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Biologi > Metabolism och teknisk mikrobiologi > Flashcards

Metabolism och teknisk mikrobiologi Flashcards

1
Q

Describe the citric acid cycle in detail. What are the substances/enzymes and end products?

A

Reaction pathway:
(Acetyl-CoA) -> Citrate -> Isocitrate -> Ketoglutarate -> Succinyl-CoA -> Succinate -> Fumarate -> Malate -> Oxaloacetate -> Citrate

Enzymes:
Citrate synthase -> Aconitase -> Isocitrate dehydrogenase -> Ketoglutarate dehydrogenase -> Succinyl-CoA synthetase -> Succinate dehydrogenase -> Fumarase -> Malate dehydrogenase -> Citrate synthase

End products:
Acetyl-CoA + Oxaloacetate + H2O -> Citrate + CoA-SH
Isocitrate + NAD -> Ketoglutarate + CO2 + NADH +H //
Ketoglutarate + NAD + CoA-SH -> Succinyl-CoA + CO2 + NADH +H //
Succinyl-CoA + GDP + P -> Succinate + CoA-SH + GTP //
Succinate + FAD -> Fumarate + FADH2 //
Fumarate + H2O -> Malate //
Malate + NAD -> Oxaloacetate + NADH + H //

In total: 3 NADH + 1 FADH2 + 2 CO2 - 2 H2O per Acetyl-CoA

Tip:
React. Can I Keep Selling Sex For Money, Officer?
Enz. Can Approve Selling For Calvin. (Rest are dehydrogenases)

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2
Q

Describe the Glyoxylate cycle in detail. What are the substances/enzymes and end products?

A

Reaction Pathway:
Citrate -> Isocitrate -> Glyoxylate + Succinate (path diverge) -> Glyoxylate + Acetyl-CoA -> Malate -> Oxaloacetate

Enzymes: Citrate -> Aconitase -> Isocitrate lyase -> Malate synthase -> Malate dehydrogenase

End products:
2 NADH from 2 Malate -> Oxaloacetate//
1 FAD + Succinate -> Fumarate + FADH2

In total: 2 NADH + 1 FADH2

Tip:
React. Can I Grow (Authentic) Money, Officer? and Can I Succed?
Enz. Can Approve Important Magical Money

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3
Q

Name substances that regulate TCA

A

Succinyl-CoA blocks steps 1 and 4.
NADH blocks 1, 3 and 4.

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4
Q

Anaplerotic

A

Anaplerosis is the act of replenishing the TCA cycle intermediates. Anaplerotic reactions are reactions that “fill up” intermediates in TCA cycle.

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5
Q

Describe each steps in Oxidative Phosphorylation and its end products.

A

Elelctron pair from NADH -> Complex 1 (4 H+ are pumped)
Electron pair reduces Ubiquinone -> Ubiquinol takes electron to Complex 3 (4 H+ are pumped)
Electrons pair travels to Complex 4 with 2 Cytochrome Cs. Complex 4 reduces oxygen with electron pair to form water (2 H+ are pumped) 2e + 4H+ 0.5 O2 -> H2O + 2H

Electron pair from FADH2 -> Complex 2 reduces Ubiquinone -> Ubiquinol takes electron to complex 3. Reaction continues as usual.

ATPase from ADP to ATP by protomotive force of proton gradient from intermembrane space to matrix. 1 turn creates 3 ATP. Usually 9 C-compartment in Eukaryotes mitochondria.

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6
Q

Explain how ATP, ADP and P are transported from mitochondria to cytolasm vice versa.

A

Outermembrane of mitochondria is freely permeable for ATP, ADP and P but the innermembrane need ATP/ADP carrier and Phosphate translocase. Switching between ADP and ATP costs H+. H2PO4 switches with OH and is electroneutral.

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7
Q

Which chemical substance can block/uncouple Oxidative Phosphorylation?

