Biol2420 - Interactions Between Cells And Their Environment #2

Front 1

True or False. Carrier proteins have specificity and can reach a transport maximum when they become saturated?

Back 1

True

Hint 1

Pg. 065

Front 2

What is the term used to define transportation across a plasma membrane using carrier proteins?

Back 2

Carrier-Mediated Transport

Hint 2

Pg. 065

Front 3

What 2 forms of transportation are considered to be Carrier-Mediated Transport?

Back 3

Facilitated Diffusion and Active Transport

Hint 3

Pg. 065

Front 4

What are the 2 distinguishing characteristics of Carrier Proteins compared to Channel Proteins?

Back 4

1) Carrier proteins are highly specific.
2) Carrier proteins can have a transport maximum if they become saturated

Hint 4

Pg. 065

Front 5

What type of transportation process utilizes carrier proteins to transport molecules passively?

Back 5

Facilitated Diffusion

Hint 5

Pg. 066

Front 6

Using an analogy of doors, what would channel proteins for inorganic ions be and what would carrier proteins in facilitated diffusion be?

Back 6

Channel proteins = Private doorways
Carrier proteins = Revolving doors

Hint 6

Pg. 066

Front 7

True or False. The rate at which glucose enters the cells depends on the steepness of the concentration gradient.

Back 7

True

Hint 7

Pg. 066

Front 8

What is the condition called when there is a fall in blood glucose levels?

Back 8

Hypoglycemia

Hint 8

Pg. 066

Front 9

What might someone who is hypoglycemia experience?

Back 9

Feeling weak, dizzy or loss of consciousness.

Hint 9

Pg. 066

Front 10

What primarily determines the rate of glucose entry into cells and why?

Back 10

The number of glucose carriers in the plasma membrane.
Because homeostasis of the blood glucose concentration is normally maintained.

Hint 10

Pg. 066

Front 11

What effect does the hormone insulin have on carrier proteins in the plasma membrane of skeletal muscle cells?

Back 11

It increases the number of carrier proteins that are inserted into the plasma membrane.

Hint 11

Pg. 066

Front 12

What type of membrane transportation moves molecules against a concentration gradient?

Back 12

Active Transport

Hint 12

Pg. 066

Front 13

What state is the carrier protein in when one of the phosphates from ATP bonds to a part it?

Back 13

A Phosphorylated state

Hint 13

Pg. 067

Front 14

What happens when a carrier protein has a phosphate bonded to it?

Back 14

It causes the carrier protein to change its shape.

Hint 14

Pg. 067

Front 15

What is the term used to describe what happens when a carrier protein has a phosphate bonded to it?

Back 15

Conformational change

Hint 15

Pg. 067

Front 16

What do Calcium pumps do in regards to the intracellular concentration of Calcium ions?

Back 16

Keep the intracellular concentration of Calcium ions low.

Hint 16

Pg. 067

Front 17

What forms of membrane transport is employed for the transportation of Calcium ions?

Back 17

Passive Transport through gated protein channels and Active Transport

Hint 17

Pg. 067

Front 18

Why is there always a difference in concentration of Ca2+ across the plasma membrane?

Back 18

It is because of active transport of Ca2+ pumps and the gates of membrane protein channels are generally closed.

Hint 18

Pg. 067

Front 19

Why do cells spend energy to pump Ca2+ ions across the plasma membrane?

Back 19

To maintain the concentration gradient, so when the gated protein channels are opened Ca2+ will stream into the cell’s cytoplasm as a consequence of net diffusion.

Hint 19

Pg. 067

Front 20

Why is the diffusion of Calcium ions into the cytoplasm of the cell an important physiological stimulus?

Back 20

It stimulates axon terminals to release neurotransmitter chemicals and it stimulates muscles to contract.

Hint 20

Pg. 067

Front 21

What is the a type of active transport carriers found in the plasma membrane of all cells?

Back 21

Na+/K+ (ATPase) pump

Hint 21

Pg. 067

Front 22

What direction are Sodium ions pumped by the Na+/K+ (ATPase) pumps?

Back 22

Outside of the cell

Hint 22

Pg. 067

Front 23

What direction are the Potassium ions pumped by Na+/K+ (ATPase) pumps?

