Exam #1 Flashcards
1
Q
Define microbiology?
A
The study of microorganisms
2
Q
What are microorganisms?
A
cellular and noncellular organisms that are too small to be seen by the naked eye
3
Q
Where do you find microorganisms?
A
on things where they can eat so that they can grow and divide
4
Q
How many microorganisms are estimated to be on Earth?
A
25 x 10^29
5
Q
How long have microorganisms been on Earth?
A
4 billion years
6
Q
How do microorganisms impact our lives through disease?
A
cause and treatment
7
Q
How do microorganisms impact our lives through agriculture?
A
microbes help plants absorb the nutrients they need
8
Q
How do microorganisms impact our lives through food?
A
beer, yogurt, cheese; microbes are used to make a lot of our food; call also spoil them
9
Q
How do microorganisms impact our lives through energy?
A
biofuels; microbes can help convert different plants into enthanol
10
Q
How do microorganisms impact our lives through biotechnology
A
use of microorganisms in industrial biosynthesis, typically by microorganisms that have been genetically modified to synthesize products (ex. Insulin) of high commercial value
11
Q
Name 6 abilities/characteristics of living cells.
A
metabolism, reproduction, communication, differentiation, movement, and evolution
12
Q
Who was the first to use a microscope to see microorganisms?
A
Robert Hooke
13
Q
What did Robert Hooke see?
A
cork cells
14
Q
What type of microscopy did Robert Hooke use?
A
glorified magnifying glass
15
Q
Who was the first to use a microscope to see bacteria?
A
Van Leeuwenhoek
16
Q
How do we know that Van Leeuwenhoek saw bacteria?
A
he drew and took pictures
17
Q
What type of microscopy did Leeuwenhoek use?
A
magnification
18
Q
List at least 4 ways microscopy is useful
A
allows cell shape and arragnement to be seen, structures to be seen, pathogens to be seen among animal cells, and distinguish gram-positive from gram-negative
19
Q
What are the four types of light microscopy?
A
brightfield, phase contrast, darkfield and fluorescent
20
Q
What must be done to a microorganism to be able to see it with brightfield light microscopy?
A
must be stained and only uses light source and lenses
21
Q
Which types of light microscopy allow you to view a live sample?
A
Phase contrast and Darkfield
22
Q
What is the maximum resolution of a compound light microscope?
A
0.2 microns
23
Q
Describe what is meant by the resolution.
A
this means that objects clsoer than 0.2 microns cannot be resolves as distinct and separate
24
Q
What are the two types of electron microscopy?
A
Transmission Electron Microscope and Scanning Electron Microscope
25
What is Transmission Electron Microscope?
for observing internal cell structure
26
What is Scanning Electron Microscope?
for 3D imaging and viewing surfaces
27
What is the maximum resolution of an electron microscope?
0.2-0.4 nm
28
What is the smallest microbial cell size discovered thus far?
0.2 microns
29
Would a cell that is 0.2 microns have a high or a low surface area-to-volume ratio compared to an average eukaryotic cell?
high surface area-to-volume ratio
30
What is the significance of a cell having a high surface area-to-volume ratio?
aids in nutrient and waste exchange with the environment
31
Discuss the problems a cell might have if it were less than 0.2 microns.
smaller than this doesn't allow them to house everything they need to make a living cell
32
What microorganisms have a phospholipid bilayer form their cytoplasmic membrane?
Bacteria and Eukarya
33
What microorganisms have a lipid monolayer form their cytoplasmic membrane?
