Module 5- Bio 264

Front 1

Which statement is a step in the function of a G protein complex?

Back 1

A) the complex separates from the receptor and the alpha subunit separates from the other subunits B) GDP is released after the receptor becomes associated with the G protein complex D) the G protein complex acts as an intermediary between a receptor and other cellular proteins

Front 2

Which of the following words does not belong with the other 3?

A) Glycolipid B) Glycogen C) Glycoprotein D) Glycocalyx

Back 2

Glycoprotein

Front 3

The function of cholesterol in the plasma membrane is

Back 3

provide stability to the plasma membrane by limiting the movement of phospholipids

Front 4

In the plasma membrane, _________________ form(s) the lipid bilayer, ________________ determine(s) the fluid nature of the membrane, and _______________ mainly determine(s) the function of the membrane.

Back 4

phospholipids, cholesterol, proteins

Front 5

The basic structure of the plasma membrane is formed by

Back 5

bilayered phospholipid structure

Front 6

Glycolipids

Back 6

are carbohydrate-binding lipids

Front 7

Which of the following is a function of the cell membrane?

Back 7

regulation of transportation in and out of the cell

Front 8

Which of the following is not a function of the cell membrane?

A) regulation of cell division B) regulation and site of exchange with the environment C) structural support of the cell D) recognition of substances outside of the cell

Back 8

A) regulation of cell division

Front 9

How does the phospholipid bilayer maintain separation between inside and outside the cell?

Back 9

The fatty acid portion of the phospholipid membrane does not easily allow water to move across the membrane

Front 10

The different types of proteins in the plasma membrane include

Back 10

integral proteins, peripheral proteins, cadherins

Front 11

A cofactor

Back 11

is a non-protein substance, like an ion or organic molecule, that an enzyme requires to function

Front 12

G protein complexes

Back 12

will only associate with a receptor that has a chemical signal bound to it

Front 13

A coenzyme

Back 13

is another name for a cofactor

is a non-protein, ionic substance that an enzyme requires to function

Front 14

Which of the following is NOT one of the functions of the membrane proteins?

A) marker molecules

B) receptor proteins

C) stability of the plasma membrane

D) enzymes

Back 14

stability of the plasma membrane

Front 15

The function of cholesterol in the plasma membrane is

Back 15

provide stability to the plasma membrane by limiting the movement of phospholipids

Front 16

Glycolipids

Back 16

are carbohydrate-binding lipids

Front 17

Which of the following is NOT one of the functions of the membrane proteins?

marker molecules

receptor proteins

stability of the plasma membrane

enzymes

Back 17

stability of the plasma membrane

Front 18

G protein complexes

Back 18

will only associate with a receptor that has a chemical signal bound to it

Front 19

How does the phospholipid bilayer maintain separation between inside and outside the cell?

Back 19

the fatty acid portion of the phospholipid membrane does not easily allow water to move across the membrane

Front 20

Which of the following statements regarding the sodium-potassium pump is incorrect?

A) For every 3 sodium ions transported out of the cell, the sodium-potassium pump transports 2 potassium ions into the cell

B) The sodium-potassium pump requires an input of energy in the form of ATP

C) The sodium-potassium pump is an integral protein

D) The sodium-potassium pump generates an extracellular sodium gradient that plays a critical role in the transport of other substances.

Back 20

D) The sodium-potassium pump generates an extracellular sodium gradient that plays a critical role in the transport of other substances.

Front 21

Active transport moves a substance __________.

Back 21

against their concentration gradient.

Front 22

Which of the following statements are true concerning transportation through the plasma membrane?

Back 22

D) lipid soluble molecules diffuse directly through the plasma membrane

Front 23

Discharging material from membranous sacs at the cells surface is called

Back 23

exocytosis

Front 24

Phagocytosis uses _____, while Pinocytosis uses_____.

Back 24

Pseudopodia/ invaginations

Front 25

How can molecules and ions can pass through a plasma membrane?

Back 25

facilitated diffusion

active transport

osmosis

Front 26

Which of the following pass through the plasma membrane using facilitated transportation?

