Deck 3: The Plasma Membrane and Membrane Potential

Question 1

What are the three major types of protein fibers that are woven through the interstitial fluid?

A)​collagen,chondroitin,elastin
B)fibronectin,lecithin,fibrinogen
C)elastin,lecithin,chondroitin
D)collagen,elastin,and fibronectin
E)​fibrinogen,collagen,chondroitin

Answer 1

D

Question 2

What kind of junctions are impermeable junctions that join the lateral edges of epithelial cells near their luminal borders,thus preventing movement of materials between the cells?

A)​gap junctions
B)desmosomes
C)luminal junctions
D)plasma junctions
E)​tight junctions

Answer 2

E

Question 3

How many layers of phospholipids make up plasma membranes?

A)​six
B)five
C)four
D)three
E)​two

Answer 3

E

Question 4

In terms of plasma membrane transport,which descriptor is the most accurate?

A)​permeable
B)selectively permeable
C)non-permeable
D)porous
E)​sealed

Question 5

What are the three important functions of the lipid bilayer of the plasma membrane?

A)​forms the basic membrane structure;hydrophilic interior acts as barrier;aids in RNA transfer
B)forms the basic membrane structure;hydrophobic interior acts as barrier;responsible for fluidity
C)forms the basic membrane structure;hydrophobic interior acts as barrier;aids in RNA transfer
D)allows electrical flow via nerves;hydrophobic interior acts as barrier;responsible for fluidity
E)​allows electrical flow via nerves;hydrophilic interior acts as barrier;responsible for fluidity

Question 6

Proteins that are embedded in the lipid bilayer are called ____.

A)​intercepting proteins
B)integral proteins
C)bilayer proteins
D)bilamina proteins
E)​penetrating proteins

Question 7

Two properties of particles influence whether they can permeate the plasma membrane without assistance: ____.

A)​size and the relative solubility of the particle in lipid
B)size and the relative solubility of the particle in water
C)shape and the relative solubility of the particle in water
D)shape and size
E)​electrical charge and shape

Question 8

Tight junctions are found primarily in what type of tissue?

A)​nerves
B)tendons
C)brain tissue
D)muscles
E)​sheets of epithelial tissue

Question 9

Water-soluble (lipid-insoluble)ions have to be smaller than what diameter in order to use protein channels for passage across the membrane?​

A)​0.1 nm
B)0.4 nm
C)0.8 nm
D)1 nm
E)​8 nm

Question 10

Gap junctions are especially abundant in what kind of tissue?

A)​nerves
B)tendons
C)cardiac muscle and smooth muscle
D)brain tissue
E)​fingernails

Question 11

What are the two passive forms of movement across a plasma membrane?

A)​diffusion down a concentration gradient and movement along an electrical gradient
B)phagocytosis and movement along an electrical gradient
C)diffusion down a concentration gradient and pinocytosis
D)phagocytosis and osmosis
E)​diffusion along an electrical gradient and osmosis

Question 12

Cadherins and integrins are examples of what type of membrane protein?

A)​cell adhesion molecules (CAMs)
B)collective additive molecules (CAMs)
C)adhesive membrane proteins (AMPs)
D)adhesive lipid molecules (ALMs)
E)​adhesive locking molecules (ALMs)

Question 13

The plasma membrane consists mostly of lipids and proteins plus small amounts of ____.

A)​collagen
B)chondroitin
C)glucosamine
D)coenzyme Q10
E)​carbohydrate

Question 14

Which type of proteins are located on the inner membrane surface and bind lock-and-key fashion with secretory vesicles?

A)docking-marker acceptors​
B)secretory acceptors
C)binding acceptors
D)lock-and-key proteins
E)​inner proteins

Question 15

What are the two general types of force that accomplish transport of substances across a membrane?

A)​push and pull forces
B)attractive and repulsive
C)negative and positive
D)passive and active forces
E)​up and down forces

Question 16

Cells organized into appropriate groupings are held together by what three means?​

A)​ALMs,extracellular matrix,and carbohydrate molecules
B)CAMs,cholesterol,and carbohydrate molecules
C)CAMs,extracellular matrix,and specialized cell junctions
D)CAMs,cholesterol,and specialized cell junctions
E)​ALMs,extracellular matrix,and specialized cell junctions

Question 17

What are the most abundant plasma membrane lipids?

A)​cholesterol
B)unsaturated fat
C)phospholipids
D)omega-6 fatty acids
E)​lecithin

Question 18

What is the main role of membrane carbohydrates?

