chemical and cellular basis of life - definitions

Question 1

Polarity

Answer 1

polarity is an uneven charge distribution within a molecule.

Question 2

Hydrogen Bonds

Answer 2

Weak attractions between the slightly polar hydrogen atom of one water molecule and the slightly polar oxygen atom of the adjacent water molecule are known as hydrogen bonds.

Question 3

Cohesion

Answer 3

Attraction between water molecules due to hydrogen bonding is known as cohesion

Question 4

Adhesion

Answer 4

Attraction between water molecules and other substances

Question 5

Carbohydrates

Answer 5

Carbohydrates are the most abundant group of organic compounds on earth with a major elemental composition of C, H, and O.

Hydrates of carbon contain the same proportion of H:O which equals to 2:1 as in water.

The general formula of carbohydrates is Cx(H20)y

Question 6

Monosaccharides

Answer 6

The simplest form of carbohydrates having the general molecular formula of (CH2O)n are monosaccharides.

Question 7

Disaccharides

Answer 7

They are the sugars formed by joining two monosaccharides by a glycosidic bond

Question 8

Glycosidic Bond

Answer 8

A glycosidic bond is formed by the removal of a water molecule from two adjacent monosaccharides by a condensation reaction.

Question 9

Polysaccharides

Answer 9

They are macromolecules and biopolymers made up of a few hundred to a few thousand monosaccharide subunits.

Question 10

Lipids

Answer 10

Lipids are a diverse group of large hydrophobic molecules which are biological molecules but not considered as polymers or macromolecules.

They consist of C,H,O and H:O ratio is not 2:1. Comparatively more H is present.

Question 11

Saturated Fats

Answer 11

Fats are made up of saturated fatty acids (fatty acids with hydrocarbons having no double bonds)

Question 12

Unsaturated Fats

Answer 12

Fats are made up of unsaturated fatty acids (fatty acids with hydrocarbons having one more more double bonds)

Question 13

Phospholipids

Answer 13

Phospholipids are major components of cells membranes composed of two fatty acids and one phosphate group attached to one glycerol molecule.

Question 14

Proteins

Answer 14

Proteins are made up of amino acids and has an elemental composition of C, H, O, N and S

Question 15

Primary Structure of Proteins

Answer 15

The unique sequence of linearly arranged amino acids linked by peptide bonds is the primary structure of proteins.

Question 16

Secondary Structure of Proteins

Answer 16

When the primary structure of a single polypeptide chain coils and folds, as a result of intra molecular hydrogen bonds between the oxygen atoms and hydrogen atoms attached to the nitrogen atoms of the same poly peptide chain backbone to form the secondary structure.

Question 17

Tertiary Structure of Proteins

Answer 17

Usually the secondary polypeptide chain bends and golds extensively forming a precise compact unique, functional and three-dimensional shape resulting from the interactions between the side chain/R-group of amino acids.

Question 18

Quaternary Structure of Proteins

Answer 18

The aggregation of two or more polypeptide chains involve in the formation of one functional protein. Separate chains are called sub units which were held together by inter and intra-molecular bonds.

Question 19

Denaturation of Proteins

Answer 19

Denaturation of proteins is the loss of its specific chemical three dimensional shape due to the alteration of weak chemical bonds and interactions.

Question 20

Nucleic Acids

Answer 20

Nucleic acids are polymers that exist as polynucleotides made up of monomers called nucleotides containing C,H,O,N and P

Question 21

Base Pair Rule

Answer 21

Always a purine base, pairs with a specific pyrimidine base