AP BIO CH 7

0.0(0)
studied byStudied by 1 person
learnLearn
examPractice Test
spaced repetitionSpaced Repetition
heart puzzleMatch
flashcardsFlashcards
Card Sorting

1/36

Study Analytics
Name
Mastery
Learn
Test
Matching
Spaced

No study sessions yet.

37 Terms

1
New cards
active transport
The movement of a substance across a biological membrane against its concentration or electrochemical gradient with the help of energy input and specific transport proteins.
2
New cards
amphipathic molecule
A molecule that has both a hydrophilic region and a hydrophobic region.
3
New cards
aquaporin
A transport protein in the plasma membrane of a plant or animal cell that specifically facilitates the diffusion of water across the membrane (osmosis).
4
New cards
concentration gradient
An increase or decrease in the density of a chemical substance in an area. Cells often maintain concentration gradients of ions across their membranes. When a gradient exists, the ions or other chemical substances involved tend to move from where they are more concentrated to where they are less concentrated.
5
New cards
cotransport
The coupling of the downhilldiffusion of one substance to the uphilltransport of another against its own concentration gradient.
6
New cards
diffusion
The spontaneous tendency of a substance to move down its concentration gradient from a more concentrated to a less concentrated area.
7
New cards
electrochemical gradient
The diffusion gradient of an ion, representing a type of potential energy that accounts for both the concentration difference of the ion across a membrane and its tendency to move relative to the membrane potential.
8
New cards
electrogenic pump
An ion transport protein that generates voltage across a membrane.
9
New cards
endocytosis
The cellular uptake of macromolecules and particulate substances by localized regions of the plasma membrane that surround the substance and pinch off to form an intracellular vesicle.
10
New cards
exocytosis
The cellular secretion of macromolecules by the fusion of vesicles with the plasma membrane.
11
New cards
facilitated diffusion
The spontaneous passage of molecules and ions, bound to specific carrier proteins, across a biological membrane down their concentration gradients.
12
New cards
flaccid
Limp. A walled cell is flaccid in surroundings where there is no tendency for water to enter.
13
New cards
fluid mosaic model
The currently accepted model of cell membrane structure, which envisions the membrane as a mosaic of individually inserted protein molecules drifting laterally in a fluid bilayer of phospholipids.
14
New cards
gated channel
A protein channel in a cell membrane that opens or closes in response to a particular stimulus.
15
New cards
glycolipid
A lipid covalently attached to a carbohydrate.
16
New cards
glycoprotein
A protein covalently attached to a carbohydrate.
17
New cards
hypertonic
In comparing two solutions, referring to the one with a greater solute concentration.
18
New cards
hypotonic
In comparing two solutions, referring to the one with a lower solute concentration.
19
New cards
integral protein
Typically a transmembrane protein with hydrophobic regions that completely spans the hydrophobic interior of the membrane.
20
New cards
ion channel
Protein channel in a cell membrane that allows passage of a specific ion down its concentration gradient.
21
New cards
isotonic
Having the same solute concentration as another solution.
22
New cards
ligand
A molecule that binds specifically to a receptor site of another molecule.
23
New cards
membrane potential
The charge difference between a cell's cytoplasm and the extracellular fluid, due to the differential distribution of ions. Membrane potential affects the activity of excitable cells and the transmembrane movement of all charged substances.
24
New cards
osmoregulation
The regulation of solute and water concentrations in body fluids by organisms living in hyperosmotic, hypoosmotic, and terrestrial environments.
25
New cards
osmosis
The diffusion of water across a selectively permeable membrane.
26
New cards
passive transport
The diffusion of a substance across a biological membrane.
27
New cards
peripheral protein
A protein appendage loosely bound to the surface of a membrane and not embedded in the lipid bilayer.
28
New cards
phagocytosis
A type of endocytosis involving large, particulate substances, accomplished mainly by macrophages, neutrophils, and dendritic cells.
29
New cards
pinocytosis
A type of endocytosis in which the cell ingests extracellular fluid and its dissolved solutes.
30
New cards
plasmolysis
A phenomenon in walled cells in which the cytoplasm shrivels and the plasma membrane pulls away from the cell wall when the cell loses water to a hypertonic environment.
31
New cards
proton pump
An active transport mechanism in cell membranes that uses ATP to force hydrogen ions out of a cell, generating a membrane potential in the process.
32
New cards
receptor-mediated endocytosis
The movement of specific molecules into a cell by the inward budding of membranous vesicles containing proteins with receptor sites specific to the molecules being taken in; enables a cell to acquire bulk quantities of specific substances.
33
New cards
selective permeability
A property of biological membranes that allows some substances to cross more easily than others.
34
New cards
sodium-potassium pump
A special transport protein in the plasma membrane of animal cells that transports sodium out of the cell and potassium into the cell against their concentration gradients.
35
New cards
tonicity
The ability of a solution to cause a cell within it to gain or lose water.
36
New cards
transport protein
A transmembrane protein that helps a certain substance or class of closely related substances to cross the membrane.
37
New cards
turgid
Very firm. A walled cell become turgid if it has a greater solute concentration than its surroundings, resulting in entry of water.