Comp Check 4.2

Which of the following is the driving force for active transport? ATP hydrolysis Phosphorylation ADP hydrolysis Concentration gradient

ATP hydrolysis

Which statement about diffusion is false? Diffusion is a random process. Diffusion continues until the molecular concentrations are in equilibrium. Diffusion does not require ATP. Simple diffusion depends upon specific carrier proteins. In diffusion, molecules move from areas of greater concentration to areas of lesser concentration.

Simple diffusion depends upon specific carrier proteins.

What is the membrane property that helps ensure the diffusion of glucose into a cell that has a high energy need? Specific carrier proteins found only in large muscle cells A glucose pump Special sensitivity to an extracellular environment high in glucose A high number of carrier proteins specific for glucose

A high number of carrier proteins specific for glucose

Membrane proteins are required for all membrane transport into and out of cells. True False

False

Simple or facilitated diffusion requires cellular energy. True False

False

One reason cancer therapy often fails is that the targeted cells become resistant to the drugs that are supposed to kill them. Which of the following is the most likely mechanism of this resistance? Channel proteins pump ions into the cancer cells. Drugs diffuse into the cancer cells via simple diffusion. Carrier proteins block diffusion of the drugs into the cancer cells. Membrane proteins actively transport the drugs out of the cancer cells. Membrane proteins pump nutrients into the cancer cells.

Membrane proteins actively transport the drugs out of the cancer cells.

Diffusion results in a net flow of solute down a concentration gradient, while active transport works against the concentration gradient. True False

True

Secondary active transport uses energy to set up a concentration gradient which then allows some passive diffusion to occur, recapturing some of the energy expended. True False

True

Plant cells transport sucrose across the vacuole membrane against its concentration gradient by a process known as facilitated diffusion. passive transport. simple diffusion. active transport. cellular respiration.

active transport.

In facilitated diffusion, molecules may be transported against their concentration gradient. ATP is used. molecules are transported directly through the phospholipid bilayer along a concentration gradient. endocytosis is involved. specific integral membrane proteins mediate transport along the concentration gradient.

specific integral membrane proteins mediate transport along the concentration gradient.