A

Oligomycin can block ATPase => no more ATP + slowed oxygen consumption
2,4-dinitrophenol uncouples and allows for H ions to cross membrane to get inside matrix. => no more ATP + increased oxygen consumption.

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8
Q

Explain how NADH from glycolysis can be transported to the electron transport chain in mitochondria.

A

NADH cannot cross the inner membrane. Bind electron pair to dihydroxyacetone phosphate (DHAP) to become glycerol-3-phosphate and reduce it at G3P dehydrogenase which creates FADH2. Or reduce oxaloacetate to become malate which is used to create one NADH. Oxaloacetate passes membrane by transamination to become Aspartate (out) and glutamine (in).

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9
Q

Name 6 inhibitors of the electron transport chain.

A

Complex I: Rotenone, Amytal.
Complex III: Antimycin A.
Complex IV: cyanide, azide, carbonmonoxide

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10
Q

Describe the structure of chloroplasts and its compartments.

A

Stroma = inside of chloroplasts
Granum = stacked thylakoids
Stroma lamella = between thylakoid granum (bridge)
Thylakoid lumen = cytpoplasm inside thylakoid
Pigments are located inside thylakoid membrane, ex chlorophyll a and b + accessory pigments like beta-carotene and lutein.
+ Antenna pigments to lower energy to the right wavelength.

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11
Q

Describe photosynthesis in detail. (Light reaction)

A
  1. 4 photons excite 4e in PS II (P680).
  2. 2 H20 + OEC -> O2 + 4H + 4e (OEC = oxygen evolving complex). The 4e replenishes PS II
  3. 4e from PS II go through an electron transportation to cytochrome b6f complex.
  4. 8H are pumped from Cytochrome b6f complex.
  5. 4 photons excite 4 electrons in PS I (P700)
  6. Electrons from Cytochrome b6f replenishes PS I
  7. Electrons from PS I are used to reduce 2NADP to 2NADPH

Tylakoids usually have ATPase with 12 C-subunits. Therefore 4H is neeeed for 1 ATP. 12H /8 photons = 1.5 H per photon. 3 ATP / 8 photons = 0.375 ATP per photon.

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12
Q

Describe the alternative cyclic of electron flow through PS I and when it is used.

A

Is used when NADPH is abundant and NADP is in short supply.

1 photon excites PS I (P700) -> e goes trough electron transport chain to cytochrome b6f (2 H is pumped) and is then used to replenish PS I back.

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13
Q

Describe the Calvin cycle in detail. (Dark reaction)

A
  1. (fixation) CO2 + Ru-1,5-bisphosphate -> 2x 3-phosphoglycerate // (RuBisCo enzyme, Co = carboxylase-oxygenase)
  2. (reduction) 2x 3PG + 2 ATP -> 2x 1,3-bisphosphoglycerate + 2 ADP//
    2x 1,3-BPG + NADPH -> 2x glyceraldehyde-3-phosphate + NADP + P (1/6 of GA3P goes to gluconeogenesis!)
  3. (acceptor regeneration) rearrange GA3P to Ribulose-5-phosphate. then Ru5P + ATP -> Ru-1,5-bisphospate + ADP

Overall:
3 CO2 + 6 ATP + 3PG -> 6 1,3-BPG + 6 ADP
6 NADPH + 6 1,3-BPG -> 6 GA3P + 6 NADP + 6P ( 1 GA3P goes to gluconeogenesis)
5 GA3P -> 3 Ru5P
3 Ru5P + 3 ATP -> 3 Ru-1,5-BP + 3 ADP

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14
Q

Describe why RuBisCo is ineffective.

A

Rubisco can react with oxygen to make Ru1,5BP to 3PG and 2PG, 2PG is not used in any reaction and needs to be recycled. It evolved when there was lots of CO2, the reaction only happens at low CO2.

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15
Q

Name an additional way for plants to fix CO2.

A

Plants can fix CO2 in mesophyll cells which can then re-release CO2 into calvin cycle.

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16
Q

What are TAG and where are they found?

