Brainscape's Knowledge GenomeTM

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


See full index

BIO 198-13 General BIO > Chapter 5: Membranes > Flashcards

Chapter 5: Membranes Flashcards

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

Membrane

A

also called plasma membrane, is found in all cells and separates the cell from the outside environment

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

The lipid layer forming the foundation of a cell’s membrane is a bilayer of ?

A

Phospholipid

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

Phospholipids include ___,

___, ___

A

glycerol phospholipids, sphingolipids, and sphingomyelin

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

Cell membranes are assembled from four components:

A

Phospholipid bilayer, Transmembrane proteins, Interior Protein Network, and Cell-Surface Markers

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

What is the function of the phospholipid bilayer?

A

Provides permeability barrier, matrix for proteins

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

What does spectrins do?

A

Determine the shape of the cell

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

What do Clathrins do?

A

Anchor certain proteins to specific sites, expecially on the exterior plasma

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

Transmembrane proteins

A

The proteins has a variety of functions like transportation and communication

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

Interior Protein Network

A

Membranes are structurally supported by intracellular proteins, reinforcing the shape

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

Cell-Surface Markers

A

Different cell type exhibit various glycoproteins + glycolipids on their surface acting as a cell identity marker

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

Why do phospholipids spontaneously form bilayers?

A

The amphipathic structure

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

What part of the phospholipid is hydrophilic?

A

the polar head group

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

What part of the phospholipid is hydrophobic?

A

the nonpolar hydrocarbon tails

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

Why is a lipid bilayer stable?

A

because water has an affinity for hydrogen bonding, and doesn’t stop.

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

What changes the degree of membrane fluidity?

A

the composition of the membrane itself

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

How does changes in the environment effect the plasma membrane of a single-celled organism?

A

Increasing temperature makes a membrane more fluid and decreasing makes it less fluid

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

What are the six key classes of membrane proteins?

A

Transporters, enzymes, cell-surface receptors, cell-surface identity markers, cell-to-cell adhesion proteins, attachments to the cytoskeleton, proteins that affect membrane structure

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

Proteins that affect membrane structure

A

Membranes tend to form spheres or sheets in aqueous solutions. Wedge-shaped proteins can cause membranes to bend allowing the formation of tubes and folded sheets.

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

Enzymes

A

Cells carry out many chemical reaction on the interior surface of the plasma membrane, using enzymes attached to the membrane.

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

Cell-to-cell adhesion proteins

A

Cells use specific proteins to glue themselves to one another. Some act forming temporary interactions and other more permanent bond.

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

How membrane proteins attach to the surface of membranes, how do they do this?

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

Transmembrane domain

A

Hydrophobic region of a transmembrane protein that anchors it in the membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Passive transport

A

The movement of substances across a cell’s membrane without the expenditure of energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Diffusion

A

A net movement of dissolved molecule or other particles from a region where they are more concentrated to a region where they are less concentrated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Facilitated Diffusion

A

The diffusion of molecules or ions through carrier proteins or ion channels, which require a concentration gradient but no energy required.

26
Q

Channel protein

A

A transmembrane protein with a hydrophilic interior that provides an aqueous channel allowing diffusion of species that can not cross the membrane.

27
Q

What types of ions use a channel protein?

A

K+, Na+, or Ca2+

28
Q

Carrier Protein

A

A membrane protein that binds to a specific molecule that can not cross the membrane and allows passage through the membrane.

29
Q

Ion channel

A

Membrane proteins that allow the passage of ions through a phospholipid bilayer used specific for a single ion, and may be found in the plasma membrane or in internal membrane.

30
Q

Three conditions that determine the direction of net movement of the ions include:

A
  • relative concentration on either side of membrane
  • voltage difference across the membrane
    the state of the gate (opened or closed)
31
Q

How do water molecules interact with dissolved solutes?

A

They form hydration shells around the charged solute molecule

32
Q

Osmosis

A

The diffusion of water across a selectively permeable membrane

33
Q

If two solutions have unequal osmotic concentrations, the solution with the higher concentration is

A

Hypertonic

34
Q

the solution with the lower concentration is

A

Hypotonic

35
Q

When two solutions have the same osmotic concentration, the solutions are

A

Isotonic

36
Q

Aquaporin

A

A membrane channel that allows water to cross the membrane more easily than by diffusion through the membrane.

37
Q

Aquaporins fall into two general categories including:

A

those that are specifically for only water and those that are allow other small hydrophilic molecules

38
Q

Osmotic Pressure

A

The potential pressure developed by a solution separated from pure water by a differentially permeable membrane.
- Higher the solute concentration = higher osmotic pressure

39
Q

Extrusion

A

Some single-celled eukaryotes like protist, use organelles called contractile vacuoles to remove water

40
Q

Isosmotic Regulation

A

Some organisms that live in the ocean adjust their internal concentration of solutes to match that of the surrounding seawater

41
Q

Turgor

A

Most plant cells are hypertonic to their environment, contain high concentration of solutes in their central vacuoles. This results in hydrostatic pressure, known as turgor pressure, where the plasma membrane presses against the interior of the cell making the cell rigid

42
Q

Active Transport

A

The pumping of ions and other molecules across a cellular membrane from a region of lower concentration to a higher concentration; this transport requiring energy

43
Q

Uniporters

A

Carrier proteins that transport a single type of molecule

44
Q

Symporter

A

A carrier protein in a cell’s membrane that transports two molecules or ions in the same direction across the membrane

45
Q

Antiporter

A

A carrier protein in a cell’s membrane that transports two molecules in opposite directions across the membrane

46
Q

Sodium-Potassium Pump

A

Transmembrane channels engaged in the active transport of Na+, exchanging them for K+, where both ions are being moved against their concentration gradients

47
Q

Bulk transport

A

Transport of large amounts of substances across plasma membrane by utilizing energy

48
Q

What are the two processes involved in bulk transport?

A

endocytosis, and exocytosis

49
Q

Endocytosis

A

The uptake of materials into cells by inclusion within an invagination of the plasma membrane; the uptake of solid material in phagocytosis and that of dissolved material in pinocytosis

50
Q

What are three types of endocytosis?

A

phagocytosis, pinocytosis, and receptor-mediated endocytosis

51
Q

Phagocytosis

A

Endocytosis of a solid particle

52
Q

Pinocytosis

A

The process of fluid uptake by endocytosis in a cell

53
Q

Receptor-mediated endocytosis

A

Process by which specific macromolecules are transported into eukaryotic cells at clathrin-coated pits, after binding to specific cell-surface receptors

54
Q

Exocytosis

A

The discharge of material from vesicles at the cell surface

55
Q

Why is exocytosis important in plant cells?

A

It’s a mean of exporting the materials needed to construct the cell wall through the plasma membrane

56
Q

How is exocytosis used in animal cells?

A

It provides a mechanism for secreting many hormones, neurotransmitters, digestive enzymes, and other substances

57
Q

Coupled Transport

A

Molecules are transported across a membrane against their concentration gradients by the cotransport of sodium ions or protons down their concentration gradients

58
Q

The fluid mosaic model of the membrane describes the membrane as

A

made of proteins and lipids that can freely move

59
Q

How are active transport and coupled transport related?

A

Coupled transport uses the concentration gradient established by active transport

60
Q

What variable(s) influence(s) whether a nonpolar molecule can move across a membrane by passive diffusion?

A

The difference in concentration of the molecule across the membrane

BIO 198-13 General BIO (4 decks)

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