bioenergetics Flashcards
List 4 factors that affect photosynthesis.
Light intensity, temperature, amount of chloropyll and carbon dioxide concentration.
How can you tell the rate of photosynthesis and light intensity?
Canadian pondweed can be used to measure light intensity
oxygen corresponds to the rate of photosynthesis- the faster the rate of oxygen production, the faster the rate of photosynthesis.
What does a greenhouse do?
It traps the suns heat and makes sure the temperature doesn’t become limiting
the level of co2 can increase by using a paraffin heater to heat the green house
light can b.e supplied by artificial light
How do farmers/gardeners adapt to temperature?
In winter a farmer/gardener might use a heater as well to keep the temperature at the ideal level
in summer it could get too hot, so they might use shades and ventilation.
What does photosynthesis produce using light?
Glucose.
Is photosynthesis endothermic or exothermic?
Endothermic- this means energy is transferred from its surroundings/the environment.
What is the word equation for photosynthesis?
Carbon dioxide + water =light= glucose + oxygen.
What is the balanced symbol equation for photosynthesis?
6co2 + 6h2o =light= c6h12o6 + 6o2.
What do plants use glucose for?
Respiration- to transfer energy from glucose- enables the plant to transfer the rest of glucose to other substances
making cellulose-glucose is converted into cellulose
making amino acids- glucose is combined with nitrate ions to make amino acids
to store as oil or fats- glucose turns into lipids for storing in seeds
to store as starch- glucose is turned into starch and stored in roots, stem and leaves- ready to be used for when photosynthesis isn’t happening e.g. in winter.
Define respiration.
The process of transferring energy from glucose which goes on in every cell.
Is respiration endothermic or exothermic?
Exothermic- it transfers energy to its surrounding/the environment.
Give 3 examples of how organisms use the energy transferred by respiration.
To build up larger molecules from smaller ones- like proteins to amino acids
animals-use it to allow the muscles to contract
mammals and birds- to keep their body temperature steady in cold surroundings.
Define metabolism.
All the chemical reactions in an organism.
Define aerobic respiration.
Respiration using oxygen- most efficient way to transfer energy from glucose.
Where does most aerobic respiration occur?
In the mitochondria.
What are the word and symbol balanced equations for aerobic respiration?
Glucose + oxygen = carbon dioxide + water
C6h12o6 + 6o2 = 6co2 + 6h2o.
Define anaerobic respiration.
Respiration without oxygen.
What happens to glucose in anaerobic respiration?
It becomes lactic acid.
Plants and yeasts can respire without oxygen.
What does happens to glucose in anaerobic respiration in a plant and yeast cell?
It becomes ethanol + carbon dioxide.
What happens when you exercise?
You respire more.
Muscles need energy to contract therefore you respire to generate energy.
What can long periods of exercise cause?
Muscle fatigue- muscles get tired and stop contracting efficiently.
Anaerobic respiration can lead to oxygen debt.
Define oxygen debt.
The amount of oxygen your body needs to react with the build up of lactic acid and remove it from the cells.
What do oxygen and lactic acid form when they react together?
Co2 and water.
How can you investigate your breathing rate and heart rate?
By counting breaths and taking the pulse.
Temperature effects the rate of photosynthesis.
What happens to the enzymes when the temperature is too low?
Enzymes needed for photosynthesis work more slowly.
