Chapter 1

Question 1

What do Microbes do?

Answer 1

Alcohol, baking, immune system, oxygen, sickness, etc…

Question 2

How small is small?

Answer 2

Bacteria are several um in diameter.

Fungi are 10+ um in diameter.

Question 3

Small but numerous

Answer 3

5x10^30 bacteria on earth.
Microorganisms comprise more biomass than all animals.
Comparable to plant life.
10x more bacterial cells in our bodies than human cells.

Question 4

Microorganisms are all cells

Answer 4

Fundamental unit of life.
Has a cell membrane (present in all cells, defines cell boundaries, determines influx and efflux).
Has a nucleus (eukaryote) or nucleoid (prokaryote).
Stores genetic info as DNA.

Question 5

Basic cell structure

Answer 5

Cytoplasmic (cell) membrane- separates the inside of the cell from the outside.
Cytoplasm- fluid that fills the cell.
Ribosomes- protein synthesis.
Cell wall- present in most bacteria, structural strength.

Question 6

Microbes are alive (Except for viruses)

Answer 6

All- grow/reproduce, metabolize, evolve.

Some- communicate, move, differentiate.

Question 7

Growth/Reproduction

Answer 7

Turning chemicals and energy into new cells.

All cells come from preexisting cells.

Question 8

Evolve

Answer 8

Cells contain genes –> genes can mutate and evolve.

Phylogenetic trees can show history and relationships.

Question 9

Metabolize

Answer 9

Uptake of chemicals and energy from the environment (cells are open systems exchanging with the environment).
Transformation within cell.
Removal of waste.

Question 10

Move

Answer 10

Some cells are capable of self propulsion.

Will move either towards or away from a stimulus.

Question 11

Differentiate

Answer 11

Some cells can form special structures such as spores.

Generally highly resistant to heat and dehydration.

Question 12

Communicate

Answer 12

Some cells can communicate with on another via released or taken up chemicals.

Question 13

Cells can be thought of as:

Answer 13

1) Machines- metabolism, energy conservation.

2) Coding objects- DNA, replication, gene expression.

Question 14

Environmental Microbiology

Answer 14

Microbial communities- populations of interacting assemblages.
Ecosystem- organisms plus chemical and physical constituents in their environment.
Microbes affect their environments.

Question 15

Robert Hooke (1635-1703)

Answer 15

First to describe molds (1665).

Question 16

Antoni van Leeuwenhoek (1632-1723)

Answer 16

First to describe bacteria (1676).

Question 17

Louis Pasteur (1822-1895)

Answer 17

Disproved spontaneous generation.

Flask experiment -> slides page 13-14.

Question 18

Robert Koch (1843-1910)

Answer 18

Showed bacteria cause disease.

Developed technique to obtain pure culture.

Question 19

Koch’s Postulates

Answer 19

1. The suspected pathogen must be present in all cases of the disease and absent from healthy animals.
2. The suspected pathogen must be grown in pure culture.
3. Cells from a pure culture of the suspected pathogen must cause disease in a healthy animal.
4. The suspected pathogen must be reisolated and shown to be the same as the original.

Question 20

Sergei Winogradsky (1856-1953)

Answer 20

Discovered chemoautotrophy.
Father of environmental microbiology.
Winogradsky column.