Membrane Transport

Question 1

solvent

Answer 1

dissolving medium
present in highest quantity
usually water

Question 2

solute

Answer 2

substances dissolved in solvent

Question 3

solute concentration

Answer 3

number of solute molecules in volume of solvent

Question 4

penetrating solutes

Answer 4

move through membrane

Question 5

non penetrating solutes

Answer 5

cannot move through membrane

Question 6

concentration gradient

Answer 6

solute concentration difference on either side of membrane

Question 7

passive transport

Answer 7

diffusion
movement from area of high solute concentration to area of low solute concentration due to kinetic energy of molecules
does not require energy

Question 8

simple diffusion

Answer 8

small, lipid soluble molecules pass through lipid portion of membrane
ex water (slowly), oxygen, carbon dioxide

Question 9

facilitated diffusion

Answer 9

protein helps it across membrane
small, water soluble molecules (glucose) require membrane carriers
follow gradient
carrier binds molecule and changes shape to move molecule across membrane
(pac man)

Question 10

osmosis

Answer 10

movement of water across semipermeable membrane
high water (low solute) concentration to low water (high solute) concentration

Question 11

tonicity

Answer 11

ability of a solution to cause a cell to gain or lose water

refers to a concentration of non penetrating solutes outside cell

Question 12

hypotonic

Answer 12

solute concentration lower outside cell than inside
water moves into cell
cell enlarges

Question 13

hypertonic

Answer 13

solute concentration higher outside cell than inside
water moves out of cell
cell shrinks

Question 14

isotonic

Answer 14

equal solute concentrations in and out of cell

equal water movement in and out

Question 15

filtration

Answer 15

movement of solutes through membrane along pressure gradient

ex: urine from blood

Question 16

active transport

Answer 16

materials move against concentration gradient from low concentration to high
requires energy and carrier proteins
moves one of more substances in one direction or in opposite directions
ex: sodium/ potassium pump

Question 17

group translocation

Answer 17

bulk transport in bacteria
phosphotransferase systen
requires ATP
cannot move back across membrane

Question 18

bulk transport

Answer 18

active transport in eukaryotes
requires ATP
materials packaged into vesicles that merge with membrane or form from membrane

Question 19

exocytosis

Answer 19

materials directed out of cell

Question 20

endocytosis

Answer 20

materials directed into cell

Question 21

phagocytosis

Answer 21

engulf substances outside cell
bring to inferior
ameoba, microphage

Question 22

enzyme

Answer 22

increase rate of chemical reaction
lower energy of activation
bring reactants close together and properly orient reactants
enzymes are unchanged after reaction

Question 23

energy of activation

Answer 23

amount of energy required for reaction to occur

Question 24

substrate

Answer 24

substance modified by enzyme

Question 25

active site

Answer 25

part of enzyme that binds to substrate

Question 26

product

Answer 26

result of enzyme reaction

Question 27

allosteric site

Answer 27

second binding site away from active site | binds inhibitors or activators

Question 28

5 types of enzyme reactions

Answer 28

1. functional group transfer 2. electron transfer 3. rearrangement 4. dehydration (condensation, synthesis) 5. hydrolysis reaction (cleavage, decomposition)

Question 29

functional group transfer

Answer 29

from 1 molecule to another | ADP + P = ATP

Question 30

electron transfer

Answer 30

from 1 compound to another | NADH

Question 31

rearrangement

Answer 31

of 1 compound into another | glucose into 2 pyruvates

Question 32

dehydration

Answer 32

forms large compounds from small compounds anabolic requires energy/ uses ATP removes water from reaction- forms metabolic water from reactants glucose + galactose = lactose + water

Question 33

hydrolysis reaction

Answer 33

splits large compounds into small compounds catabolic releases energy/ forms ATP uses water to form products, adds water to reaction lactose + water = glucose + galactose

Question 34

enzyme structure

Answer 34

globular proteins

Question 35

apoenzyme

Answer 35

protein part only

Question 36

cofactor and coenzyme

Answer 36

non protein structures required by some enzymes for function

Question 37

cofactor examples

Answer 37

ions, iron, zinc, calcium | inorganic molecules

Question 38

coenzyme examples

Answer 38

``` some vitamins niacin (NADH) riboflavin (FADH2) vitamin C organic molecules ```

Question 39

holoenzyme

Answer 39

active enzyme | all parts combined

Question 40

induced fit model

Answer 40

enzyme active site binds substrate enzyme/ substrate binding changes shape of active site to exactly fit substrate orients substrate so bonds can be broken or rearranged

Question 41

enzyme examples

Answer 41

maltase, lactase, sucrase, catalase

Question 42

catalase

Answer 42

neutralizes free radicals from hydrogen peroxide antioxidants production decreases with age composed of 4 protein subunits

Question 43

free radicals

Answer 43

atoms with unpaired elements generated by chemical reactions, radiation, tobacco smoke, air pollution may contribute to aging, cause some cancers

Question 44

inhibitors

Answer 44

denature enzymes (lose 3D shape of active site)

Question 45

inhibitor examples

Answer 45

temperature, pH, Na+

Question 46

temperature inhibitors

Answer 46

reaction rate increases with increasing temperature | rate decreases above optimum temperature

Question 47

pH

Answer 47

maximum reaction rate at optimum pH above or below decreases rate- denatures enzyme stomach- pH 2.0 small intestine- 8.0

Question 48

Na+

Answer 48

high or low Na+ in external environment disrupts hydrogen bonds holding 3-D shape

Question 49

competitive inhibitors

Answer 49

bind active site with a shape similar to substrate

Question 50

permanent competitive inhibitor

Answer 50

binds permanently to active site inactivates enzyme antibiotics (penicillin) bind bacterial enzymes

Question 51

temporary competitive inhibitor

Answer 51

temporarily binds active site | slows enzyme activity

Question 52

sulfanilamide

Answer 52

temporary competitive inhibitor blocks folic acid synthesis in bacteria similar to PABA

Question 53

carbon monoxide

Answer 53

temporary competitive inhibitor | competes with oxygen for hemoglobin

Question 54

non competitive inhibitors

Answer 54

bind allosteric site changing shape of active site

Question 55

temporary non competitive inhibitor

Answer 55

temporarily binds allosteric site

Question 56

reaction products

Answer 56

temporary non competitive inhibitor increasing product stops production decreasing product turns it back on

Question 57

permanent non competitive inhibitor

Answer 57

permanently binds allosteric site to inactivate enzyme | ex: cyanide

Question 58

negative feedback

Answer 58

excess final product inhibits first enzyme in pathway product controls own production prevents excess products or intermediates from accumulating does not waste substrate when product is not needed enzyme activity resumes as product level decreases

Question 59

ribozymes

Answer 59

non protein enzymes in eukaryotic cells and some viruses acts as catalyst, has active site, is not used up during reaction uses RNA as substrate functions as genetic material and catalytic enzyme