EXAM 2

Question 1

what is electronegativity

Answer 1

the ability of atoms to attract electrons

Question 2

what elements have the highest values of electronegativity

Answer 2

nitrogen and oxygen

Question 3

what are covalent bonds

Answer 3

link subunits into larger molecules

electron distribution is scared

Question 4

characteristics of polar bonds

Answer 4

unequal electron distribution

partial + or - charge

Question 5

characteristics of nonpolar bonds

Answer 5

equal electron distribution

neutral charge

Question 6

what are noncovalent bonds

Answer 6

turn macromolecules into macromolecular complexes
unequal electron distribution
opposite charges attract

Question 7

characteristics of ionic bonds

Answer 7

polar stable
unit charge
strength is changed by changing pH

Question 8

characteristics of hydrogen bonds

Answer 8

polar stable
partial unit
strength changes with temperature

Question 9

characteristics of van der waal’s

Answer 9

nonpolar transient
weak partial
strength changes with temperature

Question 10

many weak bonds between molecules create a:

Answer 10

strong interaction

Question 11

how do cells biosynthesize most macromolecules

Answer 11

by polymerization

Question 12

is cysteine polar or nonpolar

Answer 12

nonpolar

Question 13

what are motor proteins

Answer 13

allow subcellular/cell/tissue movement

Question 14

what are structural proteins

Answer 14

mechanical support

Question 15

what are enzyme complexes

Answer 15

localize enzymes of a pathway

Question 16

protein DNA interactions

Answer 16

regulation of gene expression

Question 17

protein RNA interactions

Answer 17

form translational complexes (ribosomes)

Question 18

monosaccharides

Answer 18

subunits

includes glucose and fructose

Question 19

polysaccharides

Answer 19

polymers

includes starch, glycogen, and cellulose

Question 20

what covalent bonds have high energy

Answer 20

C-O, C-H

Question 21

what bonds does the phosphodiester backbone create

Answer 21

ionic and hydrogen noncovalent bonds

Question 22

define amphipathic

Answer 22

possessing hydrophilic and hydrophobic properties

includes phospholipids and fatty acids

Question 23

characteristics of membranes

Answer 23

compartmentalize cellular functions and metabolites
liquid at higher temperatures with fewer van der Waals
biological living membranes must be liquid, like oil

Question 24

hydrophilic molecules

Answer 24

polar
attracts water
flat water droplet
“heads”

Question 25

hydrophobic molecules

Answer 25

nonpolar repels water beaded water droplet "tails"

Question 26

cholesterol

Answer 26

a 4-ring steroid structure with a hydrocarbon tail

Question 27

glycolipid

Answer 27

a sugar substitute for the polar head group and glycerol of the phospholipid

Question 28

galactolipid

Answer 28

only polar head group replaced (plants)

Question 29

hydrophobic effect

Answer 29

drives monolayer or bilayer membrane formation monolayer is formed at a water-oil interface a bilayer is formed in water or cytoplasm alone

Question 30

lipid bilayers

Answer 30

fold into spheres trapping water on the inside | strong hydrophobic effect

Question 31

examples of subcellular membranes

Answer 31

ER, golgi apparatus, mitochondria, chloroplast

Question 32

saturated fatty acids

Answer 32

maximum number of hydrogen atoms attached to the carbon-carbon chain 2 hydrogens per carbon is a fatty acid

Question 33

unsaturated fatty acids

Answer 33

a carbon carbon bond reduces the number of hydrogens, they interrupt van der Waals (dogleg)

Question 34

membranes at room temperature

Answer 34

saturated fatty acids are solid (butter) | unsaturated fatty acids are liquid (oil)

Question 35

membranes at 37 degrees C

Answer 35

saturated fatty acids are liquid | unsaturated fatty acids are liquid

Question 36

membranes at 4 degrees C

Answer 36

saturated fatty acids are solid | monounsaturated are partially solid (olive) polyunsaturated are liquid (canola)

Question 37

ectothermic

Answer 37

internal temperatures that vary with the ambient environment

Question 38

endothermic

Answer 38

constant internal temperatures

Question 39

small nonpolar molecules membrane diffusion

Answer 39

yes, includes O2 and N2

Question 40

small uncharged polar molecules membrane diffusion

Answer 40

some, includes H2O and ethanol

Question 41

larger uncharged polar molecules membrane diffusion

Answer 41

some but less, includes amino acids and glucose

Question 42

ions membrane diffusion

Answer 42

none, includes H+, Na+, K+

Question 43

function of transmembrane proteins

Answer 43

transport specific molecules across the membrane usually small that do not move freely they're highly selective for one type of molecule

Question 44

passive transport

Answer 44

needs no direct energy relies on a downhill gradient selective for an ion and has gated activity

Question 45

active transport

Answer 45

movement against a gradient requires energy (coupled, ATP, light) uses pumps for transport

Question 46

sodium pump

Answer 46

high Na+ and low K+ outside the cell low Na+ and high K+ inside the cell hydrolyzes ATP to ADP

Question 47

uniport

Answer 47

a passive transporter that moves only one type of molecule across the membrane

Question 48

coupled

Answer 48

active transporter that uses the gradient of one molecule to transport another molecule against the gradient

Question 49

symport

Answer 49

the movement of both molecules in the same direction

Question 50

antiport

Answer 50

movement of molecules in the opposite direction

Question 51

affect of electrical stimulation on action potential

Answer 51

slight depolarization, slightly opens the Na+ channel

Question 52

affect of Na+ channel opening

Answer 52

massive depolarization, closes the Na+ channel and opens the K+ channel

Question 53

affect of K+ channel opening

Answer 53

repolarization, closes K+ channel and activates pump

Question 54

affect of Na+ and K+ pump on

Answer 54

re-establish ion gradients, Na+ and K+ pumps are turned off

Question 55

intracellular transport

Answer 55

delivers specific proteins to specific places in the cell

Question 56

bulk delivery

Answer 56

directional movement of vesicles | out is secretory, in is endocytic

Question 57

individual delivery

Answer 57

organelles have different mechanisms for accepting specific proteins

Question 58

protein import into the ER

Answer 58

rough ER has membrane bound polyribosomes SRP receptor mediated synthesis/import start-stop transfer sequences for transmembrane proteins

Question 59

polyribosomes

Answer 59

many ribosomes bound to a single mRNA