Back 23

Inside the cell

Hint 23

Pg. 067

Front 24

What is the ratio of Sodium ions to moved to Potassium ions?

Back 24

3 Na+ ions for every 2 K+ ions

Hint 24

Pg. 067

Front 25

Why are the concentration gradients for Na+ and K+ important for electrical impulses?

Back 25

They are important for the production of electrical impulses in nerve and for skeletal muscles and heart muscle cells.

Hint 25

Pg. 067

Front 26

What is the form of active transport that involves Na+ and glucose across the plasma membrane called?

Back 26

Cotransport

Hint 26

Pg. 068

Front 27

Where are 2 places that Cotransport occurs?

Back 27

Epithelial cells in the Kidney Tubules and Epithelial cells in the small intestines

Hint 27

Pg. 068

Front 28

What direction is Na+ and glucose moved in Cotransport? (Be specific)

Back 28

Both are moved from the extracellular fluid into the cell.
Na+ moves into the cell (from a higher to lower concentration) and Glucose moves into cell (from a lower to higher concentration).

Hint 28

Pg. 068

Front 29

Why is cotransport possible?

Back 29

Because the Na+/ K+ (ATPase) pumps operate in other locations in the plasma membrane to lower the intracellular concentration of Na+.

Hint 29

Pg. 068

Front 30

What separates charges between the extracellular fluid and the cytoplasm?

Back 30

The plasma membrane

Hint 30

Pg. 068

Front 31

What is produced when there is a separation of charge between 2 substances?

Back 31

A potential difference
or
A difference in charge

Hint 31

Pg. 068

Front 32

What charge does the inside of a cells membrane have?

Back 32

It is the negative pole

Hint 32

Pg. 068

Front 33

How is the magnitude of the voltage in a resting cell primarily determined?

Back 33

It is determined primarily determined by the difference in K+ concentrations across the plasma membrane.

Hint 33

Pg. 068 and 069

Front 34

What characteristic of the plasma membrane enables it to create an unequal distribution of ions between the extracellular fluid and the cytoplasm?

Back 34

Its selectively permeable

Hint 34

Pg. 068

Front 35

What are negatively charged molecules trapped within the cytoplasm of a cell called?

Back 35

Fixed Anions

Hint 35

Pg. 068

Front 36

Why are there a many differences in ion concentrations across the plasma membrane?

Back 36

Because the permeability of the plasma membrane varies for different inorganic ions
and
Because there are active transport pumps present for the different ions.

Hint 36

Pg. 068

Front 37

What directly produces a difference in charges across the plasma membrane?

Back 37

1) Differences in inorganic ion concentrations between the inside and outside of the cell.
2) The presence of the fixed anions within the cell.

Hint 37

Pg. 068

Front 38

What is the specific term used when referring to a difference in charge across the plasma membrane?

Back 38

Membrane Potential

Hint 38

Pg. 068

Front 39

What unit is used to measure the difference in charge between 2 places?

Back 39

Voltage

Hint 39

Pg. 068

Front 40

What are the specific units of expression used to measure the potential difference across the plasma membrane?

Back 40

millivolt units (mV)

Hint 40

Pg. 068

Front 41

What is used to measure the difference in charge between 2 places and what must it have?

Back 41

Voltmeter
and
It must have 2 leads or wires

Hint 41

Pg. 069

Front 42

When could you get a voltmeter measurement of “zero” when measuring cellular voltage differences?

Back 42

If both leads were placed inside the cell or If both leads were placed outside the cell

Hint 42

Pg. 069

Front 43

What is the value for membrane potential in a typical neuron?

Back 43

-70 mV

Hint 43

Pg. 069

Front 44

What is the value for membrane potential in certain cardiac cells?

Back 44

-85 mV

Hint 44

Pg. 069

Front 45

True or False. All cells do not possess a membrane potential.

Back 45

False. All cells have a membrane potential.

Hint 45

Pg. 069

Front 46

Why do all cells have a membrane potential?

Back 46

Because all cells have fixed anions
and
All cells have Na+, K+, Cl- and Ca2+ ion concentration distributed between the inside and outside of the cell.

