Cell Membrane Composition and Variations Quiz

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Which of the following is NOT a component of the cell membrane?

Phospholipids

Proteins

Carbohydrates

Nucleic acids (correct)

What percentage of the mass of most animal cell membranes is made up of lipids?

25%

50% (correct)

75%

10%

What is the main function of transmembrane proteins in the cell membrane?

Detect and transduce signals

Catalyze reactions

Transport molecules across the membrane (correct)

Provide structural support

Which type of lipids are the most abundant in cell membranes?

Phospholipids Signup and view all the answers

What is the characteristic appearance of cell membranes when viewed in cross-section?

Three-layer structure Signup and view all the answers

Which organelle is responsible for fatty acid oxidation for energy production?

Mitochondrial membrane Signup and view all the answers

What is the main function of the cell membrane?

Separates the cellular interior from the exterior Signup and view all the answers

Which process involves the merging of two separate lipid bilayers into one?

Membrane fusion Signup and view all the answers

What is the main function of the Golgi apparatus membrane?

Coordination of different reactions Signup and view all the answers

Which organelle is responsible for the formation of vesicles to transport lipids and proteins?

ER membrane Signup and view all the answers

Which of the following is NOT a function of cell membranes?

Serving as attachment surface for cytoskeleton and ECS Signup and view all the answers

What is the main role of membrane proteins?

Regulating the movement of material into and out of the cell Signup and view all the answers

What is the composition of the lipid bilayer in cell membranes?

Lipids Signup and view all the answers

What is the purpose of cell membrane visualization techniques?

To study the structure and function of cell membranes Signup and view all the answers

What is the role of the plasma membrane in eukaryotic cells?

Compartmentalization to segregate processes and compartments Signup and view all the answers

Which type of cell membrane contains the highest percentage of proteins?

Liver cell (Mouse) Signup and view all the answers

Which type of cell membrane contains the highest percentage of lipids?

Erythrocytes (Human) Signup and view all the answers

Which type of cell membrane contains the highest percentage of carbohydrates?

Liver cell (Rat) Signup and view all the answers

What is the main function of the cell wall in prokaryotic cells?

To provide mechanical stability Signup and view all the answers

Why do phospholipid bilayers spontaneously form sealed compartments?

To prevent the exposure of hydrophobic tails to water Signup and view all the answers

Which type of lipids are found in the inner and outer layers of the cell membrane?

Phospholipids Signup and view all the answers

What is the major phospholipid found in mammalian plasma membranes?

Phosphatidylcholine Signup and view all the answers

Which layer of the cell membrane is closer to the extracellular space?

Outer membrane layer Signup and view all the answers

Which layer of the cell membrane is closer to the intracellular space (cytoplasm)?

Inner membrane layer Signup and view all the answers

What is the term for the unequal distribution of phospholipids, other lipids, and membrane proteins between the inner and outer layers of the cell membrane?

Asymmetry Signup and view all the answers

Which technique provides views of surfaces inside the cell?

Freeze-etch electron microscopy Signup and view all the answers

What is the main purpose of the freeze-fracture technique?

To visualize the internal organization of membranes Signup and view all the answers

Which type of electron microscopy is used to visualize the cell's nucleus?

Transmission electron microscopy Signup and view all the answers

What is the function of lysosomes in a cell?

To digest foreign particles Signup and view all the answers

Which phospholipid carries a net negative charge in the plasma membrane of mammalian cells?

Phosphatidylserine Signup and view all the answers