A

Triacylglycerol, is the most abundant type of lipids and are found in adipose tissue in cells called adipocytes.

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17
Q

How are fatty acids broken off from TAG?

A

Hormones activate a G-protein that subsequently activates adenylate cyclase. Adenylate cyclase turns ATP to cAMP + PP. cAMP binds to subunit R on Protein Kinase A. Subunit C of Protein Kinase A activates different lipases that detaches a fatty acid from the glycerol backbone. Glycerol can then be used in glycolysis/gluconeogenesis. Glycerol is converted to glucose in liver. Free fatty acid binds to albumin in blood.

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18
Q

How are fatty acids broken down?

A
  1. “Activation” of free fatty acid to fatty acyl:
    R-COO + ATP + CoA-SH -> R-CO-S-CoA + AMP + PP
  2. Fatty-acyl binds to carnitine and releases CoA-SH (happens thanks to CPT I enzyme):
    R-CO-S-CoA + Carnitine -> R-CO-Carnitine + CoA-SH
  3. Fatty acyl carnitine enters matrix and releases carnitine and rebinds to CoA-SH thanks to CPT II enzyme.
  4. Thereafter 2 carbons are release after each beta oxidation cycle:
    Fatty acyl-CoA + FAD + H2O + NAD + CoA-SH -> Fatty acyl-CoA (-2 C) + FADH2 +NADH + H + Acetyl-CoA
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19
Q

What happens in beta oxidation of fatty acid when there is an uneven amount of carbon atoms?

A

Propionyl-CoA is left ( 3 carbon atoms) and is turned into Succinyl-CoA which can be used in TCA cycle.

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20
Q

What happens in beta oxidation of fatty acid when there is a unsaturated fatty acid?

A

Depend on position of double bond.
If C2 = C3, no need for FAD to dehydrate.
If C3 = C4, move double bond to C2 = C3 by enoyl-CoA isomerase.

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21
Q

How are fatty acids synthesized?

A

Acyl-KS + malonyl-ACP + 2 NAPDH + 2H -> Acyl-KS (+2C) + 2 NAPD + CO2 + H2O + ACP

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22
Q

How are Malonyl-ACP and Acetyl-KS synthesized?

A

Acetyl-CoA + ACP -> Acetyl-ACP + CoA-SH //
Acetyl-ACP + KS -> Acetyl-KS + ACP //

Acetyl-CoA +HCO3 + ATP -> Malonyl-CoA + ADP + P + H//
Malonyl-CoA + ACP -> Malonyl-ACP + CoA-SH//

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23
Q

How can fatty acids be desaturated at specifik positions?

A

Fatty acyl-CoA + O2 + 3H + NADH -> Fatty acyl-CoA (desat.) + H2O + NAD

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24
Q

How are TAGs synthesized?

A

G3P + 2 Acyl-CoA -> Diacylglycerol-3-phosphate + 2 CoA-SH //
Diacylglycerol-3-phosphate + H2O -> diacylglycerol + phosphate //
diacylglycerol + Acyl-CoA -> triacylglycerol + CoA-SH //

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25
Q

How is fatty acid synthesis/degradation regulated?

A
  1. Insulin is released at elevated glucose level in blood -> activates fatty acid synthesis.
  2. Acetyl-CoA carboxylase is regulated by Protein Kinase A (negative feedback), fatty acyl-CoA (negative feedback) , citrate (positive).
  3. Malonyl-CoA inhibits beta-oxidation by inhibiting CPT I which transports fatty acyl-CoA to mitochondrion for beta oxidation.
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26
Q

How can nitrogen starvation initiate lipid accumulation?

A

In low nitrogen levels AMP is broken down to IMP to yield one NH3. AMP is used to activate isocitrate dehydrogenase in TCA cycle –> increased citrate is directed towards acetyl-CoA which is made into Malonyl-CoA.

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27
Q

How are phospholipids synthesized?

A

Diacylglycerol-3-phosphate is activated by CTP to form CDP-diacylglycerol.

