2.2.1 Biological Molecules: Key Terms

Question 1

What are the key molecules that are required to build structures that enable organisms to function?

Answer 1

1. Carbohydrates
2. Proteins
3. Lipids
4. Nucleic Acids
5. Water

Question 2

What makes carbohydrates proteins nucleic acid and lipids organic substances?

Answer 2

The Carbon (C)

Question 3

Why is carbon the key to organic compounds?

Answer 3

1. Each carbon atom can form four covalent bonds making compounds very stable
2. C atoms can form covalent bonds with oxygen, nitrogen, and sulfur
3. C atoms can bond to form straight chains branched chains or rings

Question 4

Define polymerization

Answer 4

Is when carbon compounds can form from small single subunits (monomers) that bond with many repeating subunits to form large molecules (polymers).

Question 5

Polymers can be macromolecules but not all macromolecules can be polymers?

Answer 5

Because the subunits of polymers have to be the same repeating units.

Question 6

What are the three types of macromolecules?

Answer 6

1. Polysaccharides
2. Proteins (polypeptides)
3. Nucleic acids (polynucleotides)

Question 7

How can carbohydrates be represented?

Answer 7

Cx(H2O)y

Question 8

What are the three types of carbohydrates?

Answer 8

1. Monosaccharides
2. Disaccharides
3. Polysaccharides

Question 9

Define monosaccharides

Answer 9

single sugar monomer, all are reducing sugars

Question 10

Function of monosaccharide

Answer 10

1. source of energy in respiration
2. building blocks for polymers

Question 11

Examples of monosaccharides

Answer 11

glyceraldehyde
ribose
glucose

Question 12

Define disaccharide

Answer 12

a sugar formed from two monosaccharides joined by a glycosidic bond in a condensation reaction

Question 13

Function of disaccharides

Answer 13

1. sugar found in germinating seeds (maltose)
2. mammal milk sugar (lactose)
3. sugar stored in sugar cane (sucrose)

Question 14

Examples of disaccharides

Answer 14

maltose (a- glucose +a glucose)
sucrose (a glucose + fructose)
lactose (a glucose + B galactose)

Question 15

Define polysaccharide

Answer 15

a polymer formed by many monosaccharides joined by glycosidic bonds in a condensation reaction

Question 16

Function of polysaccharides

Answer 16

1. energy storage (plants - starch; animals - glycogen)
2. structural - cell wall

Question 17

Examples of polysaccharide

Answer 17

cellulose (B- glucose)
starch (a-glucose in the form of amylose and amylopectin)
glycogen ( a-glucose)

Question 18

Why glucose known as an isomer?

Answer 18

Because it has two different forms ( alpha glucose and beta glucose)

Question 19

What is the position of the OH group in alpha?

Answer 19

below the ring

Question 20

What is the position of the OH group in beta?

Answer 20

above the ring