Biological Molecules Ch.2

Question 1

What is a polymer?

Answer 1

Repeating subunits of that are similar or identical to each other

Question 2

What is the difference between alpha and beta glucose?

Answer 2

Alpha glucose has the -OH group below the ring, while beta glucose has it above the ring.

Question 3

What is hexose and mention three forms of it

Answer 3

Type of monosaccharide with 6 carbons. Glucose, fructose, sucrose.

Question 4

Mention two functions of monosaccharide

Answer 4

Source of energy for respiration and building blocks for larger molecule like starch

Question 5

What is maltose, sucrose, and lactose

Answer 5

Maltose: Glucose + glucose
Sucrose: Glucose + fructose
Lactose: Glucose + galactose

Question 6

What type of bond is in disaccharides

Answer 6

Glycosidic bond

Question 7

What test is used to test reducing sugar?

Answer 7

Benedict test

Question 8

What test is used to test non-reducing sugar?

Answer 8

Add hydrochloric acid to break down the disaccharide into its two constituents, then add benedict solution after the acid is neutralized.

Question 9

What is polysaccharide

Answer 9

A polymer whose subunits are monosaccharides joined together by glycosidic bonds

Question 10

Explan the differences of starch, glycogen and cellulose

Answer 10

These three are common forms of polysaccharides. Starch and glycogen are made out of only alpha glucose. Starch only has 1,4 link alpha glucose, while glycogen has 1,4 and 1,6 link alpha glucose. Starch comes in the form of cylinder as it curves, while glycogen branch out. Cellulose are made out of beta glucose. One of it is 180 degree rotated to form 1,4 link.

Question 11

Explain why sugar is soluble in water.

Answer 11

Sugar is polar, which means that it has dipole groups that have unequal distribution of electrons, causing attraction on delta-charged atoms. Water molecules are also dipoles attracting sugar.

Question 12

What test is used to test starch?

Answer 12

Use iodine solution forming blue black color

Question 13

What are lipids?

Answer 13

Organic molecule insoluble in water made out of fatty acids and alcohol.

Question 14

What is triglycerides and its function

Answer 14

Three fatty acids combined with glycerol, forming three ester link. Store of energy as fat in animals, and as oil in plants

Question 15

How is phospholipid a special form of lipid?

Answer 15

One of the fatty acid is replaced with a phosphate which is hydrophilic, polar. Forms a phosphate head and is significant for membrane.

Question 16

What is the test for protein

Answer 16

Biuret test with sodium hydroxide and hydrate copper (II) sulfate, changes the color to purple

Question 17

What are the groups found in a protein

Answer 17

NH2, COOH, H, and R

Question 18

What is primary structure

Answer 18

The sequence of amino acids in a polypeptide/protein

Question 19

What are two types of secondary structure and explain each

Answer 19

Alpha helix is a helical structure with hydrogen bonds, beta pleated sheet is a loos sheet like structure also with hydrogen bonds but within parallel polypeptide chains

Question 20

What is tertiary structure

Answer 20

The compact structure of a protein resulting by the three-dimensional coiling of polypeptides

Question 21

Mention four types of bonds found in tertiary structure of protein

Answer 21

Hydrogen bond, disulfide bond, ionic bond, hydrophobic interactions

Question 22

What is quartenary structure, example?

Answer 22

Three dimensional structure of two or more polypeptides, or of polypeptide with a non-protein component, hemoglobin

Question 23

Explain globular protein and example

Answer 23

A protein whose molecules are folded into a relatively spherical shape. Hemoglobin that’s hydrophobic inside hydrophilic outside, soluble in water. Made out of two alpha globin chains and two beta globin chains.

Question 24

Explain fibrous protein and example

Answer 24

A protein whose molecules have a relatively long,thin structure that is generally insoluble and metabolically inactive. Made out of three polypeptide chains, wound around each other, form tight coil from glycine, forming fibrils, finally fibres.