Exam 6: Cell Membranes

The membrane components that enable a biological membrane to have fluidity are

Refer to the figures below: What is the correct sequence of these figures in the process of exocytosis?

Five statements about cell membranes are given.Which statement provides evidence supporting the fluid nature of the cell membrane?

Membrane fragments from different areas of a cell are constantly breaking down, moving, and in some cases fusing with other parts of a membrane.This is possible because of

Which is the most likely method for a cell to acquire one particular large molecule from the environment?

Suppose you have two identical solutions of glucose, A and B.The solutions are separated by a membrane that will allow the movement of both solutes and water.You want to establish a concentration gradient so that more glucose in solution B will move into solution A.How can you manipulate your experimental setup so that the glucose will move in that direction?

Aquaporins are membrane channels that are highly specific to the movement of water.If aquaporins are inserted into the membranes of a cell that does not normally contain them,

Channel proteins allow ions that would not normally pass through the cell membrane to pass through via the channel.The property of the channel protein that makes this possible is its pore, which is composed of

If hydrolysis of ATP is temporarily blocked, what will be the primary effect on the sodium-potassium pump?

You are examining a membrane that contains a number of proteins that appear to be involved in transport of an ion across that membrane.Design an experiment that will allow you to determine whether these transporters are passive transporters or active transporters.

Transporters that move two substances in the same direction are known as

In animal cells, tight junctions and desmosomes differ from one another in that

Refer to the figure below. How should the indicated parts of the diagram be labeled?

Protein movement within a membrane may be restricted by

Refer to the graphs below. Blood vessels constrict in response to the hormone angiotensin.Researchers questioned the roles of elastin and collagen in this response because they are proteins produced and secreted into the extracellular matrix by smooth muscle cells in blood vessel walls.The graphs show protein and mRNA levels corresponding to elastin and collagen in mouse blood vessels under conditions of prolonged angiotensin exposure.Which statement is consistent with these data?

The plasma membrane of the bacterium Pseudomonas syringae is able to remain fluid when it is extremely cold.The bacterium most likely accomplishes this by

Refer to the figures below. Researchers investigating the uptake of dipeptides by bacterial cells constructed model cells by embedding the membrane protein responsible for peptide transport in a lipid bilayer.They loaded the interior of the model cell with potassium ions and pyranine, a fluorescent molecule that undergoes a decrease in its fluorescence intensity at low pH.The researchers used the small molecule valinomycin to interact with the membrane lipids of the model cell to release potassium ions into the surrounding environment (no membrane protein is needed for this release).Upon doing this, the researchers observed an almost immediate change in fluorescence of the pyranine still inside the model cells, but only under certain conditions, as detailed in the graph.What do the results shown in the graph suggest about the membrane protein?

Osmosis is a specific form of

Which is not involved in secondary active transport?

A barrier to the rapid movement of hydrophilic compounds across biological membranes is made up chiefly of