Lecture 5 - Microbial Metabolism Flashcards
Metabolism
the sum total of all energy being used and released in the body
(anabolism + catabolism = metabolism)
Catabolism
the process of breaking down larger molecules into smaller molecules
Anabolism
the process of synthesizing (building up) larger molecules
Hydrolysis
water is added as a reactant to break chemical bonds
Dehydration Synthesis
water is relased as a byproduct as bonds are formed
rnx
reaction
Are catabolic rxns endergonic or exergonic?
exergonic
(releases E)
Are anabolic reactions endergonic or exergonic?
endergonic
(uses E)
E
energy
Energy Coupling
Endergonic rxns can be used to store E within the bonds.
When those bonds are broken during a catabolic rxn, the E is released (exergonic) and can be used in other endergonic synthesis rxns.
ATP
adenosine triphosphate
ATP synthesis
ADP + P + energy –> ATP
(making ATP stores E)
ATP degradation
ATP –> ADP + P + energy
(breaking down ATP releases E)
ADP
adenosine diphosphate
catalysts
increse the rate of rxns
Most enzymes are _____.
Proteins
How do catalysts increase the rate of rxns?
Catalysts work by lowering the activation E required to initiate a rxn.
Catalysts bind to the reatants for a rxn which brings the reactants in close enough proximity with the proper orientation to react efficiently.
Enzymes are _______.
catalysts
-ase
enzyme
Explain How the Enzyme Lactase Works
Lactase binds to Lactose to break it into glucose and galactose monomers.
Sucrase breaks apart _____.
Sucrose
-ose
sugar
Substrate
the molecule that an enzyme binds to and acts on
(substrates are the reactants in the rxn)
decarboxylase
removes carbon dioxide from the substrate
cofactor AKA
coenzyme
Cofactors are typically _____ molecules.
inorganic
i.e. metal ion (iron, zinc, magnesium)
Coenzymes are typically _______ molecules.
organic
What is the function of a cofactor/coenzyme?
Cofactors and Coenzymes bind to the enzymes to make the enzyme complete and functional.
Fe
Iron
Mg
Magnesium
Zn
Zinc
Active Site
Location on the Enzyme where Substrates bind
dehydrogenase
removes hydrogen from substrate
decarboxylase
removes CO2 from substrate
Apoenzyme
the inactive, protein portion of an enzyme
Holoenzyme
an active, functional enzyme
apoenzyme + cofactor = holoenzyme
holo-
whole
Ca
Calcium
Cofactor Critical for Blood Clotting
Ca (calcium)
4 Factors Affecting Enzymatic Activity
- pH
- temp
- substrate concentration
- chemical inhibitors
(i.e. competetive and noncompetetive inhibition)