Microbial Metabolism Flashcards
Define metabolism
sum of chemical in organisms
prokaryotic and eukaryotic cells
What are the 2 different metabolic reactions
1) catabolic reaction
2) anabolic reactions
What is catabolic reaction and 2 examples
ex: cellular respiration and fermentation
c6h12o6 +02 > 6CO2 +_ 6H2O +ATP
What is anabolic reactions and give examples
ex. photosynthesis and lipid biosynthesis
6CO2 +6H2O > C6H12O6 + 6O2
Define catabolism
- breakdown of large molecules to smaller molecules
- energy is generally released
- mediated by enzymes
Define anabolism
- synthesis of larger molecules using smaller molecules
- energy is generally used up
- mediated by enzymes
Define exergonic reaction
energy released
Define endergonic reaction
energy is utilized
What is the most common energy currency
adenosine triphosphate (ATP)
What is adenosine triphosphate
a modified nucleotide- adenine linked to 5c sugar ribose and 3 phosphate group
Which phosphate in adenosine is high energy
that last phosphate bond
Define metabolic pathway
sequence of enzymatically catalyzed chemical reactions in a cell
Define enzymes
biological catalysts
proteins of RNA molecules
substrate speciifc
active site on enzymes
Define activation energy
enzymes reduced the energy of activation
enzymes is always recycled
What is the use of oxidoreductase
catalyze
What is the use of transferase
transfer functional group
What is the use of hydrolase
hydrolysis reaction
What is the use of ligase
Enzyme that can catalyze the joining (ligation) of 2 large molecules by forming a new chemical bonds
What are the 4 components of enzymes
apoenzyme
cofactor
coenzyme
holoenzyme
Define apoenzyme
protein
Define cofactor
nonprotein component-inorganic ( metal ion,zinc ion)
activator
define coenzyme
nonprotein component-organic
define holoenzyme
apoenzyme plus cofactor
complete + catalytically active
What are 4 important coenzymes
NAD+
NADP+
FAD
Coenzyme A
What are 4 factors influencing enzyme activity q
temperture
ph
substrate concentration
inhibitors
What two influences has the ability to denature protein
temperture and pH
What are competitive inhibition
competitive inhibitor binds to same active site as substrate so it fights for spot
What is an example of a competitive inhibition
Sulfa drugs
antibiotic that competes for the active site of folic acid synthesis
in no folic acid synthese in bacteria then no DNA/RNA synthesis so no protein produced
Define noncompetitive inhibition
does not bind to active site, instead to allosteric site
changes shape of active site so substrate can’t bind
Define oxidation
removal of electrons
Define reduction
gain of electrons
Define redox reaction
an oxidation reaction paired with a reduction reaction
Define dehydrogenation reactions
removal of hydrogen
How is ATP generated
phosphorylation of ADP with the input of energy
What are the 2 mechanism of phosphorylation
1) in microorganisms
2) in chlorophyll-containing plants or bacteria
Define atp generation in microorganism and 4 examples
substrate level phosphorylation: fermentation,glycolysis,krebs cycle
oxidative phosphorylation/cellular respiration
Define atp generation in chlorophyll containing plants and bacteria
photophosphorylation
Define substrate level phosphorylation
energy from phosphate to ADP generate ATP
Define oxidative phosphorylation
energy released from transfer of electrons from one compound to another to generate ATP
electron transport chain
Define photophosphorylation
occurs only in photosynthetic cells
atp is generated by transfer of electrons from chlorophyll to a system of carrier molecules
What is needed in photophosphorylation to excite the electron
light
What are 2 energy production in microorganisms
carbohydrate catabolism
lipid+ protein catabolism
What are 2 examples of carbohydrate catabolism
cellular respiration
fermentation
What are 3 stages of cellular respiration
glycolysis
kreb’s cycle
electron transport chain (system)
Describe stage 1 of cellular respiration
what type of phosphorylation
gycolysis
substrate level phosphorylation
Describe stage 2 of cellular respiration
what type of phosphorylation
pyruvate oxidation and krebs cycle
substrate level phosphorylation
Describe stage 3 of cellular respiration
electron transport chain and chemiosmosis
oxidative phosphorylation
Where does glycolysis occur in the cell
what is the product
what are the net amounts of atp
occurs in the cytoplasm product: 3 carbon compound: Pyruvate in: 2 ATP OUT: 4 atp NET: 2 ATP 2NADH
What are the products from glycolysis per glucose molecules
4 ATP: 2 ATP invested; net gain of 2 ATP
2 pyruvate molecules
2 NADH molecules
What are 2 alternative pathways to glycolysis
1) Pentose phosphate pathway
2) entner-doudoroff pathway
Describe Pentose Phosphate Pathway
produces pentose sugars and 2 NADPH
Net gain: 1 ATP
Ex. escherichia coli, enterococcus faecalis, bacillus subtilis
Describe entner doudoroff pathway
net gain: 1 atp and 2 NADPH
some gram negative bacteria ( pseudomonas,rhizobium,agrobacterium)
does not involve glycolysys
What occurs in the intermediate stage of cellular respiration
pyruvic acid ( from glycolysis) is converted to Acetyl CoA
decarboxylation
2 pyruvic acid is produced at end of stage
What are the products of the intermediate step
2 Acetyl CoA molecules
2 CO2 molecules
