● Developments in scientific research follow improvements in apparatus—fluorescent calcium ions have been used to study the cyclic interactions in muscle contraction.
Understandings:
Bones and exoskeletons provide anchorage for muscles and act as levers
Synovial joints allow certain movements but not others
Movement of the body requires muscles to work in antagonistic pairs
Skeletal muscle fibres are multinucleate and contain specialised endoplasmic reticulum
Muscle fibres contain many myofibrils
Each myofibril is made up of contractile sarcomeres
The contraction of the skeletal muscle is achieved by the sliding of actin and myosin filaments
ATP hydrolysis and cross bridge formation are necessary for the filaments to slide
Calcium ions and the proteins tropomyosin and troponin control muscle contractions
Applications:
Antagonistic pairs of muscles in an insect leg
Skills:
Annotation of a diagram of the human elbow
Drawing labelled diagrams of the structure of a sarcomere
Analysis of electron micrographs to find the state of contraction of muscle fibres