Ch. 3 - Cells

Question 1

Name 2 transport mechanisms which require energy expenditure:

Answer 1

• Glucose symporters

* Sodium Potassium Pump

Question 2

What is the main component of the plasma membrane?

Answer 2

Phospholipids (75%)

Question 3

Name 2 types of molecules that can cross the plasma membrane without the assistance of protein channels:

Answer 3

• Hydrophobic molecules

* Gas molecules

Question 4

What’s the function of an ion channel protein membrane?

Answer 4

It forms a pore through which a specific ion can flow to get across membrane

Question 5

What’s the function of a receptor membrane protein?

Answer 5

It recognizes specific ligands and alters the cell’s function in some way.

Question 6

What’s the function of an enzyme membrane protein?

Answer 6

It catalyzes a reaction inside or outside a cell.

Question 7

What’s the function of a cell identity marker membrane protein?

Answer 7

It distinguishes your cells from anyone else’s cells

Question 8

What is the intracellular fluid that contains water, dissolved particles and suspended particles called?

Answer 8

Cytosol

Question 9

What is osmosis transport process?

Answer 9

Passive movement of water molecules across a selectively permeable membrane from an area of higher to lower water concentration until equilibrium is reached.

Substance transported: Solvent: water in living systems

Question 10

What is an active transport process?

Answer 10

Movement of substances against a concentration gradient; requires cellular energy in the form of ATP.

Polar or charged solutes

Question 11

What is an active transport process?

Answer 11

Active process in which a cell expends energy to move a substance across the membrane against its concentration gradient by transmembrane proteins that function as carriers.

Polar or charged solutes

Question 12

Primary active transport is:

Answer 12

Active process in which a substance moves across the membrane against its concentration gradient by pumps (carriers) that use energy supplied by hydrolysis of ATP.

Transports: Na+, k+, Ca2+, H+, I-, Cl-, and other ions

Question 13

Secondary active transport is:

Answer 13

Coupled active transport of two substances across the membrane using energy supplied by Na+ or H+ concentration gradient maintained by primary active transport pumps.

Transports: Antiport: Ca2+, H+ out of cells. Symport: glucose, amino acids into cells

Question 14

Transport in vesicles:

Answer 14

Active process in which substances move into or out of cells in vesicles that bud from plasma membrane; requires energy supplied by ATP.

Question 15

Endocytosis transport is:

Answer 15

The movement of substances into the cell in vesicles

Question 16

Receptor-mediated endocytosis transport is:

Answer 16

Ligand-receptor complexes trigger infolding of the clathrin-coated pit that forms a vesicle containing ligands.

Transports: Ligands: transferrin, low-density liboproteins. (LDLs), some vitamins, certain hormones, and antibodies.

Question 17

Phagocytosis transport process:

Answer 17

“Cell eating”; movement of a solid particle into a cell after pseudopods engulf it to form a phagosome.

Transports: bacteria, viruses, and aged or dead cells.

Question 18

Bulk-phase endocytosis transport is:

Answer 18

“Cell drinking”; movement of extracellular fluid into a cell by infolding of plasma membrane to form a vesicle.

Transports: Solutes in extracellular fluid

Question 19

Exocytosis transport is:

Answer 19

Movement of a substance out of a cell in secratory vesicles that fuse with the plasma membrane and release their contents into the extracellular fluid.

Transports: Neurotransmitters, hormones, and I just of enzymes

Question 20

Transcytosis transport is:

Answer 20

Movement of a substance through a cell as a result of endocytosis on one side and exocytosis on the opposite side.

Transports: substances, such as antibodies, across endothelial cells. This is a common route for substances to pass between blood plasma and interstitial fluid.