MCB 1GENERAL

MICROBIOLOGY

Quiz # 11.What are the 5 major groups of organisms

studied in Microbiology?

2.Of the 5 major groups of microorganisms, which one/s are prokaryotes?

3.Of the 5 major groups of microorganisms, which ones are eukaryotes?

4.In terms of presence/ absence of nucleus, differentiate prokaryotes from eukaryotes?

answers• What are the 5 major groups of organisms studied in

Microbiology?

• Of the 5 major groups of microorganisms, which one/s are prokaryotes?

• Of the 5 major groups of microorganisms, which ones are eukaryotes?

• In terms of presence/ absence of nucleus, differentiate prokaryotes from eukaryotes?

bacteria, protozoa, algae, fungi, viruses

bacteria

protozoa, algae, fungi

prokaryotes have no nucleus, eukaryotes have

Microbiology

deals with living things ordinarily too small to be seen without magnification

size range: 20 nm- 5 mm

metric system prefixes•pico (p) = 10-12

•nano (n) = 10-9

•micro (u) = 10-6

•milli (m) = 10-3

•centi (c) = 10-2

•deci (p) = 10-1

•kilo (p) = 103

reference: Black, J. 1999. Microbiology, Principles and Explorations (4th ed.). New Jersey: Prentice Hall

smallest

largest, 250,000x larger than the smallest

bacteria- most thoroughly studied

- unicellular

- shapes: spherical, rod, spiral

- prokaryotic

-ex: E. coli

algae

- some unicellular, some multicellular

- photosynthetic, important source of food for marine organisms

- distributed fresh water and oceans

-ex. blue-green algae

fungi-some unicellular (like yeasts and molds), some multicellular

-decomposers

-ex: bread mold/Rhizopus

virus- acellular entities

- behave like living organism when they gain entry on living organisms

-ex: flu virus

protozoa- unicellular

- eukaryotic

- obtain food by engulfing smaller microorganisms

- ex: amoeba

Microbial World and You

“We are outnumbered. The average human contains about 10 trillion cells. On that average human are about 10 times as many microorganisms, or 100 trillion microscopic beings...”

-Robert J. Sullivan, 1989

MICROBES ARE EVERYWHERE and ARE RELEVANT TO ALL ASPECTS OF

HUMAN LIFE

Reasons why we study MICROBIOLOGY

1. Microorganisms have major impact on human health;

2. Microorganisms maintain the balance of nature;

3. Microorganisms are essential to many human endeavors;

4. Microbiology provides insights into life processes in all forms of life

- nearly 2,000 different microbes cause various types of diseases (1% of all microbe types)

- infectious diseases: **10 Billion new infections/year ** most common source of death at around 13 Million/ year

1. Microorganisms have major impact on human health

“The war against infectious diseases has been won”

- William H. Stewart, 1962

1. Microorganisms have major impact on human health

many are treatable with drugs or preventable by vaccines

hardest hit are the poor countries (1/3 live on $ 1/day)

1. Microorganisms have major impact on human health

there is a current increase in number of new (emerging) and older (reemerging) diseases likeSARS, AIDS, hepatitis C, viral encephalitis

1. Microorganisms have major impact on human health

- new discovery: non infectious diseases involve microbial infection:

gastric ulcer Helicobacter pylori cervical cancer human pappiloma virus diabetes Coxsacki virus schizophrenia borna agent virus female infertility Chlamydia

1st golden age: role of microorganisms in obvious and infectious diseases 2nd golden age: role of microorganisms in quiet but slowly destructive diseases

1. Microorganisms have major impact on human health

Reasons why we study MICROBIOLOGY

1. Microorganisms have major impact on human health;

2. Microorganisms maintain the balance of nature;

3. Microorganisms are essential to many human endeavors;

4. Microbiology provides insights into life processes in all forms of life

- involved in the flow of energy and food:

a. photosynthesis

b. decomposition

2. Microorganisms maintain the balance of nature

- bacteria invented photosynthesis ** anoxygenic photosynthesis first then oxygenic photosynthesis, one that involves production of oxygen ** bacteria changed the earth’s anaerobic atmosphere to aerobic atmosphere, which eventually lead to the explosion of species diversity

- photosynthetic microorganisms account for 50% of all of earth’s photosynthesis, and serve as food to various organisms

2. Microorganisms maintain the balance of nature

-microorganisms are responsible for breakdown of dead matter and wastes **nitrogen is made available to plants

-certain microorganisms reside in the digestive tract of grazing animals

2. Microorganisms maintain the balance of nature

Reasons why we study MICROBIOLOGY

1. Microorganisms have major impact on human health;

2. Microorganisms maintain the balance of nature;

3. Microorganisms are essential to many human endeavors;

4. Microbiology provides insights into life processes in all forms of life

- microorganisms have since been used to improve life and shape civilization: **Baker’s yeast for bread **brewer’s yeast for wine and beer **In ancient Egypt, molding loaves were applied directly to wounds (Penicillin)

- genetic engineering **interferon, antibiotics and growth hormones, bioremediation

3. Microorganisms are essential to many human endeavors

Reasons why we study MICROBIOLOGY

1. Microorganisms have major impact on human health;

2. Microorganisms maintain the balance of nature;

3. Microorganisms are essential to many human endeavors;

4. Microbiology provides insights into life processes in all forms of life

- bacteria are used as model organisms because a. bacteria have simple structures b. reproduce quicklyc. gene transfers can be quickly followed

4. Microbiology provides insights into life processes in all forms of life

MICRO/BIOLOGY

scientific method