Biological molecules

Question 1

Carbohydrate

Answer 1

Respiratory substrate in cells; structural components in plasma membranes and cell walls

Question 2

lipids

Answer 2

forms bilayer in plasma membranes; some are hormones; respiratory substrate

Question 3

proteins

Answer 3

component of many cellular structures; enzymes; chemical messengers; blood components

Question 4

nucleic acids

Answer 4

form the genetic code for protein production

Question 5

monomers

Answer 5

small units that make up larger molecules

Question 6

polymers

Answer 6

large molecules made up of a large number of monomers

Question 7

monomers are joined by

Answer 7

condensations reactions, with the elimination of a water molecule

Question 8

bonds between polymers can be broken down through

Answer 8

hydrolysis, using a water molecule

Question 9

Component molecules of carbohydrates are monosaccharides. name 3

Answer 9

Glucose, galactose, fructose

Question 10

Component molecules of lipids are

Answer 10

glycerol and fatty acids (saturated and unsaturated)

Question 11

Examples of carbohydrates are polysaccharides:

Answer 11

• glycogen found in animal cells
• cellulose found in plant cells
• starch found in plant cells

Question 12

Examples of lipids are:

Answer 12

• triglycerides - made up of 3 fatty acids (R-COOH) and 1 glycerol
• phospholipids - made up of 2 fatty acids, 1 phosphate group and 1 glycerol.

Question 13

Bonds in carbohydrates

Answer 13

glycosidic bonds formed by a condensation reaction between monomers

Question 14

Bonds in lipids

Answer 14

ester bonds formed by condensation reaction between glycerol and 3 fatty acid molecules in triglycerides.

Question 15

Biochemical test for carbohydrates

Answer 15

Benedict’s solution test for reducing and non-reducing sugars
Iodine test for starch

Question 16

Biochemical test for lipids

Answer 16

emulsion test, where a milky white emulsion shows that lipids are present

Question 17

Disaccharides

Answer 17

2 monosaccaride molecules bonded together
- glucose + glucose = maltose
- glucose + fructose = sucrose
- glucose + galactose = lactose

Question 18

Properties of triglycerides

Answer 18

insoluble in water (non-polar)

Question 19

properties of phospholipids

Answer 19

hydrophilic head and hydrophobic tails, and form plasma membranes

Question 20

Glucose had 2 isomers:

Answer 20

alpha glucose -> glycogen and starch are polymers
beta glucose -> cellulose is a po;ymer

Question 21

Unsaturated lipids have

Answer 21

one or more carbon-carbon double bonds (-C=C-)