Carbohydrates

Question 1

Examples (3) of monosaccharides

Answer 1

Glucose- reactant in respiration, product of broken down carbohydrates

Fructose- found in fruits + nectar, very soluble,

Galactose- not very soluble, forms glycolipids and glycoproteins

Question 2

What are the four main macromolecules?

Answer 2

• Glycogen
• Chitin
• Cellulose
• Starch

Question 3

What are structural isomers?

Answer 3

Same molecular formula of a molecule but a different structural layout

Eg alpha and beta layout
Straight chain and ring layout

Question 4

Give examples (2) of pentose sugars;

Answer 4

• Ribose

- Deoxyribose

Question 5

What are disaccharides and give examples;

Answer 5

• two simple monosaccharides chemically joined
• maltose
• sucrose
• lactose

Question 6

Describe maltose;

Answer 6

• two glucose monosaccharides

- alpha 1-4 glycosidic bond

Question 7

Describe sucrose;

Answer 7

• glucose and fructose chemically joined

- alpha 1-4 glycosidic bond

Question 8

Describe lactose;

Answer 8

• galactose and glucose bond

- beta 1-4 glycosidic bond

Question 9

How ate disaccharides created?

Answer 9

• condensation reaction, water is removed

- leave an oxygen conjunction between the two molecules

Question 10

What are organic substances and name the four main groups;

Answer 10

• substances that contain all; carbon, hydrogen and oxygen
• carbohydrate
• lipids
• proteins
• nucleic acids

Question 11

What are monosaccharides?

Answer 11

Simple sugars;

Question 12

What does ‘amphipathic’ mean?

Answer 12

Having on hydrophilic and one hydrophobic end

Question 13

Name the 9 main elements in the human body

Answer 13

Oxygen-

Carbon-

Hydrogen-

Nitrogen-

Calcium-

Phosphorus-

Potassium

Sulphur

Sodium

Question 14

What elements make nucleic acids

Answer 14

• carbon
• oxygen
• nitrogen
• hydrogen
• phosphorus

Question 15

Test for simple sugars (reducing sugars)?

Answer 15

-Benedict’s test

• copper (II) sulphate (blue solution in alkali conditions)
  reduced to copper oxide (brick red)
• electrons are gained

Question 16

Empirical formula of carbohydrates?

Answer 16

CnH2nOn

Question 17

Test for nucleotides/ nucleic acids

Answer 17

• after hydrolysis, positive Benedict’s test

Question 18

Test for lipids?

Answer 18

• emulsion test
• dissolves in ethanol, when added to water are in droplets due to ethanol being miscible with water
• milky white appearance on

Question 19

Amino acid and protein composition

Answer 19

Carbon

Hydrogen

Oxygen

Nitrogen

Sometimes sulphur

Question 20

Describe starch’s structure

Answer 20

• 30% amylose
• 70% amylopectin

Amylose; helical unbranched, alpha glucose (1200-1500 units), 1-4 glycosidic bond

Amylopectin; branched, 200,000 glucose units, 1-6 glycosidic bond in branched chains

Question 21

Describe cellulose’s structures

Answer 21

• unbranched,
• beta glucose
• 1-4 glycosidic
• weak hydrogen bonding between chains
• glucose molecule rotates every 180

Question 22

Describe the structure of glycogen

Answer 22

• branched every 8-12 units,

1-6 glycosidic bonds

• alpha glucose

Question 23

Describe the structure of steroids

Answer 23

• 3, 6 carbon rings

- a 5 carbon ring