6. aerobic respiration

Question 1

link reaction in

Answer 1

mitochondrial matrix

Question 2

link reaction converts

Answer 2

pyruvate to acetyl co enzyme A

Question 3

steps of the link reaction

Answer 3

1. pyruvate is decarboxylated (1 C is removed to form CO2)
2. pyruvate is oxidised to form acetate. NAD is reduced to form reduced NAD
3. Acetate is combined with coenzyme A (CoA) to from acetyl coenzyme A (acetyl CoA)
4. No ATP is produced in this reaction

Question 4

products of link reaction for 1 glucose molecule

Answer 4

2 molecules of acetyl coenzyme A (go to krebs cycle)
2 CO2 molecules (waste)
2 molecules of reduce NAD (go to oxidative phosphorylation)

Question 5

kerbs cycle produces

Answer 5

reduced coenzymes and ATP

Question 6

kerbs cycle involves a series of

Answer 6

oxidation-reduction reactions

Question 7

where does krebs cycle take place

Answer 7

in the matrix of the mitochondria

Question 8

krebs cycle

Answer 8

1. acetyl co enzyme A combines with 4 C molecule to produce 6 C molecule
2. 6 C molecule looses 2 x CO2 and hyrdrogen to give a 4 C molecule (H reduces NAD and FAD)
3. 1 ATP produced
4. 4 C molecule can combine with acetly A again

Question 9

reduced NAD and FAD go to

Answer 9

oxidative phosphorylation

Question 10

oxidative phosphorylation is the process where

Answer 10

electrons from reduced coenzymes (reduced NAD / FAD) are used to make ATP

Question 11

oxidative phosphorylation involves the

Answer 11

electron transport chain

chemiosmosis

Question 12

how oxidative phosphorylation works

Answer 12

1. reduced NAD / FAD oxidised and H released. H split into protons + and electrons e-
2. electrons move down electron transport chain (made of electron carriers) loose energy at each carrier
3. energy used by electron carriers to pump protons from mitochondrial matrix into inter membrane space (space between inner and outer mitochondrial membranes)
4. concentration of protons higher in the intermembrane space than the mitochondrial matrix = electrochemical gradient
5. protons move down electrochemical gradient via ATP synthase. drives synthesis of ATP from ADP and Pi (known as chemiosmosis)
6. mitochondrial matrix at end of transport chain protons, electrons and O2 (from blood) combine to form water. O2 final electron acceptor

Question 13

stage - glycolysis
molecules produced
number of ATP molecules produced

Answer 13

2 ATP = 2 ATP molecules
2 reduced NAD = 2x2.5 = 5 ATP molecule
total of 7 ATP molecules

Question 14

stage - link reaction (x2)
molecules produced
numer of ATP molecules produced

Answer 14

2 reduced NAD = 2x2.5 = 5 ATP molecules

Question 15

stage - Krebs cycle (x2)
molecules produced
number of ATP molecules produced

Answer 15

2 ATP
6 reduced NAD = 2.5 x 6 = 15 ATP molecules
2 reduced FAD = 1.5 x 2 = 3 ATP molecules produced
total of 20 ATP molecules produced

Question 16

how do mitochondrial diseases affect ATP production

Answer 16

affect how proteins involved in oxidative phosphorylation or the kreb cyle function, reducting ATP production

Question 17

mitochondrial diseases may cause

Answer 17

anaerobic repiration to increase = lots of lactate causing muscle fatigue and weakness
some lactate will also diffuse into blood stream leading to high lactate concentrations in the blood

Question 18

substrates other than glucose that can be used in repiration

Answer 18

some products resulting from breakdown of other molecules such as fatty acids from lipids, amino acids from proteins can be converted into molecules that are able to enter the krebs cycle