Biological Molecules

Question 1

What is a Monomer?

Answer 1

-A small molecule which usually joins up with others to form larger molecules.

Question 2

What is a polymer?

Answer 2

-A large molecule consisting of many monomers

Question 3

what is a Monosaccharide?

Answer 3

A single carbohydrate monomer.

Question 4

what is a disaccharide?

Answer 4

2 carbohydrate monomers joined together.

Question 5

what is a polysaccharide?

Answer 5

A chain of monosaccharides.

Question 6

what is Condensation?

Answer 6

A reaction during which water is removed when a bond forms.

Question 7

What is Hydrolysis?

Answer 7

A reaction during which water is added in order to break a bond.

Question 8

what are examples of monosaccharides?

Answer 8

Glucose, fructose and galactose.

Question 9

what are isomers?

Answer 9

molecules with the same molecular formula as each other, but with the atoms connected in a different way.

Question 10

how are monosaccharides joined together?

Answer 10

they are joined together by condensation reactions. a glycosidic bond forms between the two monosaccharides as a molecule of water is released.

Question 11

what is the theory of evolution?

Answer 11

the theory that all organisms on earth are descended from one or a few common ancestors and that they have changed and diversified over time.

Question 12

how can biological polymers be broken down into monomers?

Answer 12

by hydrolysis reactions. A hydrolysis reaction breaks the chemical bond between monomers using s water molecule. (opposite of condensation reaction).

Question 13

what is the role of carbohydrates?

Answer 13

1) Energy supply for cells- Main role of carbohydrates.
2) Energy storage - Sugar can be stored as complex carbohydrates e.g. starch/ glycogen.
3) Structural components - Cellulose + chitin are used in cell walls.
4) Cellular recognition - Glycoproteins help cells identify each other + communicate.
5) Building blocks for biological molecules - Deoxyribose + ribose can be used to make nucleic acids.

Question 14

What are the different types of carbohydrates?

Answer 14

Monosaccharides, Disaccharides and Polysaccharides.

Question 15

Describe a Monosaccharide.

Answer 15

• One (Monomer)
• E.g. Glucose, Fructose and galactose.
• Main function is energy source.

Question 16

describe a Disaccharide.

Answer 16

• Two(Dimer)
• E.g Maltose, Sucrose, Lactose.
• Main function is a transport form.

Question 17

Describe a Polysaccharide.

Answer 17

-Many (polymer)
-E.g Starch, Glycogen,Cellulose.
- Main function is a storage form.

Question 18

name three hexose sugars. (6 carbon atoms)

Answer 18

• Glucose, Fructose and galactose.

Question 19

name two pentose sugars. (5 carbon atoms)

Answer 19

• Ribose and Deoxyribose.

Question 20

what is the general formula for a carbohydrate?

Answer 20

• CnH2nOn

Question 21

wha tis the formula for glucose?

Answer 21

C6H12O6

Question 22

how many ways can the atoms in glucose be arranged?

Answer 22

two ways meaning that there are two isomers of glucose
- Alpha glucose (α-glucose)
-Beta glucose (β-glucose)

Question 23

what is the main difference between alpha and beta glucose?

Answer 23

• The orientation of the hydroxyl group (OH) on the carbon 1
• in Alpha glucose the hydroxyl group is below and in beta glucose the hydroxyl group is above.

Question 24

What is the use for glucose?

Answer 24

1) ** it is soluble** as the hydroxyl groups can form hydrogen bonds with the water, so it can be transported around organisms.
2)its bonds store lots of energy - this energy is released when the bonds are broken.

Question 25

how are disaccharide formed?

Answer 25

• when two monosaccharides join together. eg maltose, sucrose and lactose.

Question 26

what monosaccharides join to form common disaccharide?

Answer 26

• Two alpha glucose monosaccharides join together to form maltose.
• one alpha glucose and one fructose monosaccharide join together to form sucrose.
• one alpha glucose and one galactose monosaccharide joins together for form lactose.

Question 27

What reactions used to form and break disaccharide?

Answer 27

• A condensation reaction to form the disaccharide and a hydrolysis reaction to break down the disaccharide.
  These involve the formation or breakdown of glycosidic bonds.

Question 28

give an example of a condensation reaction with two alpha glucose?

Answer 28

Glucose + Glucose = maltose +water
- When two monosaccharides join, the hydroxyl group (OH) on carbon 1 of one monosaccharide reacts with the hydroxyl group (OH) on carbon 4 of another monosaccharide.
- A 1-4 glycosidic bond is formed and a water molecule (H2O) is released.

Question 29

give an example of a Hydrolysis reaction with two alpha glucose?

Answer 29

Maltose + water = glucose + glucose
- When a water molecule (H2O) is added to a disaccharide, the glycosidic bond is broken to release the 2 monosaccharides.