molecules - exam 1

Question 1

covalent bond

Answer 1

involves sharing of electron pairs between atoms

Question 2

nonpolar

Answer 2

share electrons equally

no charge

CC & CH bonds

Question 3

polar

Answer 3

don’t share electrons equally

partial charge

water soluable

Question 4

polar covalent bonds important in molecules

Answer 4

OH
NH
SH

Question 5

hydrogen bond

Answer 5

attraction of partial charges (positive & negative)

break easily – that’s why water is fluid

water can H bond to other polar molecules but not other H20

Question 6

why can salt dissolve in water & oil can’t

Answer 6

salt is polar - polar molecules are water soluble

oil is nonpolar - water can’t break down its bonds

Question 7

hydrolysis

Answer 7

water in, monomer out

using water to break a bond in a molecule

need hydrolytic enzymes

Question 8

dehydration synthesis

Answer 8

monomer in, water out

Question 9

monosaccharide

Answer 9

monomer

single subunit

Question 10

disaccharide

Answer 10

dimer

2 monomers

Question 11

polysaccharide

Answer 11

many monosaccharides

Question 12

oligosaccharide

Answer 12

carbohydrate comprised of a relatively small number of monosaccharides

Question 13

starch

Answer 13

function: energy storage in covalent bonds

found in plants

Question 14

glycogen

Answer 14

function: energy storage in muscle & liver cells

found in animals & fungi

Question 15

cellulose

Answer 15

function: structural

found in the cell wall of plants, helps them stay upright

Question 16

chitin

Answer 16

structural

Question 17

how can cows digest cellulose

Answer 17

they have a special bacteria that can break down cellulose & then the bacteria eats it

Question 18

primary structure

Answer 18

sequence of a chain of amino acids

amino end & carboxyl end

“2D”

Question 19

secondary structure

Answer 19

localized folding created by hydrogen bonding

interactions between R-groups

still “2D”

Question 20

tertiary structure

Answer 20

3D shape

interactions between r groups maintain structure

central carbons on polypeptide backbone
r groups bond via h bonds, ionic bonds, covalent bonds, hydrophobic exclusion – giving it curly shape

blob of curly ribbon

Question 21

chaperones

Answer 21

help proteins fold in the proper way (tertiary)

Question 22

quaternary structure

Answer 22

aggregation of 2 or more polypeptides

separate they don’t work, together they do

Question 23

substrate

Answer 23

what is going to be acted on by enzyme

Question 24

enzyme substrate complex

Answer 24

enzyme = active site

substrate (2 molecules bonded) enters enzyme

H2O added to reaction

enzyme breaks down bond & produces 2 products

Question 25

physical conditions affect enzyme function

Answer 25

temp or pH shifts

denaturation = unfolding – nonfunctional

Question 26

changes on protein structure & function if amino acid is changed

Answer 26

change in primary structure does not have to change everything, but it can

Question 27

what happens if you swap a hydrophobic amino acid for hydrophilic in primary structure

Answer 27

primary structure will be changed - completely different amino acid

will also change 2nd, 3rd, 4th structures (& maybe function) because the proteins will have to fold differently

Question 28

saturated fatty acid

Answer 28

animal fats

straight

no double bond

pack tightly, solid at room temp, less fluid

increases level of LDL

Question 29

unsaturated fatty acids

Answer 29

plant fats

double bond causes bending

loosely packed, liquid at room temp, more fluid

decrease in LDL, increase in HDL

Question 30

LDL

Answer 30

low density lipoprotein

carries cholesterol from liver to cells

“bad” cholesterol
you need some but a lot can clog ur arteries

Question 31

HDL

Answer 31

high density lipoprotein

more apo proteins

picks up extra cholesterol from cells
delivers to liver for disposal / recycling

“good” cholesterol

Question 32

cis vs trans fat

Answer 32

cis - unsaturated is best for you, bent
hydrogen & carbon on same side of double bond

then saturated

then trans unsaturated
hydrogens & carbons on opposite side of double bond
partially hydrogenated

Question 33

explain why phospholipids form bilayers while triglycerides form insoluble droplets

Answer 33

phosolipids - hydrophobic tails & hydrophilic heads, put tails together on inside & heads on outside

triglycerides - very hydrophobic