Exam 5: Membranes

If you were a very thirsty cell,which process would you use to take in some nutrients secreted by one of your neighbors?

The lipid layer that forms the foundation of cell membranes is primarily composed of molecules called ________.

While eating lobster for dinner one night your friend asks what you think might happen if this marine invertebrate,which is normally isosmotic with respect to the surrounding seawater,were to be moved to a bay with a slightly lower salt concentration instead of being caught.You reply that,in order for the lobster to be isosmotic with respect to new environment,

GABA receptors play an essential role in neurotransmission in the central nervous system.In response to the appropriate signal,these receptors open up and allow Cl^- to flow into the cell.Given this information,GABA receptors can be classified as a

On the outer surface of the plasma membrane there are marker molecules that identify the cell type.Often these molecules are

Membrane potential will affect the directional movement of

When the solute concentration of solution A is lower than the solute concentration of solution B,solution A is considered

The part of a membrane protein that extends through the phospholipid bilayer is primarily composed of amino acids that are

Insulin stimulates an increase in number of glucose carrier proteins at a cell membrane's surface.What effect will insulin have on cell function? Choose all that apply.

During neuronal signaling,a change in membrane potential will cause sodium channels to open and let Na⁺ ions diffuse down their concentration gradient into the cell.Which of the following helps establish the concentration gradient necessary for this process to occur?

How are the tails and heads of membrane phospholipids oriented in their environment?

The cell's plasma membrane mediates which of the following transactions with the environment? Choose all that apply.

Matt is studying how the protein transferrin enters cells.He examines cells that have taken up transferrin,and finds clathrin-coated vesicles.What mechanism was used to take transferrin into the cell?

If a cell has a normal osmotic pressure of 4500 mmHg and is placed into a solution with an osmotic pressure of 3500 mmHg,what will happen to the cell?

Membrane proteins are not very soluble in water,because they possess long stretches of non-polar amino acids that are

Red blood cells are biconcave.Their shape is determined by interior proteins anchored to the membrane termed

What is the main component of an animal cell membrane?

The plasma membrane is a thin sheet of lipid embedded with

Carrier-mediated transport of a substance down its concentration gradient is called

Protein X contains four transmembrane domains,a short N-terminus and a long C-terminus.Following protein synthesis,the N-terminus of the protein faces the lumen (the inside)of the ER.After protein X is transported to the cell surface via exocytosis,you would expect the N-terminus of protein X to be