CTP = cytidine triphosphate.
CDP = cytidine diphosphate.

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28
Q

Give an overview of the global nitrogen cycle.

A

N2 gas is widely available, but only nitrogen fixing bacteria can make N2 to NH3. NH3 can then be used by all organisms to convert into organic nitrogen. Denitrifying bacteria are the opposite and make N2 from NH3.

Bacteria can also make NO2- (nitrite) from NH3 and gain some energy. They can then make NO3- (nitrate) and gain some more energy.

Most fungi, bacteria and plants can make NO2- from NO3-.
Most bacteria and plants can make NH3 from NO2-.

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29
Q

Name some nitrogen fixing bacteria (4x)

A
  • Photosynthetic cyanobacteria
  • Azotobacter
  • Klebsiella
  • Rhizobium
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30
Q

How does industrial fixation of nitrogen work and what is the process called?

A

Called The Haber-Bosch process.
N2 + 3H2 -> 2NH3 (under catalyst)

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31
Q

How is NH3 (ammonia) utilized in organisms?

A
  1. alpha-Ketoglutarate + NH3 + NAD(P)H + 2H -> Glutamate + H2O + NAD(P) // Enz: Glutamate dehydrogenase
    Glutamate can then be used to make several amino acids with transaminases.
  2. Glutamate + ATP + NH3 -> Glutamine + ADP + P // Enz: Glutamine Synthetase
    Glutamine is then used to make purine nucleotides, amino sugars, tryptophan, histidine and cytidine nucleotide.
  3. Oxaloacetate + Glutamate -> ketoglutarate + Aspartate //(Transamination)
  4. Aspartate + ATP + NH3 -> Asparagine + Pi + ADP // Enz: Asparagine Synthetase
  5. NH3 + CO3 + 2ATP -> Carbamoyl phosphate + 2ADP // Enz: Carbamoyl phosphate synthetase. Used to make pyrimidines, arganine, urea.
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32
Q

Describe the general rule for transamination.

A

Keto acid + amino acid -> new keto acid + new amino acid

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33
Q

Essential amino acids

A

Amino acids that are not synthesized or that are consumed at a higher rate than synthesized. These amino acids need to be consumed.

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34
Q

Auxotroph

A

Mutant that lacks the gene necessary for synthesizing a specific amino acid.

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35
Q

Prototroph

A

Previously an auxotroph but genetic engineering made it possible for the organism to produce said amino acid.

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36
Q

Where and how does degradation of protein take place?

A

Degradation can take place in lysozome that buds from golgi apparatus. Can also be done via proteasomes which are highly regulated and only degrade proteins if they have ubiquitin tag. (This is important because nitrogen cannot be stored and needs constant turnover)

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37
Q

Name 3 pathways that cells use to degrade proteins/amino acids.

A
  1. Deamination - sometimes back to glutamate
  2. Degradation of carbon skeleton
  3. Excretion of amino group
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38
Q

How is ammonia excreted?

A

Ammonia (NH3) is excreted by the liver. Glutamate is removed by glutamate dehydrogenase in liver and is then excreted as urea. Uric acid for non mammals.

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39
Q

Pyrimidines

A

Thymine, Uracil, Cytosine (only one carbon ring)

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40
Q

Purines

A

Adenine and Guanine

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41
Q

Nucleoside

A

Purine/pyrimidine is bound to ribose or 2-deoxyribose

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42
Q

Nucleotide

A

Posphorylated nucleoside, methanol on C5 is exchanged for phosphate group, can be several.

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43
Q

Nucleic Acid

A

Polymer chain of nucleotides, 5’ and 3’ end.

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44
Q

Describe all pathways in the salvage pathway of nucleotides.

