IB Muscle and muscle contraction

Identify the structure in the image

Identify the role of ATP in muscle contraction

• Break cross bridge between myosin and actin

• Expose binding sites on actin

• Stimulate the release of calcium ions

• Formation of cross bridges

Identify the structure from which calcium ions are released in a muscle fibre

Identify the state of the muscle in the image

• Relaxed

• Contracted

Identify the role of calcium ions in muscle contraction

• Binds to tropomyosin and uncovers troponin

• Exposes binding sites on myosin heads

• Binds to troponin and moves tropomyosin to expose binding sites on actin

• Causes power stroke

State the general term for the actin and myosin protein filaments found in muscle fibres

Which type of muscle is myogenic?

• Skeletal

• Smooth

• Cardiac

• Fast twitch

What happens during muscle contraction?

• The width of the dark bands is reduced.

• The distance between Z lines decreases

• The number of light bands is reduced.

• Actin and myosin filaments coil up

Identify the substance released from the pre synaptic neuron that forms a junction with muscle tissue

• Myelin

• Acetylcholine

• Calcium ions

• Pyruvate

A skeletal muscle contains bundles of elongated muscle fibre cells. What is the longest structure within each fibre?

• Sarcomere

• A myosin filament

• An actin filament

• Z line