2. Cell Chemistry & Cell Components

Biological Membranes

Open Question
According to the fluid mosaic model of membrane structure, proteins of the membrane are mostlya. spread in a continuous layer over the inner and outer surfaces of the membrane.b. confined to the hydrophobic interior of the membrane.c. embedded in a lipid bilayer.d. randomly oriented in the membrane, with no fixed inside-outside polarity.
Open Question
Which of the following is one of the major components of the plasma membrane of a plant cell?a. phospholipidsb. cellulose fibersc. collagen fibersd. pectins
Multiple Choice
The fluid mosaic model of the membrane proposed that membranes:
Multiple Choice
Why are cell membranes composed primarily of hydrophobic molecules?
Multiple Choice
Which of the following statements about the role of phospholipids in the structure and function of biological membranes is correct?
Multiple Choice
The plasma membrane is referred to as a "fluid mosaic" structure. Which of the following statements about that model is true?
Multiple Choice
Consider the currently accepted fluid mosaic model of the plasma membrane. Where in the plasma membrane would cholesterol most likely be found?
Multiple Choice
Which of the following statements concerning carbohydrates associated with the plasma membrane is correct?
Multiple Choice
Consider the currently accepted fluid mosaic model of the plasma membrane. Where in the membrane would carbohydrates most likely be found?
Multiple Choice
Which statement about the sidedness of the plasma membrane is correct?
Open Question
What is a fiber composite? How do cellular fiber composites resemble reinforced concrete?
Open Question
Which of the following factors would tend to increase membrane fluidity?a. a greater proportion of unsaturated phospholipidsb. a greater proportion of saturated phospholipidsc. a lower temperatured. a relatively high protein content in the membrane
Open Question
Which best describes the structure of a cell membrane?a. proteins between two bilayers of phospholipidsb. proteins embedded in a bilayer of phospholipidsc. a bilayer of protein coating a layer of phospholipidsd. cholesterol embedded in a bilayer of phospholipids
Open Question
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
Open Question
Mark the following statements about the plasma membrane as true or false. If a statement is false, correct it to make a true statement.

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