Explain the concept of angular momentum when a figure skater spins on ice.

Analyse the movement taking place at the figure skater’s shoulder when moving from Position A to Position B.

Outline the process of glycogenolysis.

Outline the characteristics of muscle.

angular momentum is defined as moment of inertia x angular velocity ✔

angular velocity and moment of inertia are inversely proportional ✔

angular momentum is when a body is spinning about an axis ✔

a moment of inertia is determined by the distance of the load from the rotational axis ✔

angular momentum remains constant unless the figure skater is acted upon by an unbalanced force ✔

figure skater rotates in the transverse plane about the longitudinal axis ✔

a figure skater can increase their moment of inertia by moving their limbs away from the centre of their body/axis
OR
a figure skater can increase their angular velocity by moving their limbs close to the centre of the body/axis ✔

in picture A, the figure skater has a large moment of inertia and therefore their rate of spin (angular velocity) is low
OR
in picture B, the figure skater has a small moment of inertia and therefore their rate of spin (angular velocity) is high ✔

Accept in the converse

Award max [5] if the student does not refer to figure skating.

joint is a ball and socket joint ✔

movement is adduction ✔

agonist pectoralis major and/or latissimus dorsi ✔

antagonist deltoid ✔

concentric contraction of the agonist ✔

third-class lever ✔

defined as the removal of glucose units from glycogen, producing glucose-1-phosphate
OR
defined as the breakdown of glycogen to glucose ✔

glycogen is stored in the liver ✔

glucagon acts on the liver to stimulate glycogenolysis ✔

insulin inhibits glycogenolysis ✔

requires enzymes for optimal function
OR
phosphorylase is the main enzyme ✔

it provides a rapid rate of production of glucose-6-phosphate ✔

adrenalin is released during the fight or flight system, which also stimulates glycogenolysis to raise glucose levels ✔

glucose is taken up by the muscle cells, where glycolysis takes place ✔

involves a hydrolysis reaction ✔

is controlled by nerve stimuli ✔

is fed by capillaries ✔

Contractility:
ability to generate force / create tension ✔

Extensibility:
ability to be stretched beyond its normal resting length ✔

Elasticity:
ability to return to resting length after it has been stretched ✔

Atrophy:
a decrease in myofibrils / fibre diameter due to a lack of physical activity ✔

Hypertrophy:
an increase in myofibrils / fibre diameter due to an increase in activity/training ✔

Award max [2] if only a list of characteristics is given.