Question 1

This figure shows the plasma membrane.What does "C" represent?

Accepted Answer

Glycoproteins are proteins with carbohydrate chains attached, which are often found on the extracellular surface of the plasma membrane, playing roles in cell recognition and signaling.

Question 2

Insulin is taken up by endocytosis by endothelial cells lining capillaries, and then transported across the cell to the other side, where it is released.This transport is called

Accepted Answer

Transcytosis is the process by which molecules like insulin are transported across endothelial cells, involving endocytosis on one side and exocytosis on the other.

Question 3

Sodium and glucose are transported together from the intestinal lumen into an intestinal cell.The carrier protein is a(n) and the process is called .

Accepted Answer

Sodium and glucose are transported together in the same direction (into the intestinal cell) by a carrier protein, indicating it is a symport. This process is also known as cotransport. Therefore, the best choice is A.

Question 4

Water flows through a selectively permeable membrane in a process called , but water molecules cross the membrane more easily through channels of transmembrane proteins called
)

Accepted Answer

Osmosis is the process by which water flows through a selectively permeable membrane, but water molecules cross the membrane more easily through channels of transmembrane proteins called aquaporins. Therefore, option B is the correct choice.

Question 5

A red blood cell is placed in a hypertonic solution.The concentration of solutes in the solution is than the concentration of solutes in the intracellular fluid and will cause the cell to
)

Accepted Answer

In a hypertonic solution, the concentration of solutes outside the cell is higher than inside, causing water to move out of the cell, leading it to shrink.

Question 6

Cells lining the small intestine are specialized for absorption of nutrients.Their plasma membrane has

Accepted Answer

Microvilli increase the surface area of the plasma membrane, enhancing the cell's ability to absorb nutrients efficiently.

Question 7

This figure shows the plasma membrane.What does "D" represent?

Accepted Answer

The answer of This figure shows the plasma membrane.What does...

Question 8

act like identification tags in the glycocalyx that enable the body to distinguish its own cells from foreign and diseased cells.

Accepted Answer

Glycoproteins in the glycocalyx serve as identification tags that help the immune system recognize self from non-self cells.

Question 9

A receptor protein in the plasma membrane will not bind to just any chemical in the extracellular fluid, but only to certain ones.That is to say, the receptor exhibits

Accepted Answer

Receptor proteins exhibit specificity, meaning they bind only to specific molecules or ligands that fit their binding site, much like a lock and key.

Question 10

are the most abundant molecules in the plasma membrane.

Accepted Answer

Phospholipids are the most abundant molecules in the plasma membrane, forming the basic bilayer structure.

Question 11

This figure shows the plasma membrane.What does "A" represent?

Accepted Answer

A peripheral protein is a protein that is not embedded in the lipid bilayer of the plasma membrane, but rather is attached to the surface of the membrane.

Question 12

The sodium-potassium (Na+-K+) pump transports both sodium and potassium their concentration gradients in a process called .

Accepted Answer

The Na+-K+ pump moves sodium and potassium ions against their concentration gradients using energy from ATP, which is a process known as active transport.

Question 13

is the process in which forces water and small solutes such as salts through narrow clefts between capillary cells.

Accepted Answer

Filtration is the process where water and small solutes are forced through narrow clefts between capillary cells due to hydrostatic pressure. Osmosis involves the movement of water across a semipermeable membrane from an area of low solute concentration to an area of high solute concentration, and it does not involve narrow clefts between capillary cells. Active transport involves the movement of molecules or ions against their concentration gradient, which is not the case here. Osmotic pressure is the pressure that opposes osmosis, and it is not the main force driving the movement of water and solutes in this scenario.

Question 14

are membrane proteins that bind to signals by which cells communicate.

Accepted Answer

Receptors are membrane proteins that bind to signaling molecules, allowing cells to communicate with each other.

Question 15

Although the transmission electron microscope (TEM) can magnify much more than a light microscope, even at identical magnifications the TEM has the advantage of

Accepted Answer

The TEM produces higher resolution than a light microscope even at identical magnifications.

Question 16

Transmembrane proteins that make up enzymes in the plasma membrane are made up of hydrophilic and hydrophobic regions.Most amino acids embedded in the membrane are , while most amino acids facing the extracellular fluid are .

Accepted Answer

Amino acids embedded in the membrane are hydrophobic to interact with the lipid bilayer, while those facing the extracellular fluid are hydrophilic to interact with the aqueous environment.

Question 17

consume ATP when transferring solutes from one side to the other side of the plasma membrane.

Accepted Answer

Pumps, such as ATP-powered pumps, actively transport solutes across the plasma membrane against their concentration gradient, requiring energy in the form of ATP.

Question 18

In its second-messenger role, cAMP activates enzymes called , whose job is to regulate other enzymes by adding phosphate groups to them.

Accepted Answer

Kinases are enzymes that add phosphate groups to other enzymes, serving as a regulatory mechanism. cAMP activates kinases in its second-messenger role, allowing them to perform their regulatory function.

Question 19

Gates respond to all these stimuli except

Accepted Answer

Gates in the plasma membrane respond to chemical messengers, ligands, changes in voltage, and physical deformation, but not specifically to water in the extracellular fluid.

Question 20

provide motility to a cell, act as sensory "antenna" in many cells, and increase a cell's surface area.

Accepted Answer

Flagella provide motility, cilia act as sensory antennae, and microvilli increase surface area.

Quiz 3: Cellular Form and Function