the organ that acts as the coordination center of the endocrine system is the
hypothalmus
binding substrates by multiple covalent interactions is NOT a characteristic of the active site,but
Characteristics of an active site:
1.having a relatively small part of the enzyme
2.having a well-defined three dimensional shape
3.binds substrates by multiple noncovalent interactions
digestive enzymes such as chymotrypsin and trypsin are often synthesized as long inactive precursors known as
zymogens
one of the mechanisms by which enzyme activity is regulated is for the product a metabolic pathway to be an inhibitor of an earlier enzyme-catalyzed rxn in the pathway. this type of inhibition is known as
Feedback inhibition
Methanol poisoning is treated by adminitering large amounts of ethanol.Ethanol replaces methanol in the active site of alcohol dehydrogenase until the methanol can be eliminated from the body.this is an example of
competitive inhibition
A hormone that is released into the extracellular space and diffuses to nearby cells to evoke its response is classified as
paracrine
Consider the elementary reaction A + B--> P. this reaction is
First order with respect to A
First order with respect to B
Second order overall
Ex: [A][B] or 2A
Enzymes catalyze rxns in the forward direction only DOES NOT describe enzymes
these describe enzymes:
1.Enzymes are often very specific for their substrates
2.enzyme activities can often be regulated
3.enzymes typically act under milder conditions of temperature and pH than chemical catalysts
4.enzymes typically catalyze rxns at much higher rates than chemical catalysts
in general the first step in a biochemical signaling pathway is the binding of a ligand to a_______,which causes a signal to be transmitted to the interior of the cell.
receptor protein
a substance that binds to a receptor and evokes a response is a
agonist
stabilizes the protonated form of the base that removed the proton from the nucleophilic hydroxyl group
aspartic 102
removes a proton from the hydroxyl group of the nucleophile to make it more nucleophilic
histadine 57
acts as a nucleophile to attack the carbonyl carbon atom of the scissile peptide bond
serine 195
Match the coenzyme with its vitamin form:
coenzyme A
pantothenic acid
Match the coenzyme with its vitamin form:
Flavin adenine dinucleotied
Riboflavin
Match the coenzyme with its vitamin form:
nicotinamide adenine dinucleotide
niacin
Determine the class of enzyme which catalyzes the following rxns:
Lactate dehydrogenase
catalyzes the conversion of the carbonyl group of pyruvate to a hydroxyl group to form lactate with the simultaneous conversion of NADH to NAD+
oxidoreductase
Determine the class of enzyme which catalyzes the following rxns:
Pyruvate decarboxylase
catalyzes the decarboxylation of pyruvate to form acetaldehyde and carbon dioxide
Lyase
Determine the class of enzyme which catalyzes the following rxns:
Alanine transaminase
catalyzes the movement of an amino group from the amino acid L-glutamate to pyruvate to form a new amino acid L-alanine and a-ketoglutarate
Transferase
Determine the class of enzyme which catalyzes the following rxns:
Chymotrypsin
catalyzes the cleavage of a protein b/t amino acids with bulky or aromatic side chains with the addition of water
Hydrolase
Determine the class of enzyme which catalyzes the following rxns:
Pyruvate carboxylate
catalyzes the addition of carbon dioxide to pyruvate to form oxaloacetate with the hydrolysis of ATP
Ligase
Determine the class of enzyme which catalyzes the following rxns:
Phosphoglycerate mutase
catalyzes the conversion of 3-phosphoglycerate to 2-phosphoglycerate