biological molecules

Question 1

what are monomers?

Answer 1

smaller repeating Unitas from which larger molecules are made.

Question 2

what are polymers?

Answer 2

molecules made from a large number of monomers joined together

Question 3

what is a condensation reaction?

Answer 3

a reaction that joins two molecules together to form a chemical bond whilst eliminating a molecule of water.

Question 4

what is a hydrolysis reaction

Answer 4

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

Question 5

what is a monosaccharide

Answer 5

monomers from which larger carbohydrates are made

Question 6

how is a glycosidic bond formed

Answer 6

a condensation reaction between two monosaccharides

Question 7

name the three main examples of polysaccharides

Answer 7

glycogen, starch, cellulose

Question 8

describe benedict’s test for reducing sugars

Answer 8

gently heat the solution of food sample with an equal volume of benedict’s solution for five minutes the solution turns orange brown if sugars are present

Question 9

name the two main groups of lipids

Answer 9

phospholipids, triglycerides (fats and oils)

Question 10

give four roles of lipids

Answer 10

source of energy, waterproofing, insulation, protection.

Question 11

what is an ester bond

Answer 11

a bond formed by condensation reaction between a glycerol and a fatty acid

Question 12

describe the emulsion test for lipids

Answer 12

mix the sample with ethanol in a clean test tube, shake the sample, add water, shake the sample again, a cloudy white colour indicates that lipid is present

Question 13

what are the monomers that make up proteins

Answer 13

amino acids

Question 14

draw the structure of an amino acid

Answer 14

R
|
H2N—–C—-COOH
|
H

Question 15

how is a peptide bond formed

Answer 15

a condensation reaction between two amino acids

Question 16

what is a polypeptide

Answer 16

many amino acids joined together

Question 17

describe the biuret test for proteins

Answer 17

mix the sample with sodium hydroxide solution at room temp, add very dilute copper (ii) sulfate solution, mix gently, a purple colour indicates that peptide bonds are present

Question 18

how does an enzyme affect a reaction

Answer 18

it lowers the activation energy

Question 19

give five factors which can effect enzyme action

Answer 19

temp,pH,enzyme conc,substrate conc,inhibitor conc

Question 20

what is a competitive inhibitor

Answer 20

a molecule with a similar shape to the substrate, allowing it to occupy the active site of the enzyme

Question 21

what is a non competitive inhibitor

Answer 21

a molecule that changes the shape pf the enzyme by binding somewhere other than the active site.