Lecture 4: Nutrition and Metabolism Flashcards
What are the main macronutrients that provide nutrition for microorganisms? What are the others?
Main
-Carbon, Nitrogen, Oxygen, Hydrogen
Others
-Phosphorus, Sulfur, Salts (K, Mg, Ca, Na)
What kinds of micronutrients provide nutrition for microorganisms?
Trace elements (metals) -Iron and Selenium
Growth Factors (Organic compounds like vitamins) -Niacin, Riboflavin etc
What kinds of culture media are used to grow microorganisms?
Defined Media
- Precise amounts of purified chemicals used
- Know exactly whats in there
Complex Media
- Includes extracts of impure substances
- Contains nutrients you need but don’t know exact amounts contained
- eg. Yeast
What are the two types of reactions concerning metabolism?
Catabolic Reactions
-Breaking down molecules and energy-releasing
Anabolic Reactions
-Building molecules and energy-requiring
What is the overall process of life?
- Acquiring nutrients
- Raw materials - Processing nutrients
- making precursor metabolites - Making Monomers
- the building blocks - Making Polymers
- DNA, RNA, Polysaccharides, Lipids - Assembling the polymers into macromolecules
What is the type of metabolism, Photoautotroph?
Energy source is Light
Carbon source is CO2
What is the type of metabolism, Chemoautotroph?
Energy source is Chemical
Carbon source is CO2
Example is the deep water archaea or Sulfur oxidizing bacteria
What is the type of metabolism, Photoheterotroph?
Energy source is Light
Carbon source is Organic Carbon
What is the type of metabolism, Chemoheterotroph?
Energy source is Chemical
Carbon source is Organic Carbon
What are enzymes?
Organic catalysts
-Increase rate of reaction and reduce activation energy
Mostly made of proteins
-Sometimes RNA or Coenzymes
How does an enzyme function?
Binds the substrate at the active site, releases it and is recycled
When it binds the substrate it will align reactive groups and strain specific bonds that it will break
What are cofactors?
Non-protein molecules
- Prosthetic = tightly bound (eg heme group)
- Coenzymes = Loosely bound (eg NAD)
What are REDOX reactions?
Oxidation
- Loss of electrons
- Electron donor = oxidized substance
Reduction
- Gain of electrons
- Electron Acceptor = reduced substance
ALWAYS COUPLED
How does the REDOX tower work?
Top = Strongest Electron Donors Bottom = Strongest Electron Acceptors
The further away the donor/acceptor are, the more energetically favorable the reaction energy
-Bigger the fall = the more energy generated
What are REDOX electron carriers?
Mediate the transfer of electrons between substances
- eg. NAD+/NADH and FAD+/FADH2
- Electron acceptor/donors
- Also Coenzymes
How do Cells store the energy released from REDOX reactions?
Synthesizing energy rich compounds that can hold the energy in their bonds
- Short term storage: ATP, PEP, Acetyl CoA
- Long term Storage: Poly-B-Hydroxybutyrate (PBH), Glycogen
What are two examples of catabolism?
Fermentation
- Anaerobic
- ATP from substrate level phosphorylation
Respiration
- Aerobic but can have O2 substitutes
- ATP from substrate-level phosphorylation AND Oxidative phosphorylation
What are the types of phosphorylation that generates energy?
Substrate Level Phosphorylation
-ATP Produced by intermediates
Oxidative Phosphorylation
-ATP produced by proton motive force (ETC+ATP Synthase)
What is Glycolysis & Fermentation?
Glycolysis
- Pathway in Fermentation/Respiration
- Breaks down Glucose into Pyruvate to yield 2 ATP
Fermentation
- Regenerates NAD+
- Pyruvate -> Lactic Acid
- Pyruvate -> Ethanol + CO2
- Waste products = alcohol (no purpose for cells)
How are coenzymes like NAD+ recycled during Glycolysis & Fermentation?
Glycolysis reduces NAD+ -> NADH
Fermentation oxidizes NADH -> NAD+
What is Respiration?
Form of Catabolism that breaks down Pyruvate to CO2
- Susbtrate Level = 2 ATP
- Oxidative Level = 32 ATP
What is the Krebs/Citric Acid Cycle?
Breaks down Pyruvate to CO2
- Succinyl CoA->Succinate (Substrate Level) = 2 ATP
- Electron Carriers (NAD/FAD) = 28 ATP (Oxidative)
What is the electron transport chain?
Uses electron carriers from CAC to carry electrons to enzymes within ETC
-Oxidation of these electron carriers produces energy to shuttle protons outside of cell (proton motive force)
Oxygen is the final electron Acceptor (O2->2 H20)
What is oxidative phosphorylation?
ATP Synthase uses Proton Gradient to synthesize ATP
- F0 in membrane transports H+ into cell
- F1 within cell phosphorylates ADP+P -> ATP