Back 26

glucose

Front 27

The difference between phagocytosis and pinocytosis is

Back 27

whether the particles are dissolved in a liquid and their size

Front 28

Specificity

Back 28

is a characteristic of mediated transport

Front 29

In a cellular membrane cholesterol resides in the _______, and limits _________.

Back 29

Phospholipid bilayer, lateral movement

Front 30

Solute transportation across a membrane is divided into two general categories based on what?

Back 30

Whether the transportation requires energy or not.

Front 31

Functions of the cell membrane

Back 31

I Serving as a selectively permeable barrier

II Regulating movement of materials

III Cell communication

IV Cell to cell recognition

Front 32

Compare a playground that is surrounded by a fence to a cell that is surrounded by a phospholipid membrane. The fence is impermeable with the exception of a slide that allows only a specific size of child to enter. The slide is always open to that specific size of child, however. Which cellular component is most similar to this slide?

Back 32

Channel protein

Front 33

If a drug were administered that blocked the production of ATP in cells, which of the following would be inhibited?

Antiport proteins

Pinocytosis

Ligand-gated channels

Osmosis

Back 33

Antiport proteins

Pinocytosis

Front 34

If cholesterol were absent from the cell membrane, which of the following would most likely be true?

Back 34

Changes in temperature would cause the plasma membrane to become either too fluid or too rigid to fulfill its normal functions

Front 35

Compare a playground that is surrounded by a fence to a cell that is surrounded by a phospholipid membrane. The fence is impermeable with the exception of a slide that allows only a specific size of child to enter. The far end of the slide is closed, but when a child sits on the edge of the slide, the slide tilts. This tilting closes the end behind the child and opens the far end in front of the child, allowing them into the playground. Which cellular component is most similar to this slide?

Back 35

Carrier protein

Front 36

Osmosis

Back 36

requires a semi-permeable membrane

Front 37

Placing celery sticks in fresh water will make them more turgid and harder. This is because _________.

Back 37

Freshwater is hypotonic to the celery.

Front 38

The process of water diffusing into or out of a cell is called:

Back 38

osmosis

Front 39

Sodium acetate is a commonly used food preservative with the formula NaC2H3O2. This compound is soluble in water, dissolving to form two ions (Na+ and C2H3O2-). If 2 moles of sodium acetate were dissolved in 1 Liter of water, what would be the osmolarity of the resulting solution?

Back 39

4M

Front 40

Osmotic Pressure is defined as:

Back 40

The pressure that is just sufficient to prevent a net movement of water across the membrane

Front 41

Osmosis is a special type of:

Back 41

passive transport

Front 42

In primary active transport, how do ions move against their concentration gradients?

Back 42

By using proteins that require ATP to function

Front 43

Sodium acetate is a commonly used food preservative with the formula NaC2H3O2. This compound is soluble in water, dissolving to form two ions (Na+ and C2H3O2-). If 2 moles of sodium acetate were dissolved in 1 Liter of water, what would be the molarity of the resulting solution?

Back 43

2M

Front 44

Osmosis requires which of the following to occur?

Back 44

A membrane permeable to water, but not to solutes

A concentration gradient of solutes

Front 45

A patient is slightly hypoglycemic and Nurse Ready been asked to prepare a glucosesolution for an IV. She administers and IV solution that is 5% dextrose. What kind of solution is this relative to the body cells?

Back 45

hypotonic

Front 46

After being shipwrecked and stranded on an island, you become thirsty and begin your search for fresh water. You soon discover that there isn't a single drop on the entire island. After three days your thirst is unbearable, and you drink exactly three cups of the bluest seawater you can find (seawater is hypertonic to body fluids). You would expect…

Back 46

Cells in your intestines to shrink

to be thirsty again

Front 47

Mannitol is a type of carbohydrate that does not easily cross a cell membrane (it is not a penetrating solute). Also, Mannitol has a molecular weight very near that of glucose. A doctor is thinking of giving a trauma patient with brain swelling an IV containing Mannitol. What percent of Mannitol could the IV contain to reduce brain swelling?

Back 47

10% Mannitol

Front 48

Hyponatremea can occur during intense, prolonged exercise. It results from a loss of sodium through sweat, leading to lower than normal amounts of sodium in your blood.Examine the following scenario:You are running a marathon and are very sweaty and thirsty. If you only drank pure water the entire race, what would eventually happen?

