1.1 Energy For Exercise

Question 1

What happens when ATP is broken down?

Answer 1

Energy is released

Question 2

What enzyme breaks down ATP?

Answer 2

ATPase - stimulates a high energy bond to be broken

Question 3

What is an endothermic reaction?

Answer 3

A chemical reaction which absorbs energy

Question 4

What is an exothermic reaction?

Answer 4

A reaction which releases energy

Question 5

What is the ATP-PC system used for? How long is it used for?

Answer 5

High intensity activity

2-10 seconds of exercise

Question 6

What enzyme breaks down phosphocreatine?

Answer 6

Creatine kinase

Question 7

Where is PC broken down?

Answer 7

The sarcoplasm

Question 8

What is the ratio of PC: ATP

Answer 8

1:1

Question 9

What is a coupled reaction?

Answer 9

Where the products of one reaction are used in another reaction

Question 10

What is the glycolytic system used for? How long does it last?

Answer 10

High intensity activity

10 seconds to 3 minutes of exercise

Question 11

What enzyme breaks down glucose?

Answer 11

Phosphofructokinase (PFK)

Question 12

What enzyme is released if glucose levels drop? What does it do?

Answer 12

GPP - glycogen phosphorylase

Catalyses the breakdown of stored glycogen, allows glucose concentration in bloodstream to be maintained

Question 13

What is anaerobic glycolysis? What does this result in?

Answer 13

Breakdown of glucose in the absence of oxygen

Pyruvate

Question 14

Give examples of sports that can occur during the glycolytic system phase

Answer 14

200-400m track
100m freestyle
Counter attack in football
Distancing from the pack in a marathon

Question 15

How long does the glycolytic system last?

Answer 15

Up to 3 minutes

Question 16

What enzyme catalyses the conversion of pyruvic acid into lactic acid?

Answer 16

LDH - lactate dehydrogenase

Question 17

What are the 3 aerobic systems?

Answer 17

Aerobic glycolysis
Krebs cycle
Electron transport chain

Question 18

Briefly describe what happens in the aerobic glycolysis stage (5)

Answer 18

PFK converts the glucose into pyruvic acid, releasing energy to synthesis 2 ATP molcules
GPP converts glycogen into glucose for extended periods of time
Oxygen is now in sufficient supply, pyruvic acid isn’t converted into lactic acid
It goes through the link reaction catalysed by co enzyme A, producing acetyl CoA
This allows access to mitochondria

Question 19

Briefly describe the Krebs cycle

Answer 19

Acetyl CoA combines with oxaloacetic acid to make citric acid

Question 20

Where does the Krebs cycle occur?

Answer 20

Matrix of the mitochondria

Question 21

What is the stored ATP reaction? How long does it last?

Answer 21

Store of ATP where muscle is quickly exhausted:
Quick powerful contractions

2-3 seconds

Question 22

Briefly describe the electron transport chain. (3)

Answer 22

Hydrogen atoms are carried through the ETC along cristae by NAD and FAD, splitting into electrons and H+
Hydrogen is oxidised and removed as water
Pairs of electrons carried by NAD release enough energy to resynthesise 30 moles of ATP and FAD release enough energy to resynthesise 4 moles of ATP

Question 23

How long does it take for PC stores to be 50% and 100% replenished?

Answer 23

50% - 30 seconds
100% - 3 minutes