1. Monomers, polymers and carbohydrates

What is a monomer?

Smaller units that join together to form larger molecules

What is a polymer?

Moleules formed when many monomers join together

What is a condensation reaction?

A chemical bond forming between 2 molecules and a molecule of water is produced

What is a hydrolysis reaction?

A water molecule is used to break a chemical bond between 2 molecules

What is a hexose monosaccharide?

A monosaccharide that contains six carbon atoms

What are the 3 hexose monosaccharides?

• Glucose

• Fructose

• Galactose

What is the name of the bond formed when monosaccharides react?

Glycosidic bond

What are 2 bonded monosaccharides called?

Disaccharide

What are many bonded monosaccharides called?

Polysaccharide

What are the 3 disaccharides?

• Maltose

• Sucrose

• Lactose

How is maltose formed?

Glucose + glucose

How is sucrose formed?

Glucose + fructose

How is lactose formed?

Glucose + galactose

What is the structure of starch (Amylose)?

• 1,4 Glycosidic bonds

• Helix with intermolecular H-bonds (compact)

What is the structure of starch (Amylopectin)?

• 1,4 and 1,6 Glycosidic bond

• Branched for many ends for hydrolysis

What is the function of starch?

It is a storage polmer of a-glucose in plant cells

• insoluable so there is no osmotic effect

• large so it cant diffuse out of cells

What is the structure of glycogen?

• 1,4 and 1,6 glycsidic bonds

• branched so there is many ends for hydrolysis

• insoluable to prevent osmotic effect

• compact

What is the function of glycogen?

Main storage molecule polymer of a glucose in animal cells

What is the structure of cellulose?

• 1,4 glycosidic bonds

• straight-chain, unbranched molecule

• alternate glucose are rotated 180c

• H-bonds crosslink between paralell strands from microfibrils

What is the function of cellulose?

Polymer of B-glucose gives rigidity to plant cell walls

What is the benedicts test for reducing sugars?

1. Add an equal volume of benedicts reagent to a sample

2. Heat the mixture in a water abt at 100c for 5 mins

3. Positive result- Color change from blue to orange/brick-red precipitate forming

What is the benedicts test for non- educing sugars?

1. Negative result for reducing sugars- remains blue

2. Hydrolyse non-reducing sugars into their monomers by adding 1cm³ of HCl.

3. Heat in boiling water bath for 5 mins

4. Neutrolise the mixture using sodium carbonate solution

5. Proceed wit hthe benedicts test as usual

What is the test for starch?

1. Add iodine solution

2. Positive result is a colour change from orange to blue black