Carbohydrates and Water M2

Question 1

Describe some similarities and differences between starch and cellulose

Answer 1

1. starch is formed by alpha glucose, whereas cellulose is formed by beta glucose 2. every second beta molecule in cellulose is inverted

Question 2

Two glucose molecules joint together to form what two products? under what reaction

Answer 2

maltose and water

Question 3

Name 3 functions of water

Answer 3

1. It is a reactant in lots of important chemical reactions (hydrolysis) 2. It acts as a habitat for animals, ale to temperature control and properties of ice allow it to insulate. 3. It is an essential solvent

Question 4

Name three disaccharides, and the monosaccharides that make them up.

Answer 4

1. Maltose - glucose and glucose, a - 1,4 glyosidic. 2. Sucrose - fructose and glucose, a - 1,6 glyosidic . 3. Lactose - galactose and glucose, b - 1,4 glyosidic

Question 5

Biochemical test for starch

Answer 5

add iodine, orange to black/blue means positive

Question 6

Biochemical test for non reducing sugar

Answer 6

add dilute HCL, and heat to 80 degrees, neutralise sodium hydrogen carbonate. Add benedict’s, heat to 80 degrees, if positive, brick red precipitate.

Question 7

Biochemical test for reducing sugar

Answer 7

Add benedict’s solution, heat to 80 degrees, if positive, brick precipitate.

Question 8

Biosensors

Answer 8

quantitative, device which uses a biological molecule, a chemical signal is produced and converted to an electrical; signal by a transducer

Question 9

Polarity of water

Answer 9

The hydrogens are slightly positive and the oxygen is slightly positive, meaning they partially charged differently on each side, this means the molecules are attracted to each other and form hydrogen bonds

Question 10

What is the structure of starch

Answer 10

Amylose, straight chain, a glucose 1,4 glycosidic bond. Amylpectin, branched chain, a glucose 1,4 and 1,6 glycosidic bond. Function, main energy storage. Structure, compact, insoluble, easily broken down

Question 11

Explain what a macromolecule is

Answer 11

a complex molecule with a relatively large mass eg carbohydrates, lipids, polymers