Carbohydrates: monosaccharides & disaccharides

Question 1

Macromolecules

Answer 1

A macromolecule is a giant molecule made up of many repeating units (containing c). Such molecules are called as polymers & the individual units are called monomers. The monomers are covalently linked to make a polymer by removing water; chemical process called condensation. The polymers could be broken down by the addition of water; process called hydrolysis

Question 3

Four major classes are:

Answer 3

Monosaccharides to carbohydrates
Fatty acids & glycerol to lipids
Amino acids to proteins
Nucleotides to nucleic acid

Question 4

Carbohydrates

Answer 4

They are compounds containing carbon, hydrogen & oxygen
The ratio of hydrogen to oxygen is usually 2:1
They have general formula (CH2O)n

Question 5

Carbohydrates: sugar

Answer 5

Monosaccharides and disaccharides

Question 6

Monosaccharides (monomers) example

Answer 6

Glucose
Fructose
Ribose

Question 7

Disaccharides (dimers) example

Answer 7

Sucrose
Maltose
Lactose

Question 8

Polysaccharides (polymers) example

Answer 8

Starch
Cellulose
Glycogen

Question 9

Types of carbohydrates: monosaccharides

Answer 9

Single, simple sugar

Question 10

Types of carbohydrates: disaccharides

Answer 10

Consist of two monosaccharides joined by a condensation reaction ie glycosidic bond

Question 11

Types of carbohydrates: polysaccharides

Answer 11

Polymers of many sugars joined by more than two condensation reactions ie glycosidic bonds

Question 12

Monosaccharides

Answer 12

Simple sugar units which make up all other carbohydrates which cannot be further hydrolysed into smaller units

Question 17

Disaccharides

Answer 17

Two monosaccharides can be linked by glycosidic bonds to form disaccharides
2[(CH20)n]-H20

Question 18

Condensation reaction

Answer 18

During condensation reaction, 2 monosaccharides are joined by the removal of water molecules to form a covalent bond known as a glycosidic bond

Question 19

Hydrolysis reaction

Answer 19

Hydrolysis is the splitting of a disaccharides into its monosaccharides by the addition of water molecules this process breaks glycosidic bonds

Question 20

Condensation vs hydrolysis

Answer 20

Monosaccharides forms condensation reactions which forms disaccharides.
Disaccharides forms hydrolysis reactions which forms monosaccharides.

Question 21

Condensation of monosaccharides

Answer 21

Glucose and glucose forms maltose and water
Glucose and fructose forms sucrose and water
Glucose and galactose forms lactose and water

Question 22

Hydrolysis of monosaccharides

Answer 22

Maltose and water forms glucose and glucose
Sucrose and water forms glucose and fructose
Lactose and water forms glucose and galactose

Question 23

There are three disaccharides

Answer 23

Maltose
Sucrose
Lactose

Question 24

Monosaccharides & energy: polar utility

Answer 24

It can easily enter cells & get metabolised or stored as starch or glycogen

Question 25

Monosaccharides & energy: smaller & more reactive when compared to disaccharides & polysaccharides

Answer 25

They can easily enter the cells & be broken down by respiration to provide energy for metabolic processes

Question 26

Monosaccharides & energy: ability to undergo condensation reactions & form glycosidic bonds

Answer 26

Monosaccharides are used as bulging blocks for larger & more complex carbohydrates like starch , glycogen & cellulose

Question 27

Disaccharides & energy: polar & solubility

Answer 27

Since disaccharides are polar they can dissolve in water. This is particularly useful for the transport of carbohydrates as sucrose in the phloem sap of plants

Question 28

Disaccharides & energy: ability to be hydrolysed

Answer 28

Sucrose is hydrolysed in the gut of mammals to form glucose & fructose. The glucose is then absorbed into the cell & used as a respiratory substrate