Term
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Definition
| A protein specialized in catalyzing metabolic reactions |
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Term
| What type of proteins are most enzymes? |
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Definition
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Term
| What class of enzyme acts on many chemical groupings to add or remove hydrogen atoms? |
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Definition
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Term
| What class of enzyme transfer functional goups between donor and acceptor molecules? |
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Definition
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Term
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Definition
| a transferase enzyme that phosphorylates molecules using ATP |
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Term
| What class of enzyme adds water across a bond? |
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Definition
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Term
| What class of enzyme add water, ammonia, or carbon dioxide across double bonds? This class also removes the above molecules to create double bonds. |
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Definition
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Term
| What class of enzyme carry out many kinds of isomerization? |
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Definition
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Term
| What class of enzymes catalyze reactions in which two chemical groups are joined with the use of energy from atp? |
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Definition
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Term
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Definition
| Complex enzyme composed of a protein part and a non-protein part |
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Term
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Definition
| non-covalent factor that interacts with a holoenzyme |
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Term
| What is a prosthetic factor? |
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Definition
| Covalently bonding factor involved with holoenzymes |
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Term
| Are enzymes substrate-specific? |
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Definition
| Not always. It is better to consider them reaction specific |
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Term
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Definition
| individual members of a set of enzymes that can act on the same substrate and produce the same product |
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Term
| How do optically active molecules effect enzymes? |
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Definition
| Enzymes typically can only catalyze one of the conformations |
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Term
| what is the preferred enzyme model for understanding enzyme substrate interaction? |
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Definition
| Induced fit model. Makes more sense then the lock and key because it accounts for enzyme substrate non-specificity |
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Term
| What is the transition state? |
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Definition
| State during reaction of high energy in which the reaction can go either way (either back to reactants or forward to product) |
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Term
| What is the equilibrium constant? |
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Definition
| measurement of the concentration of substrates and products at equilibrium |
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Term
| What is an exergonic reaction? |
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Definition
| One in which the Gibbs Free Energy is lower in the final state than in the initial state. Characterized as a spontaneous reaction with a release of energy |
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Term
| What is the change in free energy of a reaction? |
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Definition
| The difference in Gibbs free energy between initial and final reaction states |
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Term
| What is an endergonic reaction? |
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Definition
| Reaction in which the gibbs free energy is higher in the product than in the reactant. Characterized as a non-spontaneous, energy requiring reaction |
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Term
| How does an enzyme speed up a reaction? |
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Definition
| By lowering the energy of activation |
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Term
| What is the free energy of activation? |
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Definition
| The energy required to go from initial state to transition state |
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Term
| What is the rate limiting step in a reaction? |
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Definition
| Formation of the transition state |
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Term
| Why are transition states unstable? |
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Definition
| Have a high enthalpy and a low entropy |
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Term
| How do enzymes lower the energy of activation? |
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Definition
| By lowering enthalpy and decreasing the loss of entropy |
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Term
| How does acid-base catalysis work? |
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Definition
| acidic/basic residue on enzyme protenates of deprotenates the transition state, stabilizing it |
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Term
| What chemical mechanism do proteases use to cleave proteins? |
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Definition
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Term
| Why are peptide bonds hard to cleave? |
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Definition
| Resonance structure grants the bonds extra stability |
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Term
| What are the four classes of proteins? |
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Definition
Serine/Threonine
Aspartic
Cysteinyl
Metallo |
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Term
| Serine proteases cleave peptide bonds by forming what kind of intermediates? |
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Definition
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Term
| What is the catalytic triad? |
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Definition
The residues by which serine proteases interact with peptide bonds.
Aspartate
Histidine
Serine |
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Term
| What is the function of acetylcholinesterase? |
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Definition
Acetylcholinesterase degrades acetylcholine (a neural transmitter). This enzyme also uses a triad of residues
histidine
serine
glutamate |
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Term
| How do acetylcholinesterase inhibitors work? |
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Definition
| By forming a bond on the serine of the enzyme, clogging the active site |
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