biological molecules

Question 1

whats a monomer and give 3 examples

Answer 1

the smaller repeated units which larger molecules are made
examples are monosaccharides amino acids and nucleotides

Question 2

whats a ploymer and give 3 examples

Answer 2

are molecules made from a large number of monomers joined together
examples are starch protein and dna

Question 3

whats a condensation reaction

Answer 3

it joins two molecules together with the formation of a chemical bond and involves the elimination of a molecule of water.

Question 4

what a hydrolysis reaction

Answer 4

breaks a chemical bond between two molecules and involves the use of a water molecule

Question 5

what the difference between a chemical bond and an intermolecular force

Answer 5

a chemical bond is a strong,lasting attraction between atoms within a molecule, whereas an intermolecular force is a weaker attraction between molecules.

Question 6

whats a monosaccharide and give expamples

Answer 6

its the monomers from with larger carbohydrates are made.
examples are glucose, fructose and galactose

Question 7

how to form a disaccharide

Answer 7

by a condensation reaction of two monosaccharides. this forms a glycosidic bond.

Question 8

examples of disaccharide and how they are formed

Answer 8

glucose + glucose = maltose + water
glucose + fructose = sucrose + water
glucose + galactose = lactose + water

Question 9

whats an isomer

Answer 9

when two molecules have the same chemical formula but a different arrangement of atoms.

Question 10

glucoses two isomers

Answer 10

a-glucose which has oh at the bottom
b-glucose which has oh at the top

Question 11

how are polysaccharides formed and examples

Answer 11

polysaccharides are formed by the condensation of many glucose units.

glycogen and starch are formed by condensation of a-glucose

cellulose are formed by the condensation of b-glucose

Question 12

formula for monosaccharides and examples

Answer 12

(CH2O)n
n is number of carbons

glucose fructose and galactose are hexose sugar
ribose and deoxyribose are pentose.

they have different structures ( ring, ring simplified, straight chain)

Question 13

test for starch

Answer 13

add iodine if it goes blue black then. its present

Question 14

test for reducing sugar

Answer 14

heat with bendict solution
if it goes brick red then its present but it can be semi-quantitative. so can be yellow or orange

Question 15

test for non reducing sugar

Answer 15

heat with Benedict solution and there will be no colour change. boil with hydrochloric acid then add sodium hydrogen carbonate then heat with Benedict solution and it goes brick red then its present. the only non reducing sugar is sucrose

Question 16

starch

Answer 16

is a polysaccharide made from a-glucose
There are both unbranched and branched chains.
the unbranched has coils so is compact and stores a lot. they have 1-4 glycosidic bond and hydrogen bonds within the coil.
the branched chains have both 1-4 and 1-6 glycosidic bonds between the monomers. it has a large surface area (branches) allowing more enzymes to act upon it. starch is insoluble so water doesn’t move into it and doesn’t affect the water potential in the cell. its also large so cannot diffuse out of the cell membrane.

Question 17

cellulose

Answer 17

is a polysaccharide made form b-glucose.
its made of straight unbranched parallel chains.
it has 1-4 glycosidic bonds. it has hydrogen bonds form between monomers. many hydrogen bonds make it rigid and have strength.
it forms microfibrils and fibrils so has additional strength.

Question 18

glycogen

Answer 18

its a polysaccharide made form a- glucose. its branched and has both 1-4 and 1-6 glycosidic bonds.
large so doesn’t diffuse into cell membrane. insoluble so doesn’t affect water potential. coiled so is compact

Question 19

lipids

Answer 19

its not a polymer because it doesn’t have repeated monomer.
lipid has a higher H-O ratio than carbohydrates.
there is two lipids: triglycerides and phospholipids.

Question 20

triglycerides

Answer 20

it has 3 fatty acids and one glycerol. they are joined together by condensation reaction forming ester bonds and 3 water molecules. The R group for fatty acids can be saturated fatty acids, monounsaturated fatty acids or polyunsaturated fatty acids.

they have high energy because they have many c-h bonds and a low mass to energy ratio. they have high water production as it has high ratio of h-o. its waterproofing, insulation and protection over organs because its non polar as it has an even distribution of charges. non polar molecules doesn’t dissolve with polar solvents like water. this makes it hydrophobic so repels water.

Question 21

phospholipids

Answer 21

they form ester bonds form condensation reaction of glycerol and fatty acids.
they form bilayers in the cell membrane.
the bilayer has a hydrophilic head that has a glycerol and phosphate ion it points outwards. it also has a hydrophobic tail that has one unsaturated fatty acid and one saturated fatty acids it points inwards. this means only non polar molecules can pass through as polar molecules are not liquid soluble.

