1. (8) Energy systems in muscle cells
(A)
Creatine Phosphate
(B) Lactic Acid Metabolism
(C)
Types of skeletal muscle fibres

2. (a) Energy systems in muscle cells
State what creatine phosphate is and the cells which use it
State the role of creatine phosphate in these cells
State when creatine phosphate will run out
State how the levels of creatine phosphate are restored

3. How are the muscles organised?
We need to have a closer look at our muscular system!

4. 3 types of muscle in the body… We will look at skeletal muscle in the next lesson!

5. Inside the muscle…

6. Sources of energy for muscle cells
Our muscle cells are constantly being used and made to work therefore they need a supply of energy.
During strenuous muscle activity, the cell rapidly breaks down its reserves of ATP to release energy.

7. So… what do cells need creatine phosphate for?
Click on the bottle!

8. Sources of energy for muscle cells
Muscle cells have an additional source of energy in creatine phosphate that can be used to replenish ATP pools during rigorous bouts of exercise.
Creatine phosphate breaks down to release energy and phosphate that is used to convert ADP to ATP at a fast rate.
So… why doesn’t the cell use creatine phosphate all the time?

9. The problem with creatine phosphate
This system can only support strenuous muscle activity for around 10 seconds, when the creatine phosphate supply runs out.
When muscle energy demand is low, ATP from cellular respiration is used to restore the levels creatine phosphate.
Task: copy diagram 7.24 on page 113

10. (a) Energy systems in muscle cells
State what creatine phosphate is and the cells which use it
State the role of creatine phosphate in these cells
State when creatine phosphate will run out
State how the levels of creatine phosphate are restored