#proteins notes

-- motor protein type

-- play a role in muscle contraction

-- participate in various other motility processes in eukaryotes

-- ATP-dependent

-- responsible for actin-based motility

-- a large superfamily of genes

-- protein products share properties      -- actin binding      -- ATP hydrolysis      -- force transduction

-- most myosin molecules are made of a head, neck, and tail domain

-- red blood cells

-- biconcave shape

-- shape provides greater surface area and flexibility

-- lacks a nucleus

-- contains hemoglobin

-- globin = structural protein composed of four polypeptide chains, each containing a heme group

-- heme group = iron-containing functional part of hemoglobin

-- new cells are produced at a rate of 2 million per second

-- cells live for about 120 days

-- new cell division is controlled by erythropoietin