Microorganisms and Microbiology Flashcards
1
Q
Microbiology revolves around two themes:
A
- Understanding basic life processes
- Applying that knowledge to the benefit of humans
2
Q
The importance of microorganisms
A
- Oldest form of life
- Largest mass of living material on Earth
- Carry out major processes for biogeochemical cycles
- Can live in places unsuitable for other organisms
- Other life forms require microbes to survive
3
Q
A dynamic entity that forms the fundamental unit of life
A
cell
4
Q
All cells have the following in common:
A
- Cytoplasmic (cell) membrane
- Cytoplasm
- Ribosomes
- Cell wall
5
Q
Barrier that separates the inside of the cell from the
outside environment
A
Cytoplasmic (cell) membrane
6
Q
Aqueous mixture of macromolecules, ions, and ribosome
A
Cytoplasm
7
Q
Protein-synthesizing structures
A
Ribosomes
8
Q
Present in most microbes; confers structural strength
A
Cell wall
9
Q
No membrane-enclosed organelles, no nucleus
A
Prokaryotes
10
Q
Generally smaller than eukaryotic cells
A
Prokaryotes
11
Q
DNA enclosed in a membrane-bound nucleus
A
Eukaryotes
12
Q
- Cells are generally larger and more complex
- Contain organelles
A
Eukaryotes
13
Q
A cell’s full complement of genes
A
genome
14
Q
Prokaryotic cells generally have a single, circular DNA
molecule called a
A
chromosome
15
Q
Eukaryotic DNA is __________ and found within the ____________
A
linear; nucleus
16
Q
Prokaryotes also may have small amounts of
extrachromosomal DNA called _______________ that confer
special properties
A
plasmids
17
Q
- 4.64 million base pairs
- 4,300 genes
A
Escherichia coli genome
18
Q
Human cell has ___________________ DNA per cell than E. coli
A
1000X
19
Q
Characteristics of living cells
A
- Metabolism
- Reproduction
- Differentiation
- Communication
- Movement
- Evolution
20
Q
chemical transformation of nutrients
A
Metabolism
21
Q
generation of two cells from one
A
Reproduction
22
Q
synthesis of new substances or structures
that modify the cell (only in some microbes)
A
Differentiation
23
Q
generation of, and response to, chemical
signals (only in some microbes)
A
Communication
24
Q
via self-propulsion, many forms in microbes
A
Movement
25
genetic changes in cells that are transferred to
offspring
Evolution
26
Cells take up nutrients, transform them, and expel
wastes
Metabolism
27
Nutrients from the environment are converted into new cell materials to form new cells
Growth
28
Cells evolve to display new properties. Phylogenetic trees capture evolutionary relationships
Evolution
29
Properties of all cells
- Metabolism
- Growth
- Evolution
30
Properties of some cells:
- Differentiation
- Communication
- Genetic exchange
- Motility
31
Some cells can form new cell structures such as a spore.
Differentiation
32
Cells interact with each other by chemical messengers.
Communication
33
Cells can exchange genes by several mechanisms.
Genetic exchange
34
Some cells are capable of self-propulsion.