A)​electrical conductance
B)self-identity markers
C)transport molecules
D)barrier compounds
E)​initiates endocytosis

Question 19

What is the action of a solvent?

A)​It is a compound that dissolves in waer.
B)It is a dissolving medium.
C)It is a compound that evaporates.
D)It is a compound that forms salt.
E)​It is a compound that gains electrons.

Question 20

What tissue contains the most amount of extracellular matrix (ECM)?

A)​epithelial tissue
B)muscle tissue
C)nervous tissue
D)connective tissue 
E)​heart muscle

Question 21

Membrane potential can be calculated by using what equation?​

A)​Goldman-Hodgkin-Katz equation
B)Fick's equation
C)Nernst equation
D)Tesla equation
E)​Edison equation

Question 22

What law governs how concentration gradients and other factors influence the rate of net diffusion?​

A)​Fick's law of osmosis
B)Fick's law of movement
C)Fick's law of gradients
D)Fick's law of diffusion
E)​Fick's law of concentrations

Question 23

What happens to the diffusion rate as the distance increases?

A)​speeds up
B)no change
C)requires more energy
D)triggers the membrane to change
E)becomes slower​

Question 24

What is the equilibrium potential for sodium ions?

A)​-60 mV
B)-30 mV
C)zero
D)+30 mV
E)​+60 mV

Question 25

What ion is more concentrated in the extracellular fluid (ECF)?

A)​potassium ions
B)sodium ions
C)hydrogen ions
D)phosphorus ions
E)​nitrogen ions

Question 26

In addition to the concentration gradient,what else affects the movement of ions across plasma membranes?

A)​electrical charge
B)molecular weight
C)vibration
D)spin
E)​number of atoms

Question 27

The tonicity of a solution refers to the effect that the ____.

A)​solute has on ion volume when the solution surrounds the ions
B)solution has on cell mass when the solution surrounds the cell
C)solution has on cell volume when the solution surrounds the cell
D)solvent has on cell mass when the solution surrounds the cell
E)​solution has on ion mass when the solution surrounds the ions

Question 28

What is the principal negative ion (anion)in the extracellular fluid (ECF)that is present in high concentrations?

A)​sodium
B)potassium
C)glucose
D)calcium
E)​chloride

Question 29

How do large polar molecules,such as the protein hormones secreted by endocrine cells or bacteria ingested by white blood cells,leave or enter the cell?

A)​by the process known as vesicular transport
B)by the process of osmosis
C)by selective passive transport 
D)by the help of large lipid carriers 
E)​by the help of large protein carriers

Question 30

What two methods do cells use to accomplish selective transport processes across membranes?

A)​carrier-mediated transport and vesicular transport
B)protein-assisted osmosis and vesicular transport
C)phagocytosis and carrier-mediated transport
D)protein-assisted transport and electrical diffusion
E)​phagocytosis and electrical diffusion

Question 31

Compared to membrane carriers,how much faster are channels at allowing particles/ions to pass through the plasma membrane?

A)​2x
B)10x
C)25x
D)100x
E)​1,000x

Question 32

What are the two types of vesicular transport?

A)​protein transport and lipid transport
B)intercellular transport and intracellular transport
C)extracellular transport and extranuclear transport 
D)endocytosis and exocytosis
E)​active transport and passive transport

Question 33

What units are the membrane potentials measured in?

A)​amperes
B)milliamps
C)Teslas
D)volts
E)​millivolts

Question 34

What are active-transport mechanisms commonly called?

A)​bridges
B)pumps
C)couriers​
D)funnels
E)​engines 

Question 35

For every two potassium ions,how many sodium ions are pumped out of the cell by the sodium-potassium pump?

A)​one
B)two
C)three
D)four
E)​five

Question 36

What method do cells use to transfer small to moderate-sized water-soluble substances across the membrane?

A)​vesicular transport
B)carrier-mediated transport
C)phagocytosis
D)protein-assisted osmosis
E)​electrical diffusion

Question 37

What is the most notable example of facilitated diffusion within the body?

A)transport of sodium out of cells
B)transport of potassium out of cells
C)transport of waste products out of cells
D)transport of iron into cells
E)transport of glucose into cells

Question 38

How is O₂ (oxygen)transported across the lung membrane?

A)​by osmosis
B)by pinocytosis
C)by diffusion
D)via a carrier lipid
E)​via a carrier protein

Question 39

In what type of transport system does the carrier NOT directly split ATP to move a substance against its concentration gradient?

