2.8 cell respiration Flashcards
cell respiration
the controlled release of energy from organic compounds to produce ATP
The main organic compound used for cell respiration
carbohydrates (glucose), although lipids and proteins can also be digested
2 types of cell respiration
aerobic and anaerobic
anaerobic respiration
involves the partial breakdown of glucose in the cytosol for a small yield of ATP
aerobic respiration
utilises oxygen to completely break down glucose in the mitochondria for a larger ATP yield
cell respiration equation
glucose + 6 oxygen -> 6 carbon dioxide + 6 water + ATP
ATP (adenosine triphosphate)
a high energy molecule that functions as an immediate source of power for cell processes
where is the energy stored in ATP?
in the phosphate bonds
how is energy released from ATP?
when one of the high-energy phosphate bonds in ATP breaks, energy is released and ADP is formed
how do both anaerobic and aerobic respiration pathways begin?
with the anaerobic breakdown of glucose in the cytosol by glycolysis
purpose of anaerobic respiration
to restore stocks of NAD+ – as this molecule is needed for glycolysis
controlled release
a series of enzyme-catalyzed reactions
2 main reactions of aerobic cell respiration
- glycolysis
- citric acid cycle
glycolysis
in the cytoplasm. a step-by-step process where glucose (C6) produces 2 pyruvate (C3) molecules, 2 ATP, water, and heat energy
citric acid cycle
in the mitochondria. a cyclical reaction. pyruvate produces acetyl-CoA (C2) which is oxidized into carbon dioxide (C1). A large amount of ATP is produced.
where does anaerobic respiration occur?
- in the absence of oxygen
- in the cytoplasm
write anaerobic respiration in humans
see ipad
write anaerobic respiration in yeast
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how is anaerobic respiration used when exercising?
anaerobic respiration occurs in muscles when energy demand exceeds oxygen availability. lactate is produced, and ATP in small amounts
3 main cellular processes that use ATP as a source of energy
- active transport
- mitosis
- DNA replication/transcription, translation
(bonus: cell communication/signaling)
2 organic molecules other than glucose that can be used for respiration
- amino acids
- fatty acids
2 regions of the cell in which respiration takes place
cytoplasm and mitochondria
what do respirators do?
calculate the rate of respiration by measuring the consumption of oxygen
function of the Potassium hydroxide (soda lime) solution in the respirometer
absorbs CO2 gas
function of Capillary tube containing coloured oil in respirometer
Measure the uptake of oxygen (coloured oil will rise as oxygen is consumed)
function of Rubber stopper and glass jar in respirometer
Closed system (no input/output of gases)
function of wire mesh in respirometer
protection of mouse from lime
Describe how and why yeast is used in bread making
-Anaerobic respiration. Sugars is dough are consumed
-Produces CO2 gas → bubbles in bread.
-Ethanol is also produced but evaporates during baking.
3 activities that require anaerobic respiration
Baking
Biofuel production
High intensity sports (ex: sprinting)
Explain why anaerobic respiration can only be done for short periods of time
Produced little ATP (insufficient to fuel other cell processes).
Build up of lactic acid which is damaging to cells. Needs to be removed aerobically.
what does anaerobic respiration in yeast yield?
ethanol and CO2
What is the correct sequence of chemicals produced in the anaerobic respiration pathway?
glucose → pyruvate → lactate
What is measured by a respirometer?
rate of respiration; Rate of exchange of O2 and CO2
