Topic 4- Bioenergetics Flashcards
what does photosynthesis produce using light?
glucose.
what does photosynthesis use energy to change?
it uses energy to change carbon dioxide and water into glucose and oxygen.
where does photosynthesis take place?
in chloroplasts in plant cells.
what does chloroplasts contain?
it contains chlorophyll that absorbs light.
what is transferred to the chloroplasts from the environment by light?
energy.
what kind of reaction is photosynthesis?
endothermic meaning that energy is transferred from the the environment during the reaction.
what is the word equation for photosynthesis?
carbon dioxide + water —> (light) —> glucose + water.
what is the chemical symbol for carbon dioxide?
CO 2.
what is the chemical symbol for water?
H 2 O.
what is the chemical symbol for glucose?
C 6 H 12 O 6.
what is the chemical symbol for oxygen?
O 2.
why do plants use glucose?
- for respiration.
- for making cell walls.
- for making amino acids.
- stored as oils and fats.
- stored as starch.
why do plants use glucose for respiration?
it transfers energy from glucose which allows the plants to change the rest of the glucose into other useful substances.
why do plants use glucose to make cell walls?
glucose is changed into cellulose for making strong plant cell walls.
why do plants use glucose to make amino acids?
glucose is combined with nitrate ions to make amino acids. nitrate ions are absorbed from the soil. amino acids are used to make proteins.
why do plants use glucose to be stored as oils and fats?
glucose is turned into lipids (fats and oils) for storing in the seeds.
why do plants use glucose to be stored as starch?
glucose is turned into starch and stored in roots. stems and leaves. plants can use this starch when photosynthesis isn’t happening. starch is insoluble (can’t be dissolved). being insoluble makes starch much better for storing than glucose. this is because a cell with lots of glucose in would draw in loads of water and swell up.
what can the rate of photosynthesis be affected by?
these are limiting factors:
- light.
- temperature.
- CO2.
what is a limiting factor?
it is something that stops photosynthesis from happening any faster.
what else can be a limiting factor of photosynthesis?
chlorophyll.
what can the amount of chlorophyll in a plant be affected by?
- disease.
- the changes in the environment (e.g: lack of nutrients).
what can the limiting factor of chlorophyll cause?
it can cause chloroplasts to become damaged or to not make enough chlorophyll. this means they can’t absorb as much light, the rate of photosynthesis is reduced.
what are the three important graphs for rate of photosynthesis?
- not enough lights slows down the rate of photosynthesis.
- too little carbon dioxide can slow it down.
- the temperature has to be right.