Microbial Metabolism Flashcards
Anabolism(Biosynthesis)
Building up
Requires energy input
Catabolism
Breakdown of bonds
Release of energy
Functions of Metabolism
Builds small molecules into larger ones for cell
Breaks down large molecules into smaller ones releasing energy
Energy is conserved or released in the form of ATP
Enzymes
Proteins that facilitate chemical reactions
Increase the rate of chemical reactions without becoming part of the product or consumed in the reaction
Activation Energy
The amount of energy required to initiate a chemical reaction
What happens when enzymes die?
Metabolism shuts down
ex: high fever
What does ATPase do?
An enzyme used to break ATP
What does ATP synthase do?
An enzyme used to build ATP
Inorganic Cofactors
Usually metals
Include Fe, Cu, Mg, Mn, Zn, Co, Se
Cofactors
Often required for specific enzymes to function properly
Organic Cofactors
Coenzymes
Usually derived from vitamins
Where does NAD come from?
Vitamin B-3
Where does FAD come from?
Vitamin B-2
Dehydration Synthesis Reaction
Remove water to break bond
Hydrolosis
Add water to make bond
Oxidation
Gains an oxygen atom or the loss of a hydrogen atom
Loss of an electron
Reduction
Loss of an oxygen atom and the gaining of the hydrogen atom
Gaining of an electron
How many electrons does NADH have?
one
How many electrons does FADH2 have?
two
Most of the time what is the final electron acceptor?
Oxygen
What factors affect enzyme activity?
Temperature pH Osmotic Pressure Cofactors Enzyme Inhibitors
Temperature- High Temp
Reaction takes place too quickly resulting in useless products
If too high– permanently destroys the enzyme
Temperature- Lower Temp
The reaction is too slow resulting in an insufficient amount of product
pH
pH range- 5-8 (slightly basic or slightly acidic)
High or low pH result in useless product
Osmotic Pressure
Most enzymes prefer isotonic or hypotonic environments
Hypertonic environments result in useless product
Cofactors
Non-protein factors
Must have cofactor for enzymes to work
No cofactor= non-functioning enzyme=no product
Enzyme Inhibitors
Chemicals that inhibit enzyme function
Could be reversible ex: ATP
Could be irreversible ex: penicillin
Competitive
Compete with enzyme for binding/activation site
“Blocks the lock”
Non-competitive
Bind to other places, but change the shape of the binding/activation site
“Changes the lock”
What pathway do heterotrophs use?
Catabolic pathway
What pathway do phototrophs use?
Sunlight-driven pathway
Aerobic Respiration
Convert glucose to Co2 and allows the cell to recover significant amounts of energy
Anaerobic Respiration
Does not use molecular oxygen as the final electron acceptor
Same as aerobic just without oxygen
Fermentation
The incomplete oxidation of glucose or other carbs in the absence of oxygen
Uses organic compounds as final electron acceptor and yields small amount of ATP (ALWAYS 2)
Proceeds glycolysis when O2 is absent
Glycolysis
Splitting of glucose Anaerobic process 6 Carbon Glucose--> 2 3 Carbon pyruvate 2 ATP are used 4 ATP are produced (net gain of 2) 2 NADH are produced
Pre-Krebs
Pyruvate to acetyl CoA Occurs twice (one time for each pyruvate) 2 O2 total 2 CO2 total 2 NADH No ATP No FADH2
Krebs Cycle
Occurs twice (one time for each Acetyl CoA 2 ATP 2FADH2 4 CO2 total 6 NADH
Electron Transport Chain (ETC)
Series of redox reactions
30 ATP from NADH
4 from FADH2
O2 is the final electron acceptor
What fuels the pump in the ETC?
Electrons
How many ATP molecules can NADH produce?
3 ATP
How many ATP can FADH2 produce?
2 ATP
How many CO2 is produced during prekrebs and krebs?
6 CO2 molecules
Alcoholic Fermentation
2 net ATP
CO2
alcohol(usually ethanol)
Acidic Fermentation
2 net ATP
Acid such as lactic acide or butyric acid
Chlorophylls
Absorb solar energy & use to energize e-
Found in plants, algae, and cyanobacteria
Involved in oxygenic photosynthesis
Bacteriophylls
Absorb solar energy & use to energize e-
Found in purple & green bacteria
Involved in anoxygenic photosynthesis
Cyclic Pathway
Anoxygenic
Used to create ATP only
Energized electron comes from chlorophyll itself
Non-cyclic Pathway
Oxygenic
Used to create ATP, NADH, & O2
Excited electron from an outside source ex: H2O
Calvin Cycle ( Dark Reaction)
convert CO2 to an organic molecule (usually sugar)
No sunlight= no energy
