Chapter 5/6 - Microbial Metabolism and Growth Flashcards
0
Q
Redox Reactions
A
- oxidation and reduction (always together)
- transfer of electrons from a donor to an acceptor
- there are 3 different electron carriers = NAD, NADP, FAD
OIL RIG
1
Q
Metabolism
A
- the sum of all biochemical reactions in an organism
- catabolism and anabolism
- goal is to grow and multiply
2
Q
Oxidation
A
- when there is a loss of 1 electron
- it is often donated to an Oxygen
- most commonly shown when a molecule gains an O or loses an H
3
Q
Reduction
A
- when there is a gain of 1 electron
- sometimes shown by a molecule gaining an H
4
Q
Enzyme
A
- a biological catalyst (protein)
- not used up in a reaction
- lower the activation energy by holding the substrate in place
- an increase in temperature or pH will increase the enzymes activity until it is too hot or high and the enzyme denatures completely
5
Q
Inhibitor
A
- substances that block an enzyme’s active site
- don’t denature enzymes
- competitive, allosteric, feedback
6
Q
Competitive Inhibitor
A
- binds to the substrate binding site instead of the substrate
- can be knocked out if the substrate level is increased
7
Q
Allosteric Inhibitor
A
- binds to a different spot on the enzyme and distorts the active site so the substrate cannot bind
8
Q
Allosteric Activation
A
- binds to a different spot on the enzyme and changes the active site so that the substrate CAN bind it
9
Q
Feedback Inhibition
A
- the end product blocks the pathway somewhere earlier
- when the end product concentration is too low, the pathway begins again
10
Q
Glucose Catabolism
A
- cellular respiration
- fermentation
- glycolysis
11
Q
Glycolysis
A
- occurs in cytoplasm of most cells
- splitting of 6carbon glucose into two 3carbon sugars
- catabolism
- gain pyruvic acid, NADH, ATP
- not much energy is gained
- sends pyruvic acid on to fermentation or cellular respiration
12
Q
Cellular Respiration
A
- oxidizes pyruvic acid from glycolysis for energy
- uses three steps = synthesis of acteyl CoA, Krebs cycle, ETC
- catabolism
13
Q
Acetyl-CoA Formation
A
- first step in cellular respiration
- pyruvic acid from gylcolysis is turned into = 2 acetyl-CoA, 2 CO2, 2 NADH
- all products go into Krebs cycle
- catabolism
14
Q
Krebs Cycle
A
- second step in cellular respiration
- occurs in cytosol of Prokaryotes
- occurs in mitochondria of Eukaryotes
- acetyl CoA from synthesis starts process
- products = 2 ATP, 2 FADH2, 2 NADH, 4 CO2 (reduced molecules)
- only small amount of energy gained
- next step is ETC
- catabolism
15
Q
Electron Transport Chain
A
- third step in cellular respiration
- located in cytomplasic membrane of Prokaryotes
- located in cristae of Eukaryotes
- most ATP made in these redox reactions
- series of carrier molecules that pass electrons from one to another to the final electron acceptor, Oxygen
- most of the energy comes from oxidating reduced molecules
- if no Oxygen, anaerobic molecules use sulfate or nitrate
16
Q
Fermentation
A
- “plan B” for facultative anaerobes
- just oxidize again
- provide cells with alternative sources of NAD
- catabolism
17
Q
Anabolic Pathways
A
- synthesis reactions requiring energy from the ATP of catabolic reactions
- normally the reverse of catabolic pathways
- Gluconeogenesis = backwards Glycolysis
18
Q
Gluconeogenesis
A
- backwards Glycolysis
19
Q
Growth Requirements for Microbes
A
- Carbon
- energy
- electrons
20
Q
Apoenzyme
A
- protein part of an enzyme
21
Q
Cofactor
A
- inorganic ions needed with an apoenzyme to form a cohesive working enzyme
- ex. metals
22
Q
Coenzyme
A
- organic molecules needed with an apoenzyme to form a cohesive working enzyme
- ex. vitamins
23
Q
Holozyme
A
- all the pieces of enzymes together as a whole
24
Photoautotroph
- plants, algae
- carbon source is CO2
- energy source is light
25
Chemoautotroph
- sulfur
- carbon source is CO2
- energy source is chemical compounds
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Photoheterotroph
- nonsulfur bacteria
- carbon source is organic compounds
- energy source is light
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Chemoheterotroph
- animals, pathogens
- carbon source is organic compounds
- energy source is chemical compounds
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Obligate Aerobes
- cannot live without oxygen
| - need Oxygen as final electron acceptor in ETC
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Obligate Anaerobes
- cannot live WITH oxygen
| - cannot break down oxygen from toxic forms
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Facultative Anaerobes
- grow best in Oxygen, but can grow without it
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Aerotolerant Anaerobes
- don't use Oxygen and don't care whether it is there or not
| - tolerate Oxygen by having enzymes to break it down from toxic
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Breakdown of high energy Oxygen
- superoxide radicals (O2 with extra electron) are broken down into Peroxide Anions
- Peroxide Anions are broken down into Peroxidase
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Nitrogen
- needed for Anabolism
- all cells recycle nitrogen from amino acids and nucleotides
- 80% of the air is Nitrogen
- can use Nitrogen in the air through Nitrogen Fixation
34
Optimal Temperature Growth
- affects the 3dimensional structure of proteins
- lipid containing membranes are temperature sensitive
- too low temp = rigid and fragile membrane
- too high temp = too fluid membrane
35
Biofilm
- complex relationship among multiple microorganisms
- form from quorom sensing
- become harder to kill and more harmful
36
Generation Time
- time required for a bacterial cell to grow and divide
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Binary Fission
- when a cell grows twice its normal size and divides in half to produce two daughter cells of equal size
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Nitrogen Fixation
- reduces nitrogen to ammonia
- used by bacteria
- provides nitrogen for other species
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Microbial Growth Curve
- lag phase = no reproduction while the cell gets used to its environment
- log phase = HUGE population increase
- stationary phase = population remains constant, dying cells equal new cells
- death phase = when wastes aren't removed and no nutrients are added, death exceeds new cells