A)​passive secondary transport
B)active primary transport
C)primary active transport
D)secondary active transport
E)​carrier mediated diffusion

Question 40

What term refers to the net diffusion of water down its concentration gradient through a selectively permeable membrane?

A)​phagocytosis
B)pinocytosis
C)osmosis
D)hydrogen selectivity
E)​aquatic diffusion

Question 41

Gap junctions can be found in some non-muscle tissues,where they permit unrestricted passage of small nutrient molecules between cells.

Question 42

Cells have a membrane potential,a slight excess of positive charges lined up along the inside of the membrane and a slight excess of negative charges on the outside.

Question 43

In secondary active transport,energy is used directly in the entire process.

Question 44

The greater the lipid solubility of a substance,the slower the substance can diffuse through the membrane's lipid bilayer down its concentration gradient.

Question 45

Fibronectin promotes cell adhesion and holds cells in position.

Question 46

A common view of the membrane structure is known as the static mosaic model.

Question 47

Desmosomes are the weakest cell-to-cell connections.​

Question 48

Passage across the epithelial barrier must take place between the cells,not through them.

Question 49

A more direct means of expressing solvent concentration is the osmolarity of a solution,which is a measure of its total solvent concentration given in terms of the mass of particles.

Question 50

Membrane channels can be open or closed,but carriers are always "open for business."

Question 51

Highly lipid-soluble particles of any size can dissolve in the lipid bilayer and pass through the membrane.

Question 52

Saturation of carriers is a critical rate-limiting factor in the transport of selected substances across the kidney membranes during urine formation.

Question 53

If a substance can cross a membrane,the membrane is impermeable to that substance.

Question 54

Solutions are homogeneous mixtures containing a relatively large amount of one substance called the solvent and smaller amounts of one or more dissolved substances called solutes.

Question 55

Carbohydrate-containing surface markers are involved in tissue growth.

Question 56

Most of the abundant matrix in connective tissue is secreted by fibroblasts.

Question 57

All molecules and ions are in continuous random motion at temperatures above absolute zero as a result of thermal (heat)energy.

Question 58

If a substance can permeate the membrane,its rate of simple diffusion is inversely proportional to its concentration gradient.

Question 59

Cells are held together by a "biological glue" called the intracellular matrix.

Question 60

Many proteins on the outer surface of the cell are receptors,sites that "recognize" and bind with specific extracellular chemical messengers (signal molecules)in the cell's environment.

Question 61

In many cell types,membrane proteins form ____________________,which are channels specific for the passage of water.

Question 62

The difference in fluid composition inside and outside a cell is maintained by the ____________________.

Question 63

____________________ promotes cell adhesion and holds cells in position.

Question 64

An almost insignificant fraction of the total number of charged particles present in the body fluids is responsible for the membrane potential.

Question 65

____________________ is a rubbery protein fiber most plentiful in tissues that must easily stretch and then recoil after the stretching force is removed.

Question 66

Materials packaged for export by the endoplasmic reticulum and Golgi complex are externalized by exocytosis.

Question 67

The lipid bilayer is responsible for the ____________________ of the plasma membrane.

Question 68

The equilibrium potential for a given ion with differing concentrations across a membrane can be calculated by means of Fick's equation.

Question 69

A(n)____________________ is made up of six protein subunits arranged in a hollow,tube-like structure that extends through the thickness of the plasma membrane.

Question 70

Phospholipids have a(n)____________________ head containing a negatively charged phosphate group and two electrically neutral fatty acid chain tails.

Question 71

____________________ forces require the cell to expend energy in transporting a substance across the membrane.

Question 72

____________________ forms flexible but non-elastic fibers or sheets that provide tensile strength.

Question 73

The term membrane potential refers to a separation of opposite charges across the membrane.

Question 74

If a substance can cross a membrane,the membrane is _____to that substance.

Question 75

Transcellular transport across the cell is regulated by ____________________ and ____________________ proteins.

Question 76

____________________ act like "spot rivets" that anchor together two adjacent but non-touching cells.

Question 77

Some trans-membrane proteins form water-filled pathways,or ____________________,through the lipid bilayer.

Question 78

The net effect of simultaneous electrical and concentration gradients on an ion is called a(n)____________________ gradient.

Question 79

The balanced charges responsible for membrane potential accumulate in a thick layer along opposite surfaces of the membrane.

Question 80

____________________ proteins are polar molecules that do not penetrate the membrane.