Communicable and Non-Communicable Diseases

Communicable diseases can be transmitted between individuals, while non-communicable diseases cannot. This section focuses on pathogens, including bacteria and viruses, and their methods of transmission.

Definition: A pathogen is a microorganism that causes disease, such as bacteria, viruses, or fungi.

Bacteria and Viruses

Bacteria are single-celled organisms that can be both harmful and beneficial. They reproduce through binary fission and can damage body cells directly or produce toxins.

Highlight: Some bacteria are useful in food production, such as in making yogurt and cheese.

Viruses are smaller than bacteria and have a regular shape. They invade body cells to reproduce, causing cell damage and destruction.

Example: Both bacteria and viruses can cause symptoms like high temperature, headaches, and rashes.

Pathogen Spread and Prevention

Pathogens can spread through:

1. Air droplets (e.g., common cold)
2. Direct contact (e.g., gonorrhea)
3. Contaminated food or water (e.g., cholera, salmonella)

Prevention methods include:

• Covering mouth when sneezing or coughing
• Using contraception to prevent STIs
• Cooking food thoroughly and drinking clean water

Culturing Microorganisms in the Laboratory

Vocabulary: Culture medium - a substance used to grow microorganisms in a laboratory setting.

The culture medium for growing bacteria typically contains:

• Carbohydrates for energy
• Proteins for growth
• Minerals for vital processes
• Oxygen supply
• Warmth for optimal enzyme function

Method for Culturing Bacteria:

1. Sterilize the inoculating loop
2. Cool the loop without contamination
3. Transfer bacteria to agar plate using zigzag streaks
4. Seal and label the Petri dish
5. Store upside down to prevent condensation

Highlight: Proper sterilization and handling techniques are crucial to prevent contamination when culturing microorganisms.

Preventing Bacterial Growth

Methods to prevent bacterial growth include:

• Temperature control
• Use of disinfectants and antiseptics
• Antibiotics

Definition: Antiseptics are disinfectants safe for use on human skin.