Energy Systems -Aerobic system

Question 1

Where does the energy we use for muscle contraction in the body come from?

Answer 1

ATP - Adenosine triphosphate is made from the break down of Carbohydrates and Fats. The energy that is stored in ATP is released by breaking down the bonds which hold this compound together.

Question 2

Which enzyme breaks down ATP and what does it break it down into.

Answer 2

ATPase ATP = ADP + P giving off energy

Question 3

Name the 3 different types chemical reactions that occur in the muscle cells used to re-synthesise ATP.

Answer 3

1. The Aerobic System
2. The ATP-PC System
3. The anaerobic Glycolytic system.

Question 4

What factors determine which energy system is used for an activity?

Answer 4

Depends on Duration and intensity of the exercise and whether Oxygen is present.
High intnesity = ATP-PC system or anaerobic glycolytic system
Long duration + lower intensity = Aerobic system

Question 5

Define Glycolysis

Answer 5

A process in which glucose is converted to pryuvate to produce energy.

Question 6

Where does glycolysis occur?

Answer 6

In the sarcoplasm of the muscle cell.

Question 7

How many molecules of ATP are produced by glycolysis

Answer 7

2 ATP

Question 8

How many molecules of ATP are produced in total during oxidation of Glucose.

Answer 8

38 ATP

Question 9

Draw a diagram to show Glycolysis

Answer 9

Glycogen
        I          Phosphofructokinase
Glucose
        I          Energy (2ATP)
Pyruvic acid

Question 10

What is Pyruvic acid converted into before it enters the krebs cycle?

Answer 10

It is oxidised into 2 acetyl groups and then carried into Krebs cycle by co enzyme A

Question 11

Explain what happens in the Krebs cycle

Answer 11

The two acetyl groups diffuse into the matrix of the mitochondria and a complex cycle of reactions occurs in the krebs cycle.
The acetyl groups combine with oxaloacetic acid forming citric acid.
Hydrogen is removed from the citric acid and the rearranged form of citric acid gives off carbon dioxide and hydrogen.
The Carbon dioxide is breathed out and the Hydrogen continues on to the Electron Transport Chain.

Question 12

How many moelcules of ATP are produced as a result of the Krebs cycle?

Answer 12

2 ATP

Question 13

Explain the Electron Transport Train

Answer 13

Involves a series of chamical reactions in the cristae of mitochondria where hydrogen is oxidised to water and 34 ATP produced.

Question 14

Name the 3 energy sources used in Aerobic system

Answer 14

Carbohydrates - glucose,
fats - Fatty acids and glycerol,
protein - Amino acids

Question 15

Explain how Beta oxidation uses fats to re syntheise ATP in the aerobic system.

Answer 15

Stored fat is broken down to Glycerol and Free fatty acids for transportation in the blood
The fatty acids then under go beta oxidation whereby they are converted to Acetyl Coenzyme A, which then enters the Krebs Cycle and metabolises the same way as glucose.
More ATP is made from fat than from glucose which is why in long duration lower intensity exercise fats are the main source of energy

Question 16

Name 3 advantages of the Aerobic system in resynthesising ATP.

Answer 16

1) More ATP is produced. 38 ATP
2) There are no fatiguing by- products CO2 and H2O
3) There are lots of Glycogen amd triglyceride stores so exercise can last for a long time.

Question 17

Name 2 disadvantages of the aerobic system in resynthising ATP

Answer 17

1) This is a complicated system so cannot be used straight away. It takes a while for enough oxygen to become available to meet the demands of the activity
2) Fatty acid transportationto muscles is low and also requires 15% more oxygen to be broken down than glycogen.

Question 18

What is the sarcoplasm

Answer 18

The fluid that surrounds the nucleus of a muscle fibre and is the site of glycolysis