Module 1: Cell Transport and Signaling

Question 0

Carrier-mediated: Active vs Passive

Answer 0

Yes; Yes or No

Question 1

Concentration gradient: Active vs Passive

Answer 1

Uphill; Downhill

Question 2

Energy expenditure: Active vs Passive

Answer 2

Yes; No

Question 3

Types of Passive Transport

Answer 3

Diffusion
Facilitated diffusion
Osmosis

Question 4

Simple movement through the membrane, caused by the random motion or kinetic movement of the molecules

Answer 4

Diffusion

Question 5

Kinetic movement of molecules or ions via membrane opening or or intermolecular spaces

Answer 5

Simple diffusion

Question 6

T or F: Simple diffusion uses carrier proteins.

Answer 6

F

Question 7

Rate of diffusion is determined by:

Answer 7

Amount of substance
Velocity of kinetic motion
Number and sizes of openings

Question 8

Simple diffusion is governed by what law?

Answer 8

Fick’s Law

Question 9

Law that predicts the rate of diffusion of molecules across a biological membrane

Answer 9

Fick’s Law

Question 10

T or F: Diffusion is SLOW at higher concentration gradient.

Answer 10

F, FAST

Question 11

T or F: Diffusion is FAST at higher permeability.

Answer 11

T

Question 12

T or F: Diffusion is SLOW at higher areas for diffusion.

Answer 12

F, FAST

Question 13

T or F: Diffusion is SLOW when diffusing membrane is thicker.

Answer 13

T

Question 14

Paths of simple diffusion

Answer 14

Via interstices of lipid bilayer if diffusing substance is lipid soluble
Through water channels

Question 15

T or F: Protein pores
A. Always open
B. Non selective with size and charge

Answer 15

A. T

B. F, selective

Question 16

Molecular conformation of of the gate or its chemical bonds responds to the electrical potential across the cell membrane

Answer 16

Voltage-gated channels

Question 17

These channels are opened by a chemical substance with the protein

Answer 17

Ligand-gated channels

Question 18

Ligand-gated channels are also called

Answer 18

Chemical gating

Question 19

T or F: Facilitated diffusion requires carrier protein.

Answer 19

T

Question 20

T or F: Facilitated diffusion also follows Fick’s Law.

Answer 20

F, does not follow

Question 21

T or F: Rate at which molecules can be transported via facilitated diffusion cannot exceed the rate at which carrier protein molecule can undergo change back and forth between its two state

Answer 21

T

Question 22

Acetylcholine channel is an example of?

Answer 22

Ligand-gated channels

Question 23

Na and K channels are of what type?

Answer 23

Voltage-gated channels

Question 24

Factors that affect net diffusion

Answer 24

Net diffusion Concentration Charge Energy

Question 25

The process of net movement of water through a selective membrane caused by a concentration

Answer 25

Osmosis

Question 26

A _______ undergoes osmosis from an area of low solute concentration to an area of high solute concentration.

Answer 26

Solvent (water)

Question 27

A solute undergoes ________ from an area of high solute concentration to an area of low solute concentration.

Answer 27

Diffusion

Question 28

Homogenous mixture composed of two or more substances

Answer 28

Solution

Question 29

Substance dissolved

Answer 29

Solute

Question 30

Substance that dissolves the solute

Answer 30

Solvent

Question 31

Concentration of all osmotically active particles (osmoles) per liter of solution (osmol/L)

Answer 31

OsmolaRity

Question 32

OsmolaRity is a colligative property that can be measured by

Answer 32

Freezing point depression

Question 33

Concentration of all osmotically active particles (osmoles) per kilogram of solvent (osmol/kg)

Answer 33

Osmolality

Question 34

Determines osmotic pressure between solutions

Answer 34

Osmolality

Question 35

Two solutions that have the same osmolarity

Answer 35

Isosmotic

Question 36

Solution with the higher osmolarity

Answer 36

Hyperosmotic

Question 37

Solution with the lower osmolarity

Answer 37

Hyposmotic

Question 38

The exact amount of pressure required to stop osmosis

Answer 38

Osmotic pressure

Question 39

Osmotic pressure is calculated using

Answer 39

Van't Hoff's Law or Morse Law

Question 40

T or F: Osmotic pressure is HIGHER with higher osmolality

Answer 40

T

Question 41

T or F: Osmotic pressure is LOWER at higher temperature.

Answer 41

F, HIGHER

Question 42

T or F: The higher the osmotic pressure of a solution, the greater the tendency for water to flow into the solution.

Answer 42

T

Question 43

Measure of the osmotic pressure of two solutions separated by a semi permeable membrane

Answer 43

Tonicity

Question 44

T or F: Tonicity is influenced by solutes that can cross the membrane.

Answer 44

F, cannot cross

Question 45

T or F: Osmolarity is not the same as Tonicity.

