Respiration

Question 1

What is Aerobic Respiration?

Answer 1

Complete breakdown of glucose and requires oxygen as the final electron acceptor.

Question 2

Why is respiration described as a catabolic process?

Answer 2

Complex molecules are broken down into smaller simpler molecules.

Question 3

Why do organisms need to respire?

Answer 3

Releases energy to produce ATP for a variety of processes.

Question 4

Four stages of aerobic respiration and where they occur?

Answer 4

Glycolysis - cytosol
Link Reaction - Mitochondrial Matrix
Krebs Cycle - Mitochondrial Matrix
ETC - Inner M Membrane

Question 5

Outline the stages of glycolysis

Answer 5

Glucose phosphorylated to hexose phosphate by 2X ATP
Hexose phosphate splits into 2X triers phosphate
2 molecules of TP oxidised to 2X pyruvate

Question 6

What is the function of Krebs Cycle?

Answer 6

Releasign energy from C bonds to provide ATP, NADH2 and FADH2.

Question 7

Outline Link Reaction

Answer 7

Oxidative decarboxylation and dehydrogenation of pyruvate to form acetate
Net gain of CO2 and 2x NADH2
Acetate combines with coenzyme A to form acetyl coenzyme A

Question 8

Role of RED NAD AND FAD

Answer 8

They are a source of electrons and protons

Question 9

How does chemiosmosis produce ATP during aerobic respiration?

Answer 9

Protons flow down their conc gradient from the intermembrane space into the MM via ATP synthase
ATP S phosphorylates ADP to form ATP as protons flow through it

Question 10

Why is O important as FEA in the ETC

Answer 10

Removes e and p from matrix to prvent accumulation. ( NO p Grad,ATP S cant function, ATP not produced and cell die)

Question 11

Per turn of Krebs Cycle how much of each product is produced?

Answer 11

3 CO2
3 Red NAD
1 Red FAD

Question 12

Define Aerobic Respiration

Answer 12

A form of cellular respiration that takes place in the absence of oxygen.

Question 13

Product of anaerobic respiration in animals

Answer 13

Lactate

Question 14

Outline Anaerobic respiration in animals:

Answer 14

Only Glycolysis continues
RED NAD (from G) transfer H to pyruvate ,forming lactate

Question 15

Product anaerobic respiration in plants and fungi

Answer 15

Ethanol and CO2

Question 16

Outline Anaerobic respiration in plants and fungi

Answer 16

Only Glycolysis continues
Pyruvate is decarboxylated to form Ethanal
Ethanal is reduced to Ethanol using RED NAD producing Oxidised NAD for further G

Question 17

Why is the maximum yield of ATP in aerobic respiration never achieved?

Answer 17

ATP lost due to leaky membranes

Energy required to move pyruvate and ADP into the mitochondrial Matrix

Question 18

Name two types of molecules that can be used as alternative respiratory substrates?

Answer 18

AAs from Proteins

Glycerols and Fatty Acids from lipids

Question 19

Explain how lipids are used in respiration

Answer 19

Hydrolysed to G and FA
G converted to 3C sugar and enters glycolysis
FA broken down into 2C acetate fragments which enter as acetyle coenzyme A in KC

Question 20

Explain how proteins are used in respiration

Answer 20

Hydolysed to AAs
AAs deaminated in the liver forming keto acids and ammonia
Keto acids enter G and KC

Question 21

Explain how proteins are used in respiration

Answer 21

Hydrolysed to AAs
AAs deaminated in the liver forming keto acids and ammonia
Keto acids enter G and KC

Question 22

What happens at the start of glycolysis?

Answer 22

Phosphorylation

Question 23

Net gain of ATP for G

Answer 23

2 (4 made 2 used)

Question 24

Where does NAD carry H to next in G?

Answer 24

ETC

Question 25

Where does dehydrogenase act in g?

Answer 25

Between triose phosphate and pyruvate.

Question 26

What enzymes are involved in link reaction?

Answer 26

Dehydrogenase and Decarboxylase