Biological molecules topic 1 questions

Question 1

What is an organic compound?

Answer 1

Chemical bounds that contain carbon.

Question 2

What is an inorganic compound?

Answer 2

Chemical bounds that do not contain carbon.

Question 3

How are the structures of cellulose and glycogen different?

Answer 3

1. Glycogen has a branched structure and forms coils, whereas Cellulose is a straight chain.
2. Glycogen has both 1,4 and 1,6 Glycosidic bonds whereas Cellulose just have a 1,4 glycosidic bond.
3. Cellulose is made from beta-glucose whereas, Glycogen is made up of from alpha glucose monomers.

Question 4

How does glycogen act as an energy source?

Answer 4

1. Glycogen can be hydrolysed to Glucose

2. The glucose could be used as energy in the process of respiration.

Question 5

Name the monomer maltose is made from?

Answer 5

Glucose

Question 6

Explain how starch is adapted to its function in the cells of plants.

Answer 6

1. Insoluble in water so can be stored without affecting the water potential.
2. Helical in shape, making it compact for storage.
3. A large molecule, so is unable to leave the cell.

Question 7

What monomers is Glycogen made of?

Answer 7

Alpha glucose monomers

Question 8

What monomers is Cellulose made of?

Answer 8

β- glucose monomers

Question 9

Describe the structure of Cellulose?

Answer 9

Cellulose has a straight chain structure made from β -glucose monomers and contains 1,4 glycosidic bonds.

Question 10

Describe the structure of Glycogen?

Answer 10

Glycogen has a branched structure and forms coils. It is made up of Alpha glucose monomers and is and has 1,4 and 1,6 glycosidic bonds.

Question 11

What is structurally different between starch and cellulose that gives them different physical properties?
(A-A*)

Answer 11

Cellulose is formed by β-1,4 glycosidic linkages and crosslinks, making it rigid. Starch has α-1,4 and α-1,6 glycosidic linkages without tight crosslinks of cellulose

Question 12

Describe some of the similarities and differences between glycogen and starch?
(A-A*)

Answer 12

Starched is less branched than glycogen and is found in animals

Question 13

What is the major difference between chitin and other types of polysaccharides?
(A-A*)

Answer 13

Chitin is nitrogenous

Question 14

Why is it impossible for humans to digest food that contains cellulose?
(A-A*)

Answer 14

Human digestive enzymes cannot break to β - 1,4 glycosidic linkages in cellulose, which requires a special enzyme that is absent in humans.

Question 15

What is a polysaccaride?

Answer 15

2 or more monomers joined together.

Question 16

State 4 examples of polysaccarides?

Answer 16

Starch
Cellulose
Glycogen
Chitin

Question 17

Define a lipid?

Answer 17

Lipids are biological molecules that are only soluble in organic solvents such as alcohol.

Question 18

What are the 2 types of lipids?

Answer 18

Saturated and Unsaturated

Question 19

What is a Saturated lipid?

Answer 19

A lipid that is found in animals and contains no double bonds and is solid at room temperature.

Question 20

What is an Unsaturated lipid?

Answer 20

A lipid that is found in plants that contain double bonds and melts at lower temperatures. Usually liquid at room temperature.

Question 21

What is a Triglyceride?

Answer 21

Molecules that contain one molecule of glycerol and 3 fatty acid molecules joined by ester bonds through condensation reactions. Also insouble in water.

Question 22

What is a phopholid?

Answer 22

A Phospholipid is a molecules with hydrophilic phosphate heads and hydrophobic lipid tails.

Question 23

What is the test for lipids?

Answer 23

The emulsion test