Monosaccharide and Disaccharide

Question 1

Role of carbohydrates

Answer 1

• energy source e.g.. glucose
• energy storage such as starch
• structural e.g. cellulose

Question 2

Elements in carbohydrates and ratio

Answer 2

Carbon, Hydrogen and Oxygen
C:H:O
1:2:1

Question 3

What is a monosaccharide?

Answer 3

A simple sugar unit

Question 4

What is a Disaccharide ?

Answer 4

Two monosaccharides linked together

Question 5

What is a polysaccharide?

Answer 5

Many monosaccharides linked together
(min of 3)

Question 6

What is a monomer?

Answer 6

A small, basic molecular units eg. monosaccharides, amino acids, nucleic acids

Question 7

What is a polymer?

Answer 7

Large, complex molecules composed of long chains of monomers joined together e.g. cellulose, starch and proteins

Question 8

What is a hexose monosaccharide and example

Answer 8

6 carbon molecule
glucose

Question 9

glucose chemical formula

Answer 9

C₆H₁₂O₆

Question 10

Two forms of glucose

Answer 10

Alpha (α) and beta (β)

Question 11

Draw a glucose monomer with labelled carbons

Answer 11

Look it up

Question 12

What is the difference between alpha and beta glucose

Answer 12

Alpha glucose as the OH group below C1
Beta glucose has the OH group above C1

Question 13

Fructose

Answer 13

• hexose sugar
• main sugar in fruits and nectar
• very soluble
• sweeter than glucose

Question 14

Galactose

Answer 14

Hexose sugar
Not as soluble as fructose, used in production of glycolipids and glycoprotiens
Not as sweet as glucose

Question 15

What are pentose monosaccharides and 2 examples

Answer 15

monosacchardies that contain 5 carbon atoms
ribose and deoxyribose

Question 16

Draw ribsoe and deoxyribose

Answer 16

Look it up

Question 17

Difference between ribose and deoxyribose

Answer 17

Ribose- OH group below C2
Deoxyribsoe-H below C2

Question 18

How are disaccharides formed

Answer 18

When two alpha glucose molecules are side by side, the two hydroxyl groups react. When this happens bonds are broken and new bonds are formed, making new molecules.
When 2 alpha glucose are next to each other the C1 is closest to the C4 of the other glucose. The two OH groups form a glycosidic bond. H₂O is released. Called a condensation reaction.

Question 19

Draw a disaccharide reaction between two alpha glucose

Answer 19

look up answer

Question 20

What is the bond formed between the OH groups in a disaccharide between 2 alpha glucose

Answer 20

α 1-4 glycosidic bond

Question 21

α Lactose

Answer 21

Found in milk
Formed by beta galactose and alpha glucose
Bond is a β1-4 glycosidic bond.
Recognisable because the bond is formed upwards

Question 22

β Lactose

Answer 22

Formed from β galactose and β glucose. Bond formed is a β 1-4 glycosidic bond.
Beta bond is directed upwards

Question 23

Sucrose

Answer 23

Formed by the joining of glucose and fructose. Bond formed is a α1 β2 glycosidic bond.

Question 24

3 disaccharides and formation

Answer 24

maltose: made up of 2 glucose molecules
Lactose: Made up of glucose and galactose
Sucrose: made up of glucose and fructose.