2 NADH molecules
What occurs in stage 2 of cellular respiration: Kreb cycle
where in the cell does it occur and what products generated
cytoplasm( prokaryotes) mitochondrial matrix ( eukaryotes) each cycle generate 1 ATP 3 NADH 1 FADH2 2 CO2 processes 2 molecules of Acetyl CoA
What are the products of the Kreb cycle
2 ATP
6 NADH
2 FADH2
4 CO2
What are the 2 parts of stage 3 of cellular respiration
electron transport chain ( Aerobic respiration)
chemiosmosis
Where does electron transport chain take place and what occurs in this step
plasma membrane of prokaryotes
inner mitochondrial membrane of eukaryotes
involves electrons carried by NADH + FADH2
sense of carrier molecules ( flavoproteins,cytochrome,ubiquinone)
produces most ATPs
oxidative phosphorylation
Define chemiosmosis
energy released from the electron transport chain is used
this H+ gradient proton motive force is created
H+ ions high in periplasmic space and low in cytoplasm
ATP synthase will let the H+ ions through
Number of energy in aerobic respiration
oxygen is the final electron acceptor in electron transport chain
1 NADH = 3 ATP
1 FADH2 = 2 ATP
Why is total ATP yeild lower in eukaryotic vs prokaryotic
energy is used to transfer to mitocondira
Describe the 5 difference in anaerobic cellular respiration in prokaryotes
1) final electron acceptor is an inorganic substrate ( not oxygen)
2) nitrate ion reduced to nitrite ion,nitrous oxide or nitrogen gas
ex. pseudomonas and bacillus
3) sulfate ion reduced to hydrogen sulfide ( Desulfovibrio)
4) carbonate converted to methane
5) ATP yield is less than aerobic respiration
Define aerobic respiration in terms of final electron acceptor
the final electron acceptor in the electron transport chain is oxygen ( O2)
Define anaerobic respiration in term of last electron acceptors
the final electron acceptors in the electron transport chain is not O2
Describe carbohydrate catabolism in term of pathway involved in eukaryote cells
glycolysis: cytoplasm
intermediate step: mitochondrial matrix
kreb’s cycle: mitochondrial matrix
ETC: mitochondrial inner membrane
Describe carbohydrate catabolism in terms of pathway take place in parokaryote
glycolysis: cytoplasm
intermediate step: cytoplasm
kreb’s cycle: cytoplasm
ETC: plasma membrane
Describe fermentation
release energy from oxidation of organic molecules
does not require oxygen
does not use the krebs cycle or ETC
uses an organic molecule as the final electron acceptor
What microbe uses fermentation
streptococcis ( incapable of respiration)
faculative anaerobes
What is the main purpose of fermentation
regeneration of NAD+
What are 2 types of fermentation
lactic acid fermentation
alcohol fermentation
What is the end product of fermentation of streptococcus,lactobacillus, bacillus (1)
pyruvic acid > lactic acid
What is the end product of fermentation in Saccharomyces ( yeast)
pyruvic acid > ethanol and CO2
What is the end products of fermentation for Escherichia and salmonella (6)
ethanol lactic acid succinic acid acetic acid co2 h2
Describe enzymes used in lipid and protein catabolism(3)
extracellular enzymes
enzymes include lipase,proteases and peptidases
What does lipase do in lipid catabolism
breakdown fats to fatty acids and glycerol
ex. phospholipase-staphyloccus aureus
What does proteases and peptidases do in protein catabolism
proteases and peptidases breakdown large proteins to their amino acids
Draw out lipid catabloism
reference notebook
draw out protein catabolism
reference notebook
Why do microorganism use atp synthesise
for bio synthesis
What is biosynthesis
synthesis of polysaccharides like glycogen and peptidoglycan lipids proteins nucleic acids
What are the 2 sequential stages in photosynthesis
light dependent ( light) reaction light independent ( dark) reaction
Describe light-dependent reaction in terms of the 3 products it makes
product: oxygen, ATP, NADPH
NADP+ > NADPH
ATP- photophosphorylation
Describe light independent reaction
product: sugar
calvin cycle
Where does photosynthesis occur in prokaryotic
plasma membrane
What is the formula for oxygenic photosynthesis
6CO2 + 12H2O + LIGHT ENERGY > C6H12O6 + 6H2O + 6O2
What is the formula for anoxygenic phtosynthesis
6CO2 + 12H2S + LIGHT ENERGY > C6H12O6 + 6H20 + 12S
What are 3 photosynthetic pigments
- green plants, algae, and cyanobacteria ( chlorophyll a)
- other bacteria ( bacterioclorophylls)
- photosystems: photosystem 1- p700 and ph0totsystem 2- P680
Describe cyclic photophosphorylation
refernce notebook
describe noncyclic phtotphosphorylation
reference notebook
What are the 3 products of light reaction
ATP
NADPH
OXYGEN
Describe light independent ( dark) reaction
calvin cycle
known proiducts NADPH + ATP used to fix carbon dioxide to sugar
CO2 enters
enzymes: ribulose bisphosphate carboxylase ( RuBis CO)
product: organic sugar molecule
What 2 sources are used in classification of metabolic diversity
energy source
carbon source
What are 2 microorganism classifications based on energy source
phototrophs
chemotrophs
Define phototrophs
use energy from light
define chemotroph
use energy from redox reaction
What are 2 classifications for organisms based on carbon source
autotrophs
heterotrophs
Describe autotrophs
use carbon dioxide
lithotrophs
Describe heterotrophs
use organic carbon
organotrophs
