Physiology Review Questions - Cell

Front 1

Lipid bilayers are differentially permeable to different types of molecules. Which types of molecules can readily cross such bilayers w/out the help of transport proteins?

Back 1

Sm uncharged molecules, Oxygen, CO2, lipid soluble molecules (water & Ions through channels)

Front 2

Name some of the physical properties of molecules that prevent them from freely diffusing across lipid bilayers.

Back 2

size, polarity, molecular weight

Front 3

The opening of membrane channels can be controlled by "gates". What factors can cause these gates to open?

Back 3

Voltage changes, Ligand binding, and molecular stretch or force

Front 4

Name 3 functions of the NaK ATPase pump.

Back 4

Maintain concentration gradients of Na and K across cell membrane.
Provide gradient to be used by secondary active transport system.
Osmoregulation.

Front 5

If the vessels of the brain have a reduced amt of plasma proteins, what effect would you ecxept this to have on the volume of extracellular fluid surrounding the brain neurons?

Back 5

There would be an increase in ECF volume which would cause edema in the surrounding brain neurons.

Front 6

In simple diffusion,

Back 6

the rate of movement is controlled by temperature and molecular size.
The movement of indiv molecules is random.
Movement of molecules is independant of other molecules.
The net movement is away from the region of highest concentration.

Front 7

Oxygen, CO2, and other sm molecules cross the plasma membrane through the process of

Back 7

Diffusion

Front 8

The NaK+ pump is an example of

Back 8

active transport

Front 9

What happens to a cell placed in a hypotonic solution?

Back 9

A cell placed in hypotonic solution will swell.

Front 10

How do passive transport and active transport differ?

Back 10

Passive - no ATP required, down gradient
Active - requires ATP, against gradient

Front 11

Is facilitated diffusion active or passive?

Back 11

Passive

Front 12

Define diffusion

Back 12

the net movement of molecules or ions from regions of higher to regions of lower concentration

Front 13

Define osmosis

Back 13

the passage of water (solvent) from a more dilute to a more concentrated solution

Front 14

Define active transport

Back 14

the movement of molecules and ions across the cell membranes of epithelial cells by membrane carriers. ATP required.

Front 15

Define passive transport

Back 15

the net movement of molecules and ions across a membrane from higher to lower concentration. No ATP required.

Front 16

Why are cell membranes termed "selectively permeable"?

Back 16

They allow some things to cross, but not others

Front 17

How are lg molecules transported across cell membranes?

Back 17

Carrier proteins (facilitated diffusion), endocytosis

Front 18

What is a characteristic of all carrier proteins in a plasma membrane?

Back 18

Each exhibits a specificity for a particular type of molecule

Front 19

What are the membrane structures that function in active transport?

Back 19

integral proteins

Front 20

Cell A enlarges in size for a while, then stops; cell B continues to enlarge and finally ruptures. What is true about the beginning of the experiment

Back 20

Cell B was hyperosmotic to cell A

Front 21

Which process could result in the net movement of a substance into a cell, if the substance is more concentrated in the cell than in the surroundings?

Back 21

Active transport - movement is against the substances concentration gradient

Front 22

Which of the following substances would have the mmost trouble crossing a biological membrane by diffusing through the lipid bilayer?

Back 22

A) water
B) O2
C) Phosphate ion (PO4)
D) testosterone

C) Phosphate ion (PO4)

Front 23

Solution A contains 600 mosm of NaCl and solution B contains 250 mosm of NaCl. In which direction will osmosis occur?

Back 23

From B to A

Front 24

A contains a 150 mosm solution, B contains 300 mosm solution of glucose. In which direction does osmosis occur?

Back 24

No net movement. Both solutions are the same 300 mosm.

Front 25

Which mechanism will be used by steroid hormone molecules to get through the cell membrane?

Back 25

diffusion

Front 26

Which mechanism will be used by glucose molecules to get through the cell membrane?

Back 26

facilitated diffusion

Front 27

Which mechanism will be used by anesthetic molecules to get through the cell membrane?

Back 27

diffusion

Front 28

Which mechanism will be used by positive ion molecules to get through the cell membrane?

Back 28

ion channels

Front 29

Which mechanism will be used by negative ion molecules to get through the cell membrane?

Back 29

ion channels

Front 30

Which mechanism will be used by Vitamin E molecules to get through the cell membrane?

Back 30

diffusion

Front 31

Which mechanism will be used by water molecules to get through the cell membrane?

Back 31

aquaporins (water channels)

Front 32

Which process (diffusion, osmosis, or filtration) accounts for: injection of a drug that is hypertonic to the tissues creates a painful sensation?

Back 32

osmosis

Front 33

Which process (diffusion, osmosis, or filtration) accounts for: a person with extremely low blood pressure stops producing urine?

Back 33

filtration

Front 34

Which process (diffusion, osmosis, or filtration) accounts for: as blood passes through an artificial kidney, the urea (found at high concentration) leaves the blood & enters the dialyzing fluid of the artificial kidney where urea concentrations are lower?

Back 34

diffusion

Front 35

Which process (diffusion, osmosis, or filtration) accounts for: oxygen moves from the lungs into blood?

Back 35

difussion

Front 36

Explain what the effect of placing cells in high & low extracellular potassium solutions has on the resting membrane potential.

Back 36

Placing cells in high K+ solutions decreases the membrane potential (making it negative) and effectively depolarizes cells and conversely, placinng cells in a low extracellular solution, increases the membrane potential (more negative) and hyperpolarizes the cell.

Front 37

Based on what you know about glucose transporters, explain why diabetic drugs are useless without an increase in exercise.

Back 37

Exercise has the effect of causing insertion of glucose transporters into the cell membrane, thereby facilitating glucose uptake.

Front 38

K+ ions and Hydrogen ions both compete for binding on a transport protein. This protein functions to allow excretion of hydrogen and K+ ions in the body. Based on this info, what effect would hyperkalemia be expected to have on blood pH?

Back 38

Since they compete for the transporter for their excretion, an increase in the blood level of one will result in decreased excretion for the other molecule due to earlier saturation of the transporter. Therefore hyperkalemia will result in an elevation of blood hydrogen ion levels, resulting in acidosis.