Cell Membranes Have Distinct Inside and Outside Faces

question 61

Multiple Choice

Cell membranes have distinct inside and outside faces. Which of the following statements is the most likely explanation for the membrane's asymmetrical nature?

• A) Since the cell membrane forms a border between one cell and another in tightly packed tissues such as epithelium, the membrane must be asymmetrical.
• B) Since cell membranes communicate signals from one organism to another, the cell membranes must be asymmetrical.
• C) The two sides of a cell membrane face different environments and carry out different functions.
• D) Proteins only function on the cytoplasmic side of the cell membrane, which results in the membrane's asymmetrical nature.

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Definitions:

Sarcoplasm

A type of cytoplasm found in muscle cells, rich in stored lipids, glycogen, and the proteins necessary for muscle contraction.

Intercalated Discs

Specialized structures located at the cell boundaries in cardiac muscle fibers that facilitate the coordinated contraction of the heart muscle.

Cardiac Muscle

Involuntary, striated type of muscle found in the vertebrate heart. Compare with smooth muscle and skeletal muscle.

Rigor Mortis

A temporary stiffening of muscles occurring after death as a result of chemical changes in muscle tissues.