Motility
35
protein catalysts of the cell that accelerate chemical reactions
Enzymes
36
DNA produces RNA
Transcription
37
RNA makes protein
Translation
38
common ancestral cell from which all cells descended
Last universal common ancestor (LUCA)
39
Earth is ________________ years old
4.6 billion
40
First cells appeared between __________________________ years
ago
3.8 and 3.9 billion
41
The atmosphere was ____________ until ~__________________
anoxic; 2 billion years ago
42
43
Life was exclusively microbial until
1 billion years ago
44
The process of change over time that results in new varieties and species of organisms
Evolution
45
Evolutionary relationships between organisms
Phylogeny
46
is excellent for determining phylogeny
Ribosomal RNA (rRNA)
47
Comparative rRNA sequencing has defined three distinct
lineages of cells called
domains
48
Domains
- Bacteria (prokaryotic)
- Archaea (prokaryotic)
- Eukarya (eukaryotic)
49
are NOT closely related
Archaea and Bacteria
50
are more closely related to Eukarya than Bacteria
Archaea
51
were the ancestors of multicellular organisms
Eukaryotic microorganisms
52
From the last universal common ancestor (LUCA),
evolution proceeded to form two domains
- Bacteria
- Archaea
53
Archaea later diverged to form two domains
- Archaea
- Eukarya
54
Microorganisms exist in nature in populations of interacting
assemblages called
microbial communities
55
The environment in which a microbial population lives is its
habitat
56
refers to all living organisms plus physical and
chemical constituents of their environment
Ecosystem
57
is the study of microbes in their natural environment
Microbial ecology
58
Diversity and abundances of microbes are
controlled by
resources (nutrients) and environmental conditions (e.g., temp, pH, O2)
59
are found in almost every environment imaginable
Microbes
60
are Bacteria and Archaea that can grow in extremely harsh environments
Extremophiles
61
The extent of microbial life
- Global estimate is
5 ✕ 10^30 cells
62
Most microbial cells are found in
oceanic and terrestrial subsurfaces
63
are key reservoirs of essential nutrients
cells
64
Many aspects of agriculture depend on microbial
activities
- Positive impacts
- Nitrogen-fixing bacteria
- Cellulose-degrading microbes in the rumen
- Regeneration of nutrients in soil and water
65
Many aspects of agriculture depend on microbial
activities
Negative impacts
Diseases in plants and animals
66
High numbers of microorganisms occur in
olon and oral cavity
67
Microbiology began with the
microscope
68
the first to describe microbes
Robert Hooke (1635–1703)
69
Illustrated the fruiting structures of molds
Robert Hooke (1635–1703)
70
the first to describe bacteria
Antoni van Leeuwenhoek (1632–1723):
71
founded the field of bacterial classification and discovered bacterial endospores
Ferdinand Cohn (1828–1898)
72
Discovered that living organisms discriminate between
optical isomers
Louis Pasteur (1822–1895)
73
Discovered that alcoholic fermentation was a biologically
mediated process (originally thought to be purely
chemical)
Louis Pasteur (1822–1895)
74
Demonstrated the link between microbes and infectious
diseases
Robert Koch (1843–1910)
75
Identified causative agents of anthrax and tuberculosis
Robert Koch (1843–1910)
76
- Developed techniques (solid media) for obtaining pure
cultures of microbes, some still in existence today
- Awarded Nobel Prize for Physiology and Medicine in
1905
Robert Koch (1843–1910)
77
Observed that masses of cells (called ____________) have
different shapes, colors, and sizes
colonies
78
- field that focuses on nonmedical aspects of
microbiology
- Roots in 20th century
Microbial diversity
79
Developed enrichment culture technique
Martinus Beijerinck (1851–1931)
80
Demonstrated that specific bacteria are linked to
specific biogeochemical transformations (e.g., S and N
cycles)
Sergei Winogradsky
81
Proposed concept of chemolithotrophy
Sergei Winogradsky (1856–1953)
82
Proposed concept of chemolithotrophy
Sergei Winogradsky (1856–1953)
83
In the 20th century, microbiology developed in two
distinct directions:
Applied and basic
84
Fueled by the genomics revolution
Molecular microbiology
85
Major subdisciplines of applied microbiology
Medical microbiology:
* Immunology
* Agricultural microbiology:
* Industrial microbiology:
* Aquatic microbiology:
* Biotechnology:
86
infectious diseases
Medical microbiology
87
immune system
Immunology
88
microbes associated with soil
Agricultural microbiology
89
production of antibiotics alcohols, and other chemicals
Industrial microbiology
90
water, wastewater, and drinking water
Aquatic microbiology
91
products of genetically engineered microorganisms
Biotechnology
92
Basic science subdisciplines in microbiology
- Microbial systematics
- Microbial physiology
- Microbial ecology
- Microbial biochemistry
- Bacterial genetics
- Virology
93
The science of grouping and classifying microorganisms
Microbial systematics
94
Study of the nutrients that microbes require for
metabolism and growth and the products that
microorganisms generate
Microbial physiology
95
Study of microbial diversity and activity in natural habitats
Microbial ecology
96
Study of microbial enzymes and chemical reactions
Microbial biochemistry
97
Study of heredity and variation in bacteria
Bacterial genetics
98
Study of viruses
Virology
99
study of all of the genetic material (DNA) in living cells
Genomics
100
study of RNA patterns
Transcriptomics
101
study of all the proteins produced by cell(s)
Proteomics
102
study of metabolic expression in cells
Metabolomics
103
are excellent models for understanding cellular
processes in unicellular and multicellular organisms
Microbes
