Chapter 5 Microbial Metabolism Flashcards
ATP
- adenosine triphosphate
- stored energy within bonds
enzyme+ATP=_____
macromolecules
2 Basic Metabolic Chem RXN
1 Catabolism
2 Anabolism
Catabolism
- break larger moles into smaller products
- exergonic (release energy)
- heterotrophic organisms acquire energy thru catabolism of nutrients
Anabolism
- synthesize large molecules from smaller products of catabolism
- endergonic
ex) protein synthesis
Exergonic
release of energy
Endergonic
require more energy than they release
Enzymes
- organic catalysts
- enzyme+substrate fit like a lock and key
catalyst
increases the likelihood of a biological rxn
6 categories of enzymes
1 LIGASE or POLYMERASE 2 hydrolases 3 isomerases 4 lyases 5 oxidoreductases 6 transferases
Carbohydrate Catabolism
- many organisms oxidize carbohydrates as primary energy source for anabolic rxn
- glucose is most common carb used
2 processes glucose is catabolized by
1 Cellular Respiration (requires Oxygen) 2 Fermentation (does NOT require Oxygen)
Glycolysis
- (catabolic/exergonic)
- occurs in cytosol
- involves splitting a 6-carbon-glucose into 2 3-carbon-pyruvic acids;
- produces NADH and ATP
- precursor step to respiration and fermentation
Glycolysis Net Gains
4 ATP moles
2 NADH (e- carriers)
2 Pyruvic Acid
Cellular Respiration
- pyruvic acid is oxidized completely to produce ATP by a series of redox rxn
- occurs in MITOCHONDRIA
Cellular Respiration
- pyruvic acid is oxidized completely to produce ATP by a series of redox rxn
- occurs in MITOCHONDRIA
- use of ion gradient to produce ATP
- redox rxn in ETC create proton gradient
- protons flow down gradient to phosphorylate ADP to ATP
3 stages of Cellular Respiration
1 synthesis of acetyl-CoA (pyruvates are oxidized into acetyl-coa)
2 Krebs cycle
3 final series of redox rxn (E- transport chain)
redox rxn in electron transport chain creates ____
proton gradient
__ ATP moles are formed from 1 glucose mole in ECT
34 ATP molecules
Phosphorylation
inorganic phosphate is added to a substrate
- catabolic
- cells phosphorylate ADP to ATP
ATP > ADP
anabolic pathway that removes a phosphate to use energy
Ligase
an enzyme
- takes 2 molecules of something and binds them together
- “reattach”
Polymerase
- an enzyme
- -builds really long polymers
ex) RNA and DNA polymerase
Net Products of Glycolysis
1 6-carbon-glucose >
2 3-carbon-pyruvic-acid
2 ATP (4 produced, 2 used)
2 NADH (e- carrier)
Pyruvate to Acetyl-CoA
- occurs in Cellular Respiration
- pyruvic acid is oxidized (CO2 is released) and the remainder is Acetyl-CoA
Kreb Cycle
- in mitochondria
- series of redox rxn by a series of enzymes
- produces ATP, NADH (e- carriers), and FADH2 (e- carriers)
Electron Transport Chain
- in mitochondria
- final series of redox rxns in Cellular Respirations
- all e- carriers (NADH + FADH2) drop of their e- and pump their H atoms across the membrane
- created proton gradient that flows down and phosphorylates ADP to ATP
- forms 34 ATP
ATP synthase
at the end of the electron transport, the H that were released by NADH +FADH2 will activate the ATP synthase to phosphorylate 34 ADP to 34 ATP
ONLY OCCURS IF O2 is waiting on the inside portion of ATP synthase
Prokaryotic Aerobic Net Gains
38 ATP
Fermentation
- carb catabolism for cells that can’t completely oxidize (doesn’t need oxygen)
- substrate-level phosphorylation
- cells need a constant source of NAD+ ( e carriers) which fermentation provides
- partial oxidation of sugar to release energy using an organic molecule as final e- acceptor (acid or alcohol)
Fermentation stage
1A. pyruvate turns into lactic acid which releases NADH, NAD+
1B. pyruvate at the same time turns to Acetaldehyde while releasing CO2
2B. acetaldehyde turns to Ethanol while releasing NADH + NAD+
2 types of fermentation
- alcohol fermentation (pyruvate>acetaldehyde>ethanol)
- yeast
- lactic acid fermentation (pyruvate>lactic acid)
- bacteria
Eukaryotic Aerobic Net Gains
36 atp
Fermentation Net Gain
2 atp
Anabolic Rxn
synthesis rxn requiring energy + precursor metabolites
- energy put into anabolic rxn comes from ATP produced in the catabolic rxn
- many anabolic pathways are the reverse of catabolic pathways i.e. protein synthesis
