biochemical

Question 1

define monomer

Answer 1

a small molecules, many of which can be joined tgt to form a polymer

Question 2

name the monomer and polymer of carbohydrate, proteins and nucleic acid

Answer 2

carbohydrate: monosaccharide, polysaccharide
protein: amino acid, polypeptides and proteins
nucleic acids: nucleotides, DNA or RNA

Question 3

define condensation

Answer 3

methods which joins small molecules tgt to form larger ones

Question 4

definee hydrolysis

Answer 4

method which splits larger molecules up into smaller ones

Question 5

what are the elements in carbohydrate

Answer 5

carbon, hydrogen and oxygen

Question 6

examples of carbohydrates and their uses

Answer 6

glucose- energy sources released during respiration
starch- energy stored in plants
cellulose- structural building blocks for cell wall

Question 7

explain monosaccharides and give examples (and where they are found)

Answer 7

simple sugars which are soluble in water.
examples are glucose(end products of digestion), galactose(found in milk) and fructose(found in honey and fruits)

Question 8

explain disaccharides and give examples

Answer 8

soluble in water, 2 molecules of monosaccharides, can be broken down by hydrolysis
example: maltose(starch partially digested) , lactose(found in milk) and fructose(sugar cane,storage roots)

Question 9

explain polysaccharides and give examples

Answer 9

complex sugar, not rlly soluble
examples: starch, glycogen(storage for animals, kept in muscles tissues and liver cells) and cellulose

Question 10

why is polysaccharides a good storage

Answer 10

they are not rlly soluble

Question 11

name the 4 elements in protein

Answer 11

carbon, hydrogen, oxygen and nitrogen

Question 12

2 reasons why proteins are essential in our lives

Answer 12

they provide raw materials for building blocks in growth and repairing of tissues; used to make antibodies and enzyme

Question 13

proteins are made of what subunits

Answer 13

amino acid

Question 14

_____are made up of amino acid chains

Answer 14

peptides

Question 15

polypeptides are made of?

Answer 15

a few peptide forming a large complex molecule

Question 16

how are amino acids joined tgt?

Answer 16

by condensations and peptide bonds

Question 17

how are the peptide bond broken down?

Answer 17

by hydrolysis and the addition of water molecules

Question 18

2 amino acids joined tgt are known as a?

Answer 18

dipeptide

Question 19

true or false: the shape of the protein molecules does not affect their function

Answer 19

false; the shape directly determines their function

Question 20

what does a nucleotides consist of? (3)

Answer 20

5 carbon sugar, phosphate grp and nitrogenous base

Question 21

what are nucleotides joined tgt at and what do they form

Answer 21

phosphate grp to form a chain of nucleic acid

Question 22

what is a double helix?

Answer 22

2 chains of nucleotides are held tgt by a hydrogen bond between bases. the double strand is twisted to form a double helix

Question 23

how are the bases paired tgt?

Answer 23

a with t and c with g

Question 24

usage of lipids (5)

Answer 24

source of energy, storage of energy, components making up cell membranal, insultations to reduce heat lost, protection

Question 25

does double bonds make it easier or harder to to break down

Answer 25

easier

Question 26

how is the lipid molecule made

Answer 26

1 glycerol linked to 3 fatty acids

Question 27

which has more cholesterol? saturated or unsaturated fat?

Answer 27

saturated

Question 28

what is cholesterol and what is it made up of?

Answer 28

class of lipid; four carbon based rings

Question 29

why can hormones such as testosterone readily pass through plasma membrane

Answer 29

because it as cholesterol/ lipid nature

Question 30

important uses for water? (6)

Answer 30

photosynthesis, digestion, makes up plasma in the blood, transport medium in plants, excretion, body temp and metabolic reactions

Question 31

how does water act as a transport medium for humans?

Answer 31

transport dissolved substances like co2, digested food and hormones in plasma

Question 32

how is water a transport medium in plants (2)

Answer 32

transport dissolved mineral ions in xylem and transport sugar and amino acid in phloem

Question 33

how to test for starch?

Answer 33

place iodine in food sample; will turn from brown to black

Question 34

how to test for sugar

Answer 34

use benedicts solution, heat solution up; turns from blue to brick red

Question 35

how to test for non reducing sugars?

Answer 35

break it down by using strong acid

Question 36

how to test for protein

Answer 36

biuret test ( sodium hydroxide and copper sulfate); if protein is presents, purple halo if not remains blue

Question 37

test for fats

Answer 37

put sample in oil then shake it then dump it in water. if got oil then mixture breaks up into many tiny droplets- emulsification

Question 38

how to test for vitamin C

Answer 38

vitamin c decolourises in DCPIP solution. the more vitamin c the lesser food sample needed to decolourise DCPIPI and faster solution turns colourless

Question 39

why shld we not shake solution of vitamin c and DCPIPI?

Answer 39

because it is easily oxidise