Enzymes Part I
Quiz yourself by thinking what should be in
each of the black spaces below before clicking
on it to display the answer.
Help!
|
|
||||
|---|---|---|---|---|---|
| In equilibrium the reaction is not stopped | the concentrations just become constant
🗑
|
||||
| Keq= | [product]/ [reactant]
🗑
|
||||
| if one arrow is larger in an eq rxn, the larger arrow denoted | the more favorable direction of the reaction
🗑
|
||||
| if arrow on top is larger pointing to right, the [product]/ [reactant] will be | greater than 1
🗑
|
||||
| if equilibrium arrow on bottom is larger in favor of the left side of the reaction the [product]/ [reactant] will be | less than 1 because rxn favors left side
🗑
|
||||
| if Keq is >1, delta G will be | negative; if delta G is positive, the reaction has no tendency to go forward (concentration of products higher than reactants)
🗑
|
||||
| if delta G is positive, the reactants are | in higher concentration; Keq < 1
🗑
|
||||
| Enzymes are typically | globular proteins; speed rxn by lowering AE
🗑
|
||||
| For a rxn that is zero order, the velocity doesn't depend on concentration of substrate | no answer
🗑
|
||||
| small molecule required for enzyme activity; organic or inorganic; tight or loose | cofactor
🗑
|
||||
| ORGANIC; LOOSELY bound enzyme, like a substrate | coenzyme- Ex: NADP(H), NAD(H), ATP
🗑
|
||||
| organic or inorganic cofactor that is TIGHTLY bound to enzyme | prosthetic group. Ex: Heme, iron- sulfur clusters, metal ions
🗑
|
||||
| folded polypeptide chain of a cnjugated protein | apoprotein
🗑
|
||||
| complete, biologically active protein conjugate, consisting of folded polypeptide chains and relevant cofactors | holoprotein
🗑
|
||||
| as temp increases, kinetic energy of molecules increase including substrate | how heat affects proteins
🗑
|
||||
| Temperature increase affects reaction rates of proetin denaturing until | max level is achieved then it drops off with further increase in temp
🗑
|
||||
| most animal proteins denature at | 40 degrees; optimal is 37 degrees
🗑
|
||||
| pH can cause enzyme to perform better or worse depending on | R group; if outside pH range the protein will denature; cause a configuration change
🗑
|
||||
| region of an enzyme that accepts substrate (and cofactors); contributes catalytic residues that directly participate in making/ breaking of bonds | active site
🗑
|
||||
| active site is 3D and dynamic | also takes up a small are and is usually a cleft or crevice
🗑
|
||||
| substrates are bound to active sites by | non-covalent bonds
🗑
|
||||
| active site is specifically catered to a specific molecule | no answer
🗑
|
||||
| If an enzyme has 5 active sites and all are filled with substrates it is | saturated
🗑
|
||||
| Enzymes ability to reduce delta G | entropy reduction; acid- base catalysis; covalent catalysis
🗑
|
||||
| one or more substrates bind in active site with correct orientation | Entropy reduction- "S"; disorder
🗑
|
||||
| some enzymes can have multiple active sites | true
🗑
|
||||
| Substrate protons important for reactivity are accepted or donated by amino acid in the active site | General acid- base catalysis; structural mechanism for delta G reduction; accounts for pH dependence of enzyme activity
🗑
|
||||
| transient (brief) covalent bond is formed between enzyme and substrate- usually for cleavage | Covalent catalysis; delta G reduction
🗑
|
||||
| 6 classes of enzyme reactions | oxidoreductase; transferase; hydrolase; lyase; isomerase; ligase/synthetase
🗑
|
||||
| Enzyme reactions:catalyze oxidation/reduction reactions, transfer electrons from one compound to another, thus changing the oxidation state of both substrates. | Oxidoreductases:dehydrogenases (transfer H-); oxygenases (oxidizes with O2); peroxidases (i.e. catalase)
🗑
|
||||
| Enzyme reactions:catalyze reactions in which a functional group is transferred from one compound to another | Transferases; (kinases; adds phosphate group, ATP is source of phosphate)
🗑
|
||||
| Enzyme reactions:cleave carbon-oxygen, carbon-nitrogen, or carbon-sulfur bonds by adding water across the bond. | Hydrolases
🗑
|
||||
| the equation describes the relationship between rate, substrate, and Michaelis constant so the lower the Km value the higher the affinity for enzyme toward substrate (look at the graph) | MM MM notes
🗑
|
||||
| more specific indicator of liver inflammation than AST | ALT; found predominately in the liver
🗑
|
||||
| if AST high and ALT normal, there is likely damage to | organ other than liver
🗑
|
||||
| cleaves C-O, C-N, or C-S bonds by adding water across bond | Hydrolases
🗑
|
||||
| normal AST level | 7-27
🗑
|
||||
| normal ALT level | 1-21
🗑
|
||||
| ALT is more specific and AST may also be elevated in | heart or muscles in MI or pancreatitis
🗑
|
||||
| too much tylenol or drinking | ALT and AST levels both high
🗑
|
||||
| Maltose --> Glucose with Maltase enzyme | hydrolase
🗑
|
||||
| Cleaves C-O, C-N, or C-S WITHOUT addition of water AND without oxidizing or reducing substrates | Lyases; water can be a produt but not used to break hydrate the molecule
🗑
|
||||
| catalyze intramolecular rearrangements of functional groups that reversibly interconvert optical or geometric isomers | Isomerases
🗑
|
||||
| catalyze formation of new chemical bonds by coupling their formation to the cleavage of a high-energy compound | Ligases/Synthetases;Ligases differ from lyases in that they utilize the energy obtained from cleavage of a high-energy bond to drive the reaction usually ATP.
