Muscle Contraction Flashcards
What does a muscle convert ATP into?
Mechanical energy
What are the different types of muscle found in vertebrates?
Skeletal, smooth and cardiac
What are skeletal/striated muscle used for?
Voluntary movements
What do myofibrils contain?
Proteins actin, myosin and control proteins
What are actin and myosin filaments?
Actin= twisted chain of monomers Myosin= ordered bundles of tad pole like molecules
What are sarcomeres?
Repeating units along myofibrils and the basic functional units of muscle
How long are sarcomeres in vertebrate skeletal muscle?
2.0-2.6um long
What does the Z line in the sarcomere do?
Provides an anchor for actin filaments and Titin
What does titin do?
It’s an elastic structural protein that holds bundles of myosin filament in position
What is the term called when a myosin head binds to the actin filament?
A cross bridge
What do actin and myosin filaments overlap to become?
Myofibrils
How is skinning/taking a muscle apart carried out?
By cold glycerol or Triton-X which removes cells and other lipid membranes
And in conc salt soln with no calcium actin and myosin separate from each other
What did HE Huxley and AF Huxley both conclude?
During contraction the sarcomeres of muscle fibre would shorten but the muscle fibres themselves would not
What theory did HE Huxley and AF Huxley come up with?
The sliding filament theory: muscle fibres slide over each other during contraction
Who proved the sliding filament theory and what did they do?
Gordon, Huxley and Julian: measured the force produced at different sarcomere lengths
The number of cross bridges it forms determines the force a muscle can generate
