Unit 02 - Chemical and Cellular Basis of Life (2)

Question 1

What is the most abundant group of organic compounds on earth?

Answer 1

Carbohydrates

Major elemental composition is C, H, and O.

Question 2

What is the general formula for carbohydrates?

Answer 2

C(H2O)n

Hydrates of carbon contain H:O in a 2:1 ratio as in water.

Question 3

What are the three major groups of carbohydrates?

Answer 3

• Monosaccharides
• Disaccharides
• Polysaccharides

Question 4

Define monosaccharides.

Answer 4

The simplest form of carbohydrates with the general molecular formula (CH2O)n

Number of C atoms varies from 3-7.

Question 5

What is the range of carbon atoms in monosaccharides?

Answer 5

3-7

Question 6

What are the classifications of monosaccharides based on the number of carbon atoms?

Answer 6

• 3C - Triose (e.g. Glyceraldehydes)
• 4C - Tetroses (e.g. Erythrose)
• 5C - Pentoses (e.g. Ribose)
• 6C - Hexoses (e.g. Glucose)

Question 7

What are the two types of carbonyl groups in monosaccharides?

Answer 7

• Aldoses
• Ketoses

Question 8

Give examples of aldoses.

Answer 8

• Glucose
• Galactose

Question 9

Give an example of a ketose.

Answer 9

Fructose

Question 10

What are disaccharides?

Answer 10

Sugars formed by joining two monosaccharides by a glycosidic bond.

Question 11

How is a glycosidic bond formed?

Answer 11

By removal of a water molecule from two adjacent monosaccharides through a condensation reaction.

Question 12

What are examples of disaccharides?

Answer 12

• Maltose
• Sucrose
• Lactose

Question 13

Which disaccharides are reducing sugars?

Answer 13

• Maltose
• Lactose

Question 14

What is a non-reducing sugar among disaccharides?

Answer 14

Sucrose

Question 15

Define polysaccharides.

Answer 15

Macromolecules and biopolymers made up of few hundred to a few thousand monosaccharide subunits.

Question 16

Are polysaccharides crystalline or non-crystalline?

Answer 16

Non-crystalline

Question 17

What types of polysaccharides are there based on function?

Answer 17

• Storage polysaccharides
• Structural polysaccharides

Question 18

Name examples of storage polysaccharides.

Answer 18

• Starch
• Glycogen

Question 19

Name examples of structural polysaccharides.

Answer 19

• Cellulose
• Hemicellulose
• Pectin

Question 20

What are linear forms of polysaccharides?

Answer 20

• Cellulose
• Amylose

Question 21

What are branched forms of polysaccharides?

Answer 21

• Glycogen
• Amylopectin
• Hemicellulose

Question 22

What is the monomer and function of starch?

Answer 22

• Monomer: Glucose
• Function: Stored in plants

Question 23

What is the monomer and function of glycogen?

Answer 23

• Monomer: Glucose
• Function: Stored in animals and fungi

Question 24

What is the monomer and function of cellulose?

Answer 24

• Monomer: Glucose
• Function: Component of cell wall

Question 25

What is the function of monosaccharides?

Answer 25

* Building blocks of disaccharides and polysaccharides * Components of nucleotides (DNA, RNA)

Question 26

What is the storage sugar in milk?

Answer 26

Lactose

Question 27

What is the translocation sugar in phloem?

Answer 27

Sucrose

Question 28

Fill in the blank: Starch stores glucose as energy source in ______.

Answer 28

plants

Question 29

Fill in the blank: Glycogen stores glucose as energy source in ______.

Answer 29

animals and fungi

Question 30

Fill in the blank: Cellulose is found in the cell walls of ______.

Answer 30

plants

Question 31

What is the monomer and function of pectin?

Answer 31

* Monomer: Galacturonic acid * Function: Component of middle lamella of plant cell wall

Question 32

What is the monomer and function of chitin?

Answer 32

* Monomer: Glucosamine * Function: Component of fungal cell walls and exoskeleton of arthropods