Biochemistry - Carbohydrates

Question 1

Name the elements found in a carbohydrate molecule

Answer 1

Oxygen, Carbon, Hydrogen

Question 2

What type of carbohydrate is Glucose? What is it’s formula

Answer 2

Hexose, C6H12O6

Question 3

How many carbon atoms are contained within a Triose sugar

Answer 3

3

Question 4

Name and define the two isomers of Glucose

Answer 4

Alpha, and beta.

On Carbon 1, the position of the OH and H alters the isomeric structure of the two.

Question 5

Define the term “Disaccharide”

Answer 5

A carbohydrate consisting of two monosaccharides joined by 1,4-glycosidic bonds

Question 6

What is meant by “1,4” in the term 1,4-glycosidic bond?

Answer 6

The bond is between Carbon 1 and Carbon 4 on the two monosaccharides

Question 7

What type of carbohydrate is Ribose?

Answer 7

Pentose monosaccharide

Question 8

What is the reaction called when two monosaccharides are joined together to form a disaccharide?

Answer 8

Condensation

Question 9

In a reaction between two Glucose molecules. Name the resulting products

Answer 9

Water, and maltose

Question 10

Name the two components (monomers) of Sucrose

Answer 10

Glucose and fructose

Question 11

As well as Glucose, name the monosaccharide found in Lactose

Answer 11

Galactose

Question 12

Name the reaction that breaks a disaccharide into two monosaccharide molecules

Answer 12

Hydrolysis

Question 13

Name the reagent used to test for sugar

Answer 13

Benedicts Reagent

Question 14

What colour is Benedicts Reagent before a test?

Answer 14

Blue

Question 15

Name a type of sugar that will produce a negative result in a benedicts test

Answer 15

Non-reducing sugar (sucrose)

Question 16

Define the term “reducing sugar”

Answer 16

A sugar that will react with the Cu2+ ions in Benedicts to produce a positive (brick red) solution

Question 17

Describe the reaction that allows Sucrose to become a reducing sugar

Answer 17

Add HCl and heat

Question 18

Define the term “Polysaccharide”

Answer 18

A complex carbohydrate containing multiple monosaccharide components

Question 19

Name a storage polysaccharide used in plants and identify 2 advantages of its use

Answer 19

Starch

• has no osmotic effect on a cell
• cannot diffuse out of a cell
• is compact and can be stored in small places
• carries a lot of energy in C-H and C-C bonds

Question 20

Explain how Amylose differs in stucture to Amylopectin

Answer 20

Amylose is a linear molecule containing only 1,4-glycosidic bonds between alpha Glucose molecules

Amylopectin is a branched molecule with the addition of 1,6 - glycosidic bonds.

Question 21

Explain where cellulose is naturally found, and why it is useful

Answer 21

Plant cell walls. It has a strong structure consisting of beta-Glucose molecules, rotated at 180°. Microfibrils form when 60-70 cellulose molecules tightly link. Fibres are formed from multiple microfibrils, increasing the strength of the structure

Question 22

Why is chitin different to other carbohydrate molecules?

Answer 22

Contains a nitrogen group

Question 23

Name the nitrogen group found in Chitin?

Answer 23

Acetylamine group