Biological Molecules

Question 0

How much carbohydrates make up a person

Answer 0

0.5%

Question 1

How much water is there in a person

Answer 1

70%

Question 2

How much protein makes up a person

Answer 2

12%

Question 3

How much lipids make up a person

Answer 3

15%

Question 4

How much inorganic ions make up a person

Answer 4

2.5%

Question 5

What are elements make up carbohydrates

Answer 5

C H O

Question 6

What elements make up protein

Answer 6

C H O N

Question 7

What elements make up lipids

Answer 7

C H O

Question 8

What is the definition of inorganic

Answer 8

Simple compounds found occuring naturally such as CO2

Question 9

What is the definition of organic

Answer 9

Complex compunds made by living organisms such as proteins, lipids and carbohydrates

Question 10

What is the name of a single sugar unit

Answer 10

Monosaccharides

Question 11

What is name of 2 sugar units

Answer 11

Disaccharides

Question 12

What is the name of many sugar units

Answer 12

Polysaccharides

Question 13

What are the characteristics of monosaccharides

Answer 13

It is soluble and tastes sweet.

Some examples are glucose (C6 H12 O6)

Question 14

What are the characteristics of disaccharides

Answer 14

Made from 2 monosaccharides joined together. They are sweet and soluble. Some examples include maltose, sucrose and lactose

Question 15

What are the characteristics of polysaccharides

Answer 15

Many hundreds of sugar units joined together. They are NOT sweet and soluble and they are strong. Examples include starch and glycogen which are used for storage

Question 16

What are the smaller units of proteins

Answer 16

Amino acids. There are 20 different acids and it is the specific sequence of amino acids that determine the protein that is formed. There is a huge variety of different proteins

Question 17

What do proteins look like

Answer 17

Some are highly folded into a special shape for a specific function. Such as haemoglobin in red blood cells is folded to carry oxygen molecules or enzymes are highly folded and have an active site
Others are less folded and have a straighter structure for strength such as keratin

Question 18

What is the difference between fats and oils

Answer 18

Fats are solid at room temperature

Oils are liquid at room temperature

Question 19

What is the structure of lipids

Answer 19

They are made of 3 fatty acids and 1 glycerol

Question 20

What is the function of lipids

Answer 20

Insulation
Store of energy
Protection of organs

Question 21

What is the difference between lipids in oils and fats

Answer 21

Lipids in fats are saturated fats

Lipids in oils are unsaturated fats

Question 22

Describe the food test for sugar

Answer 22

Add an equal volume of Benedicts solution. Benedicts solution is blue. Place the test tube in a hot boiling water bath for 3 and a half mins

Question 23

What is the positive colour for the sugar test

Answer 23

Brick red

Question 24

Describe the starch test

Answer 24

Few drops of iodine solution. Iodine is orange brown

Question 25

What is the colour for the positive result for the starch test

Answer 25

Blue black

Question 26

Decribe the protein test

Answer 26

Peform the biuret test

Add 2cm2 of Sodium Hydroxide and Copper Sulfate

Question 27

What is the positive colour for the protein test

Answer 27

Purple

Question 28

Decribe both tests for lipids

Answer 28

Grease spot test
Rub the sample onto filter paper and allow it to dry

Emulsion test
Add a reasonable quantity of ethanol which dissolves. Then add water

Question 29

What is the positive result for the grease spot test

Answer 29

The filter paper should be translucent

Question 30

What is the positive result for the emulsion test

Answer 30

The ethanol should be a milky white colour