Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Bio 111 > Cell Bio Quiz 2 > Flashcards

Cell Bio Quiz 2 Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

Phospholipids are ____________ which means that they are molecules that have both hydrophilic and hydrophobic regions.

A

amphipathic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

The region of a phospholipid molecule that is hydrophilic is characterized by

A

a phosphate containing group

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Phospholipids added to water automatically orient into

A

bilayers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Phospholipds, cholesterol, and glycolipids share which of the following characteristics? (choose all that apply–the characteristic must be present in all three types of molecules)

A

all can be found in biologic membranes

are amphipathic

have hydrocarbon tails

have hydrophilic regions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Individual phospholipid molecules are free to migrate laterally within one layer of the phospholipid bilayer.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Individual phospholipid molecules often spontaneously flip from one layer of the phospholipid bilayer to the other without the aid of a transporter.

A

False

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Phospholipids with shorter fatty acids tend to be more _______ than phospholipids with longer fatty acids.

A

Flexible

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Consider the phospholipids that compose the biological membranes in arctic fish as opposed to tropical fish. Which of the following is correct about these two groups.

A

the membranes of the arctic fish would contain more unsaturated fatty acids as compared to the membranes of the tropical fish

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

New membrane phospholipids are synthesized at:

A

the cytosolic leaflet of the endoplasmic reticulum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

___________ is a transporter that is responsible for the random flip flopping of membrane phospholipids at the endoplasmic reticulum.

A

Scramblase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Most biological membranes are symmetric, i.e., they have the same phospholipids, proteins, and glycolipids present in both layers of the bilayer.

A

False

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

___________ are integral membrane proteins that extend completely through both layers of the phospholipid bilayer.

A

transmembrane proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

____________ can be removed from the membrane only by disrupting the membrane with detergents.

A

integral membrane proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

The great majority of the membrane-spanning segments of transmembrane proteins extend through the bilayer in the conformation of

A

alpha helix

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Which of the following characterizes the transmembrane spanning region of a single pass polypeptide?

A

all of the side chains of the amino acids in the transmembrane spanning region are hydrophobic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

The PM of animal cells is reinforced by the presence of a meshwork of filamentous proteins known as the _________ and attached to the cytosolic layer of the PM.

A

cell cortex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Membrane proteins can concentrate in one specific region in a membrane known as a

A

membrane domain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Which of the following is a mechanism for limiting the migration of membrane proteins and creating membrane domains? (Choose all that apply)

A

Membrane proteins can be tethered to proteins of the extracellular matrix.

Membrane proteins can be tethered to membrane proteins of adjacent cells.

Membrane proteins may be tethered to proteins of the cell cortex.

Membrane proteins may be confined to one region of the membrane by tight junctions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

The ___________ is a “sugar coating” at the extracellular surface that is responsible for cell protection, lubrication, and cell to cell communication/recognition.

A

glycocalyx

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Which of the following can pass through the phospholipid bilayer of a biological membrane unassisted at a rate fast enough to be biologically relevant? (Choose all that apply)

A

small, nonpolar solutes

small uncharged, polar solutes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Which of the following is the major cation in the extracellular fluid.

A

Na+

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

The bulk (majority) of the intracellular fluid and the extracellular fluid is electrically neutral.

A

True

23
Q

Most living cells have a resting membrane potential that is ___________.

A

Negative

24
Q

Define a membrane potential.

A

The voltage difference across the membrane generated from electrical imbalances in the membrane

25
Q

Which of the following apply to passive membrane transporters? Choose all that apply.

A

they are composed of protein.

they participate in facilitated diffusion.

26
Q

Compare and contrast the three different categories of pumps: ATP-driven pumps, Gradient-driven pumps, Light-driven pumps.

A

All three pumps require energy, made of proteins, embedded in membranes, all moving substances against a concentration gradient

but all use different sources. For example, ATP-driven pumps use ATP for energy, while gradient-driven pumps use ion gradients, and light-driven pumps use light for energy. For ATP-driven pumps specifically, they provide energy to move solutes against their electrochemical gradient. They also have a Na+ and K+ ATPase pump. For gradient-driven pumps, the gradient in any solute across a membrane can be used to drive the active transport of a second molecule. It has a symport and antiport component. For light driven pumps, a photon of light provides energy for membrane protein to move a solute from an area of low to high concentration against gradient.

27
Q

Pumps are active transporters that:

A

transport solutes against an electrochemical gradient

28
Q

Regarding gradients across the plasma membrane of a typical animal cell at rest choose the correct answer from the drop down.

Na+ is more concentrated…

K+ is more concentrated….

