| Date | May 2015 | Marks available | 2 | Reference code | 15M.3.SL.TZ1.6 |
| Level | Standard level | Paper | Paper 3 | Time zone | Time zone 1 |
| Command term | Explain | Question number | 6 | Adapted from | N/A |
Question
State the names and functions of the antagonistic muscles of the human elbow joint.
[2]
a.
Explain the role of ATP in muscle contraction.
[2]
c.
Markscheme
a. biceps flexes/bends the arm;
b. triceps extends/straightens the arm;
a.
a. ATP binds to myosin heads;
b. ATP used to break cross bridges;
c. energy released when ATP forms ADP and phosphate;
d. myosin head reset;
e. actin slides over myosin;
c.
Examiners report
Most candidates knew the functions of the biceps and triceps muscles.
a.
There was much confusion over the exact role of ATP in muscle contraction.
c.
