CHEMICALS OF LIFE

Question 1

What are the compounds found in the body of living organisms

Answer 1

Chemicals of life

Question 2

What elements are carbohydrates made of

Answer 2

Carbon, hydrogen and oxygen (1:2:1)

Question 3

Classes of carbohydrates

Answer 3

Monosaccharides,(oligosaccharides) disaccharides, polysaccharides, muco-polysaccharide

Question 4

Monosaccharides are of 2 types namely

Answer 4

Pentose(5 carbon atoms), hexose( 6 carbon atoms)

Question 5

Examples of pentoses are

Answer 5

Ribose & deoxyribose

Question 6

Examples of hexose are

Answer 6

Glucose(dextrose, grape sugar) , fructose(nebulose,fruit sugar)

Question 7

CH2OH
|
C ——– O H
H / | \ |
| H
C OH H C
| \ | | / |
C —— C
| |
H OH

Is the structure of

Answer 7

Glucose

Question 8

Examples of disaccharides

Answer 8

Sucrose(glucose&fructose), lactose (glucose & galactose), Maltose(glucose &glucose)

Question 9

Sources of various disaccharides

Answer 9

Maltose (breakdown of starch)
Lactose(milk)
Sucrose(sugar beet)

Question 10

Examples of polysaccharides and where they are found

Answer 10

Cellulose(cell wall),
lignin(cell walls of older plants),
chitin(exoskeleton, cell wall of some plants like yeast),
starch

Question 11

Muco-polysaccharides are found where

Answer 11

In bacteria cell wall

Question 12

Why are Amino acids are said to be amphoteric

Answer 12

They have carboxylic(acid) and amino(basic) groups

Question 13

What elements make up proteins

Answer 13

Carbon, hydrogen, oxygen, nitrogen sulphur(in some cases)

Question 14

Why is Fat is a triglyceride

Answer 14

It is an Easter of glycerol and three fatty acids

Question 15

Why are Triglyceride fats not natural

Answer 15

They have no free acid or basic group

Question 16

Examples of lipids are

Answer 16

Fats, waxes, phospholipids, carotenoids, sterol

Question 17

What are phosphoric acids

Answer 17

Thay are types of lipids that contain phosphorus, they are made up of three hydroxyl groups from glycerol, 2 fatty acids and one phosphoric group

Question 18

What is the simplest form of phospholipids

Answer 18

Phosphaditic acids

Question 19

What is lecithin

Answer 19

It’s a type of phospholid and it’s found in the cell membrane, it helps to maintain balance between the inner and outer medium of a cell, and it allows fat soluble materials to dissolve in it because of hydrophobic compound

Question 20

What are waxes

Answer 20

They are examples of lipids that are esters of aliphatic alcohol and fatty acids(C24 - C30 -C36)

Question 21

What are amphipathic lipids

Answer 21

They are lipids with hydrophobic and hydrophilic parts

Question 22

What are the main characteristics of sterols

Answer 22

They have free hydroxyl groups, high solubility in fat solvents and they are amphipathic.
Examples are cholesterol(in vertebrates),
Beta-sitosterol(in plant cells), ergosterol(in fungi)

Question 23

What are cell walls made of

Answer 23

Cellulose, gelatinous materials, wax

Question 24

What are the functions of the cell wall

Answer 24

It gives rigidity, elasticity, and form to the cell, it protects the cell

Question 25

What is autolysis/celldigestion

Answer 25

It is the process whereby a cell breaksdown due to the enzymes of the lysosome

Question 26

Describe the structure of the cell membrane

Answer 26

It has a phospholipid bi layer which has protein

Question 27

Where are membranes(cell membrane) found in the cell

Answer 27

Nucleus, around the cell, the mitochondria, endoplasmic recticulum, lysosomes

Question 28

What are the functions of the cell membrane

Answer 28

It controls entry and exit of material, it provides support, it is the barrier between the interior and exterior of the cell ,it enables formation of distinct organelles

Question 29

What are the functions of ribosomes

Answer 29

They synthesize protein and are also involved in some fat metabolism

Question 30

What are ribosomes composed of

Answer 30

RNA and proteins

Question 31

What does the lysosome do

Answer 31

It breaks down worn out cells

Question 32

Describe the centrosome

Answer 32

It is made up of a granular interior (centriole), a condensed cytoplasm (centrosphere), it's found closed to the nucleus, it is important in forming spindle fibres during cell division

Question 33

What are the types of plastids

Answer 33

Chromoplast(yellow(xantophyll) and orange-red(carotene) pigments), chloroplast(green pigments(chlorophyll A and B in the ratio 3:1), leucoplast(no pigment)