Ca2+ is more concentrated…

A

Na+ is more concentrated outside the cell

K+ is more concentrated inside the cell

Ca2+ is more concentrated outside the cell

29
Q

Which of the following is true regarding the gradient-driven transport of glucose across the apical (luminal) membrane of epithelial cells lining the digestive tract? (Choose all that apply)

A

glucose is transported against its concentration gradient from the lumen of the digestive tract into the epithelial cell.

the transport of glucose into the epithelial cell from the lumen of the digestive tract is carried out by a symporter that is powered by a gradient in a driving ion.

As glucose moves into the cell at the apical/luminal membrane the symporter also moves Na+ against the Na+ electrochemical gradient out of the cell.

30
Q

Concerning the gradient-driven transport of glucose at the apical/luminal membrane of epithelial cells lining the digestive tract, which of the following would occur if the Na+-K+ ATPase pumps at the basolateral membrane were inhibited?

A

Decreased rate of glucose transport at the apical membrane.

31
Q

Plants cells, fungi, and bacteria typically rely on gradients of ________ to drive the import of sugars and amino acids.

A

H+

32
Q

Which of the following is a light-driven pump?

A

Bacteriorhodopsin

33
Q

Match each statement with either “ion channel” or “pump.”

allow ions to move down their electrochemical gradients across a membrane

A

ion channels

34
Q

Match each statement with either “ion channel” or “pump.”

passive membrane transport

A

ion channels

35
Q

Match each statement with either “ion channel” or “pump.”

move ions against their electrochemical gradients across a membrane

A

pump

36
Q

Match each statement with either “ion channel” or “pump.”

facilitated diffusion

A

ion channels

37
Q

Match each statement with either “ion channel” or “pump.”

active membrane transport

A

pump

38
Q

Match each statement with either “ion channel” or “pump.”

Na+ moved out of a typical animal cell

A

pump

39
Q

Compare and contrast leak ion channels and gated ion channels. Name three categories of gated ion channels.

A

Ion channels are highly selective and allow passive movement of specific ions down an electrochemical gradient. Leak ion channels are open most of the time regardless of conditions around the channel while gated channels are open only under specific conditions. Some of these gated channels are mechanically-gated, which open in response to physical forces that deform the membrane. Another one is ligand-gated, which open in response to the specific bind of extracellular chemicals. The third is voltage-gated, which open in response to a change in membrane potential.

40
Q

New proteins synthesized by free ribosomes in the cytosol that do not have a sorting signal

A

will remain in the cytosol

40
Q

Which of the following is not a member of the endomembrane system? (Choose all that are NOT part of the endomembrane system)

A

mitochondria

chloroplasts

41
Q

The endomembrane system is believed to have evolved when:

A

the Plasma membrane of a primitive archaea invaginated forming an envelope around the DNA and formed the ER.

41
Q

Use the table to determine the final destination of a polypeptide that contains the sequence, “lys-asp-glu-leu-COO-“?

A

ER

42
Q

Which organelles directly receive proteins from ribosomes in the cytosol without the protein having to go through some other organelle first. Choose all that apply.

A

nucleus

mitochondria

ER

43
Q

Which of the following describes the structure of a nuclear pore?

A

a complex of about 30 different proteins with unstructured regions extending into the pore.

44
Q

The specific sequence of amino acids that indicates that a polypeptide should enter the nucleus is called the:

A

nuclear localization signal (NLS)

45
Q

A nuclear import receptor binds to

A

the nuclear localization signal and escorts a protein across a nuclear pore.

46
Q

Which of the following statements apply to the mitochondria and chloroplasts. (Choose all that apply)

A

they both have a double membrane structure.

they evolved from prokaryotes that were engulfed by eukaryotes in a symbiotic relationship.

they both contain their own DNA.

new proteins enter directly from the cytosol through protein translocators.

47
Q

The import receptor protein located at the mitochondrial membrane: (choose all that apply)

A

binds the signal sequence of cytosolic polypeptides destined to enter the mitochondrial matrix.

is associated with a protein translocator in the outer membrane of the mitochondrial (TOM)

48
Q

New proteins that enter the ER

A

enter into the ER as they are being translated by a ribosome associated with the ER.

49
Q

The figure below depicts the events of protein translocation at the ER. Identify each of the numbered structures.

A

1) mRNA

2) Ribosome

3) ER signal sequence

4) Signal recognition particle (SRP)

5) SRP receptor

6) Protein translocator

50
Q

For single-pass transmembrane proteins synthesized by ribosomes associated with the ER there is (are) ______ hydrophobic stop translocation sequence(s).

A

one

51
Q

__________ is the process by which the PM invaginates to form a vesicle around some extracellular “cargo” which is then brought into the cell.

A

endocytosis

52
Q

Which of the following is a commonly studied coat protein that causes the formation of vesicles at the membrane?

A

clathrin

Bio 111 (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions