bio lect chap 3

Question 1

Membrane Lipids
A) 75% are?
B) 5% ?
C) 20% ?

Answer 1

A) phospholipids (lipid bilayer)
Phosphate heads: polar and hydrophilic
Fatty acid tails: nonpolar and hydrophobic (Review Fig. 2.16b)

Question 2

Primary Active Transport?

Answer 2

Energy from hydrolysis of ATP causes shape change in transport protein so that bound solutes (ions) are “pumped” across the membrane

Question 3

In Primary Active Transport what happen?

Answer 3

Sodium-potassium pump (Na+-K+ ATPase)

Question 4

Primary Active Transport
A) Located ?
B) involved ?
C)Maitains?

Answer 4

A) Located in all plasma membranes
B)Involved in primary and secondary active transport of nutrients and ions
C)Maintains electrochemical gradients essential for functions of muscle and nerve tissues

Question 5

Active Transport
A)Requires
B)Moves

Answer 5

A) Requires carrier proteins (solute pumps)

B) Moves solutes against a concentration gradient

Question 6

what r the types of ctive transport?

Answer 6

Primary active transport

Secondary active transport

Question 7

Membrane Transport: Active Processes. types?

Answer 7

Active transport

Vesicular transport

Question 8

Both active process use what?

Answer 8

Both use ATP to move solutes across a living plasma membrane

Question 9

Secondary Active Transport
A)Depends on ?
B)Energy stored in ?

Answer 9

Depends on an ion gradient created by primary active transport
B)Energy stored in ionic gradients is used indirectly to drive transport of other solutes

Question 10

Secondary Active Transport
A) what happen?
B) Symport system?

C) Antiport system: ?

Answer 10

A) Cotransport—always transports more than one substance at a time
B) Symport system: Two substances transported in same direction
C) Antiport system: Two substances transported in opposite directions

Question 11

Vesicular Transport
A) what is it?
B) Requires ?

Answer 11

A) Transport of large particles, macromolecules, and fluids across plasma membranes
B) Requires cellular energy (e.g., ATP)

Question 12

Vesicular Transport

functions?

Answer 12

A) Exocytosis—transport out of cell
B) Endocytosis—transport into cell
C) Transcytosis—transport into, across, and then out of cell
C) Substance (vesicular) trafficking—transport from one area or organelle in cell to another

Question 13

Endocytosis

Answer 13

Phagocytosis—pseudopods engulf solids and bring them into cell’s interior
Macrophages and some white blood cells

Question 14

Endocytosis in fluid phase?

Answer 14

endocytosis (pinocytosis)—plasma membrane infolds, bringing extracellular fluid and solutes into interior of the cell

Question 15

where is Nutrient absorption done in Endocytosis in fluid phase ?

Answer 15

Nutrient absorption in the small intestine

Question 16

Endocytosis
A) Receptor-mediated endocytosis….
B) Uptake of ….

Answer 16

A) Receptor-mediated endocytosis—clathrin-coated pits provide main route for endocytosis and transcytosis
B) Uptake of enzymes low-density lipoproteins, iron, and insulin

Question 17

Exocytosis Examples?

Answer 17

Examples: 
Hormone secretion 
Neurotransmitter release 
Mucus secretion 
Ejection of wastes

Question 18

Generation and Maintenance of RMP
A)The Na+ -K+ pump ….
B)Some K+ continually diffuses …
C)Membrane interior becomes…

Answer 18

The Na+ -K+ pump continuously ejects Na+ from cell and carries K+ back in
Some K+ continually diffuses down its concentration gradient out of cell through K+ leakage channels
Membrane interior becomes negative (relative to exterior) because of large anions trapped inside cell Most important