cc3 - cell membranes + transport

Question 1

principle components of plasma membrane

Answer 1

intracellular + extracellular proteins
glycoproteins
phospholipids
cholesterol

Question 2

fluid mosaic model

Answer 2

membrane structure as a sea of mobile phospholipids studded with various proteins

Question 3

intrinsic proteins

Answer 3

proteins found in phospholipid bilayer
includes channel + carrier proteins

Question 4

functions of intrinsic proteins

Answer 4

structural support
carry water soluble molecules across phospholipid bilayer
form ions channels to enable active transprt

Question 5

extrinsic proteins

Answer 5

proteins found at edge of phospholipid bilayer

Question 6

functions of extrinsic proteins

Answer 6

receptors
act as antigens, enabling cell recognition
help cells adhere to each other

Question 7

glycocalyx

Answer 7

glycoprotein + glycolipid coating surrounding the cell e of some cell

Question 8

factors affecting permeability of plasma membrane

Answer 8

temperature
organic solvents
pH

Question 9

how temp affects permeability of plasma membrane

Answer 9

as temp increases, phospholipids have more kinetic energy + move more, increasing fluidity + permeability of plasma membrane

Question 10

what happens to plasma membrane if temp becomes to high

Answer 10

channel + carrier proteins become denatured, affecting membrane permeability
cell will eventually break down completely

Question 11

how organic solvents affect permeability of plasma membrane

Answer 11

dissolve membranes, disrupting cells
increases fluidity + permeability of plasma membrane

Question 12

diffusion

Answer 12

passive movement of small non polar lipid soluble molecules from area of high concentration to area of low concentration

Question 13

factors affecting rate of diffusion

Answer 13

temperature
steepness of concentration gradient
size of molecule
diffusion distance
surface area

Question 14

osmosis

Answer 14

passive diffusion of water molecules from region of high water potential to region of lower water potential (down water potential gradient) through a selectively permeable membrane

Question 15

water potential

Answer 15

measure of tendency of water molecules to move from one area to another

Question 16

incipient plasmolysis

Answer 16

effect produced by placing plant cell in an isotonic solution
cause cell membrane to pull away from cell wall in some area
cell is neither plasmolysed nor turgid

Question 17

facilitated diffusion

Answer 17

net movement of substances from high concentration to lower concentration (down concentration gradient) through transport proteins without use of energy

Question 18

example of facilitated diffusion

Answer 18

co-transport

Question 19

active transport

Answer 19

movement of substances from low concentration to higher concentration (against concentration gradient) through carrier proteins with use of energy in form of ATP

Question 20

how cyanide affects active transport

Answer 20

inhibits cytochrome oxidase, stopping production of ATP
prevents active transport

Question 21

2 mechanisms of bulk transport

Answer 21

endocytosis
exocytosis

Question 22

endocytosis

Answer 22

bulk uptake of substance into cell by invagination of membrane to form a vesicle
uses energy in form of ATP

Question 23

2 types of endocytosis

Answer 23

phagocyctosis
pinocytosis

Question 24

pinocyctosis

Answer 24

bulk uptake of liquids into cell using energy in form of ATP

Question 25

phagocytosis

Answer 25

bulk uptake of solids into cell using energy in form of ATP

Question 26

exocytosis

Answer 26

bulk transport of substances out of a cell via a vesicle that fuses with the plasma membrane uses energy in form ATP