Briefly describe the mechanism of muscle contraction.
In muscle, myosin protein has 'heads' that act as cross-bridges as they bind to actin, another protein. When ATP binds to myosin, its head detaches from actin, swings forward and rebinds. Rebinding releases ADP and a phosphate ion, and rage the actin filament alongside the replacement of the myosin head, causing the contraction of muscle.
HG
Related Biology A Level answers
All answers ▸Compare the mammalian heart to that of an amphibian. Use a diagram.
How is the structure of DNA related to its function
Using knowledge of the pathogenicity of HIV, explain why it can't be transmitted through inanimate objects or hand shakes with an infected person.
What precisely is autoregulation in the kidney? Is it solely the ability to vary the diameters of the afferent and efferent arterioles? If so how is this controlled?