Biomolecules

Question 1

Acid soluble fraction/filtrate?-micromolecules?

Answer 1

Monosaccharides, amino acids, nucleotides

Question 2

Acid insoluble fraction/filtrate?-macromolecules?

Answer 2

Polysaccharides, proteins, nucleic acids, lipids

Question 3

Why are lipids found in acid insoluble fraction?

Answer 3

Lipids which are less than 800 daltons are found in acid insoluble fraction because lipids form an integral part of cell membrane therefore during the grinding process, lipids break and form small vesicles which increases their size from their original and therefore does not pass through the filter

Question 4

General structure of an amino acid

Answer 4

Amine group(NH2), carboxyl group(COOH), variable R group, and hydrogen

Question 5

Types of amino acids, describe and examples

Answer 5

1. Acidic amino acid- have additional carboxyl group, eg: aspartic acid
2. Basic amino acid- have additional amine group, eg: lysine, arganine
3. Neutral amino acid- have equal number of carboxyl and amine groups, eg: glycine
4. Aromatic AA- have a cyclic structure as the R group

Question 6

Glycine R group

Answer 6

Hydrogen atom is the R group

Question 7

Alanine R group

Answer 7

Ch3, methyl

Question 8

Serine R group

Answer 8

Ch2OH, alcohol

Question 9

What is zwitter ion formation?

Answer 9

Refers to the ionisable property of carboxyl and amine group, resulting in the formation of a molecule with both positive and negative charge co-existing together.

Question 10

What happens in acidic pH?

Answer 10

H+ added to the carboxyl group in order to form COOH, therefore it becomes a cation as NH3+ is positive charge

Question 11

What happens in basic PH?

Answer 11

H+ is removed from NH3+ which combines with OH- to form water thus it becomes an anion due to negative charge of carboxyl group

Question 12

Neutral pH?

Answer 12

There is existence of both ions

Question 13

What is a peptide bond and how is it formed?

Answer 13

A peptide bond is formed to link 2 amino acids resulting in the formation of a di peptide. This bond is formed when the carboxyl group ofthe first is linked to the amine group of the second AA by losing a water molecule (dehydration reaction)

Question 14

Describe Primary Structure of proteins

Answer 14

Consists of polypeptide chain of amino acids with free carboxyl group at one end known as c terminal amino acid and amine group at other end known as N terminal amino acid

Question 15

Describe Secondary Structure of proteins

Answer 15

Can occur in 2 forms:
Alpha helix: the helical structure is formed due to hydrogen bonding between the first AA and 5th AA
ẞ pleated sheet: This structure occurs due to hydrogen bonding between distant AA on a polypeptide chain giving rise to a sheet like appearance

Question 16

TERTIARY STRUCTURE

Answer 16

it is a 3-D structure formed due to various interactions between the amino acids in the form of peptide, hydrogen, ionic bonds, di sulphide bridge, hydrophobic interactions, This folded appearance gives rise to crevices which creates a befitting space for the substrate molecule to fit in for enzymatic catalysis

Question 17

Quaternary Structure

Answer 17

Consists of multiple polypeptide chains. Eg: haemoglobin, 2 alpha and 2ß structures each with a centre called heme which has Fe2+ ions to help bind with oxygen.

Question 18

What is 1,4 glycosidic linkage

Answer 18

When 2 monosaccharides are linked by a glycosidic bond in which a water molecule is removed by combining H from OH group at 1C to OH group at 4C of another monosaccharide