Biochemistry Wk 2

Question 1

What do organic molecules of the body consist of

Answer 1

Carbon
Hydrogen
Oxygen
Nitrogen
Sulfur
Phosphorus

These are joined by covalent bonds

Question 2

What is oxidation

Answer 2

Loss of electrons and results in the loss of hydrogen atoms, gain of oxygen atom or hydroxyl group

Question 3

What is reduction

Answer 3

Gain of electrons and results in the gain of hydrogen atoms or loss of an oxygen atom

Question 4

What charge do acidic groups contain

Answer 4

Proton groups that can dissociate, usually leaving the remainder of the molecule as an anion with a negative charge

Question 5

What are the major anionic substituents

Answer 5

Carboxylate
Phosphate
Sulfate
Groups

Question 6

What charge do nitrogen compounds contain

Answer 6

Usually basic and can acquire a positive charge

Question 7

What are the four types of carbohydrates and what is its function

Answer 7

Monosaccharides
Disaccharides
Oligosaccharides
Polysaccharides

It is the main source of energy for the body

Question 8

What do glycosidic bonds join to

Answer 8

To monosaccharides or longer chains to other carbohydrates, forming disaccharides, oligosaccharides and polysaccharides

Question 9

Describe the formation of O glycosidic bond

Answer 9

If the anomeric carbon of the sugar forms the bond with the oxygen atom in the hydroxyl group in the alcohol the bond is named as O glycosidic bond

Question 10

Describe the formation of N glycosidic bond

Answer 10

If the anomeric carbon of the sugar forms the bond with the nitrogen atom of an amine it forms an N glycosidic bond

Question 11

What is a disaccharide

Answer 11

Contains two monosaccharides joined by an O- glycosidic bond

Question 12

What is an oligosaccharide

Answer 12

Contain from 3 to roughly 12 monosaccharides linked together. They are often found attached through N or O glycosidic bonds to proteins to form glycoproteins

Question 13

Examples of monosaccharides

Answer 13

Glucose
Fructose
Galactose

Question 14

Examples of disaccharides

Answer 14

Sucrose
Lactose
Maltose

Question 15

Examples of oligosaccharides

Answer 15

Raffinose
Stachyose

Question 16

Examples of polysaccharides

Answer 16

Starch
Glycogen
Cellulose

Question 17

What are fatty acids

Answer 17

They are usually straight aliphatic chains with a methyl group at one end (called the omega (w)- carbon) and a carboxyl group at the other end

Question 18

Do saturated fatty acids have a double bond and what is the most common saturated fatty acids

Answer 18

No

Palmitic acid (c16)
Stearic acid (c18)

Question 19

Unsaturated fatty acids have…

Answer 19

One or more double bonds

Question 20

What does the ratio stand for (for example- 18:1delta9)

Answer 20

18 denotes the number of carbon atoms
1 denotes the number of double bonds
And delta 9 denotes the position of the double bond between the 9th and 10th atoms

Question 21

What are acylglycerols

Answer 21

It comprises of glycerol with one or more fatty acids attached through ester linkages

Question 22

What are phosphoacylglycerols and give an example

Answer 22

Contains fatty acids esterified to positions 1 and 2 of glycerol and a phosphate attached to carbon 3

Phophatidylcholine is one of the major phosphoacylglycerols found in membranes. The amine is positively charged at neutral ph and the phosphate is negatively charged so the molecule is amphipathic

Question 23

What are sphingolipids

Answer 23

They do not have a glycerol backbone; they are formed from a sphingosine

For example, ceramides are amides formed from a sphingosine by attaching a fatty acid to amino group

Question 24

What are steroids

Answer 24

They are a four ring structure
For example, cholesterol is not very water soluble it is converted to amphipathic water soluble bile salts such as cholic acid

Question 25

What are functional groups

Answer 25

Biochemical molecules are defined both by their carbon skeleton and by structures

Question 26

What is a monosaccharide

Answer 26

Consist of linear chain of three or more carbon atoms, one of which forms a carbonyl group through double bonds with oxygen

The unmodified monosaccharide contains hydroxyl groups

If the carbonyl group is an aldehyde it is Aldose sugar
If the carbonyl group is a ketone it is ketose sugar