Exam 6: Cell Membranes, Transport, and Communication

Channel proteins provide a means for large _____________ [hydrophobic or hydrophilic] molecules to move across the plasma membrane.

Active carrier proteins use energy to carry passive carrier proteins into cells.

During ___________ endocytosis, specific substances interact with proteins located on the plasma membrane of the cell.

Plasmodesmata are not found in animal cells.

When the solute concentration outside of a cell is equal to the solute concentration inside of the cell, the cell is in a(n) ____________ solution.

When you eat a meal, cells in your pancreas deliver insulin by the process of _________.

Hydrophilic signaling molecules interact with cells by interacting with cell surface _____.

The hormone insulin initiates a signal transduction pathway that results in the uptake of glucose by cells. In the early stages of many cases of type II diabetes, people produce insulin but their cells are unable to allow the glucose to enter. Provide a hypothesis as to why this might be the case.

Which of the following would supply energy directly to an active carrier protein?

Multicellular organisms have various specialized cells because

Tight junctions prevent the movement of the extracellular matrix between cells.

Cell signaling

What is the effect of the signaling molecule nitric oxide?

People are often warned to watch their blood cholesterol level to be sure it does not become too high. In fact, some people do not eat any cholesterol-containing foods at all. Even though we associate elevated cholesterol levels with a risk of heart attack and stroke, why does the body make some cholesterol even if none is eaten?

Active transport

Cells surrounded by a hypertonic solution would lose water.

The viscous coating found around most animal cells is called the extracellular _________.

Animal cells are attached to neighboring cells by

The concentration of solutes is higher within the mitochondria than it is in the cytosol. The cytosol is ______ [hypertonic, hypotonic, or isotonic] to the inside of the mitochondrion.

The human hormone insulin is produced only by a single organ, the pancreas, yet insulin is used to move glucose from the bloodstream into cells all over the body. What aspect of hormones makes it possible for insulin to work throughout the body?