Chapter 12

Question 1

4 main systems of respiration

Answer 1

glycolysis, link reaction, krebs cycle, electron transport chain

Question 2

Glycolysis simple

Answer 2

6-carbon glucose is split into two molecules of 3-carbon pyruvate

Question 3

Link reaction simple

Answer 3

3-carbon pyruvate is oxidised into carbon dioxide and acetylcoenzyme A

Question 4

Krebs Cycle simple

Answer 4

Acetylcoenzyme A enters a cycle of redox reactions that produce ATP and a large number of electrons stored in reduced NAD and reduced FAD

Question 5

Electron Transport Chain simple

Answer 5

the electrons stored in reduced NAD from the Krebs cycle are used to generate ATP, with water as a waste product

Question 6

3 steps of glycolysis

Answer 6

phosphorylation of glucose, splitting the phosphorylated glucose into triose phosphate, oxidation of triose phosphate to pyruvate which produces 2 ATP and 2x reduced NAD

Question 7

anaerobic respiration in plant cells

Answer 7

pyruvate is converted into ethanol via ethanal

Question 8

anaerobic respiration in animal cells

Answer 8

pyruvate is converted into lactate

Question 9

link reaction

Answer 9

pyruvate is oxidised to form acetate producing reduced NAD and releasing a molecule of carbon dioxide, acetate combines with coenzyme A to produce acetyl coenzyme A.

pyruvate + NAD + CoA —> acetyl coenzyme A + CO2 + reduced NAD

Question 10

site of the krebs cycle

Answer 10

matrix of the mitochondria

Question 11

Products of the krebs cycle

Answer 11

3 reduced NAD, 1 reduced FAD molecules, 2 ATP, 2 CO2

Question 12

Process of the Krebs cycle

Answer 12

2C, 6C, 4C

between 6C and 4C all products are released

Question 13

ATP produced in all 4 stages

Answer 13

glycolysis - net 2, link reaction - 0, krebs cycle - 2, electron transport chain - 26-34

Question 14

Electron Transport Chain

Answer 14

The electron from FAD Passes from one electron carrier to another. During this, some energy is wasted, which is used to pump protons through the inner mitochondrial membrane into the inter-membrane space. The protons diffuse back through the inner mitochondria membrane. Why a protein channels called ATP synthase. As they diffuse through ATP synthase, catalyses the phosphorylation of ADP into ATP at the end of the electron transport, chain, electrons, and protons form hydrogen which reacts with oxygen to form water. Oxygen is therefore the final electron acceptor.