BIOL 2160 Exam 2 Practice

Which molecule is most likely to cross a plasma membrane by simple diffusion?

Steroid hormone

Facilitated diffusion differs from simple diffusion because it:

Uses membrane proteins

The Na+/K+ ATPase directly uses ATP to:

Move ions against gradients

In most resting cells, potassium concentration is:

Higher inside

The chemical driving force on Na+ at rest generally moves Na+:

Into the cell

A resting membrane potential of -70 mV means:

Inside is more negative

Which ion contributes most to the resting membrane potential?

Potassium

Cotransport is best illustrated by:

Na+-glucose transporter

Which solution contains more free water?

2 M glucose

Osmosis is the movement of:

Water across a membrane

A cell that shrinks after being placed in a solution was likely in a _____ solution.

Hypertonic

A cell with 5 M sucrose placed in 2 M sucrose will:

Swell

Large solid particles are commonly taken into cells by:

Phagocytosis

Release of neurotransmitter from neurons occurs primarily by:

Exocytosis

Which is a passive transport mechanism?

Simple diffusion

Which chemical messenger typically travels the greatest distance?

Hormone

Hydrophobic messengers are often transported in blood:

Bound to carrier proteins

Receptors for hydrophilic messengers are usually located:

On the plasma membrane

A receptor's specificity refers to:

How many ligands it recognizes

A ligand that binds a receptor but triggers no response is a(n):

Antagonist

G protein-coupled receptors signal through:

Alpha, beta, gamma subunits

An inactive G protein is bound to:

GDP

Steroid hormones most commonly produce responses by:

Changing gene expression / protein synthesis

Gap junctions primarily allow:

Movement of ions between cells

p53 helps protect against cancer by:

Increasing p21 production

What is a major function of p21?

Block cyclin-dependent kinases

Most cancers require approximately how many mutations?

5-6

Anti-angiogenesis drugs are designed to:

Prevent new blood vessel formation

Tamoxifen acts primarily by:

Blocking estrogen receptors

Cancer patients may receive erythropoietin to:

Stimulate red blood cell production