Hint 46

Pg. 069

Front 47

What cells are the only ones capable of changing their membrane potential when stimulated?

Back 47

Neurons and Muscle cells

Hint 47

Pg. 069

Front 48

What word is used to describe “the only cells capable of changing their membrane potential when stimulated” ability?

Back 48

Excitable

Hint 48

Pg. 069

Front 49

What is produced by neurons and muscle cells when they are stimulated?

Back 49

Impulses

Hint 49

Pg. 069

Front 50

What cells are classified as being the only excitable cells?

Back 50

Neurons and Muscle Cells

Hint 50

Pg. 069

Front 51

What is “the difference in charge across the plasma membrane” of excitable cell called before stimulation called?

Back 51

Resting Membrane Potential

Hint 51

Pg. 069

Front 52

Why is the resting membrane potential determined mostly by the difference in K+ concentrations across the plasma membrane?

Back 52

1) Because K+ ions compared to all other ions can cross the resting membrane the easiest.
2) The membrane is almost more permeable to K+ because it possess 2 kinds of K+ channels (one gated and one that is not gated)

Hint 52

Pg. 069

Front 53

What is the state of the membrane’s K+ channels of “excitable cells” when they are not producing impulses (or at rest)?

Back 53

The gated channels are closed and the ungated channels are open.

Hint 53

Pg. 069

Front 54

What are K+ channels that are always open called?

Back 54

Leakage Channels

Hint 54

Pg. 069

Front 55

Why does K+ diffuse out of the at rest cell and through what channels does they diffuse?

Back 55

It occurs because there is a higher concentration of K+ inside the cell.
and
K+ diffuses out of the cell though the ungated channels or “Leakage Channels.”

Hint 55

Pg. 069

Front 56

In contrast to K+ ions diffusing in regard to concentration gradient with an excitable cell at resting membrane potential, why does Na+ not diffuse with regard to concentration gradient also?

Back 56

The diffusion is prohibited because the plasma membrane only contains gated Na+ channels, and these channels are closed in the resting membrane.

Hint 56

Pg. 069

Front 57

What occasionally allows Na+ to diffuse with regard to concentration gradient when an excitable cell is at resting membrane potential that usually does not occur?

Back 57

The gated Na+ channels can “flicker” open occasionally.

Hint 57

Pg. 069

Front 58

What would happen to the resting membrane potential if the diffusion of K+ out of a cell and Na+ into a cell were not prevented?

Back 58

The resting membrane potential would change because the concentrations of ions in the intracellular and extracellular fluids would be changed.

Hint 58

Pg. 069

Front 59

What prevents the resting membrane potential from changing as a consequence of K+ diffusing out of the cell and Na+ diffusing into the cell?

Back 59

The constant activity of the Na+/K+ (ATPase) pumps

Hint 59

Pg. 069

Front 60

True or False. Na+/K+ (ATPase) pumps help contribute to the resting membrane potential.

Back 60

True. They help contribute to the unequal distribution of charges.

Hint 60

Pg. 069

Front 61

What 3 factors contribute to the resting membrane potential?

Back 61

1) The presence of fixed anions.
2) The greater permeability of the resting plasma membrane to K+.
3) The activity of the Na+/K+ (ATPase) pumps.

Hint 61

Pg. 070 or Pg. 78 in text

Front 62

What type of molecules are Hormones and Neurotransmitters?

Back 62

Regulatory molecules

Hint 62

Pg. 070

Front 63

What do regulatory molecules do?

Back 63

Influence the activities of their target cells.

Hint 63

Pg. 070

Front 64

What must occur in order for regulatory molecules to be able to influence the activities of their target cells?

Back 64

The molecules must first bind to specific receptor proteins.

Hint 64

Pg. 070

Front 65

Where are the receptors for polar regulatory molecules located?

Back 65

In the plasma membrane. Polar regulatory molecules bind to receptors located in the plasma membrane.

Hint 65

Pg. 070

Front 66

Where are the receptors for nonpolar regulatory molecules located?

Back 66

Inside the target cells. "Nonpolar regulatory molecules bind to receptors located inside the target cells."

