Energy Systems

Question 1

What is metabolism?

Answer 1

Sum of all processes going on in the body’s cells sustaining life

Question 2

What is a nutrient?

Answer 2

sustain life, are needed to survive

Question 3

What is a macro-nutrient?

Answer 3

nutrient consumed in large quantities: carbohydrates, proteins, fats, alcohol

Question 4

What is metabolic regulation?

Answer 4

how foods are channelled and how they are later use

Question 5

What is anabolic regulation?

Answer 5

making macro-nutrients from vitamins and small particles

Question 6

What is catabolic regulation?

Answer 6

breaking down macro-nutrients into energy for use

Question 7

What is the composition of ATP?

Answer 7

Adenosine + 3 phosphates linked together by very high energy phosphate bonds; ATPase breaks down these bonds and energy is released

Question 8

How does the ATP-PCr system work?

Answer 8

1. ATP broken down into ADP
2. Phosphocreatine (creatine + phosphate) linked by high energy phosphate bond
3. Creatine Kinase enzyme breaks down this bond and energy is released
4. Loose phosphate molecule is used to resynthesise ATP

Question 9

What is the cause of fatigue of the ATP-PCr system?

Answer 9

A depletion of PCr: the rate of demand is greater than rate of replenishment

Question 10

How quickly does PCr depletion occur?

Answer 10

Within 3 to 15 seconds of an all out sprint

Question 11

How quickly is PCr fully replenished?

Answer 11

Within a few minutes after a sprint

Question 12

What is glycolysis?

Answer 12

Glycolysis is the process of converting glucose into pyruvate

Question 13

What are the anaerobic energy systems?

Answer 13

the ATP-PCr system
the Lactic Acid system
they both function without oxygen

Question 14

What is the second energy system used?

Answer 14

The Lactic Acid system or anaerobic glycolysis

Question 15

How does the Lactic Acid system work?

Answer 15

Occurs when muscle are working above their lactate threshold
Glycogen is broken down and releases energy to resynthesize ATP
Enzyme: phosphorylase
By-product: Pyruvic Acid, converted into lactic acid due to absence of oxygen

Question 16

When does Lactic Acid system start and how long does it last?

Answer 16

During high intensity exercise, takes about 10secs to kick it and lasts for another 20secs; good for stop/start games , field and court sports

Question 17

What is the third energy system used?

Answer 17

Aerobic Glycolysis (requires oxygen)

Question 18

When does Aerobic glycolysis work?

Answer 18

After 30secs of intensive physical activity for up to 2 hours, aerobic system becomes main source of energy

Question 19

What are the benefits of the ATP-PCr system?

Answer 19

1. Stored in the muscle so it is readily available
2. Does not require oxygen
3. Very simple reaction so can happen quickly
4. No negative by-products

Question 20

What are the disadvantages of the ATP-PCr system?

Answer 20

Very quickly depleted so it is useful for short explosive exercise (e.g. javelin throw) but not for longer than 10secs

Question 21

What are the 3 benefits of the Lactic Acid System?

Answer 21

1. Does not require oxygen
2. Produces a lot more ATP than ATP-PCr system
3. Lasts up to a few minutes

Question 22

What are the 2 disadvantages of the Lactic Acid System?

Answer 22

1. Lasts no more than a few minutes, requires another system for longer exercise
2. Lactate builds up in the blood which increases muscle acidity and causes fatigue

Question 23

What are the 4 benefits of the Aerobic System?

Answer 23

1. Can produce energy for a very long time
2. Can use fat as a fuel and spare glycogen (provided there is enough oxygen available)
3. Abundant energy produced compared to anaerobic systems
4. No harmful waste products

Question 24

What is the disadvantage of the Aerobic System?

Answer 24

Slow to get going due to complicated process

Question 25

What is the metabolism for glycerol?

Answer 25

Aerobic Glycolysis; requires oxygen
Fuel: glycerol
Produces Acetyl CoA through phosphoglyceraldehyde and begins the Citric Acid Cycle

Question 26

What are the 3 causes of fatigue of the oxidative system (aerobic glycolysis and lypolysis)?

Answer 26

1. Muscle glycogen depletion
2. Liver glycogen depletion
3. Hypoglycaemia

Question 27

What is the metabolism for glycerol?

Answer 27

Aerobic Glycolysis (fat)

Question 28

What is the role of ATPase?

Answer 28

ATPase breaks down high energy phosphate bonds of ATP to release energy

Question 29

What is ATP?

Answer 29

Fuel of daily activity

Question 30

How many cal/mol is ATP?

Answer 30

12 cal/mol

Question 31

How heavy is ATP? (g/mol)

Answer 31

551g/mol

Question 32

How does the Lactic Acid system work?

Answer 32

Uses glucose (bloodstream) or glycogen (muscle or liver) as fuel and does not require oxygen

Question 33

How long does is take to replenish glycogen stores after aerobic glycolysis fatigue?

Answer 33

Takes 24-48hours to replenish glycogen

Question 34

How does aerobic glycolysis (CHO) work?

Answer 34

Fuelled by glycogen
Regulated by the enzyme PFK
Produces Pyruvic Acid which becomes Acetyl-CoA at the mitochondria

Question 35

When does the Citric Acid Cycle begin?

Answer 35

After oxidative system produces Acetyl CoA

Question 36

How does beta-Oxidation work?

Answer 36

Fuelled by NEFA (non-esterified fatty acids)
Produces Acetic Acid then Acetyl CoA
Begins the Citric Acid Cycle

Question 37

What is the metabolism for fatty acids?

Answer 37

beta Oxidation (aerobic: requires oxygen)

Question 38

How does aerobic glycolysis (fat) work?

Answer 38

Fuelled by glycerol
Produces phosphorusglyceraldehyde then Acetyl CoA
Begins the Citric Acid Cycle

Question 39

What can PCr recovery measurements be useful index for? (2 answers)

Answer 39

1. Relative muscle oxidative capacity
2. Mitochondrial content in the muscle
   (Haseler et al. 1999)

Question 40

What is the recovery of PCr limited by?

Answer 40

O2 supply

Haseler et al. 1999