Question 22

test for lipids

Answer 22

add ethanol shake then add water and if present there will be a white emulsion

Question 23

amino acid

Answer 23

r
/
nh2-c-cooh
/
h
they have a variable region.
many amino acids together make a polypeptide and a peptide bond (c-n) through condensation reaction.

Question 24

protein

Answer 24

in the primary stage: sequence of amino acids and peptide bonds
secondary stage: fold into b- pleated sheet or a- helix they also form hydrogen bonds ( o-h) between the amino group and carboxylic group.
tertiary stage- it folds into a 3d shape and has hydrogen ionic and disulfide bridge( only is cystine) bonds.
quaternary stage- many polypeptide chains together.

Question 25

test for protein

Answer 25

add biuret goes lilac if present

Question 26

what are enzymes and name its types

Answer 26

its a biological catalyst. they speed up the rate of reaction. # they are protiens. the way the amino acids fold in the tertiary structure and the binds form make the active site. they are anabolic ( join together) catabolic (break down) intracellular ( within cells) extracellular ( outside cells)

Question 27

the induced fit model

Answer 27

substrate enter active site of enzyme enzyme change shape slightly as substrate binds they form enzyme product complex. product leaves active site and the active site returns back to original shape

Question 28

how to enzymes work

Answer 28

they place stress on the bonds on the substrate so lower the activation energy

Question 29

factors that affect rate of enzyme controlled reaction and how it’s determined

Answer 29

the rate of an enzyme controlled reaction is determined by the number of enzyme substrate complexes temperature ph enzyme concentration substrate concentration

Question 30

temperature on enzyme controlled reaction

Answer 30

as temp is below optimum there is less ke is so less binding so less enzyme substrate complex as temp increases above optimum the hydrogen bonds in the tertiary structure are overcome changing the ts shape changing the as shape so denature so less e-s complexes at optimum its the highest so more binding and more enzyme substrate complex

Question 31

ph equation

Answer 31

-log10(h+)

Question 32

ph on enzyme controlled reaction

Answer 32

below optimum ph there is high concentration of H+ ions. change in H+ in the external solution can change the charges of amino acids so particularly affects hydrogen and ionic bonds so changes tertiary structure. so changes as so less e-s complexes above optimum ph there is low concentration of H+ ions so this changes the charges of amino acids so partially affects hydrogen and ionic bonds so changes tertiary structure. so changes as so less e-s complexes

Question 33

enzyme concentration on enzyme controlled reaction

Answer 33

initially as the enzyme concentration increases so does the rate because the is more as so more binding so more e-s complex however the graph then plateaus because substrate is the limiting factor so the e-s complex remain the same

Question 34

substrate concentration on enzyme controlled factor

Answer 34

initially as the substrate increases there more binding so more e-s complex however the graph plateaus so the enzyme is the limiting factor so the e-s complex remains the same

Question 35

how to find the initial rate of reaction

Answer 35

you draw a line from 0 and up the graph the steeper the gradient the faster the rate

Question 36

inhibitor

Answer 36

it reduces the rate of reaction competitive inhibitor does it by blocking the as non competitive inhibitor changes the shape of the as

Question 37

competitive inhibitor

Answer 37

it has a similar shape to the substrate so binds to the as. means fewer e-s complexes as substrates can't bind with the as. the graph compared to the normal is that is less steep and the rate of reaction decreases because there is less e-s complexes

Question 38

non competitive inhibitor

Answer 38

they are complementary to the allosteric site of the enzyme so it binds and changes the shape of as forever so the substrate doesnt fit so no e-s complexes the graph compared to the normal one and ci graph is less steeper and then plateaus cux there is no e-s complexes

Question 39

dna and rna

Answer 39

deoxyribonucleic acid and ribonucleic acid are important information-carrying molecules. In all living cells, DNA holds genetic information and RNA transfers genetic information from DNA to the ribosomes. ribosomes are formed from rna and protiens.

Question 40

dna structure

Answer 40

its a polymer of nucleotide its a double helix with two polynucleotide chains ( anti-parallel) held together by hydrogen bonds between specific complementary base pairs. The components of a DNA nucleotide are deoxyribose, a phosphate group and one of the organic bases adenine, cytosine, guanine or thymine.

Question 41

two nucleodies reaction

Answer 41

A condensation reaction between two nucleotides forms a phosphodiester bond. the phosphate and deoxyribose 3-5 phosphodiester bonds. they are strong bonds and form the backbone

Question 42

complementary bases

Answer 42

cytosine - guanine adenine- thymine thymine and cytosine are with the base pyrimidine adenine and guanine are with the base purine ribose has one extra oxygen. and it replaces thymine the phrase cute the pyramid

Question 43

formation of dna

Answer 43

dna codes for protiens 3 nucleiodies make a amino acid amino acids order determine dna

Question 44

rna molecule

Answer 44

its a short polynucleotide chain