Chapter 2.1: Biological Molecules: (Intro & Carbohydrates)

Question 1

Define Monomer

Answer 1

Individual subunits that make up a polymer

Question 2

Define Polymer

Answer 2

Long chain of repeated subunits

Question 3

Define Macromolecule

Answer 3

Large biological molecule

Question 4

Monomer of Lipids

Answer 4

3 Fatty Acids + Glycerol

Question 5

Monomer of Proteins

Answer 5

Amino Acid

Question 6

3 uses for Carbohydrates

Answer 6

• Energy storage
• Energy source
• Structural support in Plants

Question 7

Monomer for Carbohydrates

Answer 7

Monosaccharides

Question 8

Covalent Bond in Carbohydrates

Answer 8

Glycosidic Bond

Question 9

Covalent Bond in Proteins

Answer 9

Peptide Bond

Question 10

Covalent Bond in Lipids

Answer 10

Ester Bond

Question 11

Define condensation reaction

Answer 11

Reaction in which 2 smaller molecules combine to form a larger molecule and water is a byproduct

Question 12

Define hydrolysis reaction

Answer 12

Reaction in a larger molecule is broken down into smaller molecules by the addition of water

Question 13

3 Monomer of Carbohydrates

Answer 13

• Glucose
• Fructose
• Galactose

Question 14

3 Disaccharides of Carbohydrates

Answer 14

• Maltose
• Sucrose
• Lactose

Question 15

Differentiate between α-glucose and β-glucose

Answer 15

• In β-glucose, the hydroxide group is found above the carbon 1 while in α-glucose, the hydroxide group is found below carbon 1.
• When forming chains of α-glucose and β-glucose, β-glucose must be turned 18- degrees for a glycosidic bond to form

Question 16

Benedict’s Test is used to identify the presence of ______?

Explain the colour change for positive and negative results

Answer 16

-Reducing sugars

• PRESENT: BrickRed
• NOT PRESENT: Blue

Question 17

Ethanol Emulsion Test is used to identify the presence of ______?
Explain the colour change for positive and negative results

Answer 17

-Lipids

• PRESENT: Cloudy-white
• NOT PRESENT: Colourless; Clear

Question 18

Biuret Test is used to identify the presence of ______?

Explain the colour change for positive and negative results

Answer 18

-Proteins

• PRESENT: Purple
• NOT PRESENT: Blue

Question 19

Iodine Test is used to identify the presence of ______?

Explain the colour change for positive and negative results

Answer 19

-Starch

• PRESENT: Blue-black
• NOT PRESENT: Yellow

Question 20

4 main polysaccharides

Answer 20

Amylopectin & Amylose (Starch), Glycogen, Cellulose

Question 21

Differentiate between amylose and amylopectin

Answer 21

• Amylose (1,4 glycosidic bonds) & Amylopectin (1,4 & 1,6 glycosidic bonds)
• Amylose (helical) Amylopectin (highly-branched)
• Amylose (ideal for storage) Amylopectin (ideal for releasing energy as there are many ends for enzymes to work on)
• Amylose (Blue: iodine test result) Amylopectin (Red)
• Amylose (Soluble in water) Amylopectin (insoluble in water)

Question 22

Differentiate between amylopectin and glycogen

Answer 22

• Glycogen has shorter chains but is more highly branched than amylopectin
• Glycogen is found in animals while amylopectin is found in plants

Question 23

Differentiate between cellulose and other polysaccharides

Answer 23

• Cellulose is composed of β-glucose while other polysaccharides are composed of α-glucose.
• Function of cellulose is structural support while other polysaccharides are for energy storage.

Question 24

Why is starch suitable for energy storage?

Answer 24

1. Insoluble and therefore does not affect water potential of the cell
2. It won’t diffuse out of the cell
3. Amylose is helical and therefore compact
4. Amylopectin has many ends for enzymes to work on for fast release of energy
5. Can be hydrolyzed to produce glucose