________ can lower the activation energy of a chemical reaction.

__________ is the process in which __________ forces water and small solutes, such as salts, through narrow clefts between capillary cells.

In this feedback loop, what is the receptor?

The most abundant molecules in the plasma membrane are __________.

The pH of blood plasma is approximately 7.4, which is slightly acidic.

Facilitated diffusion requires energy and can transport molecules against a concentration gradient.

Which letter represents the effectorof this feedback loop?

What level of structural hierarchy is represented by the letter E?

An enzyme issubstrate-specific because of the shape of its __________.

The constant appearance of new strains of influenza virus is an example of __________.