Back 48

Water could flow into cells causing them to bulge and possibly rupture.

Front 49

You are working in a medical lab analyzing blood samples. You decide to rinse a sample of red blood cells in distilled water. After the rinse, you look at the red blood cells under a microscope. Which of the following are you most likely to see?

Back 49

Many of the cells have lysed (ruptured) because the cells were hypertonic to the water

Front 50

A cell is placed into a beaker containing sodium chloride dissolved in water. Water rushes out of the cell and it shrivels up. Which of the following terms best describes the relationship between the solution inside the beaker and the interior of the cell?

Back 50

The solution was hyperosmotic with respect to the interior of the cell

Front 51

For osmosis to occur, in a solution with only one type of solute, the membrane must be __________ to the solute, and the concentration of the solute must be _________ on the two sides of the membrane.

Back 51

impermeable, different

Front 52

Which of the following words best describes the volume of a human cell placed in a hypertonic solution?

Back 52

shrunken

Front 53

If there are more solutes than there are available carrier proteins, we describe the proteins as being:

Back 53

Saturated- there are too many solutes and not enough proteins

Front 54

A cell is placed into a beaker containing sodium chloride dissolved in water. Water rushes out of the cell and it shrivels up. Which of the following terms best describes the solution inside the beaker compared to the interior of the cell?

Back 54

Hypertonic

Front 55

What is true regarding graded potentials?

Back 55

They cannot be propagated for a very long distance

B) The magnitude of the response is proportional to the to the strength of the stimulus

C) They can summate, or add upon each other D) They always precede an action potential

Front 56

The resting membrane potential

Back 56

A) is measure in millivolts

B) has a value between -70 and -90 in neurons and muscle fibers

C) is the net charge difference between ions in an unstimulated cell

Front 57

Which of the following is true regarding resting membrane potential?

Back 57

K+ has a higher concentration inside of the cell.

Front 58

The plasma membrane of a cell is more permeable to K+ because ________

Back 58

more non-gated channels exist for K+ than for Na+.

Front 59

Which of the following is TRUE regarding the generation of a membrane potential?

Back 59

The maintenance of the Resting Membrane Potential (RMP) depends on ion concentration gradients and electrical gradients.

Front 60

At resting membrane potential, ______________________.

Back 60

extracellular sodium levels are high

Front 61

Concerning resting membrane potential, the inside of the membrane is _______ compared to the ________ charged outside.

Back 61

negative, positively.

Front 62

Which of the following statements best describes the environment outside a resting cell plasma membrane compared to that within the resting cell plasma membrane?

Back 62

The external environment is positively charged compared to the internal environment.

Front 63

Local potentials differ from action potentials in that local potentials are ___, and action potentials are ___.

Back 63

graded; all or nothing

Front 64

Which is a characteristic of a graded potential?

Back 64

A) Spreads in a decremental fashion

B) Can result from changes in voltage across the membrane

C) Can summate

Front 65

If extracellular concentration of K+ increases, what will the effect be on the resting membrane potential?

Back 65

The increase in extracellular K+ concentration will decrease the normal K+ gradient; because of this K+ has less of a tendency to diffuse out of the cell. The resting membrane potential becomes less negative (depolarizes).

Front 66

The resting membrane potential of a cell is = -60mV, and the intracellular and extracellular Cl- concentrations are [Cl-]inside = 7 mM and [Cl-]outside = 105 mM, respectively. Which of the following statements is FALSE?

Back 66

The Cl- electrical gradient is inward

Front 67

Which of the following would cause the resting membrane potential of a neuron to move from: –85mv to –50mv?

Back 67

Increased permeability to Na+

Front 68

The flu virus increases cellular membrane permeability to K+. You would expect the cells of someone suffering from the flu to _______.

A) repolarize

B) depolarize

C) hyperpolarize

D) more information is needed.

Back 68

C) hyperpolarize

Front 69

If you increased the concentration of extracellular Na+ of a membrane at resting membrane potential, what would happen?

Back 69

hardly any change in the membrane potential

Front 70

If a cell membrane became more permeable to Na+ what would happen to the resting membrane potential?

