Week 4

Question 1

Explain ATP

Answer 1

High energy, 3 phosphate groups attached to a ribose sugar

Question 2

What is released from ATP when hydrolysed?

Answer 2

Chemical energy causing a loss of 1 phosphate group

Question 3

What do catabolic reactions do?

Answer 3

Release energy, used in ATP synthesis

Question 4

What does ATP do during exercise?

Answer 4

Supplies demand of energy from skeletal muscle and other tissue

Question 5

What maintains ATP during hard/anaerobic exercise?

Answer 5

A Myokinase reaction

Question 6

Why does a myokinase reaction maintain ATP during hard/anaerobic exercise?

Answer 6

Reduces ATP, Increases ADP, Breaks down AMP and excretes via urea cycle

Question 7

What does creatine kinase do?

Answer 7

Drives ATP synthesis during hard exercise

Question 8

Why does PCr outweigh Cr in muscle?

Answer 8

To favour the conversion of Cr and ATP

Question 9

During ATP regeneration, what is ATP supplied through?

Answer 9

The breakdown of carbohydrates and fats

Question 10

What increases during ATP regeneration during exercise and why?

Answer 10

Pi and ADP, as myokinase reuses ADP to generate more ATP

Question 11

What does glucose yield?

Answer 11

Energy

Question 12

What is the 1st step of Carb digestion?

Answer 12

Amylase hydrolyses in the mouth

Question 13

What is the 2nd step of Carb digestion?

Answer 13

Oligosaccharides are broken down into disaccharides in the villi of the small intestine

Question 14

What is the 3rd step of carb digestion?

Answer 14

Lactase, Maltase and Sucrase breakdown disaccharides into monosaccharides

Question 15

What is the 4th step of carb digestion?

Answer 15

Monosaccharides are absorbed into cytosol of enterocytes and transported into capillaries taht empty into venous blood and the vein that supplies the liver.

Question 16

Where is glycogen mainly stored?

Answer 16

Liver (3-7%) and muscle (1-1.5%)

Question 17

In muscle where is glycogen optimally located?

Answer 17

Between thick and thin filaments and near the mitochondria

Question 18

What is enhanced by the breakdown of liver glycogen during exercise?

Answer 18

ATP provision in muscle

Question 19

What is the process of glycogen synthesis?

Answer 19

UTP reacts with glucose to provide energy to build the glycogen chain

Question 20

What is the process of glycogen breakdown?

Answer 20

A phosphate group is added to glucose to release it from the glycogen chain

Question 21

What does exercise do for glycogen?

Answer 21

Regulates the breakdown of glycogen

Question 22

During exercise, what happens to the rate of glycogen breakdown in skeletal muscle?

Answer 22

It increases within seconds of muscle contraction due to the high demand for ATP

Question 23

Where else is glycogen breakdown increased during exercise?

Answer 23

In the liver supplying the muscle with more glucose

Question 24

What causes the increase of glycogenolysis in the liver?

Answer 24

Adrenaline (systemic change)

Question 25

What system is increased post exercise?

Answer 25

Glycogen synthesis

Question 26

How many phases are there in glycogen resynthesis post exercise?

Answer 26

2

Question 27

What are the 2 phases of glycogen resysnthesis called?

Answer 27

Insulin independent and dependent

Question 28

What is the difference between the 2 phases of glycogen resynthesis?

Answer 28

ii is 0-4 hours after, id is 4-24 hours after, id has a lower rate of synthesis

Question 29

What can the breakdown of carbohydrates supply in metabolism?

Answer 29

Protons and electrons for ATP

Question 30

When a substrate is oxidised, how many hydrogen atoms does it give up and why?

Answer 30

2, turns one into NAD+ or FADH from a hydride ion and the other one is released as a proton lowering the pH.

Question 31

Is Glycolysis an aerobic or anaerobic pathway?

Answer 31

Anaerobic

Question 32

Does glycolysis have a high or low energy yield taking place in the cytosol?

Answer 32

Low

Question 33

What is the reactant in glycolysis?

Answer 33

Glucose

Question 34

What 4 factors speed up the rate of glycolysis during exercise?

Answer 34

Substrate availability, Physiological factors, Cellular factors, Molecular factors

Question 35

Is the Krebs cycle aerobic or anaerobic?

Answer 35

Aerobic

Question 36

Does the krebs cycle have a high or low energy yield in the mitochondrial matrix?

Answer 36

low

Question 37

What is the reactant in the krebs cycle?

Answer 37

Acetyl CoA

Question 38

What causes pyruvate oxidation?

Answer 38

Shutting of pyruvate to the mitochondria yielding large amounts of ATP, Pyruvate is then oxidised to Acetyl CoA through pyruvate dehydrogenase which generates NADH

Question 39

What are the site of multiple oxidation reactions?

Answer 39

Mitochondria

Question 40

What is the krebs cycle?

Answer 40

A series of 9 reactions that oxidises acetyl coA into carbon dioxide

Question 41

How much ATP is produced from the krebs cycle?

Answer 41

Small amount

Question 42

What happens to the metabolites in the krebs cycle?

Answer 42

They are recycled

Question 43

Is oxidative phosphorylation aerobic or anaerobic?

Answer 43

Aerobic

Question 44

Is the energy yield of oxidative phosphorylation high or low?

Answer 44

High

Question 45

Where does oxidative phosphorylation take place?

Answer 45

Mitochondrial intermembrane space and matrix

Question 46

What does the electron transport chain do?

Answer 46

Reoxidises reduced coenzymes (NADH and FADH2) back to their oxidised forms

Question 47

During the electron transport chain, how many protons and electrons are lost?

Answer 47

2 electrons and 1 proton

Question 48

What happens to NAD+ and FADH at the end of the electron transport chain?

Answer 48

They are recycled back to the cytosol and mitochondrial matrix

Question 49

What is oxidative phosphorylation?

Answer 49

Reduction of oxygen to generate high energy phosphate bonds in the form of ATP

Question 50

Where is ATP synthase embedded?

Answer 50

Cristae of the inner mitochondrial membrane

Question 51

How many molecules of ATP can 1 glucose molecule yield?

Answer 51

30 ATP molecules

Question 52

How is the resynthesis optimised for different activities?

Answer 52

By using different energy systems

Question 53

In anaerobic conditions how is lactate produced in muscle?

Answer 53

From pyruvate via lactate dehydrogenase

Question 54

Why is lactate production often associated with muscle fatigue and soreness during exercise?

Answer 54

Lactate leaves active muscle fibres down a concentration gradient which enters less active muscle fibres, reforming pyruvate

Question 55

What is liver glycogen a source of during exercise?

Answer 55

A source of glucose

Question 56

What is gluconeogenesis?

Answer 56

When carbon skeletons from other molecules are used to synthesise glucose for energy provision

Question 57

What process uses pyruvate as a substrate?

Answer 57

Gluconeogenesis