CH 1 Test Review

Question 1

Famous Scientists Who Changed the Course of Microbiology

Answer 1

Anton van Leeuwenhoek: First to observe and describe microorganisms using a microscope
-known as the “father of microbiology.”

Robert Koch: Developed Koch’s Postulates, a method to prove that a specific organism is the cause of a particular disease.

Question 2

Classification of Microbes & Other Organisms

Answer 2

Prokaryotes: Includes bacteria and archaea. Simple cells without a nucleus.

Bacteria: Diverse organisms with peptidoglycan cell walls.

Archaea: Unicellular organisms with unique cell walls (pseudomurein).

Eukaryotes: Organisms with a nucleus and membrane-bound organelles.

Fungi: Molds
Protists: Single-celled organisms (algae).
Animals: Multicellular organisms.
Plants: Multicellular, photosynthetic organisms.

Question 3

Common Features of All Cells (Eukaryotic and Prokaryotic)

Answer 3

Plasma Membrane: Encloses the cell, controlling the movement of substances in and out.

Ribosomes: Sites of protein synthesis.
Cytoplasm: Jelly-like substance where cellular processes occur.

Genetic Material (DNA): Stores information necessary for cell function and reproduction.

Energy Source: All cells generate energy, usually in the form of ATP.

Question 4

Microorganisms vs. Microbes

Answer 4

Microorganisms: Organisms that are too small to be seen with the naked eye (e.g., bacteria, fungi, protozoa).

Microbes: Broad term used to describe any microscopic organism, which includes microorganisms as well as viruses (which are not considered living organisms).

Question 5

Uses of Microorganisms

Answer 5

Medicine, food (fermentation), biotechnology, research

Question 6

Viruses

Answer 6

Non-living entities that cannot reproduce on their own. They require a host cell to replicate.

Structure: Consists of a protein coat (capsid) and genetic material (either DNA or RNA).

Question 7

ATP

Answer 7

The main energy carrier in cells. Provides energy for cellular activities like muscle contraction, protein synthesis, and active transport across membranes.

Question 8

Sizes of Microbes

Answer 8

Viruses: 20–300 nm (nanometers).
Bacteria: 0.2–10 μm (micrometers).
Fungi: Yeasts and molds typically range from 2–10 μm.
Protists: 10–100 μm.
Human Cells: Typically 10–30 μm in diameter

Question 9

Organic Molecules

Answer 9

Carbohydrates: Provide energy (e.g., glucose) and structural support (e.g., cellulose in plants).

Proteins: Made of amino acids, they perform various functions including enzymes, structural support, and transport.

Lipids: Fats and oils that store energy and form cell membranes (phospholipids).

Nucleic Acids: DNA and RNA, store and transmit genetic information.

Question 10

Koch’s Postulates

Answer 10

A set of criteria to establish a causative relationship between a microbe and a disease:

1. Must be present in every case of the disease.
2. Isolated from the diseased host and grown in pure culture.
3. Must cause the same disease when introduced into a healthy host.
4. Must be re-isolated from the experimentally infected host.

Question 11

Scientific Naming

Answer 11

System: Organisms are given two names: a genus and a species.

Genus: Capitalized.
Species: Lowercase.

Example: Homo sapiens (humans).

Importance: Standardized naming system used worldwide to avoid confusion and provide clarity in the classification of organisms.

Question 12

Scientific Method

Answer 12

A systematic way to investigate natural phenomena and obtain reliable knowledge.

Observation
Hypothesis
Experimentation
Data Collection
Conclusion
Peer Review