Archaea
34
What does a phospholipid bilayer made of?
fatty acid, glycerol, phosphate, and ester linkages
35
What does a lipid monolayer made of?
glycerol and ether linkages
36
What advantage would microorganisms with lipid monolayer have over those with a lipid bilayer?
more resistant to peeling apart than bilayers, no hydrophobic interaction, and stronger than bilayer
37
What are the functions of the cytoplasmic membrane?
permeability barriers, protein anchor, transport, and energy conservation
38
What is meant by permeability barriers?
prevents leakage, functions as a gateway for transport of nutrients into and wastes out of cell
39
What is meant by protein anchor?
site of many proteins that participate in transport, bioenergetics and chemotaxis
40
What is meant by energy conservation?
site of generation and use of the proton motive force
41
What are the three classes of transport systems?
simple transport, group translocation, and ABC transport
42
What is simple transport?
driven by the energy in the proton motive force, one in and one out
43
What is group translocation?
chemical modification of the transported substance driven by phosphoenolpyruvate
44
What is ABC transport?
periplasmic binding proteins are involved and energy comes from ATP
45
Where are transport systems located in the cell?
proteins that are in the membrane
46
What are transport systems made of?
12 polypeptides that weave back and for through the membrane to form channels
47
What are the three types of transport events?
uniport, symport, and antiport
48
What is uniport?
proteins that carry a substance unidirectional across membrane either in or out
49
What is symport?
cotransporters, they transport molecules along with a 2nd substance, typically a proton
50
What is antiport?
are proteins that transport one substance into the cell while simultaneously transporting a second substance out
51
What proteins make up the eukaryotic cytoskeleton>
polymers of actin (microfilaments) and polymers of tubulin (microtubules)
52
What function is common to both microfilaments and microtubules?
maintain cell shape
53
What functions are unique to microtubules?
cell motility by flagella and cilia
54
What functions are unique to microfilaments?
cell motility by cytoplasmic streaming
55
What prokaryotic proteins are similar to the eukaryotic proteins, actin and tubulin?
Fts Z is similar to tubulin and Fts A and Mre B are similar to actin
56
What is Fts Z?
it determines where cell division will occur
57
What is Fts A and Mre B?
Fts A helps hold Fts Z proteins in place and Mre B proteins determine where new cell walls will be inserted in an expanding, diving cell
58
What is the difference between mitochondrion and hydrogenosomes?
mitochondrion are found in aerobic cells whereas hydrogenosomes are found in anaerobic cells
59
Which organelles produce ATP for the cell?
mitochondrion
60
Which organelles are made of continuous membrane system?
endoplasmic reticulum
61
Which organelles are double-membrane bound?
chloroplast
62
Describe the flow of information within the cell for a digestive enzyme starting with the DNA in the nucleus.
Nucleolus --> travels through nucleus via pores on nuclear membrane --> rough ER (where ribosomes are waiting for mRNA) --> could go to smooth ER if involved in carbohydrates or lipid synthesis since it's digestive it goes toward Golgi to be packaged --> golgi sends it lysosome
63
In what ways are members of Planctomycetes like prokaryotic cells?
has ribosomes, nuclear envelope with nucleoid, structures that look like rough ER
64
Where is the cell wall located relative to the cytoplasmic membrane?
outside of cytoplasmic membrane
65
What bacteria lack cell wall?
mycoplasma and chlamydia
66
what are most Bacteria cell walls made of?
Peptidoglycan
67
The amount of peptidoglycan in the cell walls of Bacteria distinguishes what types of Bacteria?
gram-negative and gram-positive
68
Describe the peptidoglycan structure.
N-Acetlyglucosamine (G) linked to N-Acetlymuramic Acid (M) by beta 1,4 oxygen with a tetrapeptide crosslink
69
The glycosidic bond between the two N-acteyl-glucose sugars in the peptidoglycan can be cleaved by what enzyme?
lysozyme because it weakens the wall and allows the cell to be opened to lysis
70
Describe what would happen if a bacterial cell were put in a solution with lysozyme added.
