Chemical elements are joined together to form biological compounds

Question 1

What are the monomers for starch, cellulose and glycogen?

Answer 1

Starch= alpha glucose
Cellulose= beta glucose
Glycogen= alpha glucose

Question 2

What is the structure of starch, cellulose and glycogen?

Answer 2

Starch= amylose (helix/coiled), amylopectin (branched)

Cellulose= long straight lines, held in parallel with strong hydrogen bonds to form fibrils

Glycogen= a very branched molecule

Question 3

What are the bonds between monomers in starch, cellulose and glycogen?

Answer 3

Starch= 1-4 glycosidic bonds in amylose, 1-4 and 1-6 glycosidic bonds in amylopectin

Cellulose= 1-4 glycosidic bond

Glycogen= 1-4 and 1-6 glycosidic bonds

Question 4

Explanation for the structure of starch, cellulose and glycogen?

Answer 4

Starch= helix can be compacted to fit loads of glucose, branched structure has a large surface area for rapid hydrolysis

Cellulose= Many hydrogen bonds create a collective strength

Glycogen= branched structure allows rapid hydrolysis back to glucose

Question 5

What is the definition of a condensation reaction?

Answer 5

Joining two molecules together, creating a chemical reaction, removing water

Question 6

What is the definition of a hydrolysis reaction?

Answer 6

Breaks a chemical reaction bond between two molecules, involves water

Question 7

What are the three monosaccharides in carbohydrate molecules?

Answer 7

Glucose
Fructose
Galactose

Question 8

What are the three disaccharides in carbohydrate molecules?

Answer 8

Maltose
Sucrose
Lactose

Question 9

What are the three polysaccharides in carbohydrate molecules?

Answer 9

Starch
Cellulose
Glycogen

Question 10

Describe disaccharides:

Answer 10

Two monosaccharides are joined together by a glycosidic bond, which is done by a condensation reaction

Question 11

What are 5 key properties of water?

Answer 11

1. Metabolite (used in chemical reaction)
2. Important solvent
3. High heat capacity
4. Large latent heat of vaporisation
5. Strong cohesion

Question 12

What are the 4 inorganic ions and what are their uses?

Answer 12

Magnesium ions-> Needed in bones and chlorophyll for plants

Iron ions-> Component of haemoglobin in the transport of oxygen

Calcium-> Strengthens the structure in bones and teeth

Phosphate ions-> A component of DNA and ATP

Question 13

What is the difference between saturated fatty acids and unsaturated?

Answer 13

Saturated- hydrocarbon chains has only single bonds between carbons

Unsaturated- hydrocarbon chains have atleast one double bond between carbons

Question 14

Properties of triglycerides:

Answer 14

-Energy storage
-Metabolic water source, can release water if oxidised
-Hydrophobic, repel water
-Low mass, can be stored without increasing mass as much as other tissues
-protection of organs
-thermal insulation

Question 15

Definition of primary structure:

Answer 15

The sequence of amino acids in a polypeptide chain

Question 16

Definition of secondary structure:

Answer 16

The sequence of amino acids causes parts of a protein molecule to bend into a-helix shapes or fold into b-pleated sheets. Hydrogen bonds hold the secondary structure.

Question 17

Definition of tertiary structure:

Answer 17

Further folding of the structure, forming a unique 3D shape. Held in place by ionic, hydrogen and disulphide bonds.

Question 18

Quaternary structure:

Answer 18

A protein made up of more than one polypeptide chain

Question 19

Test for starch:

Answer 19

Add iodine to solution, should go from a orange to blue/black

Question 20

Test for reducing sugars:

Answer 20

Add blue benedicts reagent and heat, turns from blue to brick red

Question 21

Test for non-reducing sugars:

Answer 21

following negative Benedicts test, add acid and boil (acid hydrolysis). Cool solution and add an alkali to neutralise. Add Benedicts reagent and heat. Should go from blue to orange. (Sucrose is a non-reducing sugar, during the experiment it hydrolysis the sucrose into glucose and fructose)

Question 22

Test for proteins:

Answer 22

Biuret solution turns it from blue to violet