Lecture 11: Use and Synthesis of Carbon Compounds Flashcards
Distinguish between anabolic and catabolic reactions.
Catabolic: Release energy. Break down materials. Negative free energy change.
Anabolic: Requires energy. Build up materials. Positive free energy change.
Understand that a reduction reaction requires energy that can be provided by the energy released by oxidation reaction.
energy in electrons => reducing power.
Explain how redox energy is transferred by electrons.
Energy released when electrons are transferred. If compound A is reduced, compound B gains energy (is oxidized). Energy carried in electrons is reducing power.
Explain how an enzyme functions as a biological catalyst.
Holds the substrates in the correct conformation so that it reacts most efficiently. Enzymes help carry out reactions. Helps bring 2 molecules together to interact in certain orientation in order to carry out the activity.
Induced Fit of enzyme and substrate
Distinguish between competitve and non-competitve (allosteric) enzyme inhibitors.
Competitive: Must look like the substrate so it can fit in the active site, must be different enough so that the enzyme no longer functions. Higher concentration of inhibitor=more likely it’ll bind instead of the substrate.
Noncompetitive: Binds to allosteric site. Change shape of the enzyme (inhibits induced fit). Not concentration dependent
Understand how the denaturing of enzymes causes organisms to die.
If you denature an enzyme then it won’t be able to carry out it’s process.
Sketch an overview diagram of bacterial metabolism including glycolysis, pentose phosphate pathway, fermentation, pyruvate oxidation, the TCA cycle, and the respiratory chain.
Central Metabolism: Glycolysis, Pyruvate Oxidation, and TCA cycle.
Accessory Pathways: Pentose Phosphate Pathway (Shunt pathway: takes carbohydrate out and replaces it back in as glceraldehyde 3 phosphate later), Fermentation, Respiratory Chain
1-Glycolysis: Glucose goes in, NAD reduced to NADH, ATP release, Pyruvate gets oxidized (produces NADH and CO2), acetyl CoA (enters TCA cycle)
2-TCA Cycle: NAD to NADH and CO2 released, NAD to NADH CO2 released, ATP produced by substrate level phosphorylation, FADH2 produced, NAD to NADH
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Explain the concept of bacterial central catabolism, with modular additions.
Modular additions are either going to produce some substrate used by central metabolism or use up some product of central metabolism.
State the purpose and list 3 main products of glycolysis.
1-NADH
2-ATP
3-Pyruvate
Release energy from glucose
Explain how the oxidative decarboxylation of pyruvate produces energy.
Produces reducing power via a redox reaction that oxidizes pyruvate which releases electrons that reduces NAD.
State two ways to metabolically recycle NADH.
NAD is too expensive to remake every time. Electrons are recycled in order to reproduce NAD. Without NAD, all of the reactions that have it would not happen (example: Pyruvate would not produce Acetyl CoA). Recycling NADH requires electron acceptors:
1-Respiratory chain: Energy in electrons is stored as a pmf from redox reactions.
2-Cells can use organic electron acceptors (Example: Pyruvate). Fermentation is the donation of organic molecules to an acceptor without producing a pmf. Energy in electrons is wasted. Dehydrogenase oxidizes a substrate by a reduction reaction that removes one or more hydrogens from a substrate to an electron acceptor.
Distinguish between acid fermentation and alcoholic fermentation.
Acid fermentation: Pyruvate => Lactate
Alcohol fermentation: Produces CO2 and the fermentation product. Pyruvate => Acetaldehyde => Ethanol
Big difference in enzymes required
List some of the main commercial products of microbial fermentation reactions.
Depending on enzymes the cell has, a lot of different products can be produced. Ex: Foods, alcohol, acid, etc
Using the metabolic diagram you drew above, explain how bacteria can catabolize carbohydrates, lipids, and proteins.
Catabolize carbohydrates => Glycolysis
Catabolize lipids => Hydrolysis (glycerol and fatty acids)
- –Glycerol made into acetate
- –Fatty acids turned into acetyl CoA via oxidation and feeds into TCA cycle.
Hydrolyze peptide bonds and deamination occurs to catabolize proteins and enter central catabolism at TCA cycle, Glycolysis, and Pentose Phosphate Pathway
Using the metabolic diagram you drew above, show where the precursors come from for the anabolism of polysaccharides, lipids, nucleic acids and amino acids.
Polysaccharides from glycolytic intermediates.
Lipids from glycerol and acetate built up to form fatty acids.
Nucleic acids from pentose phosphate shunt.
Amino acids from various places.
