Biochem Exam One Set two

achapss's version from 2017-10-02 14:30


Question Answer
Allosteric Proteinprotein with multiple ligand binding sites that effect each other
Structure of hemoglobin vs myoglobinHemoglobin is a four subunit (two dimers) protein with an O binding pigment, myoglobin is a single subunit protein with heme
substratereactants in enzyme catalyzed reactions
proteolytic enzymescatalyze hydrolysis of peptide bonds ex: trypsin, chymotrypsin etc.
Holoenzymean enzyme with its cofactor
Apoenzymean enzyme without its cofactor
Prosthetic Groupscovalently bonded coenzymes
Exergonicmore negative or spontaneous letting out more energy, large keq
Endergonicless negative conserving energy small key
First order Reactionwhen the velocity of a reaction is directly proportional to reactant concentration (S^-1)
Second Order Reaction
Turnover #Kcat or K2 the amount of substrate turned to product per second measuring the catalytic efficiency
Krate of formation of ES complex
Diffusion Controlled enzymesenzymes whom are limited by the max rate of diffusion 10^8-10^9
Positive Effector vs Negative Effectorpositive increases E activity and negative decreases
Positive Feedbackproduct of the last step inhibits the first enzyme in the loop (allosteric enzyme) by binding to its regulatory site (usually build up of substrate prompting the need for formation of more product )
Negative Feedbackbuild up of product shuts off
Covalent Catalysisactive site contains a nucleophile that is covalently modified
General Acid Base Catalysissomething other than water donates or accepts a proton
Metal Ion Catalysismetal ions function as an electrophilic catalyst
Approximation and orientation catalysisthe enzyme brings two substrates together to facilitate catalysis
Competitive Inihibitonreversible inhibition where a competitor and substrate compete for the same enzyme, can bind at the active site, can add substrate to outcompete
Noncompetitive Inhibitionreversible inhibition where a competitor binds to the ES complex OR the enzyme, adding substrate does not improve
Uncompetitivereversible inhibition where a competitor binds to the ES complex only making it challenging to form product adding substrate does not improve
Affinity Labels or Substrate Analogsirreversible inhibitors that are structurally similar to the enzyme's substrate and inhibit the enzyme by covalently binding to the enzyme and creates an inhibitor by modifying an amino acid at the active site of the enzyme creating a high affinity for the unnatural substrate
Suicide inhibitors or Mechanism Basedirreversible inhibitors that bind the enzyme as substrate and when the reaction begins, modifies the substrate by inhibiting the actual substrate taking advantage of the enzyme