B8-9 Bioenergetics Flashcards
What is the equation for photosynthesis?
Photosynthesis is represented by the equation:
carbon dioxide + water >>>>>>>> glucose + oxygen
Is photosynthesis an endothermic (takes energy in) or exothermic (gives energy out) reaction?
Photosynthesis is an endothermic reaction (energy is taken in from the environment to the green chloroplasts by light.)
What is the effect of increasing temperature on the rate of photosynthesis?.
Plants cannot photosynthesise if it gets too hot.
What is the effect of increasing light intensity on the rate of photosynthesis?
Without enough light, a plant cannot photosynthesise very quickly, even if there is plenty of water and carbon dioxide. Increasing the light intensity will boost the speed of photosynthesis.
What is the effect of increasing carbon dioxide concentration on the rate of photosynthesis?
Sometimes photosynthesis is limited by the concentration of carbon dioxide in the air. Even if there is plenty of light, a plant cannot photosynthesise if there is insufficient carbon dioxide.
What is the effect of increasing the amount of chlorophyll on the rate of photosynthesis?
As chlorophyll is needed to capture the light energy for photosynthesis increasing chlorophyll will increase the rate of photosynthesis?.
What is the effect of decreasing temperature on the rate of photosynthesis?
If it gets too cold, the rate of photosynthesis will decrease.
(HT only) What do we mean by the phrase the limiting factor” in photosynthesis?
(HT only) A limiting factor is a chemical or requirement for photosynthesis that is missing. This slows down (limits) the rate rate of photosynthesis. Limiting facors include light intensity, carbon dioxide concentration and temperature. Thesefactors interact and any one of them may be the factor that limits photosynthesis.
(HT only) Why are limiting factors important in the economics of growing crops in greenhouses?
(HT only) Limiting factors are important in the economics of growing crops in greenhouses because if growers enhance the conditions in greenhouses to gain the maximum rate of photosynthesis they will increase their yeild. As long as they don’t spend too much on equipment they will also increase their profit.
What is the glucose produced in photosynthesis used for?
The glucose produced in photosynthesis may be: •• used for respiration •• converted into insoluble starch for storage •• used to produce fat or oil for storage •• used to produce cellulose, which strengthens the cell wall •• used to produce amino acids for protein synthesis. To produce proteins, plants also use nitrate ions that are absorbed from the soil.
Is respiration an endothermic (takes energy in) or exothermic (gives energy out) reaction?
Respiration is an exothermic reaction which is continuously occurring in living cells.
Why do all living things respire?
The energy transferred in respiration supplies all the energy needed for living processes.
What is aerobic respiration?
Aerobic respiration uses oxygen to transfer energy.
This is a mitochondrion which is the place where it happens in a cell.
What is anaerobic respiration?
Anaerobic respiration doesn’t need oxygen to transfer energy. Aerobic respiration is represented by the equation:
glucose + oxygen >>>>>>>>carbon dioxide + water
All living things use respiration to release energy. What do they need this energy for?
Organisms need energy for: •• chemical reactions to build larger molecules •• movement •• keeping warm.
What is the advantage for an organism of using aerobic rather than anaerobic respiration?
Anaerobic respiration releases much less energy than in aerobic respiration.
What is the equation for anaerobic respiration in plant and yeast cells?
Anaerobic respiration in plant and yeast cells is represented by the equation:
glucose >>>>>> ethanol + carbon dioxide
What is anaerobic respiration in yeast cells called and why is it important?
Anaerobic respiration in yeast cells is called fermentation and has economic importance in the manufacture of bread and alcoholic drinks.
