Membranes

Question 1

membrane asymmetry

Answer 1

the inside and outside of the plasma membrane are not the same

Question 2

why do phospholipid bilayers form

Answer 2

due to a hydrophobic tail and hydrophilic head (amphipathic)

Question 3

what are membranes influenced by

Answer 3

lipid type and concentration

Question 4

what does the fluid mosaic model show

Answer 4

that membranes move (are fluid)

Question 5

why does it matter that membranes are fluid

Answer 5

matters for proper function, adaptability, and homeostasis

Question 6

factors that influence membrane fluidity

Answer 6

temperature, structure and composition of phospholipids (kinks?), cholesterol levels

Question 7

structure of saturated hydrocarbon tails and affect on membrane

Answer 7

no double bonds meaning no kinks/bend, makes more viscous membrane

Question 8

structure of unsaturated hydrocarbon tail and effect on membrane

Answer 8

double bonds present meaning more kinks/bends, meaning more fluid

Question 9

what does it mean when phospholipids have longer tails

Answer 9

makes a more viscous (tighter bound) membrane

Question 10

importance of cholesterol in membranes

Answer 10

helps maintain proper membrane fluidity in response to temperature changes (fluidity buffers)

Question 11

function of membrane proteins

Answer 11

transporters, enzymes, signal transduction, cell surface attachment and recognition

Question 12

types of membrane proteins

Answer 12

integral membrane proteins and peripheral proteins

Question 13

where are peripheral membrane proteins located

Answer 13

on the surface of the plasma membrane

Question 14

where are integral membrane proteins found

Answer 14

on both sides going through the plasma membrane

Question 15

how can an integral membrane protein cross the membrane bilayer

Answer 15

stretches of non-polar amino acids

Question 16

types of transport across the membrane

Answer 16

passive, active, and endo/exocytosis

Question 17

difference between passive and active transport

Answer 17

passive- no energy required, moving with the concentration gradient
active- energy required, moving against concentration gradient

Question 18

types of passive transport

Answer 18

simple diffusion and facilitated diffusion

Question 19

simple difusion

Answer 19

things move through plasma membrane (bounce against each other) until they reach equilibrium

Question 20

what can go through membrane in simple diffusion

Answer 20

non-polar molecules and small uncharged polar molecules

Question 21

facilitated diffusion

Answer 21

membrane proteins form a channel to facilitate diffusion across the membrane

Question 22

is facilitated of simple diffusion faster

Answer 22

facilitated

Question 23

types of proteins

Answer 23

channel proteins, gated channel proteins, and carrier proteins

Question 24

which protein channel is made for large molecules

Answer 24

carrier proteins

Question 25

types of active transport

Answer 25

primary and secondary

Question 26

primary transport

Answer 26

uses ATP to move molecules against concentration gradient (often out of cell)

Question 27

secondary transport

Answer 27

uses electrochemical gradients as energy (acts like a seesaw with ions, as one goes down the other goes up and vice versa)

Question 28

what is symport

Answer 28

type of secondary active transport where the ions move in the same direction as the driving ion (both go in or out)

Question 29

what is antiport

Answer 29

secondary active transport where ions moves in direction opposite form the driving ion (one goes in other goes out)

Question 30

exocytosis

Answer 30

vesicle moves things to the outside of cell and exports them (kicks them out)

Question 31

bulk-phase endocytosis (pinocytosis)

Answer 31

vesicle imports water and other substances from outside the cell inside

Question 32

receptor mediated endocytosis

Answer 32

vesicle imports specific molecules as they attach to receptors

Question 33

phagocytosis

Answer 33

when the cytoplasm extends outwards to “eat” its prey

Question 34

what is osmosis

Answer 34

the regulation of water movement as the water

Question 35

in osmosis what passes through the membrane

Answer 35

water, solute cannot pass through

Question 36

where does water want to go in osmosis

Answer 36

moves to where the solute is (make it equal on both sides)

Question 37

what does hypo mean in osmosis (hypotonic)

Answer 37

less solute in the surrounding environment

Question 38

what does hyper mean in osmosis (hypertonic)

Answer 38

more solute in the surrounding environment

Question 39

signal transduction step 1

Answer 39

reception- binding of a signaling molecule to a receptor on the outside of cell

Question 40

signal transduction step 2

Answer 40

transduction- signal changed into form for the cellular response, often a signaling cascade

Question 41

signal transduction step 3

Answer 41

response- signal causes a specific cellular response depending on signaling molecule

Question 42

what is a kinase

Answer 42

an enzyme that adds phosphate (phosphorylates other proteins) using ATP