Microbial Metabolism Flashcards
(88 cards)
1
Q
What is metabolism?
A
Sum of all chemical reactions in a living organism
2
Q
What are the two types of metabolism?
A
Anabolism and Catabolism
3
Q
What biosynthesis reaction is found in anabolism? What does it require?
A
Building; it requires energy (endergonic)
4
Q
Catabolism is a _____ reaction meaning it ________ down. It is ____ so it_____ energy.
A
Degrative reaction, breaks, exergonic, releases
5
Q
What are enzymes?
A
Biological catalysts
6
Q
Enzymes ____ the activation energy.
A
Reduce
7
Q
Enzymes are ___ specific.
A
Substrate
8
Q
What do biological catalysts do?
A
Speed up chemical reactions without getting used up
9
Q
What is activation energy?
A
Minimum energy required for a chemical reaction to occur
10
Q
Specific substrates are built on a lock and key mechanism. Enzymes are the ___ while the substrates are the____.
A
Locks, keys
11
Q
What is the process of how enzymes work?
A
- Substrate contacts the active site of the enzyme 2. Enzyme-substrate complex forms 3. substrate is transformed, broken down or compounded 4. transformed substrates (products) released 5. unchanged enzyme free to interact with other substrates
12
Q
What is the active site?
A
where substrate binds
13
Q
What is the allosteric site?
A
where other molecules (other than a substrate) attach
14
Q
What are simple enzymes?
A
proteins with catalytic activity
15
Q
What are holoenzymes?
A
conjugated enzymes
16
Q
What is the protein portion of holoenzymes?
A
apoenzyme
17
Q
What are the non-protein portions of holoenzymes?
A
cofactor and coenzyme
18
Q
What are cofactors and examples?
A
inorganic ions; iron, zinc, magnesium, calcium
19
Q
What are coenzymes and examples?
A
organic molecules; vitamin derivatives (NAD+, FAD, CoEnzyme A)
20
Q
Enzymes usually end in ____.
A
“ase”
21
Q
What do enzymes describe in their name?
A
substrate
22
Q
How are enzymes classified?
A
based on chemical reactions
23
Q
What is oxidoreductase?
A
oxidation-reduction
24
Q
What is transferase?
A
transfer of function groups
25
What is hydrolase?
hydrolysis
26
What is Lyase?
removal of atoms without hydrolysis
27
What is Isomerase?
rearrangement
28
What is Ligase?
going 2 molecules
29
Where do exoenzymes function?
outside of the cell
30
Where do endoenzymes function?
inside of the cell
31
When are constitutive enzymes produced?
They are produced at constant rates all the time
32
When are inducible enzymes produced?
They are produced only when substrates are present
33
What are the four factors influencing enzymatic activity?
1. Temperature 2. pH 3. substrate concentration 4. inhibitors
34
Enzymes have an optimal temperature. What happens when the temperature is decreased?
increasing temperature increases the rate of collision and reaction, but too much heat will denature the enzyme
35
Enzymes have an optimal pH. What happens during extreme pH?
It will denature the enzyme
36
Increasing substrate increases activity until _____.
Saturation
37
What is saturation?
When active sites get filled with substrate
38
What are the two types of inhibitors?
Competitive and non-competitive
39
What are competitive inhibitors?
chemicals that mimic substrate and bind to active sites
40
What is the result of competitive inhibitors?
slows down the enzyme's interactions with the substrate
41
What are two examples of competitive inhibitors?
penicillin, sulfanilamide
42
What are non-competitive inhibitors?
chemicals that bind to allosteric sites or cofactors
43
What is the result of non-competitive inhibitors?
changes shape of enzymes active site making them non-functional
44
What are 2 examples of non-competitive inhibitors?
enzyme poison, i.e. cyanine and fluoride
45
What is feedback inhibition?
concentration of end product of a pathway regulates activity of the first enzyme
46
What are the steps of feedback inhibition?
