Carbohydrates

Question 1

Describe Carbohydrates

Answer 1

Carbohydrates are organic compounds and the primary energy storage molecules in organisms, also formed from the building blocks of small molecules called sugars :
contain elements C,H, O
general formula Cx(H2O)y
includes monosaccharides, disaccharides, polysaccharides
have a ratio of 2:1 of H:O

Question 2

How many molecules do monosaccharides, disaccharides & polysaccharides have?

Answer 2

Monosaccharides(1 sugar molecule), disaccharides(2 sugar molecules covalently linked tgt), polysaccharides(many sugar units linked covalently tgt).

Question 3

Describe Glucose

Answer 3

Glucose with the formula C6H12O6. It is a polar molecule therefore water soluble. It is the form of carbohydrate that is transported in the blood of animals. It is readily taken up by cells and metabolised:
to provide a source of energy in respiration
polymerised to form a polysaccharide for energy storage
used as a raw material to make other compounds

Question 4

What is the definition of a hydrolysis and condensation reaction?

Answer 4

Hydrolysis reaction is where water is added to break a glycosidic bond
Condensation reaction is where two molecules combine to form a single molecule

Question 5

What are glycosidic bonds and linkages?

Answer 5

Glycosidic bond is a type of covalent bond and is very strong

Glycosidic linkages are used to create disaccharides or polysaccharides

Question 6

What are reducing and non reducing sugars?

Answer 6

A reducing sugar(glucose, fructose) is a sugar that in a solution has an aldehyde or a ketone group
A non reducing sugar lack aldehyde or ketone and cannot reduce other substances

Question 7

What are pentoses and hexoses?

Answer 7

Pentoses(5 carbon sugars) eg ribose and deoxyribose used in dna and rna
Hexoses(6 carbon sugars) eg glucose and galactose

Question 8

What are polysaccharides?

Answer 8

Polysaccharides(macromolecules) are made from monomers.

Question 9

What are the 3 energy storage polysaccharides?

Answer 9

There are three energy storage polysaccharides amylose, amylopectin and glycogen.

Question 10

Describe the 3 energy storage polysaccharides

Answer 10

Storage polysaccharides are insoluble in water, un reactive and compact. Amylose and amylopectin are stored in plants cells as starch grains and glycogen is stored in animal cells as smaller granules.