Describe an example of a muscle contraction in a lower appendage joint and identify the bones of origin and insertion involved

Most animal cells membranes have proteins that pump ions out of the cell and potassium ions into the cell

What happens as electrons move along the chain of molecules known as the electron transport chain? they gain energy, which causes atp molecules to lose phosphate groups. they gain energy, which causes h *ions to join with oxygen to produce water. they lose energy, which is then used by the cell to make atp. they lose energy, which is then used to break down atp.

Why do mountaineers become breathless as they reach high altitudes