Back 70

Na+ diffuses into the cell causing depolarization.

Front 71

You are observing a simple diffusion experiment of green food coloring being carefully added to the surface of two containers holding an equal volume of water, one at 0 degrees C and the other at 100 degrees C. Your original hypothesis is that because the food coloring is being added to the surface, it will be traveling down the concentration gradient in both cases. Therefore diffusion in both systems will be complete at the same time. Is your hypothesis correct or incorrect?

A) Correct, all substances naturally travel down their concentration gradients.

B) Incorrect, all substances naturally travel up their concentration gradients.

C) Incorrect, because of the increased speed and motion of the water particles in the 100 degree system it will finish diffusion much faster than the 0 degree system.

D) Correct, because there is an equal volume of water in each system it will take the same amount of time for diffusion to complete (time to diffuse is proportional to the square of the distance).

Back 71

C) Incorrect, because of the increased speed and motion of the water particles in the 100 degree system it will finish diffusion much faster than the 0 degree system.

Front 72

If the plasma membrane becomes more permeable to K+, what effect will it have on the resting membrane potential?

Back 72

Because the membrane is more permeable to K+, more K+ will diffuse out of the cell. The inside of the cell becomes more negative resulting in hyperpolarization.

Front 73

If the extra cellular fluid around a muscle cell is replaced with an isotonic saline solution that contains less K+ than the normal extra cellular fluid, the result would be:

Back 73

hyperpolarization

Front 74

Repolarization results

Back 74

from the increase in potassium moving out of the cell

Front 75

This allows the action potential to propagate in an one-way direction.

Back 75

Absolute refractory period

Front 76

Depolarization occurs when there is a rapid inflow of _______

Back 76

Cations

Front 77

Which of the following word (phrase) pairs are correctly matched?

A) Neuromuscular Junction :: A type of electrical synapse

B) Threshold :: point where voltage gated K+ channels all open

C) Relative Refractory period :: An action potential is possible if most of the activation gates are closed

D) All of the above answers are correct E) None of the above answers are correct

Back 77

C) Relative Refractory period :: An action potential is possible if most of the activation gates are closed

Front 78

During the absolute refractory period another stimulus cannot cause another action potential because _________.

Back 78

The voltage-gated sodium inactivation gate is closed

Front 79

Voltage-gated Na+ channels are sensitive to changes in the extracellular concentration of what?

Back 79

Ca++

Front 80

If the RMP (Resting Membrane Potential) becomes more negative (less positive), what has happened?

Back 80

hyperpolarization

Front 81

The "All-or-None" principle

Back 81

whether the stimulus is just strong enough to reach threshold or if it is so strong to surpass the threshold, the action potential will proceed without stopping

Front 82

Depolarization occurs...

Back 82

as sodium rushes into the cell

Front 83

In repolarization of an action potential, certain voltage-gated channels open and certain voltage-gated channels close. This causes a(n)_______________ in sodium permeability and a(n) ______________ in potassium permeability of the membrane.

A) Increase; decrease

B) Decrease; increase

Back 83

B) Decrease; increase

Front 84

What occurs during depolarization?

Back 84

There is a rapid influx of Na+ ions.

Front 85

What event will cause depolarization?

Back 85

Increased K+ ions in extracellular fluid.

Front 86

When does the absolute refractory period end?

Back 86

When the inactivation gates of voltage-gated Na+ channels reopen.

Front 87

The change in permeability of the membrane is due to

Back 87

the opening and closing of voltage gated channels

Front 88

During the depolarization phase, the permeability of the plasma membrane to:

Back 88

Na+ increases

Front 89

Which of the following statements regarding action potentials are true?

Back 89

A) The rising phase of an action potential may be caused by a rapid increase in the permeability to Na+. B) Threshold can be achieved in response to a decrease in K+ permeability. C) During the repolarization phase there is a decrease in Na+ permeability and an increase in K+ permeability.

Front 90

The reason more and more Na+ channels open during depolarization is:

Back 90

a positive feedback cycle

Front 91

The effect of a reduced extracellular concentration of sodium ion on the magnitude of the action potential is

Back 91

the magnitude is decreased