3.1 Biological Elements

Question 1

What are abundant and common elements in biology

Answer 1

Carbon
Hydrogen 
Oxygen
Nitrogen 
Phosphorus 
Sulfur

Question 2

What are the bonding rules in ionic and covalent bonding

Answer 2

A covalent bond occurs when 2 atoms share a pair of electrons.

In Ionic bonding, one atom donates an electron to another atom. This forms positive and negative ions that are held together by the attraction of the opposite charges.

The electrons used to form the bond are unpaired and orbit both atoms.

‘HONC’:
Hydrogen = 1 bond with another atom
Oxygen = 2 bonds with other atoms 
Nitrogen = 3 bonds 
Carbon = 4 bonds

Question 3

What are ions

Answer 3

An atom or molecule in which total number of electrons is not equal to the total number of protons = ion

If an atom loses one or more electrons it has a positive charge. = cation

If it gains it becomes a negative charge. = anion

Question 4

What are electrolytes

Answer 4

Ions in a solution is called electrolytes.

Cations:
Calcium ions are necessary for nerve impulse transmission.

Sodium ions are necessary for nerve impulse transmission.

Hydrogen ions are necessary for catalysis of reactions.

Anions:
Nitrate ions are necessary for nitrogen supply to plants for amino acid and protein formation.

Hydroxide ions are necessary for catalysis of reactions.

Question 5

What are examples of biological molecules

Answer 5

Carbohydrates- carbon, hydrogen, oxygen , in ratio Cx(H2O)x

Lipids- carbon, hydrogen, oxygen

Proteins- carbon, hydrogen, oxygen, nitrogen, sulfur

Nucleus acids - carbon, hydrogen, oxygen, nitrogen, phosphorus