Exam 2 Flashcards

study for exam 2

You may prefer our related Brainscape-certified flashcards:
1
Q

Cell theory

A
  • Cells are the smallest unit of life
  • All life is made of one or more cells
  • Cells can only come from other cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Bacteria

A
  • No nuclear membrane
  • Circular chromosomes
  • No DNA packaged in histones
  • Simple RNA polymerase enzyme for protein making machinery
  • Formeylmethionine start codon
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Archaea

A
  • No nuclear membrane
  • Circular chromosomes
  • DNA packaged in histone proteins
  • Complex RNA polymerase enzyme for protein making machinery
  • Methionine start codon
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Eukaryotes

A
  • Nuclear membrane
  • No circular chromosomes
  • DNA packaged in histones
  • Complex RNA polymerase enzyme for protein making machinery
  • Methionine start codon
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Cyanobacteria

A
  • Photosynthetic, oxygen-producing bacteria (formerly known as blue-green algae).
  • Single celled and colonial
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Stromatolites

A
  • Mineralized deposits caused by cyanobacterial mats

- Direct evidence of life 3.5 BYA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

MRSA

A
  • 1/3 people carry S. aureus on their bodies
  • 1/5 carry MRSA
  • Sub-dermal infection that causes skin rash, boils, fever, loss of limbs, death
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Penicillin

A
  • first discovered by Alexander Fleming in 1928 (by accident)
  • Difficult to synthesize
  • Chemical structure confirmed by Dorthy Crowfoot Hodgkins in 1945
  • Drastically reduced death due to disease
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Clostridium difficile

A
  • Another antibiotic-resistant bacterial species
  • Increasing prevalent in hospitals (becomes an issue after treatment with antibiotics)
  • Causes severe diarrhea, intestinal cramping, death
  • Linked to 30,000 deaths/year in US
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

gut microbiome

A
  • the microbial communities present in the animal gastrointestinal tract
  • Probiotics are supplements with “good” bacteria
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Human Ecosystem

A
  • human body contains 500-1000 different species of bacteria

- 10 times more bacterial cells than human cells (about 100 trillion human cells)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

nitrogen fixation

A

process of converting nitrogen gas into nitrogen compounds that plants can absorb and use

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

nitrogen fixation process

A
  1. atmospheric nitrogen not in an easily usable form in nature
  2. Bacteria break apart the strong and stable bonds of atmospheric nitrogen
  3. Nitrogen is converted into molecules with a single nitrogen atom, and is then usable by plants
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

bacterial & plant alliance

A
  1. A plant secretes a bacteria- attracting compound
  2. Bacteria enter the roots
  3. The plant delivers sugars to the bacteria
  4. Bacteria produce and release usable nitrogen into the plant
  5. The plant distributes and absorbs the nitrogen
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Halophiles

A

Can survive being embedded in salt crystals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Thermophiles

A

Archaea that thrive in very hot environments (above the boiling point of H20), such as volcanic springs

17
Q

Acidophiles

A

Can live in a pH 1

18
Q

horizontal gene transfer

A

transfer of genes between cells of the same generation

19
Q

Transformation

A

(genetics) modification of a cell or bacterium by the uptake and incorporation of exogenous DNA

20
Q

Transduction in bacteria

A

..type of bacterial recombination (create genetic diversity) in which there is an exchange of bacterial DNA through bacteriophages - viruses that infect bacteria. There are two types of transduction: generalized and specialized transduction.

21
Q

Conjugation in bacteria

A

Bacterial cells can join together and pass plasmid DNA from one bacterial cell to another. This process can take place between bacteria of different species and is of concern in terms of passing plasmid-located genes for antibiotic resistance.

22
Q

Concepts to define a bacterial species

A
  • Morphological: determined through enrichment cultures

- Phylogenetic: determined through direct sequencing

23
Q

Enrichment

A
  • Can be grown in either liquid or solid medium

- the easiest bacteria to culture are usually ecologically isignificant

24
Q

Shapes of bacterial cells

A

Coccus (circles)
Rod (bacilli)
Spirillum (corkscrew/spiral)