Proteins can be either structural or functional. Proteins that are structural . Proteins that are functional .

which

what is a measurement of the earth’s history divided into time periods?

> fossil record <

sedimentary rock

> geologic time scale <

radioactive elements

geographic isolation

while the heads of the phospholipid structure attract water, the tails are hydrophobic. the model shows how the hydrophilic section folds around the fluid molecules to bring them into the cell so they don’t need to pass through the hydrophobic tails.