🗑
|
||||
| Enzymes that catalyze the same reaction, but differ in structure or sequence are called | isoenzymes(isozymes) Ex: lactate dehydrogenase. May also have different reaction rates/tissue distributions. They usually share the same name and are differentiated by the addition of letters or numbers (i.e. LDH1, LDH2, LDH3, etc.)
🗑
|
||||
| direct, reversible inhibition at an enzyme’s active site by the product of the enzyme-catalyzed reaction | Product inhibition; simplest form of enzyme regulation
🗑
|
||||
| Products can often weakly inhibit the enzymes that produced them because | reactant and product are similar in structure and can compete for binding site
🗑
|
||||
| simplest form of enzyme regulation | product inhibition
🗑
|
||||
| Allosteric regulators bind enzyme at a location distinct from the active site | this can increase or decrease enzyme activity because it changes the conformation of the protein
🗑
|
||||
| when a downstream product inhibits an upstream enzyme | feedback inhibition
🗑
|
||||
| phosphorylation reults in conformational changes that | can increase or decrese an anzymes catalytic activity
🗑
|
||||
| protein phosphatases do what | remove phosphate group from enzyme
🗑
|
||||
| a large inactive form of an enzyme that can be activated by proteolytic cleavage | zymogen; ex: digestive enzymes are synthesized as zymogens which can be activated on demand by proteases.
🗑
|
||||
| Pancreatitis is causes by premature activation of digestive zymogens | they end up digesting pancreatic tissue
🗑
|
||||
| Enzyme synthesis and deradation | form of regulation that occurs over hours to days
🗑
|
||||
| Vmax is proportional to the amount of enzymes present | amount of enzyme generated can be increased or decreased based on physiological needs; ex, insulin can induce synthesis of an enzyme
🗑
|
||||
| Mechanisms of Enzyme regulation (6) | product inhibition; allosteric regulation; covalent modification; protein-protein regulation; zymogen cleavage; enzyme synthesis and degradation
🗑
|
||||
| Damaged cells can release ____when diseased | isoenzymes; normally in the cell but are released into the blood
🗑
|
||||
| Following an acute cell damage (like heart attack) it takes how long for enzyme levels to spike? | 18-36 hours; in chronic disease, like cancer, blood enzymes are elevated
🗑
|
||||
| most common enzymes used to diagnose MI are | CK (creatine phosphokinase) and LDL (lactate dehydrogenase)
🗑
|
||||
| Three isozymes of Cystolic CK | CK-BB; CK-MB; and CK-MM each made of two polypeptides (M or B)
🗑
|
||||
| CK-BB isozyme is usually seen where? | In the brain
🗑
|
||||
| The CK-MM isozyme is usually seen where? | Skeletal muscle; also in heart muscle
🗑
|
||||
| Which CK isozyme is more predominant in the heart? | CK-MB
🗑
|
||||
| Baseline CK activity in the plasma is usually | 95% CK-MM
🗑
|
||||
| Two plasma CK assays are useful in diagnosing heart attack | Total Ck activity; if elevated could mean heart attack or some other muscle damaging disorder. If CK-MB is high then we know there is a heart prob
🗑
|
||||
| Heart attack = elevated CK-MB levels | no answer
🗑
|
||||
| Elevated LDL1 is indicative of what? | heart attack; LDL2 is normally higher but if LDL1 level surpasses it (levels are 'flipped') there is heart attack;
🗑
|
||||
| Total LDL elevation OTHER than the "flip" scenaario indicate what? | damage or disease in a tissue other than the heart
🗑
|
||||
| AST indicates what | liver damage; ALT also indicates but is more specific
🗑
|
||||
| ALP (not as frequent as ALT or AST) | congestion of bile tract; GGT can also indicate this but is more specific to liver
🗑
|
||||
| GGT (not as frequent as AST or ALT) | congestion of bile tract and or liver damage; more specific to the liver that ALP
🗑
|
||||
| Can dissolve a clot in an emergency; not used as maintenance med; therapuetic enzyme | Streptokinase (streptase)
🗑
|
||||
| Reduce the size of a thrombus after a heart attack | Tissue Plasminogen Activator
🗑
|
||||
| starves and kills acute lymphoblatic leukemia (ALL) cells | Asparaginase (Elspar)
🗑
|
||||
| Catalyses conversion of dietary lactose to galactose and glucose | Lactase (Lactaid);undigested lactose is bacterially fermented in intestines, produces gas; enzymes from Aspergillis fungi
🗑
|
Review the information in the table. When you are ready to quiz yourself you can hide individual columns or the entire table. Then you can click on the empty cells to reveal the answer. Try to recall what will be displayed before clicking the empty cell.
To hide a column, click on the column name.
To hide the entire table, click on the "Hide All" button.
You may also shuffle the rows of the table by clicking on the "Shuffle" button.
Or sort by any of the columns using the down arrow next to any column heading.
If you know all the data on any row, you can temporarily remove it by tapping the trash can to the right of the row.
To hide a column, click on the column name.
To hide the entire table, click on the "Hide All" button.
You may also shuffle the rows of the table by clicking on the "Shuffle" button.
Or sort by any of the columns using the down arrow next to any column heading.
If you know all the data on any row, you can temporarily remove it by tapping the trash can to the right of the row.
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Created by:
angieryx
Popular Agriculture sets