Socrative Questions Chapter 11 Cell Bio

Question 1

Considering the phospholipid molecules that are present in a phospholipid bilayer membrane, which of the following types of movements are common?

Answer 1

Flex within one leaflet

Rotation within one leaflet

Lateral diffusion within one leaflet

Question 2

If a yeast cell was moved from a warm environment to one with colder temperatures, which of the following would you expect to observe with respect to the composition of the phospholipid bilayer of the plasma membrane?

Answer 2

The composition would change to include more phospholipids with unsaturated fatty acids

Question 3

Cholesterol is an amphipathic molecule

Answer 3

True

Question 4

New phospholipid molecules are produced at the:

Answer 4

ER membrane

Question 5

______ are enzymes that mediate the random flip of phospholipids from one leaflet to another at the ER membrane

Answer 5

Scramblases

Question 6

Which of the following describes the phospholipid bilayer of the ER membrane?

Answer 6

The two leaflets are symmetric and contain roughly the same proportions of different phospholipid types

Question 7

_______ are enzymes that mediate the flip of specific phospholipids from one leaflet of the bilayer to another at the Golgi

Answer 7

Flippases

Question 8

Which of the following is true about phospholipid bilayers?

Answer 8

One leaflet is always on the cytosolic side and the other leaflet (noncytosolic) always faces the lumen of an organelle or the extracellular environment

Question 9

The portions of single-pass transmembrane proteins that are exposed to the ECF or ICF tend to have ______ amino acids, and the portions that run through the hydrophobic core of the phospholipid bilayer tend to have ______ amino acids

Answer 9

hydrophilic; hydrophobic

Question 10

The great majority of membrane-spanning segments of polypeptides traverse the phospholipid bilayer as ______

Answer 10

Alpha helix

Question 11

Transmembrane proteins that span the phospholipid bilayer in a _______ conformation are often found as large water filled pores in bacterial cells or mitochondria that allow the passage of small hydrophilic substances

Answer 11

Beta barrels

Question 12

Which compound is covalently attached to bacteriorhodopsin and changes shape when it is exposed to a photon of light?

Answer 12

Retinal

Question 13

The protein meshwork found at the cytosolic side of the plasma membrane of animals cells that stabilizes structure, changes shape, and can function in the uptake if materials from the extracellular fluid is known as the

Answer 13

Cell cortex

Question 14

________ are regions of membranes that contain specific proteins confined to that region

Answer 14

Membrane domains