Answer 45

T

Question 46

______ accounts for all solutes while, _______ accounts for only non-permeating solutes.

Answer 46

Osmolarity; Tonicity

Question 47

Isosmotic volume expansion (eg. Isotonic NaCl infusion)

Answer 47

Gain of water and Na in the ECF, no change in ECF osmolarity, inc ECF volume, no change in ICF volume

Question 48

Isosmotic volume contraction (eg. Diarrhea)

Answer 48

Loss of water and Na in the ECF, No change in ECF osmolarity, dec ECF volume, No change in ICF volume

Question 49

Hyperosmotic volume expansion (eg. High NaCl intake, Conn's)

Answer 49

Gain of Na in the ECF, Inc ECF osmolarity, Inc ECF volume, Dec ICF volume

Question 50

Hyperosmotic volume contraction (eg. Sweating, fever, DI)

Answer 50

Loss of water in the ECF, Inc ECF osmolarity, Dec ECF volume, Dec ICF volume

Question 51

Hypoosmotic volume expansion (eg. SIADH)

Answer 51

Gain of water in the ECF, Dec ECF osmolarity, Inc ECF volume, Inc ICF volume

Question 52

Hypoosmotic volume contraction (eg. Adrenal insufficiency, Diuretics overuse)

Answer 52

Loss of Na in the ECF, Dec ECF osmolarity, Dec ECF volume, Inc ICF volume

Question 53

Types of vehicular transport

Answer 53

Exocytosis | Endocytosis

Question 54

Secretory vehicles fuse with cell membrane, extruding their contents outside the cell

Answer 54

Exocytosis

Question 55

Molecules are absorbed and internalized by coating with membrane phospholipids forming a vesicle that detaches form cell membrane

Answer 55

Endocytosis

Question 56

Calcium-dependent: Exocytosis or Endocytosis

Answer 56

Exocytosis

Question 57

Cell drinking

Answer 57

Pinocytosis

Question 58

T or F: Pinocytosis does not require ATP and calcium in the ECF.

Answer 58

F, requires

Question 59

Cell eating

Answer 59

Phagocytosis

Question 60

Events in phagocytosis

Answer 60

Contact.. Invagination.. Pinching off.. Vacuole formation

Question 61

Receptor-mediated endocytosis

Answer 61

Clathrin-mediated Endocytosis

Question 62

Transport of glucose, amino acids, and other polar molecules through the cell membrand

Answer 62

Carrier-mediated Transport

Question 63

Characteristics of Carrier-mediated Transport

Answer 63

Stereospecificity Saturation Competition

Question 64

Types of Active Transport

Answer 64

Primary Active Transport | Secondary Active Transport

Question 65

Occurs UPHILL against an electrochemical gradient, requires direct input of metabolic energy, carrier-mediated transport

Answer 65

Primary Active Transport

Question 66

Give examples of Primary Active Transport

Answer 66

Na/K-ATPase in virtually all cells Ca-ATPase in sarcoplasmic reticulum H/K-ATPase in parietal cells of stomach H-ATPase in intercalated cells of kidneys

Question 67

Transport of Na from ICF to ECF and K from ECF to ICF against electrochemical gradient

Answer 67

Na/K-ATPase

Question 68

Usual stoichiometry in Na/K-ATPase

Answer 68

3 Na/2 K

Question 69

Transport of two or more solutes is coupled

Answer 69

Secondary Active Transport

Question 70

T or F: One of the solutes (usually Na) is transported UPHILL and provides energy for the DOWNHILL transport of other solutes

Answer 70

F, DOWNHILL; UPHILL

Question 71

Types of Secondary Active Transport

Answer 71

Co-transport | Countertransport

Question 72

Co-transport is also called

Answer 72

Symport

Question 73

Occurs if the solutes move in the same direction across the cell membrane

Answer 73

Co-transport

Question 74

Examples of co-transport

Answer 74

Na glucose co-transport in the intestines Na/K/2Cl co-transport in loop of Henle Na/Cl co-transport in distal convoluted tubule

Question 75

Also called exchange transport or antiport

Answer 75

Countertransport

Question 76

Occurs if the solutes move in opposite directions across the cell membrane

Answer 76

Countertransport

Question 77

Examples of countertransport

Answer 77

Na-Ca countertransport in virtually all cells | Na/H countertransport in proximal tubule

Question 78

Signaling molecules

Answer 78

``` Peptides and proteins Catecholamines Steroid hormones Iodothyronines Eicosanoids ```

Question 79

Mechanisms of cellular communication

Answer 79

``` Endocrine Neurocrine Paracrine Autocrine Juxtacrine ```

Question 80

Transport of hormones along the bloodstream to a distant target organ

Answer 80

Endocrine Signaling

Question 81

Transport of neuro-transmitters from a presynaptic cell to a postsynaptic cell

Answer 81

Neurocrine Signaling

Question 82

Release and diffusion of local hormones with regulatory action on neighboring target cells

Answer 82

Paracrine Signaling

Question 83

A cell secretes hormones or chemical messengers that bind to the same cell

Answer 83

Autocrine Signaling

Question 84

Contact-dependent signaling

Answer 84

Juxtacrine Signaling

Question 85

Types of receptors

Answer 85

Signal transducers Membrane receptors Nuclear receptors

Question 86

Plasma membrane receptors

Answer 86

Ion-channel linked G-protein coupled receptors Catalytic receptors Transmembrane receptors

Question 87

Types of signal transduction pathways

Answer 87

G proteins Ion channels Protein kinases

Question 88

Mediate direct and rapid synaptic signaling between electrically excitable cells

Answer 88

Ion-channel linked signal transduction pathways

Question 89

Heterotimeric complexes - alpha, beta, gamma subunits

Answer 89

G protein-coupled signal transduction pathways

Question 90

Active or Inactive: GTP with alpha subunit, activation via guanine nucleotide exchange factors

Answer 90

Active

Question 91

Active or Inactive: GDP, inactivation via GTPase-accelerating proteins and RGS proteins

Answer 91

Inactive

Question 92

An enzyme that modifies other proteins by phosphorylation

Answer 92

Kinase