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Flashcards in Chapter 3.3 Deck (62)
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1
Q

What is Diffusion?

A

the tendency of atoms, molecules, and ions in a liquid or air to move from areas of higher concentrations to areas of lower concentrations

2
Q

Concentration Gradient

A

A difference of concentration between two different areas

3
Q

Diffusional Equilibrium

A

Random movements continue, but there is no further net movement, and the concentration of a substance remains uniform through the solution

4
Q

Diffusion can only occur if

A

the cell membrane is permeable to that substance and a concentration gradient exists such that the substances is at a higher concentration on one side of the membrane or the other

5
Q

What smalled solutes are not lipid-soluble?

A

Ions of sodium, potassium, and chloride, may diffuse through specific protein channels in the membrane

6
Q

Facilitated Diffusion

A

This type of movement follows the concentration gradient, and because it requires membrane proteins it is considered to be “helped”

7
Q

Facilitated diffusion can move

A

molecules only down a concentration gradient

8
Q

What is Osmosis?

A

The movement of water across a selectively permeable membrane into a compartment containing solute that cannot cross that membrane.

9
Q

One can think of impermeant solute as

A

solute that is “trapped” on one side of the membrane.

10
Q

Osmotic Pressure

A

This ability of osmosis to generate enough pressure to lift a volume of water

11
Q

Isotonic

A

Any solution that has the same osmotic pressure as body fluids

12
Q

Hypertonic

A

Solutions that have a higher osmotic pressure than body fluids.

13
Q

What happens if cells are put in a Hypertonic solution?

A

Water moves by osmosis out of the cell into the surrounding solution, and the cell shrinks

14
Q

What happens if cells are put in a Hypotonic solution?

A

Has lower osmotic pressure than body fluids, gain water by osmosis and swell.

15
Q

Filtration

A

Another process that foces molecules through membranes by exerting pressure.

16
Q

What is Active Transport?

A

Movement against a concentration gradient. It requires energy, which comes from ATP molecules that split during the process of cellular metabolism.

17
Q

What are “pumps”

A

Because these carrier transport substances from regions of lower concentration to regions of higher concentration

18
Q

Endocytosis

A

conveys molecules or other particles too large to enter a cell by other means to the inside in a vesicle that forms from budding inward of a section of the cell membrane

19
Q

Pinocytosis

A

Cells take in tiny droplets of liquid from their surroundings, as a small portion of cell membrane indents.

20
Q

Phagocyotsis

A

Similar to pinocytosis, but the cell takes in solids rather than liquids.

21
Q

Phagocytes

A

They can take in solid particles such as bacteria and cellular debris. When a particles outside the cell touches the cell membrane, a portion of the membrane projects outward and draws it inside the cell

22
Q

What is a Phagosome

A

The part of the cell’s membrane surrounding the particle then detaches the cell’s surface, forming this vesicle

23
Q

What is a Phagolysosome?

A

When a lysosome joins a phagosome, it forms this

24
Q

What is Receptor-Mediated Endocytosis

A

Moves very specific types of particles into the cell. It uses protein molecules that extend though the cell membrane and are exposed on its outer surface.

25
Q

What are ligands?

A

Molecules that bind to specific receptors

26
Q

How do cholesterol molecules enter the cell?

A

Through receptor-mediated endocytosis.

27
Q

Cholesterol molecules synthesized in liver cells are packaged into

A

large spheerical particles called low-density lipoproteins (LDL)

28
Q

What is Exocytosis?

A

When the packaging of substances made in the cell into vesicles that fuse with the cell memrbane and are released outside the cell.

29
Q

What is Transcytosis?

A

Combines endocytosis and exocytosis to selectively and rapidly transport a substsance or particles from one end of a cell to the other. Moves susbtances across barriers formed by tightly connected cells

30
Q

What are exosomes?

A

These vesicles bud from one cell and then encounter, merge with, and enter other cells.

31
Q

What do exosomes carry?

A

They carry lipids, proteins, and RNA. Remove debris, transport immune system molecules from cell to cell, and provide a vast communication network among cells

32
Q

Diffusion Characteristics

A

Molecules move through the phospholipid bilayer from regions of higher concentration towards regiions of lower concentration

33
Q

Diffusion source of energy

A

Molecular Motion

34
Q

Diffusion Example

A

Exchange of oxygen and carbon dioxide in the lungs

35
Q

Facilitated Diffusion Example

A

Ions move through channels, or molecules move by carrier proteins, across the membrane form a region of higher concentration toward one of lower concentration

36
Q

Facilitated Diffusion Source of Energy

A

Molecular Motion

37
Q

Facilitated Diffusion Examples

A

Movement of glucose through a cell membrane

38
Q

Osmosis Characteristics

A

Water molecules mvoe through a selectively permeable membrane thoward the solution with more impermeant solute (greater osmotic pressure)

39
Q

Osmosis SOurce of Energy

A

Molecular Motion

40
Q

Osmosis Examples

A

Distilled water entering a cell

41
Q

Filtration Characteristics

A

Smaller molecules are forced through porous membranes from regions of higher pressure to regions of lower pressure

42
Q

Filtration Source of Energy

A

Hydrostatic Pressure

43
Q

Filtration Examples

A

Molecules leaving blood capillaries

44
Q

Active Transport Characteristics

A

Carrier molecules transport molecules or ions through membranes from regions of lower conentration toward regions of higher concentrations

45
Q

Active Transport SOurce of Energy

A

ATP

46
Q

Active Transport Examples

A

Movement of various iosn and amino acids through membranes

47
Q

Pinocytosis Characteristics

A

Membrane engulfs droplets containing dissolved molecules from surroundings

48
Q

Pinocytosis Source of Energy

A

ATP

49
Q

Pinocyotsis Examples

A

Uptake of water and solutes by all body cells

50
Q

Phagocytosis Charcteristics

A

Membrane engulfs solid particles from surroundings

51
Q

Phagocytosis Source of Energy

A

ATP

52
Q

Phagocytosis Examples

A

White blood cell engulfing bacterial cell

53
Q

Receptor-Mediated Endocytosis Characteristics

A

Membrane engulfs selected molecules combined with receptor proteins

54
Q

Receptor-Mediated Endocytosis Source of Energy

A

ATP

55
Q

Receptor-Mediated Endocytosis Exxamples

A

Cell removing cholesterol-containing LDL particles from its surroundings

56
Q

Exocytosis Characteristics

A

Vesicles fuse with membrane and release contents outside of cell

57
Q

Exocytosis Source of Energy

A

ATP

58
Q

Exocytosis Examples

A

Protein secretion, neurotransmitter release

59
Q

Transcytosis Characteristics

A

Receptor-mediated endocytosis and exocytosis move particles through (into and out of) a cell

60
Q

Transcytosis Source of Energy

A

ATP

61
Q

Transcytosis Examples

A

HIV Crossing A Cell LAyer

62
Q

Three Types of Endocytosis

A

Pinocytosis
Phagocytosis
Receptor-Mediated Endocytosis