Lecture 2A: Introduction to the Microbial World Flashcards

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1
Q

elements of microbial structure

A
  • cytoplasmic (cell/plasma) membrane
  • cytoplasm
  • ribosomes
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2
Q

barrier that separates the inside of the cell from the outside environment

A

cytoplasmic (cell/plasma) membrane

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3
Q

matrix of macromolecules, small organics, ions, and ribosomes inside cell, with water as the major component

A

cytoplasm

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4
Q

protein-synthesizing structures

A

ribosomes

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5
Q

no membrane-enclosed compartments (organelle), no nucleus

A

prokaryotes (Bacteria and Archaea)

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6
Q
  • plants, animals, algae, protozoa, fungi
  • contain organelles
  • DNA enclosed in a membrane-bound compartment = nucleus
A

eukaryotes

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7
Q

What is an organelle?

A
  • sub-cellular
  • specialized function
  • morphologically and chemically
    consistent structure across life forms
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8
Q

Distinguishing Features of Procaryotic Cells: DNA is

A
  • Not enclosed within a nuclear membrane.
  • A single circular chromosome.
  • Not associated with histone proteins.
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9
Q

Prokaryotic cells:
- ___ of membrane-enclosed organelles like mitochondria, chloroplasts, Golgi, etc.
- Cell walls usually contain ___, a complex polysaccharide, or ___or S-layer
- Divide by ___

A
  • lacks
  • peptidoglycan
  • pseudopeptidoglycan
  • binary fission
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10
Q

Eukaryotic cells: DNA is…

A
  • Enclosed within a nuclear membrane.
  • Several linear chromosomes.
  • Associated with histones and other proteins.
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11
Q

a cell’s full complement of genes

A

genome

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12
Q

(extrachromosomal DNA) that confer
special properties (e.g., antibiotic
`resistance)

A

plasmids

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13
Q

prokaryotic cell’s DNA generally have single circular chromosome that aggregates to form the __

A

nucleoid region

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14
Q

The properties of microbial cells. Major activities ongoing in cells in the microbial community

A
  • metabolism
  • growth
  • evolution
  • differentiation
  • communication
  • genetic exchange
  • motility
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15
Q

cells take up nutrients, transform them, and expel wastes
1. genetic (___,___,___)
2. catalytic (___,___)

A

METABOLISM
- replication
- transcription
- translation
- energy
- biosyntheses

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16
Q

nutrients from the environment are converted into new cell materials to form new cells

A

GROWTH

17
Q

cells evolve to display new properties. _____ capture evolutionary relationships

A

EVOLUTION
- Phylogenetic trees

18
Q

some cells can form new cell structures such as a ___

A

DIFFERENTIATION
- spore

19
Q

Cells interact with each other by ___

A

COMMUNICATION
- chemical messengers

20
Q

cells can exchange ___ by several mechanisms

A

GENETIC EXCHANGE
- genes

21
Q

some cells are capable of ___

A

MOTILITY
- self-propulsion (ex. flagellum)

22
Q
  • Earth is ___ years old.
  • First cells appeared between ___ years ago.
  • The atmosphere was __ (no O2) until ___ billion years ago.
    – only anaerobic metabolisms
    – first anoxygenic phototrophs ___ billion years ago
  • plants and animals ___ billion years ago
A
  • 4.6 billion
  • 3.8 and 4.3 billion
  • anoxic
  • ~2.6
  • ~3.6
  • ~0.5
23
Q

At its origin, Earth was ___ . Cellular life was present on Earth by 3.8 billion years ago (bya). ___ began the slow oxygenation of Earth About 3bya but current levels of O2 in the atmosphere were not achieved until 500-800 million years ago.

A
  • sterile
  • Cyanobacteria
24
Q

The three domains of cellular organisms are ___, ___, and ___. ____ and ____ diverged long before eukaryotic cells appear in the fossil record.

A
  • Bacteria, Archaea, Eukarya
  • Archaea, Eukarya
25
Q

LUCA

A

last universal common ancestor

26
Q

examples of phototrophic microorganisms

A
  • Photosynthetic microbial mats
  • Purple sulfur bacteria
  • Green sulfur bacteria
  • cyanobacteria
27
Q

there are ___ microbial cells on Earth

A

~2 x 10^30

28
Q

live in habitats too harsh for other life forms

A

extremophiles

29
Q

refers to all living organisms plus
physical and chemical constituents of their environment.

A

ecosystem

30
Q

___ is the study of microbes in their natural environment.

A

Microbial ecology

31
Q

extremophile:
temp: high

A

hyperthermophile

32
Q

extremophile:
temp: low

A

Psychrophile

33
Q

extremophile:
pH: low

A

Acidophile

34
Q

extremophile:
pH: high

A

Alkaliphile

35
Q

extremophile:
pressure: high

A

Barophile (piezophile)

36
Q

extremophile:
Salt (NaCl)

A

Halophile