A

From diet or intracellular turnover:
1. Endonucleases -> cuts at specific/non-specific combination -> forms oligonucleotides

  1. Exonucleases -> cuts at either 5’ or 3’ end -> forms mononucleotides.
  2. Mononucleotides can be reused or broken down to nucleosides or nucleobases:
    nucleobase + ribose-1-phosphate <-> nucleoside + P (nucleoside phosphorylases) //
    nucleoside + ATP -> mononucleotide + ADP (nucleoside kinase) //
    mononucleotides + H2O -> nucleoside + P (nucleotidases) //
  3. PRPP + nucleobase <-> mononucleotide + PP (phosphoribosyl transferase) //
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45
Q

Describe all pathways in the de novo biosynthesis of nucleotides.

A

Different for different organisms.
PURINES:
PRPP + glutamine -> Inosine monophosphate //
IMP -> AMP or GMP //
PYRIMIDINES:
Aspartate + carbamoyl phosphate + PRPP -> uridine monophosphate //
UMP -> CMP //
dUTP -> dTTP//

46
Q

What is difference between ex: dAMP and AMP.

A

dAMP = deoxyadenosine monophosphate
AMP = adenosine monophosphate.

47
Q

Respiration

A

Gain energy from electron transfer between donor and electron acceptor via oxidative phosphorylation. There is aerobic respiration (uses oxygen as electron acceptor) and anaerobic respiration (uses something else).

48
Q

Fermentation

A

No electron acceptor for oxidative phosphorylation. Therefore donor and acceptor come from the same substrate. Ex: lactic acid or ethanol. For eukaryotes this usually happens when there is no oxygen.

49
Q

How does redox potential work and describe the reduction reaction of oxygen to water.

A

Molecules have redox potential = reduction/oxidation potential.

0.5 O2 + 2H + 2e -> H2O E = +0.82 V

50
Q

Chemoorganotroph

A

Uses organic compound as electron donor. (only chemoorgranotroph can undergo fermentation)

51
Q

Chemolithotroph

A

Uses non-organic compound as electron donor.

52
Q

Facultative chemolithotroph and example

A

Can use both organic and inorganic as electron donor.
Example hydrogen bacteria:
Soluble dehydrogenase that turns NAD to NADH and fixes CO2 using ATP. Also if hydrogen bacteria only has membrane bound hydrogenase then NADH can be made in reverse.

53
Q

Sox system

A

Sulfur oxidation cylce (like TCA cycle bur for sulfur oxidation). Takes place in periplasm and releases 6 electrons. Commonly found in bacteria near hydrothermal vents or polluted environment.

54
Q

Name different examples of fermentation and describe their reactions.

A

Alcoholic fermentation:
2 ethanol

homolactic:
2 lactate

heterolactic: (if aldolase missing)
Uses parts of PPP and creates 1 lactate + 1 ethanol

Fermenation without substrate-level popshorylation:
Uses ions to power ATPase if energy for oxidative phoshporylation is too high. No electron transport.

55
Q

Clostridial fermentation

A

Obligate fermentative anaerobs. From glucose, byturic acid is often fermentation product. If pH drops, swtiches to butanol instead of byturic acid. Can use amino acids as substrate.

56
Q

Syntropy

A

Nutritional symbiosis, example ethanol fermenter and methanogen.

57
Q

Describe each era of biotech.

A

First era:
Fermentation and invention of microscope.

Second era:
Pure cultures of single bacteria. Citric acid by fungi A.Niger and acetone by bacteria C.Acetobutylicum.

Third era:
1928 penicillium first discovered its antibiotic properties.
1940 mass production of penicillin.

Fourth era:
Genetic technologies 1980-

58
Q

Taxonomy

A

Classification, description, identification and naming of living organisms.

59
Q

How are phylogenic trees made from rRNA?

A

rRNA is highly conserved in genome. (Without rRNA organism can’t reproduce). Isolate rRNA sequence then PCR then analyze the rRNA alignment in genom to identify organism and its phylogenic tree.

60
Q

How does archaea differ from bacteria?

A
  1. different evolutionary history
  2. different cell walls/membranes
  3. unique variants of glycolysis
  4. often not sensitive to antibiotics
  5. live in extreme environments
  6. not known as any human pathogen
61
Q

Describe the advantages of having a small shape.

