enzyme action

Question 1

during a chemical reaction

Answer 1

a new substance is formed as a substance changes from one form to the other

Question 2

the substance of which the enzyme acts is known as

Answer 2

the substrate

Question 3

enzymes

Answer 3

protein that has a particular shape to enable it to perform its speciifc function

Question 4

enzymes are substrate specific meaning

Answer 4

a specific enzyme can only act on a specific substrate

Question 5

active site

Answer 5

the part of the enzyme where substrate molecules bind and a chemical reaction takes place. The active site is made up of amino acid residues that establish temporary bonds with the substrate (binding site) as well as residues that catalyse that substrate’s reaction (catalytic site).

Question 6

the substrate molecule fits into

Answer 6

the enzyme’s active site as a key fits into a lock to ensure the specificity of the enzyme then a temporary enzyme substrate complex is formed.

Question 7

anabolic reaction in an active site

Answer 7

Anabolic reactions utilize energy to synthesize larger molecules from smaller units. Example- formation of glycogen from simple sugar molecules is an anabolic reaction.

Question 8

temperature

Answer 8

enzymes are sensitive to temperature change. low temperatures make enzyme temporarily inactive .

Question 9

the temperature at which enzymes work the best is known as their optimum temperature which is

Answer 9

35 to 40 degrees in humans (body temperature is 37)

Question 10

at high temperatures

Answer 10

usually above 45 the shape of the enzyme begins to change and the substrate no longer fits into the active site. The enzyme can’t perform its function. the enzyme denatures

Question 11

denaturation is an irreversible process

Answer 11

when the enzyme denatures it cannot return to its proper shape when the temperature is lowered again.When the enzyme becomes inactive as a result of low temperature it can become active again once the temperature rises.

Question 12

optimum ph

Answer 12

each enzyme has a narrow ph range within which it can function. some enzymes qork optimally in acidic medium whereas others in a neutral or alkaline medium. enzymes denature at extreme ph levels

Question 13

properties of enzymes

Answer 13

1) spherical proteins
2) sensitive to chnages in temperatures in high temperature the enzyme denatures whereas low tempratures to make temporarily inactive
3)substrate specific
$4)can be used over and over again
5) a small amount of enzyme can change a large amount of subtrate

Question 14

enzymes in everyday life

Answer 14

biological washing powder such as bio tex/classic contain enzymes that break up/remove biological stains. these enzymes usually act on proteins and are known as protease stains caused by blood/sweats consist of difficult porteins to remove therefroe the enzyme in the washing powder break down the proteins down into smaller soluble molecules easily removed by cleaning agents

Question 15

catalase

Answer 15

enzyme found in most animal and plant cells that accelerates the breakdown of hydrogen peroxides into water and oxygen. oxygen is released during this reaction as bubbles

Question 16

saccharides

Answer 16

Sugars

Soluble in water

Question 17

monosaccharide

Answer 17

A simple sugar

Question 18

The chemical formula of
glucose is:

Answer 18

C6H12O6

Question 19

monosaccharides

Answer 19

These are simple
sugars.

They all have a single
ring, six sided
structure as shown in
the picture
alongside-this picture
is called a structural
formula.

Glucose and fructose
are examples of
monosaccharide’s.

Question 20

A monosaccharide is the simplest form of
carbohydrates.

Answer 20

In other words they are the smallest units that
more complex carbohydrates are made up of.

The smallest or simplest unit of any substance is
called its building block.

Another word for building block is monomer.

The monomer of a carbohydrate is the
monosaccharide.

Question 21

monomer

Answer 21

is a building block or simplest
unit of a more complex substance.

Question 22

Carbohydrates have three main functions.

Answer 22

Energy. They are an important source of
energy. During cellular respiration glucose is
broken down to release energy.

Storage. They serve as storage substances
for energy. For example in the human body
extra glucose (energy source) is converted into
glycogen and stored in the liver.

Building materials. For example they
supply cellulose for the making of plant cell
walls.

Question 23

nucleic acid

Answer 23

Nucleic acids are organic compounds found
in the cells.

Question 24

two types of nucleic acid

Answer 24

They are:-

Deoxyribonucleic acid

Ribonucleic acid

Question 25

DEOXYRIBONUCLEIC
ACID

Answer 25

It is found in the nucleus of
the cell.

It forms a part of the
chromosome that is found in
the nucleus.

Question 26

structure of the dna

Answer 26

The structure of DNA is based on a model put
forward by two scientist, James Watson and
Francis Crick, in 1953

Question 27

DNA is made up of building block or monomers called

Answer 27

nucleotides

Question 28

A specific length of DNA is called a

Answer 28

gene.

Question 29

Genes carries the code for the

Answer 29

formation of
proteins. Since proteins are necessary for the
formation of cells we can say that the genes controls
the structure of organisms.

Question 30

Genes also determine the enzymes that are formed.

Answer 30

Enzymes control all chemical reactions in a cell.
Therefore we can say that genes control the
functioning of the organism.

Question 31

Genes are responsible for the transfer of

Answer 31

characteristics from parent to offspring.

Question 32

RNA occurs

Answer 32

There many
different types of
RNA.

Some occur in the
nucleus and some
occur in the
cytoplasm.

They are single
stranded.

They are involved in
protein synthesis.

Question 33

Vitamins are organic compounds.

They are found in

Answer 33

very small quantities in
natural food.

They are required for the maintenance of
the metabolism in the body.

They are absorbed from the small intestine.

Question 34

vitamin A

Answer 34

Essential for the
correct functioning of
the eye.
Liver, milk, milk
products, fruit
and vegetables
Night blindness:
difficulty in
seeing in dim light

Question 35

vitamin b

Answer 35

Acts as a co-enzyme in
cellular respiration

Whole grains of
cereals, nuts,
meat and yeast.

Beri-beri:
stunted growth
and heart
disorders

Question 36

vitamin c

Answer 36

Maintains intercellular
substance in cartilage,
bone & dentine. May
acts as a catalyst in
cell respiration

Citrus fruit,
guavas, tomatoes,
potatoes.

Scurvy: bleeding
gums, under the
skin especially at
the joints. Poor
healing of
wounds.

Question 37

VITAMIN D SOURCES AND DEFEINCY

Answer 37

Increases absorption
of calcium &
phosphate salts.

Diary
products, egg
yolk

Rickets in
children:
abnormal bone
formation.

Osteomalacia in
adults:
compressed
vertebrae,
bow-shaped legs,
swollen joints.

Question 38

VITAMIN E

Answer 38

Prevents oxidation of
unsaturated fatty
acids

Leafy green
vegetables

Excessive
bleeding-known as
haemorrhage