Topic 1: Introduction to Biology

Assalamualaikum wbt & A very good day....

As for the first topic, we will define and locate important terms, components, and designs to the world of biology. We will discuss all the basic things needed to proceed with the more complex discussion of our hollistic syllibus.

Our Objectives:
At the end of the 1st topic, everybody should be able to:

1. Define biology and other important basic terms in biology.
2. Discuss biological level of organization.
3. Discuss important bonds, water and functional groups and Identify their distinctive roles.

Let us start;

1) Biology

• Definition: Study of living organism and their relationship
• have many subdivision; ecology, cell biology, molecular biology, physiology, parasitology etc.
• said to be a complex and messy subject because of the infinite number of interactions that must be considered

If to compare between animate and inanimate; certain points will be very usefull

• Life is organized (hierarchy)
• Life is require energy-energy utilization
• Living thing grow, develop & reproduce
• Response to the Environment (sensitivity)
• Living thing must maintain an internal constancy (homeostasis)
• Living things adapt (evolutionary change over many generations)

2) Biological level of organization.

Next we will be discussing the 3rd objectives; to discuss

3) important bonds, water and functional groups and Identify their distinctive roles.

Important Bonds;

i) Ionic Bonds -Combination of two atoms by transferring of electrons. Thus one atom will gain electrons (anion) and the other one will loses electrons (cation)

ii) Covalent Bonds -Electrons do not have to be completely lost or gained for atoms to become stable. Instead they can be shared in a way that each atom is able to fill their valence shell.

iii) Hydrogen Bonds-Weak bonds that formed when a hydrogen atom bound to one electron-hungry atom (eg; oxygen, nitrogen) is attracted by another electron-hungry atom.

Water Molecules~Composed of: 1 Oxygen Atom and 2 Hydrogen Atoms

~Share electrons forming strong covalent bonds.

Characteristics of water
- Dipolar and uneven distribution of charge
- Hydrogen bonding

Properties of water
- denser than ice
- high latent heat of vaporisation
- high specific heat capacity
- high cohesion

Importance of water
- As a universal solvent
- In metabolism
- As a lubricant
- Giving support

These molecular components are known as functional groups composed of
- hydroxyl, -OH
- carboxyl, -COOH
- carbonyl, -CHO of aldehyde and ketone
- amine, -NH2
- phosphate, -OPO32- and
- sulfhydryl, -SH

Based on their positions, these groups play a major role in the molecular interactions in cells as well as building block of complex biological molecules.

See you again!!

Best Regards;
Sir Ishak