A

If bacteria are small the surface to volume is large. More transporters interact with environment and their is not much volume to duplicate at division. Large surface area means more transporters which interacts with environment and take up nutrients, thus leading to faster growth. To grow faster the surface/volume ratio needs to be as high as possible.

62
Q

Describe the cell wall for G-negative and G-positive bacteria and what it’s used for.

A

The cell wall maintains morphology and prevents lysis.

G+ have a peptidoglycans layer outside membrane.
G- have peptidoglycans in between two cell membranes.

N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM) are linked together in a long chain. Each NAG and NAM have a tetrapeptide going down:

G- (Ala-Glu-DAP-Ala).
G+ (Ala-Glu-Lys-Ala)

G- have linkage between DAP and Ala in tetrapeptide to link upper and lower layer of peptidoglycan.
G+ have a pentapeptide bridge made of five Gly that connects Ala to Lys.

63
Q

Name some of the different types of bacteria shapes.

A

Coccus, rod, spirillum, spirochete, stalk and hypha budding, filamentous

64
Q

Name the advantages of prokaryotic DNA.

A

Has less DNA to duplicate -> faster growth
Only one copy of gene -> prevents masking of mutation

65
Q

Name different ways organism can store energy.

A

Sulfur and polyphosphates, triacylglycerols, PHB (poly-beta-hydroxybutyric acid), glycogen, di-and polysaccharides

66
Q

Name different type of cell divisions.

A

binary fission, budding, hyphal growth

types of hyphal growth:
- septate hyphae (membrane between them)
- coenocytic hyphae (no membrane between)
- pseudohyphae

67
Q

What are the macronutrients often found in living organism?

A

C H O N S P

68
Q

What are the micronutrients often found in living organism?

A

Fe Co Mn Zn Cu Ni Mo Vitamins/growth factors

69
Q

Describe the different types of culture medium.

A

Defined: All components are known, contains “building blocks”
Complex: Not all components are known, contains complex components
Selective: Only some types can grow
Differential: Some color change related to what organism grows

70
Q

What defines growth rate?

A
  • Genetic background
  • Temp
  • pH
  • culture medium
71
Q

Name 3 different types of method of quantifying microbial growth.

A
  • Direct measure: (Microscope cell counter, coulter counter, flow cytometry, CFU)
  • Indirect measure: Cell turbidity
  • Measure biomass
72
Q

Name different types of Cultivation methods.

A
  • Solid
  • Liquid: Batch, Fed-batch, continuous
73
Q

How do organisms survive cold?

A

Make proteins more flexible so that less energy is needed for reaction.
- more alpha-helices
- less beta-sheets
- membrane have shorter fatty acids
- antifreeze (glycerol)

74
Q

How do organisms survive heat?

A

Make proteins more rigid so that more energy is needed for reaction. Stiffer proteins = less chance of denaturation.
- more beta-sheets
- less alpha-helices
- proteins have highly hydrophobic interiors
- membranes have long saturated fatty acid.

75
Q

What are the different categories of temperature organisms can survive in?

A

Psychrophile, Opt: < 15 C
Mesophile, Opt: - 40 C
Thermophile, Opt: > 45 C
Hyperthermophile, Opt: > 80 C (usually archaea)

76
Q

What are the different categories of pH level organisms can survive in?

A

Acidophile, pH < 5.5
Neutrophile, pH 5.5 - 8.0
Alkaliphile, > 8.0

77
Q

What intracellular pH range does all organism have and why?

A

pH: 5-9
DNA is sensitive to low pH.
RNA is sensitive to high pH

78
Q

What are the different categories of water activity organisms can survive in?

A

Osmophile = high osmolarity
Xerophile = low osmolarity

79
Q

What are the different categories of salt concentration organisms can survive in?

A

Nonhalophile: 0-1%
Halotolerant: 0-10% Opt: 2%
Halophile: 0-12% Opt: 6%
Extreme Halophile >10% Opt: > 17.5%

80
Q

What are the different categories of aerobic and anaerobic organisms?