1. substrate converted to various intermediates 2. intermediates converted to end products 3. end of products in excess, will bind to allosteric site of first enzyme 4. first enzyme is now activated 5. as end products are used up, first enzyme is reactivated
47
What are redox reactions?
coupled oxidation and reduction reactions
48
What is oxidation?
removal (loss) of electrons from a molecule
49
What is reduction?
addition (gain) of electrons to a molecule
50
What are the three characteristics of ATP?
1. energy currency of cells 2. stores energy to 2 high energy bonds 3. when bonds are broken, energy is released
51
What is the generation of ATP?
ADP is phosphorylated which means phosphate group attaches in a high energy bond
52
What are the three types of phosphorylation?
1. substrate level phosphorylation 2. photophosphorylation 3. oxidative phosphorylation
53
What is substrate level phosphorylation?
high energy phosphate from a substrate is directly transferred to ADP
54
In what cells does photophosphorylation happen?
only in photosynthetic cells
55
What is photophosphorylation?
convert light energy to chemical energy ATP
56
Where does oxidative phosphorylation happen?
in the electron transport system
57
What is oxidative phosphorylation?
electrons are passed through carriers to O2.
58
What are electron carriers?
coenzymes that accept electrons during chemical reactions. They drop off electrons at the ETS
59
What are two examples of electron carriers?
Nicatinamide adenine dinucleotide (NAD+) and Flavin adenine dinucleotide (FAD)
60
Nicatinamide adeninine dinucleotide
oxidized (Empty): ___
reduced (fully):____
Oxidized: NAD+
Reduced: NADH
61
Flavin adenine dinucleotide
Oxidized (empty):_____
Reduced (fully):_____
Oxidized: FAD
Reduced: FADH2
62
What is carbohydrate catabolism?
microbes oxidize carbohydrates as a primary source of energy
63
What is the most common source of carbohydrate catabolism?
glucose
64
What are the two ways energy an be obtained?
respiration and fermentation
65
What are the two types of respiration?
Aerobic and Anaerobic
66
What is the energy math during glycolysis?
2 NADH= 6 ATP and 2 ATP= 2 ATP
67
What is the energy math during transition reaction?
2 NADH= 6 ATP
68
What is the energy math Krebs Cycle?
2 ATP= 2 ATP, 6 NADH= 18 ATP, 2 FADH+ = 4 ATP
69
How many ATP are produced during aerobic respiration for prokaryotes? Eukaryotes?
Prokaryotes= 38 ATP; Eukaryotes= 36 ATP
70
What 3 differences happen in anaerobic respiration than in aerobic respiration?
1. oxygen is not the final electron acceptor 2. not all carriers participate in ETS 3. ATP yield is not as high
71
What are three examples of anaerobic respiration?
Nitrate --> Nitrite
Sulfate --> Hydrogen Sulfide
Carbonate--> Methane
72
What are the 5 characteristics of fermentation?
1. anaerobic 2. substrate level phosphorylation 3. no Krebs cycle or ETS 4. Organic molecule as final electron acceptor 5. Produces 2 ATP (from glycolysis)
73
What are the two types of fermentation?
1. Lactic Acid Fermentation 2. Alcohol Fermentation
74
What is the final electron acceptor during lactic acid fermentation?
pyruvic acid
75
What is the end product during lactic acid fermentation?
Lactic acid
76
What two organisms are used during lactic acid fermentation?
Streptococcus, Lactobacillus
77
What does homolactic mean?
only produce lactic acid
78
What does heterolactic mean?
produce lactic acid and other acids or alcohols
79
What is the final electron acceptor during alcohol fermentation?
acetaldehyde
80
What are the end products during alcohol fermentation?
ethanol and CO2
81
What organism is used during alcohol fermentation?
Saccharomyces cerevisiae
82
What is lipid catabolism?
lipases break down lipids to glycerol and fatty acids
83
What process breaks down glycerol?
glycolysis
84
How are fatty acids broken down?
beta oxidation --> Acetyl CoA --> Krebs cycle
85
What is protein catabolism?
proteases break down proteins to amino acids
86
How are amino acids converted?
Deamincation and Decarboxylation
87
What is deamination?
Removal of amino group
88
What is Decarboxylation?
removal of CO2
