Exam 2 Flashcards
study for exam 2
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
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
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
4
Q
Eukaryotes
A
- Nuclear membrane
- No circular chromosomes
- DNA packaged in histones
- Complex RNA polymerase enzyme for protein making machinery
- Methionine start codon
5
Q
Cyanobacteria
A
- Photosynthetic, oxygen-producing bacteria (formerly known as blue-green algae).
- Single celled and colonial
6
Q
Stromatolites
A
- Mineralized deposits caused by cyanobacterial mats
- Direct evidence of life 3.5 BYA
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
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
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
10
Q
gut microbiome
A
- the microbial communities present in the animal gastrointestinal tract
- Probiotics are supplements with “good” bacteria
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)
12
Q
nitrogen fixation
A
process of converting nitrogen gas into nitrogen compounds that plants can absorb and use
13
Q
nitrogen fixation process
A
- atmospheric nitrogen not in an easily usable form in nature
- Bacteria break apart the strong and stable bonds of atmospheric nitrogen
- Nitrogen is converted into molecules with a single nitrogen atom, and is then usable by plants
14
Q
bacterial & plant alliance
A
- A plant secretes a bacteria- attracting compound
- Bacteria enter the roots
- The plant delivers sugars to the bacteria
- Bacteria produce and release usable nitrogen into the plant
- The plant distributes and absorbs the nitrogen
15
Q
Halophiles
A
Can survive being embedded in salt crystals