Bioenergetics Flashcards
(31 cards)
What does the stoma in a plant do?
Allows gases into and out of the leaf.
What does the spongy layer in a plant do?
Contains air spaces p, allowing CO2 to diffuse throughout the leaf
What does the palisade layer in a plant do?
Contains cells with lots of chloroplasts, therefore the main site of photosynthesis.
What does the waxy layer in a plant do?
Reduces amount of water evaporating.
What does the guard cell in a plant do?
Open and close the stomata.
What is the equation for photosynthesis?
Carbon dioxide + water -> (light) glucose + oxygen
CO2 + H2O -> C6H12O6 + O2
What is required to produce energy by photosynthesis?
Energy because the reactions are endothermic- they take heat in. The energy is supplied by sunlight, it is trapped by chlorophyll.
What are limiting factors?
Factors that stop the reaction going any faster.
What are the limiting factors?
- Temperature
- Carbon dioxide concentration
- Light intensity
- Chlorophyll concentration
How is temperature a limiting factor?
- As the temperature increases so does the rage of photosynthesis.
- This is because more energy is provided for the reaction.
- As the temperature approaches 45 degrees Celsius , the rate of photosynthesis drops to 0 because the enzymes controlling photosynthesis have been destroyed.
How is carbon dioxide concentration a limiting factor ?
- As the CO2 concentration increases, so does the rate of photosynthesis
- This is because CO2 is needed in the reaction
- After reaching a certain point, an increase in CO2 has no further effect
How is light intensity a limiting factor ?
- As light intensity increases so does the rate of photosynthesis
- This is because more energy is provided for the reaction
- After a certain point light intensity has no further effect.
How is chlorophyll concentration a limiting factor?
- This does not vary in the short term but may change if plants are grown in soil without enough minerals to make chlorophyll.
- Magnesium if needed for chlorophyll production. If the growing medium is deficient in magnesium, the plant will be able to produce chlorophyll.
How do you maximise plant growth?
- More magnesium in soil
- Optimum temperature
- More intense temperature
- More intense lights artificial light
- CO2- burn fossil fuel
- Nutrients can be controlled with hydroponics and fertilisers.
- Greenhouses, farmers can control lighting, temperature and CO2
When doing an experiment for light intensity how is the inverse square law involved?
Doubling the distance between the lamp and pondweed will reduce the light intensity by a quarter, this is called the inverse square law.
What is the glucose produced in photosynthesis used for?
- Respiration
- Converted to insoluble starch for storage, which can be stored in the roots, leaves , stems, potato and carrot plants store a lot of starch underground over the winter so a new plant can grow from it the following spring.
- Produce fat/oil for storage
- produce cellulose
- amino acids, combined with nitrated to make amino acid
What is respiration?
An exothermic reaction which is continuously occurring in living cells. It releases energy from glucose molecules for use by the body.
Why do organisms need energy from respiration?
- For chemical reactions to build larger molecules
- For movement
- To keep warm
In which two different ways can respiration take place?
Aerobically (using oxygen) or anaerobically (without oxygen) to transfer energy.
What is the equation for aerobic respiration?
Glucose + oxygen -> carbon dioxide + water
C6H12O6 + O2 -> CO2 + H2O
Where does aerobic respiration take place?
Mitochondria
Why is there less energy to transfer in anaerobic respiration than in aerobic respiration?
In anaerobic respiration, the glucose is not completely broken down.
How is the process of anaerobic respiration different in animals to the process in plants and yeast?
In animals lactic arctic is produced:
Glucose -> lactic acid
In plants and yeast, alcohol (ethanol) and carbon dioxide are produced:
Glucose -> ethanol + CO2
Anaerobic respiration in yeast cells is called fermentation , important manufacture of bread and alcoholic drinks.
Why does the rate of respiration need to increase during exercise?
The body demands more energy. The heart rate, breathing rate and breath volume all increase to supply the muscles with more oxygen and glucose for the glucose in aerobic respiration.
