CLASSIFICATION

STRUCTURE

• procaryotic unicellular organisms which are found everywhere.•Small group of bacteria are harmful but generally bacteria are benefit (useful). •Useful bacteria are used in the production of yoghurt and cheese.

• Some bacteria cause diseases. This type of bacteria is called pathogenic bacteria.

• Pathogenic bacteria cause disease such as tuberculosis, cholera, diptheria, pneumonia, typhoid and teeth decay.

• *have cell membrane, cytoplasm, and hereditary material (DNA).

• *have also cell wall.• *Have ribosomes to produce

protein.

STRUCTURE OF BACTERIA

•Some bacteria have mesosome

• Aerobic respiration takes place in mesosome of bacteria.

• Energy is produced at the end of the aerobic respiratoin.

• Reproduce by binary fission.

•Some bacteria may contain free chlorophyll in its structure..

• Most bacteria also have flagella to provide motion.

Types of bacteria according to their shape; a)

Bacillus b) Coccus c) Vibrio d) Spirillia

Types of bacteria according to their nutrition

•Hetetrophs•Autotrophs

1. Autotrophic Bacteria:

• can synthesize their own food.

• If bacteria use sunlight as an energy source, they are known as phototrophs.

• However some bacteria obtain their energy from NH3 ad H2O. This type of bacteria are called chemotrophs.

2. Hetetrophic Bacteria: obtain their foodstuffs from other organisms.

*Sabrobes (Saprophytes) are hetetrophs which live on dead organisms.

• They decompose dead organisms.

• They have an important role in the recycling of material such as Nitrogen.

• Some hetotrophic bacteria are parasitic.

Types of bacteria according to their oxygen dependency;

a)Anaerobic bacteria

b)Aerobic bacteria

•Aerobic bacteria are require O2 to obtain energy from food. •Anaerobic bacteria don‘t need oxygen for production of energy.

Types of bacteria according to the gram staining;

a)Gram (+): A group of bacteria which paints with gram stain.

b)Gram (-): A group of bacteria which doesn't paint with gram stain.

Types of bacteria according to their flagella;

a) Flagellate:A group of bacteria that have flagella.

b)Non-flagellate: A group of bacteria that don’t have flagella.

• Bacteria reproduce both sexually and asexually.

• They divide into 2 parts to form new offsprings by binary fission.

• They reproduce sexually by Conjugation.