Exam 5: Membrane Structure and Function

You are helping your roommate study for her biology exam.You ask her to draw a picture of a phospholipid bilayer.She draws the phosphate heads pointing inwards and the fatty acid tails pointing outward.Is her drawing accurate? Why or why not? Explain.

Fluidity of a membrane increases as the percentage of unsaturated fatty acids in the phospholipids decreases.

What type of transport mechanism is required to move sodium ions against their concentration gradient?

Which of the following is an example of active transport through a cell membrane?

All life forms currently have a basic cell membrane so we hypothesize that the earliest cells also had membranes.It is likely that the primordial environment was acidic.In order for a cell to function in this type of environment,the cell membrane would have to include

Sugars and amino acids are carried into the cell by means of

Plants show turgor pressure when

Why can nonpolar molecules freely cross the cell membrane while polar molecules require energy?

A 10% glucose solution is placed in the thistle tube.The thistle tube is placed in a beaker that contains a 5% glucose solution.There is a differentially permeable membrane across the broad end of the tube,which is permeable to water but not to the sugar glucose.What will occur over time to the water? To the solute?

The process by which cholesterol is transported into the cell by the binding of LDL to its receptor and the internalization of the receptor-LDL complex is

Which scenario is most likely to occur if the mitochondria in the kidney cells were to decrease in function?

Proteins in a membrane are

Which of the following is the reason why plants wilt if they are watered with a salt solution?

Study the series of pictures to identify the process through which materials are being transported across the membrane.Explain how you arrived at your answer.

Which cell junction will allow the movement of molecules between two plant cells?

Which of the following is true with respect to plant cell walls?

Freshwater protozoans react to a/an ________ environment by removing water through ________.

Receptor-mediated endocytosis involves the use of specific proteins in the cell membrane.

Why do membranes self-assemble into their characteristic phospholipids bilayer?

Having similar ________ would allow tissues and organs to be transplanted easily.