12.0 Respiration Flashcards
What does respiration produce?
ATP
What makes ATP a good source of energy?
Only a single hydrogen bond needs to be broken, releases a small amount of energy
What are the four stages of aerobic respiration?
- Glycolysis
- Link reaction
- Krebs cycle
- Oxidative phosphorylation
What is the difference between aerobic and anaerobic respiration?
Aerobic uses oxygen while anaerobic does not
Where do the four stages of respiration take place?
- Glycolysis = cytoplasm
- Link reaction = matrix
- Krebs cycle = matrix
- Oxidative phosphorylation = cristae membrane
Where does anaerobic respiration take place?
Cytoplasm
How much ATP is created in aerobic and anaerobic respiration?
38 in aerobic
2 in anaerobic
What are the end products of aerobic respiration?
Carbon dioxide and water
What are the end products of anaerobic respiration?
Animals = lactate
Plants/fungi = ethanol
What is oxidation?
Loss of electrons or hydrogen atoms
What is reduction?
The gain of electrons or hydrogen atoms
What is NAD?
A coenzyme
What are the three stages of glycolysis?
- Phosphorylation of glucose into glucose phosphate
- Production of triose phosphate
- Oxidation of triose phosphate into pyruvate
How is glucose converted into glucose phosphate?
2 ATP molecules undergo hydrolysis to become ADP. The 2 phosphate molecules bond to the glucose which lowers the activation energy for the link reaction
How is triose phosphate created?
A glucose phosphate splits to become 2 molecules of triose phosphate
How is triose phosphate converted into pyruvate?
A hydrogen molecule is removed from the triose phosphate by NAD to become NADH. 2 ADP molecules react with 2 triose phosphate to become 2 ATP molecules and 2 pyruvate molecules
How many ATP molecules are created during glycolysis?
Net gain of 2
What are the products of glycolysis?
2 ATP
2 pyruvate
2 NADH
In anaerobic respiration what happens to pyruvate?
Converted to ethanol in plants and fungi and lactate in animals
What happens to pyruvate in aerobic respiration?
It is taken to the mitochondrial matrix in order to take part in the link reaction
What is the name of the reaction that uses pyruvate from glycolysis?
The link reaction
What happens to the pyruvate in the link reaction?
It is oxidised to acetate
Why can pyruvate enter the mitochondria but glucose cannot?
Pyruvate is smaller
What molecule accepts the 2 hydrogens released from pyruvate in the link reaction?
NAD - it forms NADH
What molecule combines with the acetate created during the link reaction?
Coenzyme A - it forms acetylcoenzyme A
What is the overall equation for the link reaction?
Pyruvate + NAD + CoA = Acetyl CoA + NADH + CO2.
What are the products of the link reaction?
2 NADH
2 acetyl CoA
2 CO2
What process occurs after the link reaction in aerobic respiration?
The Krebs cycle
What is a coenzyme?
A molecule which assists some enzymes in
functioning. Those involved in respiration and
photosynthesis carry Hydrogen atoms from one
molecule to another.
What are the 3 main coenzymes?
NAD - used throughout respiration; FAD - used
in the Krebs cycle; NADP, used in
photosynthesis.
What is produced in a single krebs cycle?
3 NADH, 1 FADH, 1 x ATP, 2 x CO2
What type of phosphorylation occurs in the Krebs cycle?
substrate-level phosphorylation
Describe chemiosmosis
reduced NAD and reduced FAD release the hydrogen atom (H+/e-) they are carrying. the H+
build up in the matrix of the mitochondria. the e-
enter the ETC. the electron (e-) moves along the
chain releasing energy, this pumps the protons
(H+) from the matrix into the intermembranal
space. the H+ build up in the intermembranal
space, then diffuse back into the matrix via a
transport protein carrying ATP Synthase enzyme
. this leads to the production of ATP = oxidative
phosphorylation. oxygen is used as a final
electron acceptor and proton acceptor. it removes
the electron from the end of the ETC, so the ETC
can continue. it removes the proton from the
matrix, hence maintaining concentration
gradient. it becomes wate
How is oxidative phosphorylation carried out?
Electrons are transferred through a series of
carier molecules which together form the
Electron Transfer Chain.
What is the role of oxygen in the ETC?
It acts as a final electron acceptor
Why doesn’t the ETC occur in anaerobic respiration?
No oxygen so no final electron acceptor
Why doesn’t the Krebs cycle and link reaction occur in anaerobic respiration?
reduced NAD and FAD are not regenerated in
the ETC and so the process has to stop
What is produced in anaerobic respiration in animals?
lactate
What is produced in anaerobic respiration in plants/yeast?
ethanol and CO2
What are the alternative respiratory substrates?
Amino acids - converted into pyruvate and intermediates in the Krebs cycle based on the number of carobs
Fatty acids - become acetyl CoA and glycerol becomes triode phosphate
