week 6

Question 1

Plasma Membrane

Answer 1

bio membrane that separates the internal contents of a cell from its external environment

Question 2

Leaflet

Answer 2

Half a phospholipid bilayer that faces a different region in the cell (asymmetrical)

Question 3

glycolysation

Answer 3

process of covalently attaching a carbohydrate to a protein or lipid

Question 4

glycolipid

Answer 4

a lipid with attached carbohydrate

Question 5

Glycoprotein

Answer 5

a protein with attached carbohydrate

Question 6

cell coat or glycocalyx

Answer 6

carbohydrate-rich zone on the cell surface that protects from mechanical and physical damage

Question 7

simple diffusion

Answer 7

without the aid of a transport protein (directly through the channel)

Question 8

facilitated diffusion

Answer 8

diffusion across a membrane with the aid of transport proteins (energetically favorable)

Question 9

passive transport

Answer 9

simple and facilitated diffusion

Question 10

active transport

Answer 10

low to high conc.
NOT energetically favorable
spends ATP to move molecule against concentration gradient

Question 11

hydrophobicity

Answer 11

a key determinant of how readily a small molecule can diffuse across the bilayer

Question 12

osmosis

Answer 12

movement of water across membranes in response to solute concentration gradients

Question 13

isotonic

Answer 13

solute concentration outside the cell is equal to the inside of the cell

Question 14

hypertonic

Answer 14

the solute concentration outside the cell is higher to the inside of the cell

Question 15

hypotonic

Answer 15

the solute outside the cell is less to the inside of the cell (think ‘HYPE’ for water)

Question 16

turgor pressure (opposite of osmosis)

Answer 16

generates osmotic pressure that stops the net flow of water in hypotonic environment

Question 17

transport proteins

Answer 17

channels, transporters

Question 18

channels

Answer 18

most are gated
transmembrane proteins that form a passageway for the facilitated diffusion of ions or molecules across the membrane

Question 19

transporters

Answer 19

membrane proteins that bind to a solute and undergo a conformational change that moves to the other side of the membrane

Question 20

gating mechanisms

Answer 20

ligand-gated channels
voltage-gated channels
mechanosensitive channels
non covalent binding of intracellular regulatory proteins or covalent attachment of a small molecule can also trigger opening

Question 21

active transport

Answer 21

movement of a solute across a membrane against its gradient, from a region of low concentration to higher concentration

Question 22

endocytosis

Answer 22

plasma membrane folds inward to form a vesicle that brings substances into the cell (end-enter)

Question 23

exocytosis

Answer 23

packages material inside the cell into vesicles that will be extracted into the extracellular environment (transport to plasma membrane and out of cell)