A

Obligate aerobic or obligate anaerobic. (requires O2 vs O2 is toxic)
Facultative aerobes. (Not required O2 but faster growth with O2)
Aerotolerant. (Not required and growth is unaffected)

81
Q

How do you improve aeration in a liquid culture medium?

A
  • sparging
  • stirring
  • shake flask
  • high rate sparge (needs stirring)
  • increase oxygen concentration in gas
  • increase air pressure
82
Q

How do you remove oxygen from liquid culture medium?

A
  • chemically by reducing to H2O
  • by sparging with N2
83
Q

Name the 3 different categories of controlling/killing microbes.

A
  • Sterilization (Killing/removing all microbes.)
  • Disinfection (Inactivate most microbes on surface)
  • Sanitation (Reduce bacterial load, not necessarily viruses)
84
Q

What types of methods are there for killing/controlling microbes?

A

Physical methods:
- Heat
- Radiation
- Filtration

Chemical methods:
- Alcohol (or other disinfectant)
- Antibiotics/antimicrobial

85
Q

Autoclavation

A
  • High temperature to kill microbes
  • Steam is better than dry -> water conducts heat
  • Dry can take longer time
  • Also used in pasteurization
86
Q

Radiation

A
  • Uses ionizing radiation, x-rays, gamma-rays
  • Used on medical supplies, pharmaceuticals and some food products
  • Also uses UV radiation, usually 220-300 nm
  • Damages DNA, thymine dimers are created.
87
Q

Filtration

A
  • Good for heat sensitive components, like vitamins and amino acids in growth medium
  • Used in removal of gasses such as O2, N2, air in bioreactor.
  • Pore-size typically 0.2 um
88
Q

Chemical control of growth

A
  • bacteriostatic (growth halted, ex. inhibits protein synthesis)
  • bacteriocidal (death but remains intact, lowers viable cell count)
  • bacteriolytic (death + lysis)
  • fungi
89
Q

MIC

A

Minimum inhibitory concentration, lowest concentration that prevents growth.

90
Q

Name 3 types of antimicrobial.

A
  • natural
  • synthetic
  • semi-synthetic (most modern antibiotics)
91
Q

Explain broad- vs narrow-spectrum antibiotics.

A

Broad-spectrum antibiotics can cause super infection but is good when pathogen is unknown.

Narrow-spectrum = less risk for resistance spreading.

92
Q

Antimetabolites

A

Similar to metabolites but act as a competitive inhibitor. They are bacteriostatic and removal restores growth.

93
Q

Ribosome interference

A

Different types of drugs can interfere with ribosome.
- tetracyclines: broad spectrum, used a lot in livestock farming, binds to 3Os ribosomal subunit
- aminoglycosides: binds to 30S and impairs proofreading
- macrolides, chloramphenicol and lincosamides, binds to 5OS and prevents peptide bond formation.

94
Q

Name the different methods of drug resistance.

A
  • Efflux pump
  • Blocked penetration
  • Target modification
  • Inactivation by enzymes
95
Q

Name the different methods drug resistance can spread from organism to organism.

A
  • Random mutation, selective pressure
  • Horizontal gene transfer
96
Q

What is a lysozyme?

A

Enzyme that breaks down NAG-NAM bond in peptidoglycan layer.

97
Q

What are coenzymes and cofactors?

A

Cofactors = organic/inorganic (metal ions) compound that is required for an enzyme to work as a catalyst. Coenzymes are organic cofactors that can be further divided into two groups, prosthetic group or cosubstrate.

Called apoenzyme when it is without its cofactor.
Called holoenzyme when it is with its cofactor.

98
Q

Name the three types of inhibition.

