Bioenergetics Flashcards Preview

Biology GCSE > Bioenergetics > Flashcards

Flashcards in Bioenergetics Deck (18)
Loading flashcards...

What is the word equation for photosynthesis?

carbon dioxide + water -> glucose + oxygen


How do plants use glucose?

-For respiration to transfer energy
-Making cellulose (for plant cell walls)
-Making amino acids
-Stored as lipids (oils and fats) in seeds
-Stored as starch in roots, stems or leaves to be used for when photosynthesis can't occur


What are the limiting factors of photosynthesis?

-light intensity
-CO2 concentration


How does light affect the rate of photosynthesis?

Light provides the energy for photosynthesis so as it is increased the rate of photosynthesis increases however this is only up to a certain point.


How does the concentration of carbon dioxide affect the rate of photosynthesis?

Carbon dioxide will increase the rate of photosynthesis but only up to a certain point.


How does temperature affect the rate of photosynthesis?

Enzymes need to have the right conditions for photosynthesis. If too cold, they will work slowly but if above 45° the enzymes will be destroyed.


What is the inverse square law (relating to light intensity)?

light intensity ∝ 1/distance²


What is respiration?

The process of transferring energy from glucose. It takes place in every cell.


What do organisms use the energy from respiration for?

-building larger molecules from smaller molecules
-for muscle contraction (in animals)
-body temperature


What is aerobic respiration?

Respiration using oxygen that occurs all the time in animals and plants.


What is anaerobic respiration?

Respiration without oxygen that occurs when not enough oxygen is being supplied to your cells


What is the word equation for aerobic respiration?

glucose + oxygen -> carbon dioxide + water


What is the word equation for anaerobic respiration in animals?

glucose -> lactic acid


What is the word equation for anaerobic respiration in plants and yeast?

glucose -> ethanol + carbon dioxide


What happens to a body when it exercises?

-increased respiration
-breathing rate increases
-breath volume increases
-heart rate increases


What happens when you do vigorous exercise?

Your body can't supply enough oxygen so starts to respire anaerobically. This could lead to lactic acid building up in the muscles, which can be painful. It could also lead to muscle fatigue.


What is oxygen debt?

After exercising and respiring anaerobically, the body will need extra amounts of oxygen to react with the lactic acid in the cells to remove it. As the oxygen needs to be repaid, you will have to keep breathing hard after you've stopped exercising.


What is an alternative way to repaying oxygen (which is in debt) to get rid of a build up of lactic acid?

The blood transports lactic acid to the liver so that the liver can transport it back to glucose.