chapter 1

Question 1

what is a monomer

Answer 1

a smaller unit from which larger molecules are made

Question 2

compare structures of cellulose and glycogen

Answer 2

-cellulose is made up of B-glucose / glycogen is made up of A-glucose
-cellulose molecule has straight chains / glycogen is branched and coiled
-glycogen has 1-4 / 1-6 glyosidic bonds and cellulose has only 1-4 glyosidic bonds

Question 3

how are starch molecules adapted to their function

Answer 3

-insoluble - don’t affect water potential
-helical - compact more in the same space
-large molecules- cannot leave the cell

Question 4

how are cellulose molecules adapted for their function

Answer 4

-long and straight chains
-becomes linked together by many hydrogen bonds to form fibrils
-provide strength (to cell wall)

Question 5

how glycogen act as a source of energy

Answer 5

hydrolyzed to glucose, glucose is used in respiration

Question 6

features of starch that make it good storage molecule

Answer 6

-insoluble in water, don’t change water potential
- branched, molecule is compact
-polymer of A-glucose so provides glucose for respiration
-branched faster enzyme action
- large molecules so it can’t cross the cell membrane

Question 7

test for lipids

Answer 7

EMULSION TEST
- add ethanol
-add distill water
-add sample
white emulsion formed

Question 8

test for proteins

Answer 8

-add biuret reagent in the sample
- solution changes from blue to purple

Question 9

polymer

Answer 9

made from lots of monomers bonded together

Question 10

3 monomers example

Answer 10

-glucose
-amino acid
-nucleotide

Question 11

condensation reaction

Answer 11

joining two molecules together by removing water

Question 12

hydrolysis reaction

Answer 12

slitting apart molecules through addition of water

Question 13

monosaccharide

Answer 13

monomers of carbohydrates

Question 14

how are disaccharides formed

Answer 14

• made from 2 monosaccharides
• joined together by glyosidic bond
• formed via condensation reaction

Question 15

word equation for formation of disaccharide

Answer 15

• glucose + glucose —-> maltose +water
• .glucose + fructose —–> sucrose + water
• glucose + galactose ——> lactose + water

Question 16

test for reducing sugar

Answer 16

• add benedict’s reagent and heat
• solution turns from blue to orange/ brick red

Question 17

test for non-reducing sugar

Answer 17

-following a negative benedict’s test
- add acid and boil ( acid hydrolysis - hydrolysis glyosidic bond
- cool solution then add alkali to neutralize
- add benedicts reagent and heat
- solutions turn from blue to green-red

Question 18

test for starch

Answer 18

-add iodine
- solution turns from orange to blue/black

Question 19

triglycerides

Answer 19

1 glycerol bonded to 3 fatty acids, they are held by an ester bond

Question 20

saturated fatty acid

Answer 20

hydrocarbon chains has only single bonds between carbons

Question 21

unsaturated fatty acid

Answer 21

hydrocarbon chains consists of at least one double bond between carbons

Question 22

phospholipids

Answer 22

has 2 fatty acids chains a glycerol and a phosphate group

Question 23

reaction that joins amino acids together

Answer 23

condensation reaction, peptide bonds form between OH of carboxyl group and a H from an amine group of another amino acid

Question 24

primary structure of protein

Answer 24

the sequence of amino acids in a polypeptide chain

Question 25

secondary structure

Answer 25

amino acid sequence coil into alpha helix or beta pleated sheets

Question 26

tertiary structure

Answer 26

further folding of the secondary structure
forms a unique 3D shape
held in place by ionic hydrogen and disulfide bonds

Question 27

quaternary structure

Answer 27

there’s more than 1 polypeptide chain in the protein

Question 28

induced-fit model

Answer 28

the enzyme’s active site and substrate are not perfectly complementary in shape initially

the enzyme’s active site in induced or slightly changes shape, to molded around the substrate, once the substrate binds to the active site

Question 29

enzymes

Answer 29

the active site is unique in shape due to the specific folding and bonding in the tertiary structure of the protein. Due to this specific active site, enzyme can only attach to substrate that are complementary in shape. The enzyme and substrate then form an enzyme-substrate complex

Question 30

factors that effect the rate of enzyme-controlled reactions

Answer 30

• temperature
• pH
• substrate concentration
• Enzyme concentration
• inhibitors

Question 31

how does temperature affects the rate of enzyme reactions

Answer 31

at lower temperatures as the temperature increases so does the rate of reaction

beyond the optimum temperature the rate of reaction rapidly decreases

Question 32

affect of pH on enzyme action

Answer 32

low pH: there will be an excess of H+ ions, this can break the ionic and hydrogen bonds holding tertiary structure causes active site to change shape

high pH: there will be an excess of OH- ions released which can break hydrogen and ionic bonds changes shape of active site

Question 33

how does enzyme concentration affects enzyme reaction

Answer 33

at a low concentration enzyme concentration is the limiting factor
when more enzyme is added rate increases
more available active site
more successful collisions

Question 34

how substrate concentration effects enzyme reactions

Answer 34

at low concentration substrate is limiting factor
more substrate is added the rate increases there will be more successful collisions

Question 35

competitive inhibitors

Answer 35

same shape as the substrate and can bind to the active site
prevents the substrate t bind
no enzyme-substrate complex formed
no reaction can happen

Question 36

non-competitive inhibitor

Answer 36

binds to the enzyme away from the active site
in the allosteric site
causes the active site to change shape
substrate can’t bind to substrate