A
  • Competitive Inhibiton: inhibitor competes with substrate. Vmax unchanged, more [S] is needed to arrive at Vmax. Applied Km > Km
  • Uncompetitive Inhibition: Inhibitor binds to other site (allosteric inhibitor), Vmax reduced, Applied Km < Km
  • Noncompetitive Inhibition: (mixed competitive + uncompetitive), Vmax reduced, Applied Km is unchanged.
99
Q

Autotrophs

A

Synthesize metabolites from CO2

100
Q

Heterotrophs

A

Require carbon compounds from other organism

101
Q

Futile Cycle

A

Two metabolic pathway run simultaneously in opposite direction.

102
Q

How can metabolic pathways be regulated?

A
  • Enzyme levels (genetic regulation)
  • Enzyme activity (substrate levels, allosteric sites, covalent modification)
  • Signal transduction (hormones, growth factors, first and second messenger)
103
Q

Describe Glycolysis pathway, substrate and enzyme in detail.

A
  1. Glucose + ATP –hexokinase–> Glucose-6-phosphate + ADP
  2. Glucose-6-phosphate –phosphoglucose isomerase–> fructose-6-phostphate
  3. fructose-6-phosphate + ATP –phosphofructokinase–> fructose-1,6,-bisphosphate + ADP
  4. fructose-1,6-bisphosphate –aldolase–> glyceraldehyde-3-phosphate + dihydroxyacetone phosphate
  5. glyceraldehyde-3-phosphate + Pi + NAD –G3P dehydrogenase–> 1,3-bisphosphoglycerate + NADH +H
  6. 1,3-bisphosphateglycerate + ADP –phosphoglycerate kinase–> 3-phosphoglycerate + ATP
  7. 3-phosphoglycerate –phosphoglycerate mutase–> 2-phosphoglycerate
  8. 2-phosphoglycerate –enolase–> phosphoenolpyruvate + H2O
  9. phosphoenolpyruvate + ADP –pyruvate kinase–> pyruvate + ATP
104
Q

Describe Gluconeogenesis pathway, substrate and enzyme in detail.

A
  1. pyruvate + ATP + CO2 –pyruvate carboxylase–> oxaloacetate + ADP + Pi
  2. oxaloacetate + GTP –phosphoenolpyruvate carboxykinase–> phosphoenolpyruvate + CO2

Rest is the same except two first investment ATP needing steps for glycolysis are phosphatase instead of kinase.

105
Q

Give examples of disaccharides and what monosaccharides they can be broken down to.

A
  • Maltose, can be broken down to 2 glucose by maltase.
  • Lactose, can be broken down to 1 galactose and 1 glucoseby lactase.
  • Sucrose, can be broken down to 1 fructose and 1 glucose by sucrase.
106
Q

Give example of larger polysaccharides and how they are broken down.

A
  • Starch (stärkelse) = amylose (long central chain) + amylopectin (branches)
  • Glycogen (more branched version of amylopectin)
  • Amylase breaks down starch and is found in mouth.
  • Glucosidase breaks down glycogen and is found in intestine.
107
Q

How is glycogen synthesized?

A

G6P + UTP –> UDP-glucose + 2Pi
glycogen + UDP-glucose –glycogen synthase–> glycogen(+1) + UDP

108
Q

How does hormones regulate glycogen breakdown?

A
  1. Glucagon or adrenaline binds to receptor.
  2. Activates adenylate cyclase via G-protein.
  3. cAMP activates proten kinase A.
  4. Activates phosphorylase b kinase.
  5. Phosphorylase b –> phosphorylase a.
  6. Phosphorylase a catalyzes glycogen breakdown.
109
Q

What is the Pentose Phosphate Pathway?

A

A reaction pathway that branches off from glucose-6-phosphate and is used to generate NADPH and produce ribose-5-phosphate.

There is an oxidative and non-oxidative part.

110
Q

Explain the reactions in the oxidative part of PPP.

A

G6P + NADP -> 6-phosphogluconolactone + NADPH //
6-phosphogluconolactone + H2O -> 6-phosphogluconate + H //
6-phosphogluconate + NADP -> ribulose-5-phosphate + NADPH + CO2 //

Biologi (2 decks)

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