Molecular Biology 2.3

Question 1

What are monomers of carbs ?

Answer 1

Monosaccharides

Question 2

3 most common Monosaccharides

CnH2nOn

Answer 2

1) Trioses C3H6O3
2) Pentoses C5H10O5
3) Hexoses C6H12O6

Question 3

Sucrose

Answer 3

Glucose +fructose

Question 4

Maltose

Answer 4

2 Alpha D glucose

Question 5

Lactose

Answer 5

Alpha D glucose + Galactose

Question 6

C6H12O6

Answer 6

Glucose and Fructose are isomers of each other because they have same molecular formula.

Question 7

Water as a product of condensation reactions

Answer 7

1) One of the two monosaccharides donates OH- ion
2) The other monosaccharides donates H+ ion
3) These two combines to form water molecule.

Question 8

Examples of Polysaccharides

Answer 8

1) Starch : Product of photosynthesis
2) Cellulose : Plant cell walls, gives plants rigidity
3) Glycogen : Animals store excess glucose.Stored in liver and muscle tissue.

Question 9

Polymers of glucose

Answer 9

Starch , Glycogen and Cellulose are made up of same monomer unit called glucose.

Question 10

Sub components of starch

Answer 10

1) Amylose

2) amylopectin

Question 11

Amylose

Answer 11

Only one of the 3 glucose polysacchruides with no side branching

1) Linear molecule
2) Less soluble in water
3) 20-30% of starch

Question 12

Amylopectin

Answer 12

1) Branched polysacchride
2) Highly branched
3) Soluble in water

Question 13

What are main components of fatty acids

Answer 13

1) Carboxyl group (COOH) end
2) Methyl end (CH3)
3) In between these two ends, there is usually 11-23 Carbon long chain

Question 14

Saturated fatty acids

Answer 14

1) Contains the maximum no of Hydrogen atoms.
2) Typically found in animal products : Red meat, bacon, butter etc.
3) These fats are generally solids at room temperature.
4) No double or triple bonds
5) The shape of the molecules is straight: there are no bents or kinks along the chain.

Question 15

What is omega end ?

Answer 15

The end with methyl group in fatty acids is called Omega end.

Question 16

Monounsaturated fatty acids

Answer 16

1) If 1 double bond exists in the chain of hydrocarbons

2) Causes molecule to bend at the zone where the double bond exist.

Question 17

Polyunsaturated fatty acids

Answer 17

1) have at least 2 double bonds in the carbon chain.
2) Typically come from plants
3) Eg: Olive oil
4) tend to be liquids at room temperature.
5) they have so many bends and kinks

Question 18

Hydrogenation

Answer 18

1) Polyunsaturated fatty acids are hydrogenated or partially hydrogenated
2) Double bonds(kinks/bends) are eliminated by adding hydrogen
3) It straightens the natural bent shape of the unsaturated fatty acids
4) Naturally curved fatty acids= Cis fatty acids
5) Hydrogenated straighten ones= trans fatty acids
6) Application = food processing factories

Question 19

What is omega-3 ?

Answer 19

1) Category of cis fatty acids
2) First carbon double bond to be found on the third carbon atom counting backwards from the omega end.
3) Fish is a good source of Omega-3

Question 20

Lipids as energy source

Answer 20

1) they have twice the energy content per gramme compared with other molecules such as carbs or proteins
2) As a long-term energy source, they are extremely beneficial because they are insoluble in water so they dont upset the osmotic balance of solutions whereas if glucose were to store for long period of time in large concentrations then those cells would swell.