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Microbial Metabolism Lecture Micro 101 MJC
Microbial Growth Lecture Test 2
What is Metabolism?
The sum of all chemical reaction within a living organism.
Metabolism = anabolism (building up) and catabolism (breaking down)
What do we need to know about microbial metabolism?
Metabolism forms the basis of all forms of microbilogy
Knowledge of metabolism from the basis of antibiotic therapy
What is catabolism?
It is the breakdown of complex organic molecules into simpler molecules.
What is an anabolic reaction?
Anabolism is the synthesis of complex organic molecules from simpler molecules.
What is the role of ATP (adenosine triphosphate) in metabolism?
ATP stores the energy generated by catabolic reaction and makes it available for anabolic reactions.
What are enzymes?
They are biolofical catalysts that speed up chemical reactions and are not consumed in the reaction.
They have a unique shape and only work on specific substrates.
How much faster does an enzyme make a reaction work?
They will increase reaction time by 10^8 to 10^10 times.
Why are enzymes needed?
They are needed in order to increase reactions to be able to sustain life.
How do enzymes work?
They decrease the activation energy required to initiate a chemical reaction.
How to enzymes and substrates interact?
Each enzyme has an active site where only a specific substrate can fit into.
What is an enzymes turnover number?
Is the maximum number of substrate molecules an enzyme molecule can convert to product each second.
: DNA polymerase (DNA synthesis) --> 250 per/sec
Catalase (breakdown of H2O2) --> 20,000 per/sec
What is a simple enzyme?
Made entirely of protein.
What does a conjugated enzyme consist of?
It consists of a Apoenzyme (the protein component) and a Cofactor (non-protein component) such as Mg or Ca ions.
An organic molecule that is a cofactor is called a coenzyme.
What is it called when you have a Apoenzyme and a cofactor together?
What is a apoenzyme.
It is a enzyme that requires a cofactor to become active.
What coenzyme is important in cellular metabolism?
NAD+ (Nicotinamid adenine dinucleotide) involved in catabolic reactions
and NADP+ (Nicotinamide adenine dinucleotide phosphate)involved in anabolic reactions
Name two other important coenzymes?
: FMN and FAD flavin adenine dinucleotide
: Used in intermediate step between glycolsis and TCA
What is Oxidoreductase
Oxidation-reduction (redox) reactions. Loss or gain of electrons
What is Transferase
Used for the transfer of functional groups (e.g., -NH2 or -PO4
What is Hydrolase
It cleaves bonds on molecules with the addition of water (Hydrolysis)
What is Lyase
For the removal or addition of groups of atoms without hydrolysis
What is Isomerase
Used for the rearrangement of atoms within a molecule
What is Ligase
Used for joining two molecules (using energy from the breakdown of ATP)
What factors can affect enzymatic activity?
Temperature, pH, Substrate concentration
What is a Exoenzyme?
Are usually active only out side the cell, used to breakdown nutrients that are too large to enter the cell
What is an endoenzyme?
Active inside the cell, and most metabolic enzymes are endoenzymes
What is a metabolic pathway?
Is a pathway usually containing many steps each with an individual enzyme
What are the different types of metabolic pathways.
Cyclic - TCA
How can you control a metabolic pathway?
By messing up the enzyme.
What are the types of enzyme inhibitors?
Competitive and non-competitive
What is a competitive inhibitor?
Fills the active site and competes with the substrate, are similar in shape to the substrate, but the enzyme does not have a reaction with the enzyme
What is a noncompetitive inhibitor?
It interacts with a site other than the active site changing the shape of teh active site so that the substrate will not attach to the enzyme.
What is feedback inhibition?
The end product of a metabolic pathway is a non-competitive inhibitor of the pathway.