2. Cell Chemistry & Cell Components

Which of the following best describes the arrangement of the main component of the plasma membrane?

a. A monolayer of phospholipids with the phosphate heads facing the cytosol and the fatty acid tails facing the extracellular fluid

b. A bilayer of phospholipids with the phosphate heads facing the cytosol and extracellular fluid, and the fatty acid tails facing one another

c. A bilayer of phospholipids with the phosphate heads of one layer facing the fatty acid tails of the other

d. A bilayer of phospholipids with a layer of triglycerides sandwiched in the middle

Mark the following statements about the plasma membrane as true or false. If a statement is false, correct it to make a true statement.

Integral membrane proteins generally span the width of the plasma membrane, whereas peripheral proteins are found on only one side of the membrane.

Mark the following statements about the plasma membrane as true or false. If a statement is false, correct it to make a true statement.

Cholesterol provides the plasma membrane with stability in the face of changing ion concentrations.

Mark the following statements about the plasma membrane as true or false. If a statement is false, correct it to make a true statement.

Membrane cholesterol is vital for cell-cell recognition.

Mark the following statements about the plasma membrane as true or false. If a statement is false, correct it to make a true statement.

The overall structure of the plasma membrane is a mosaic with the components locked tightly in place.

Explain how the members of the endomembrane system interact.

Which of the following would you expect to find in or on cells whose main function is absorption?

Which of the following are possible functions of the glycoproteins in the plasma membrane?

a. Determination of blood groups

b. Binding sites for toxins or bacteria

c. Aiding the binding of sperm to egg

d. Increasing the efficiency of absorption

The major types of lipids found in the plasma membranes are (choose two):

a. Cholesterol

b. Triglycerides

c. Phospholipids

d. Fat-soluble vitamins

Describe the four structural components of the plasma membrane and the function of each.

Think carefully about the chemistry of the plasma membrane, and then answer this question: Why is minor damage to the membrane usually not a problem?