Chapter 6 Flashcards
Importance of microbial metabolism
- Model to study eukaryote metabolism (E.coli)
- Food from fermentation
- Method to ID bacteria
- Designing and understanding antimicrobial drugs
- Biofuels
Metabolism
All chemical reactions in a cell
Two types of metabolism
Catabolism
Anabolism
Catabolism
processes that degrade compounds, often release energy
ex. Cellular respiration breaking down glucose to form ATP
Anabolism
process that synthesize macromolecule subunits, use ATP energy
Ex. Photosynthesis, protein synthesis, DNA synthesis
Enzymes
protein catalysts
Catalyst
molecules that speed up chemical reactions but are not altered by the reaction
Enzymes and catalysts
Some enzymes are catalysts but not all.
Substrate
combines with enzyme at the active site and product is released.
Enzymes are very specific to substrate and the reaction
Enzymes have optimal ranges of…..
temperature, pH, salt concentration.
Outside optimal range can denature the enzyme or slow it down
3 types of enzyme inhibitors
Competitive inhibition
Non-competitive inhibition
Feedback inhibition
Competitive inhibition
- not permanent
- binding site is blocked by the other inhibitor to inhibit enzyme
- sulfa drugs inhibit an enzyme that makes folic acid
Non-competitive inhibition
- permanent change to enzyme
ex. mercury breaks sulfer bonds in amino acid cysteine and changes the proteins shape.
Feedback inhibition
- can be permanent, but most of the time not
- When final product is available from an outside source the enzyme will stop making it to conserve energy.
- Final product binds to allosteric site which changes the active site to make it unable to make more final products
Cofactor
non-protein helpers
- must be present for substrate to bind to active site and work
Coenzymes
organic cofactors, often made from vitamins
Electron carriers
NAD+/NADH, NADP+/NADPH, FAD/FADH2
NAD is derived from which vitamin
Niacin
FAD is derived from which vitamin
Riboflavin
Overall equation for cellular respiration
C6H12O6 + 6O2 -> 6CO2 + 6H2O + ATP
3 steps of cellular respiration
Glycolosis
Transition Step (Krebs or Citric Acid Cycle)
Electron Transport
Electron Transport
prokaryote vs eukaryote
Differences in transport proteins and location
Prokaryote Electron Transport Proteins
- Differences between types of prokaryotes
- Cytochrome C found in Neisseria, Psudomonas, Caphylobacter can be tested for with OXIDASE TEST
- Menaquinone found in some prokaryotes is also a source of vitamin K
Source of vitamin K
Menaquinone
Oxidase test tests for…
Cytochrome C: found in Neisseria, Pseudomonas, and Camphylobacter
ATP Yield
3 ATP from each NADH
2 ATP from each FADH2
38 total ATP in prokaryotes
36 total ATP in eukaryotes
Why is there a difference in ATP yield between prokaryotes and eukaryotes
Difference is due to transport of NADH from glycolysis
Fermentation
- occurs if oxygen is not available or electron transport mechanisms are not present.
- Does not make ATP, but makes NAD+ which can go back to glycolysis
Glycolysis
Glucose -> pyruvate + 2 ATP + 2 NADH
Lactic Acid fermentation
Glucose -> pyruvate -> Lactic acid
Tooth decay
Food products