Biological Molecules AS level biology 970

What is a monomer?

It is the basic unit of a polymer.

How can polymers break down into its monomer?

hydrolysis reaction. (opposite of condensation reaction)

what are carbohydrates?

hydrates of carbon because the ratio of Hydrogen and Oxygen is the same as in water.

what are the different types of carbohydrates (with examples)?

1. monosaccharides

   • glucose

   • fructose

   • galactose

2. disaccharides

   • sucrose

   • maltose

   • lactose

3. polysaccharides

   • starch

   • cellulose

   • glycogen

what are some characteristics of monosaccharides?

• building blocks for di and poly saccharides

• primary fuel for respiration

• soluble in water (polar)

• reducing sugar

what’s the general formula of monosac?

(CH2O)n

• n is more than 3

what’s the molecular formula of glucose?

C6H1206

What’s the structural formula of glucose? (draw it on some paper and then check)

What are the two isomers of glucose?

alpha and beta glucose

what are the two types of pentose?

ribose and deoxy ribose

what is the difference between ribose and deoxy ribose?

deoxy ribose does not have OH in the second carbon only H

what are disaccharides?

two monosaccharides condensed together (water removal)

what monosaccharides make up maltose?

alpha glucose

what is the bond name of the bond in maltose

alpha 1,4 glycosidic bond

what are polysaccharides?

polymers made up of many monosaccharides repeatedly joined up together.

what are the two functions of polysacs?

as storage and for structure.

why are polysaccharides the preferred form for storage?

• they are compact and hence take up less space

• they are insoluble in water so they won’t interfere with osmotic properties

• they cannot leak out of the cell because of large molecular mass

• they don’t take part in unnecessary reactions

• they can be hydrolysed whenever needed

what is starch?

a mixture of the two polysaccharides amylose and amylopectin.

what is amylose made up of?

alpha glucose

what are the bonds found in amylopectin?

• alpha 1,4 glycosidic bond

• alpha 1,6 glycosidic bond

what is the difference between amylose and amylopectins appearance?

amylose: helix

amylopectin: branched