaerobic respiration?
Glucose -> lactic acid
Why is anaerobic respiration less efficient than aerobic respiration?
Glucose not completely broken down so less energy transferred
Why can anaerobic respiration lead to muscle fatigue?
Lactic acid builds up in muscles- prevent efficient contraction
What is an oxygen debt?
Amount of oxygen needed to convert lactic acid back into glucose after anaerobic respiration
What is fermentation?
Type of anaerobic respiration that occurs in yeast cells
What is the equation for fermentation?
Glucose -> ethanol + CO2
Why is fermentation important?
Used in production of bread and alcoholic drinks
What are the differences between aerobic and anaerobic respiration?
- Aerobic requires oxygen
- Aerobic produces CO2+H2O, anaerobic produces lactic acid
- Aerobic transfers more energy
How do muscles store glucose?
As glycogen