The cell would undergo osmotic lysis
71
Describe the Gram-positive cell wall.
many layers o peptidoglycan, as it synthesized, it become cross-linked to form an even stronger cell wall structure
72
What is the function of teichoic acids and lipoteichoic acids?
teichoic acids: negatively charged polymers containing glycerphosphate or ribiol residues, binding Calcium and Magnesium
lipoteichoic acids: teichoic acids covalently linked to membrane lipids
73
Describe the Gram-negative cell wall.
bacteria have only a few layers of peptidoglycan and membrane on the outside is more wavy and irregular
74
What is the lipopolysaccharide layer?
two components made up of core polysaccharides and O-specific polysaccharides
75
What part of the LPS is toxic?
the outer membrane, Lipid A-endotoxin
76
What is the difference between pseudomurien and peptidoglycan?
pseudomurien: N-acetylglucosamine, and N-acteylminuronic acid, beta 1,3 bond and L-stereoisomer
peptidoglycan: N-acetylglucosamine, and N-Acetylmurmaic acid, beat 1,4 bond
77
What types of cell walls are found in Archaea species?
pseudomurien and polysaccharide cell walls
78
What types of cell walls are found in Eukarya species?
protein, glycoproteins, and polysaccharides
79
What is the difference between cellulose and chitin?
cellulose is a polymer of glucose and chitin is a polymer of N-acetlyglucosamine
80
What are the functions of the cell wall?
protection, maintain cell shape, prevents osmotic lysis, and interacts with envrionment
81
How are the species of Mycoplasma and Chlamydia similar?
both lack cell walls
82
What are fimbriae?
short protein filaments that use their stickiness to attach to things
83
What is a pilus?
longer protein filaments; conjugation motility adhesion of pathogens to host tissue with a tube connecting them so that they can share genetic information
84
Where would an S-layer be found?
the outer most cell wall made of interlocking molecules of protein or glycoprotein
85
What is the purpose of the S-layer?
to withstand osmotic pressures without other walls
86
Call all bacteria forma a capsule?
if there is enough energy
87
What is a capsule made of?
polysaccharides and peptide layers that grow and protect whatever is around the cell
88
Slime is made for what purpose?
Motility
89
What type of microorganisms make slime?
prokaryotes
90
Movement using slime secretion is called what?
gliding
91
List the three mechanisms of gliding.
Slime secretion, twitching motility, and Ratchet-Protein mechanism
92
What are the three main parts of the prokaryotic flagellum?
filament, hook, motor
93
What is the filament in the flagellum for?
composed of many proteins called flagelin
94
What is the hook in the flagellum for?
consist of a single type of protein and connects the filament to the flagellum motor
95
What is the motor in the flagellum for?
anchored in the cytoplasmic membrane and cell wall consist of a central rod that passes through a series of rings
96
What are taxes?
directed movement toward or away form a chemical or physical signal
97
What are the three types of taxes?
chemotaxis, phototaxis, and aerotaxis
98
What does a cell use to sense the environment?
sensory proteins in the cytoplasmic membrane that interact with the environment
99
How do cyanobacterium could move to obtain optimum wavelengths of light for photosynthesis?
gas vesicles
100
Where do gram-negative purple sulfur bacteria store sulfur?
periplasm
101
What does the carboxysome store for some bacteria and cyanobacteria?
carbon and oxygen separately
102
Describe the process of sporulation.
the endospore is a t a vegetative state --> cell division (elongating) and forming of the prespore septum and the mother cell --> mother cell engulfs the prespore --> the cortex, the cell wall, and the cytoplasmic membrane form --> coat forms --> cell lysis and free endospore is formed and there is no longer the cell that was around at the vegetative state
103
How does the structure of an endospore help it to be a survival structure?
the layers and layers and layers of the spore coat, cortex, exosporium, core wall, and core
104
Where is an endospore formed?
terminal, subterminal, central
105
Describe the process of germination
when conditions become favorable the spore transforms into vegetative cell genetically identical to the vegetative cell that made the spore
106
What age is the oldest known endospore to have germinated? Where was the endospore found?
250 million years ago in Salt Crystals of Permian age
107
Name at least 3 genera of bacteria that form endospores.
clostridium, thermoactinomyces, bacillus
