Chapter 5 - Membranes Flashcards Preview

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Flashcards in Chapter 5 - Membranes Deck (34):
1

Main component of cell membranes; phospholipids naturally associate inside with hydrophobic fatty acids oriented to inside and hydrophilic phosphate groups facing outward on both sides.

Phospholipid bilayer

2

Type of membrane protein that is permanently attached to the biological membrane. All transmembrane proteins are IMPs, but not all IMPs are transmembrane proteins. Comprise a significant fraction of the proteins encoded in an organism's genome.

Integral protein

3

Proteins that adhere only temporarily to the biological membrane with which they are associated. Attach to integral membrane proteins, or penetrate the peripheral regions of the lipid bilayer.

Peripheral protein

4

A type of membrane protein spanning the entirety of the biological membrane to which it is permanently attached. Span from one side of a membrane through to the other side of the membrane.

Transmembrane protein

5

Protein molecule modified withing the Golgi complex by having a short sugar chaing (polysaccharide) attached

glycoprotein

6

Lipid molecule modified within the Golgi complex by having a short sugar chain (polysaccharide) attached.

glycolipid

7

Carrier-assisted diffusion of molecules across a cellular membrane through specific channels from a region of higher concentration to lower concentration. Driven by concentration from gradient. Doesn't require ATP

facilitated diffusion

8

Movement of substances across cell's membrane without expenditure of energy

passive transport

9

Net movement of dissolved molecules or other particles from a region where they are more concentrated to another where they are less concentrated

diffusion

10

A transmembrane protein with a hydrophilic interior that provides an aqueous channel allowing diffusion of species that cannot cross the membrane. Usually allows passage of specific ions such as K+, Na+ or Ca2+

channel protein

11

A membrane protein that binds to a specific molecule that cannot cross the membrane and allows passage through the membrane

Carrier protein

12

Condition in which a membrane is permeable to some substances but not to others (allows some molecules to pass, but not others).

Selectively permeable

13

Pore-forming membrane proteins whose functions include establishing a resting membrane potential, shaping action potentials and other electrical signals by gating the flow of ions across the cell membrane, controlling the flow of ions across secretory and epithelial cells, and regulating cell volume.

Ion channel

14

Protein channels that only open under certain conditions.

Gated channel

15

Difference in electric potential between the interior and the exterior of a biological cell.

membrane potential

16

Diffusion of water across a selectively permeable membrane.

Osmosis

17

Solution with a higher concentration of solutes than the cell. Cell tends to lose water by osmosis.

Hypertonic

18

Solution with a lower concentration of solutes than the cell.

Hypotonic

19

Solution with same concentration of solutes as cell.

Isotonic

20

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

Aquaporin

21

Pressure inside a plant cell, resulting from osmotic intake of water. Presses cell membrane tightly against cell wall, making cell rigid.

Turgor pressure

22

Pumping of ind. ions or other molecules across cell membrane from region of lower conc. to one of higher conc. Requires ATP.

active transport

23

Carrier protein in a cell's membrane that transports only a single type of molecule or ion.

uniporter

24

Carrier protein in a cell's membrane that transports two molecules or ions in same direction across membrane.

symporter

25

Carrier protein in a cell's membrane that transports two molecules in opposite directions across membrane.

antiporter

26

Transmembrane channels engaged in active (ATP-driven ) transport of Na+, exchanging them for K+, where both ions are being moved against their respective concentration gradients; maintains the resting membrane potential of neurons and other cells

sodium-potassium pump

27

The linked, simultaneous transport of two substances across a cell membrane

coupled transport

28

Movement of macromolecules such as proteins or polysaccharides into or out of the cell. Exocytosis and endocytosis.

bulk transport

29

A type of bulk transport out of cells in which a vacuole fuses with the plasma membrane, discharging the vacuole's contents to the outside.

Exocytosis

30

The uptake of material into cells by inclusion within an invagination of the plasma membrane. Phagocytosis & pinocytosis.

Endocytosis

31

Endocytosis of a solid particle; the plasma membrane folds inward around the particle (which may be another cell) and engulfs it to form a vacuole.

Phagocytosis

32

The process of fluid uptake by endocytosis in a cell.

Pinocytosis

33

A protein located just inside the plasma membrane in eukaryotic cells, in indentations called...

Clathrin; clathrin- coated pits

34

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

receptor-mediated endocytosis