biological molecules overview

Question 1

what are monomers

Answer 1

a small unit from which larger molecules are made

Question 2

what are polymers

Answer 2

a large number of monomers joined together

Question 3

give 3 examples of a monomer

Answer 3

monosaccharides
amino acids
nucleotides

Question 4

what is a condensation reaction

Answer 4

joining two molecules together with the formation of a chemical bond and the elimination of water

Question 5

what is a hydrolysis reaction

Answer 5

it breaks down chemical bonds between two molecules by using water

Question 6

what is a monosaccharide

Answer 6

a monomer which makes larger carbohydrate molecules.

Question 7

give 3 examples of a monosaccharide

Answer 7

glucose
galactose
fructose

Question 8

what type of bond does the condensation reaction between two monosaccharides form

Answer 8

glycosidic bonds

Question 9

how are disaccharides formed

Answer 9

a condensation reaction between two monosaccharides

Question 10

how is maltose formed

Answer 10

condensation reaction between two alpha glucose

Question 11

what type of bonds does maltose have

Answer 11

1-4 glycosilic

Question 12

how is sucrose formed

Answer 12

condensation of glucose and fructose

Question 13

how is lactose formed

Answer 13

condensation of glucose and galactose

Question 14

what is an isomer

Answer 14

two molecules with the same formula but a different structure

Question 15

what are polysaccharides

Answer 15

many glucose units joined together by glycosidic bonds in a condensation reaction

Question 16

what two polysaccharides are formed by the condensation of alpha glucose

Answer 16

glycogen
starch

Question 17

what polysaccharide is formed by the condensation of beta glucose

Answer 17

cellulose

Question 18

what is the structure of glycogen

Answer 18

alpha glucose
1-4 & 1-6 glycosidic bonds
highly branched
insoluble in water

Question 19

what is the function of glycogen

Answer 19

storage in animals

Question 20

what makes glycogen good at its function

Answer 20

it is highly branched which means there are more reducing ends.
this allows glucose to be released quickly and efficiently so animals can respire aerobically

Question 21

what is the structure of starch

Answer 21

alpha glucose
1-4 & 1-6 glycosidic bonds
not much branching
coiled and compact
insoluble

Question 22

what is starches function

Answer 22

storage in plants

Question 23

what makes starch good at its function

Answer 23

starch is coiled and compact which mean that glucose cannot quickly be released so instead it is stored
(this is because plants do not need to quickly run away )
it is insoluble so it doesn’t affect water potential of a plant
it is large so it cannot diffuse from the cell

Question 24

what is the structure of cellulose

Answer 24

beta glucose
straight chains
1-4 glycosidic bonds
hydrogen bonds between parallel cellulose bonds
fully permeable in water

Question 25

what is the function of cellulose

Answer 25

structural - cell walls in plants

Question 26

what makes cellulose good at its function

Answer 26

lots of hydrogen bonds make it strong and they form microfibrils and fibrils

Question 27

name and describe the biochemical test for reducing sugars

Answer 27

benedict's solution put a sample in a test tube add benedict's solution put it in a water bath for a controlled period of time brick red is positive the closer to brick red the more monosaccharides are present

Question 28

what is the difference between alpha glucose and beta glucose

Answer 28

they have a 180 degree rotation at the C1

Question 29

explain how the benedict's solution test shows a positive result (chemically)

Answer 29

benedict's reagent becomes reduced (gains electrons) from the reducing centre of glucose. sugar becomes oxidised (looses electrons)

Question 30

how do you get a positive result in benedict's solution with a non reducing sugar

Answer 30

boil the sugar with hydrochloric acid to return it to a monomer then neutralise it with an alkali the add benedict's solution

Question 31

name two lipids groups

Answer 31

triglycerides and phospholipids

Question 32

how are triglycerides formed

Answer 32

condensation of one glycerol molecule and three fatty acid molecules

Question 33

what bond is formed during the reaction between a glycerol and fatty acid

Answer 33

ester bond

Question 34

what about their structure means that unsaturated fatty acids liquid at room temperature

Answer 34

the kink in the chain of molecules where the double carbon bond is means that not as many chains can pack together

Question 35

what about their structure means that saturated fatty acids are solid at room temperature

Answer 35

chains are in straight lines which means they can be closely packed together

Question 36

what is the difference between a triglyceride and a phosolipid

Answer 36

phosolipids only have two fatty acids and a phosphate head bonded to the glycerol instead of three triglycerides repel water - phospholipids attract water

Question 37

what is the function of a triglyceride

Answer 37

energy source

Question 38

describe the emulsion test

Answer 38

put a food sample in a test tube add ethanol shake it inorder to dissolve any lipids in the sample add an equal amount of water as ethanol and gently shake cloudy white liquid means a lipid is present

Question 39

what is an amino acid

Answer 39

the monomer which proteins are made of

Question 40

draw an amino acid

Answer 40

r I H2N - C - COOH I H

Question 41

what is H2N in an amino acid

Answer 41

the amine group

Question 42

what is COOH in an amino acid

Answer 42

carboxyl group

Question 43

what is R in an amino acid

Answer 43

carbon containing side chain ( it is different in every amino acid )

Question 44

what bond is formed during the condensation reaction of two polypeptides

Answer 44

peptide bonds

Question 45

how many polypeptides in an functional protein

Answer 45

one or more

Question 46

what three amino acids repeat in collagen

Answer 46

glycine , promine , alomine

Question 47

what is the primary structure protein

Answer 47

sequence of amino acids if this changes than it will effect everything else

Question 48

what is the secondary structure protein

Answer 48

folding of primary structure into an alpha helix or beta pleated sheet

Question 49

what bonds form in the secondary protein structure

Answer 49

hydrogen bonds form between hydrogen in the amine group and double oxygen bond in carboxyl group

Question 50

what bonds form in the primary protein structure

Answer 50

peptide bonds

Question 51

what is the tertiary structure

Answer 51

folding of secondary sequence into a 3D shape not all polypeptides have tertiary structure

Question 52

what bonds happen in the tertiary structure protein

Answer 52

disulfide , ionic, hydrogen hydrophobic interactions larger round proteins (enzymes ) make lots of bonds structural proteins (collagen) dont make any

Question 53

what is the quaternary structure protein

Answer 53

multiple polypeptides join together the addition of prosthetic group not all polypeptides have this

Question 54

what are the two types of protein

Answer 54

globulas and fibrous

Question 55

what are globulas proteins

Answer 55

functional highly specific irregular

Question 56

what are fibrous proteins

Answer 56

one error wont change the function repetitive strengthening

Question 57

describe the biurets test

Answer 57

put a sample in a test tube with biurets reagent if it turns purple then protein is present blue indicates protein is absent

Question 58

what is an anabolic reaction

Answer 58

making larger moleclues

Question 59

what is a catabolic reaction

Answer 59

breaking down of moleclues

Question 60

what glyosidic bond does sucrose have

Answer 60

1-2