Topic 2: Biological Molecules

Question 1

Amino Acid

Answer 1

These are the building blocks of protein molecules. They contain the element carbon, hydrogen, oxygen, nitrogen, and sometimes sulphur. There are 20 different types of amino acid which can join together in different ways to form different proteins. Amino acid are joined together through condensation reaction.

Question 2

Cellulose

Answer 2

This is a polysaccharide molecule found in the cell wall of plants. It is a polymer of the monosaccharide β-glucose where successive β-glucose units are joined together at 180 degree to each other.

Question 3

Condensation Reaction

Answer 3

This is the joining of monomers together which results in the loss of water molecules.

Question 4

Covalent Bond

Answer 4

A bond formed by sharing of pairs of electrons between two atoms.

Question 5

Dipeptide

Answer 5

The product formed when two amino acids react together.

Question 6

Disaccharide

Answer 6

This is a molecule comprising two monosaccharides joined together by a glycosidic bond through a condensation reaction.

Question 7

Disulphide Bond

Answer 7

These are strong bonds which form between two cysteine amino acids which stain sulphur molecules.

Question 8

Globular Structure

Answer 8

A protein molecule whose molecules curl up into a spherical shape is described as having a globular structure. These molecules are often water soluble metabolically active.

Question 9

Glycogen

Answer 9

A polysaccharide made of many glucose molecules linked together. Glycogen acts as a glucose storage molecule in the liver and muscle cell.

Question 10

Glycosidic Bond

Answer 10

the C-O-C link between two monosaccharide molecules formed by a condensation reaction.

Question 11

Haemoglobin

Answer 11

This is a protein molecule which is found in red blood cells which gives the cell its red colour. Its molecules contain four iron atoms within a globular protein made up of four polypeptides and that combine reversibly with oxygen.

Question 12

Hydrogen Bond

Answer 12

A bond formed by the attraction between a group with a small positive charge on a hydrogen atom and another group carrying a small negative charge, e.g. Oδ- and Hδ+

Question 13

Hydrolysis

Answer 13

A reaction in which a complex molecule is broken down to simpler ones involving the addition of water.

Question 14

Hydrophobic Intereaction

Answer 14

This is an reaction between a polar and a non-polar compound

Question 15

Ionic Bond

Answer 15

The electrostatic interaction between oppositely charged ions.

Question 16

Metabolism

Answer 16

The sum of the chemical reactions that take place inside the cells of a living organism.
Catabolic and Anabolic reactions are part of the body’s metabolism.

Question 17

Molecular Formula

Answer 17

The formula that tells us the actual numbers of each type of atom in a molecule.

Question 18

Monomer

Answer 18

A small, reactive molecule that reacts to make long-chain molecules called polymers

Question 19

Monosaccharide

Answer 19

A single sugar. A carbohydrate whose molecules are made of just one sugar unit.

Question 20

Peptide Bond

Answer 20

This is the bond that exists between two amino acids formed from a hydrolysis reaction. The bond is between the -COOH group of another amino acid.

Question 21

Phospholipid

Answer 21

This is a lipid molecule with a phosphate group attached. Phospholipids are part of the composition of the cell membrane.

Question 22

Polar (Covalent Bond)

Answer 22

A covalent bond in which the two bonding electrons are not shared equally by the atoms in the bond. the atom with greater share of electrons has a partial negative charge and the other has a partial positive charge.

Question 23

Polysacchide

Answer 23

A carbohydrate whose molecules are made of hundreds of sugar units linked in long chains through glycosidic bonds.
e.g. starch, cellulose and glycogen

Question 24

Polymer

Answer 24

A long chain molecule made up of many repeating units.

Question 25

Primary Structure

Answer 25

The sequence of amino acids in a polypeptide chain of a protein.

Question 26

Quaternary Structure

Answer 26

The three dimensional arrangement of two or more polypeptides, or of a polypeptide and a non-protein component such as haem, in a protein molecule.

Question 27

Saturated Bond

Answer 27

a single covalent bond

Question 28

Secondary Structure

Answer 28

The structure of a protein molecule resulting from the regular coiling or folding of the chain of amino acids.
e.g. alpha helix and beta pleated sheets.

Question 29

Structural Formula

Answer 29

This is the formula that tells us about the atoms bonded to each carbon atom in an organic molecule.

Question 30

Tertiary Structure

Answer 30

The compact structure of a protein molecule resulting from the three dimensional coiling of the already-folded chain of amino acids

Question 31

Triglyceride

Answer 31

A lipid whose molecules are made up of a glycerol molecule and three fatty acids.

Question 32

Unsaturated Bond

Answer 32

A molecule which contains only a double or triple bond.