Flashcards in 2: Cell Respiration Deck (13):
What do all living cells need?
a continual supply of energy
What is energy used by cells used for? Where does this energy come from (chemically)?
- a wide range of processes including active transport and protein synthesis
- energy in form of ATP (adenosine triphosphate)
How do cells get ATP?
- produce it themselves through cell respiration:
- carbon compounds e.g. glucose or fat are carefully broken down and the energy released by doing this is used to make ATP
Define 'cell respiration'.
controlled release of energy from organic compounds to produce ATP
Is ATP a good source of energy?
yeaa boi - immediately available as an energy source:
- it can diffuse to any part of the cell and release its energy within a fraction of a second
Contrast aerobic cell respiration and anaerobic cell respiration.
1. oxygen used?
- aerobic: yes
- anaerobic: no
- aerobic: glucose or lipids
- anaerobic: glucose only
3. yield of ATP per glucose
- aerobic: large
- anaerobic: small
- aerobic: CO2 and water
yeast: CO2 and ethanol
Draw a flow diagram of aerobic cell respiration. (p32)
pyruvate -> large amount of ATP + water + CO2
Draw a flow diagram of anaerobic cell respiration. (p32)
glucose -> pyruvate + small amount of ATP
State an advantage of anaerobic respiration over aerobic respiration when providing energy for muscles. When is anaerobic respiration often used?
- although anaerobic makes less ATP per glucose, it can supply ATP at a more rapid overall rate than aerobic (for a short time - about 2 mins)
- during very vigorous exercise e.g. sprinting or weight lifting
Why can we only anaerobically respire for a very short time?
- lactate (lactic acid) and hydrogen ions are produced by anaerobic respiration
- hydrogen ions lower the pH of blood
- after ~2mins, concentration of hydrogen ions is too high, making blood too acidic, so aerobic cell respiration must be used
What are the two products of anaerobic respiration in yeast?
ethanol and CO2
How is CO2 (produced by anaerobic respiration of yeast) used?
In baking industry:
- yeast mixed into dough before baking
- rapidly uses up all oxygen present and then produces ethanol and CO2
- CO2 forms bubbles making bread rise, and less dense (leavened)
- when baked, ethanol evaporates