Hint 66

Pg. 070

Front 67

What are the cells called that respond to a particular regulatory molecule?

Back 67

Target cells

Hint 67

Pg. 070

Front 68

What are the types of regulatory molecules called that are released into the extracellular fluid by different tissue cells that belong to the same organ as the target cells?

Back 68

Paracrine Regulators

Hint 68

Pg. 070

Front 69

What are Paracrine Regulators?

Back 69

Regulatory molecules released into the extracellular fluid by different tissue cells and belong to the same organ as the target cells.

Hint 69

Pg. 070

Front 70

What is the epithelial lining of blood vessels called?

Back 70

Endothelium

Hint 70

Pg. 070

Front 71

What type of regulatory molecule is depicted in the following example? The epithelial lining of blood vessels releases a variety of a certain type of regulatory molecules that can stimulate the smooth muscle layer of the same vessel to either relax or contract.

Back 71

Paracrine Regulators

Hint 71

Pg. 070

Front 72

What are the types of regulatory molecules released by the functional connection of a neuron’s axon terminal?

Back 72

Neurotransmitters

Hint 72

Pg. 070

Front 73

What are Neurotransmitters?

Back 73

Types of regulatory molecules released by the functional connection of a neuron’s axon terminal.

Hint 73

Pg. 070

Front 74

What are the functional connections of axon terminals called?

Back 74

Synapses

Hint 74

Pg. 070

Front 75

What is the name of the other cell, a neuron’s axon terminal makes a functional connection with?

Back 75

Postsynaptic cell

Hint 75

Pg. 070

Front 76

What are some examples of postsynaptic cells?

Back 76

another Neuron, a Muscle cell, or a Gland cell.

Hint 76

Pg. 070

Front 77

What are the types of regulatory molecules that are secreted into the blood by endocrine glands called?

Back 77

Hormones

Hint 77

Pg. 070

Front 78

What are Hormones?

Back 78

Regulatory molecules secreted into the blood by endocrine glands.

Hint 78

Pg. 070

Front 79

True or False. The blood helps carries the regulatory molecules secreted into the blood by endocrine glands to only the target cells and does not expose any other cells in the body to it.

Back 79

False. The blood carries the hormones to every cell in the body, however only the target cells for a particular hormone can respond.

Hint 79

Pg. 070

Front 80

How are Receptor proteins like enzyme protein and membrane carrier proteins?

Back 80

They also have specificity.

Hint 80

Pg. 070

Front 81

Why is the specificity of receptor proteins important?

Back 81

It allows a given cell to respond in different ways to many different regulatory molecules.

Hint 81

Pg. 071

Front 82

True or False. A polar regulatory molecule can travel by dissolving in blood?

Back 82

True

Hint 82

Pg. 071

Front 83

True or False. In general a polar regulatory molecules enter directly into the target cell.

Back 83

False

Hint 83

Pg. 071

Front 84

When are “Second Messengers” required to be utilized to influence the activity of a target cell?

Back 84

When the regulatory molecule cannot enter into the cell. (Ex: Polar Regulatory Molecules)

Hint 84

Pg. 071

Front 85

What are some examples of polar regulatory molecules?

Back 85

The hormones Insulin
and
Epinephrine
and the neurotransmitter Acetlycholine.

Hint 85

Pg. 071

Front 86

What is the hormone Epinephrine also known as?

Back 86

Adrenalin

Hint 86

Pg. 071

Front 87

Why can nonpolar molecules easily pass through the plasma membrane?

Back 87

Because they are lipid soluble.

Hint 87

Pg. 071

Front 88

What class of regulatory molecules can activate specific genes and synthesize messenger RNA and the production of specific proteins?

Back 88

Nonpolar Regulatory Molecules

Hint 88

Pg. 071

Front 89

What are some examples of nonpolar regulatory molecules?

Back 89

The Hormone Thyroxine
and
Steroid Hormones produced by the gonads
(Estradiol, Progesterone and Testosterone).

Hint 89

Pg. 071

Front 90

What produces the hormone Thyroxine?

Back 90

The Thyroid Gland

Hint 90

Pg. 071