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 __________.

What is the study of the structure at E called?

If a cell doubled in diameter, it would have twice as much cytoplasm to maintain.

Water flows through a selectively permeable membrane in a process called __________, but water molecules cross the membrane more easily through channels of transmembrane proteins called __________.

The plasma membrane of cells lining the small intestine has __________, which are specialized for absorption of nutrients.