exam 2 biochem practice questions Flashcards

Question

where can you find alpha keratin what is alpha keratin made of and what is ti strengthened by what is the fact from legally blonde how isa super tight coiled coil made how is permanent waving of hair done

Answer 1

Hair, nails, hooves, horns, outer skin made of Strong, RH α-helix; LH parallel super helix; strengthened by cross-links by covalent disulfide bonds – stabilizes! perm removes disulfide bonds Super-twisting helices, in a left-handed fashion, wrap around each other to make a very tight coiled-coil permanent waving of hair: reduce disulfide bonds, moist heat breaks H-bonds and causes uncoiling of alpha heckles, remove reducing again, add oxidizing agent, new SS bonds

Answer 2

Provides tensile strength and structure (~30 types of collagen). can be found in Connective tissue (tendons, cartilage, organic matrix of bone, cornea) Each protein folds into a left-handed helix (α-chains; NOT α-helix) Coiled-coil of three separate α-chains supertwisted around each other in a right-handed manner to provide strength (like a rope). find Gly, Ala, Pro, HyLys and HyPro (essential! specific to collagen) Lys-HyLys (Hydroxylysine) form cross-links for added strength 30+ variants in mammals

Answer 3

In antiparallel β-sheets, the H-bonded strands run in opposite directions Resulting in linear H-bonds (stronger) Individual strands can be close, or distant, in the primary structure Rich in Ala and Gly antiparallel β-sheets Fully extended: no stretching Extensive hydrogen bonding and van der Waals interactions between sheets, but no covalent cross-links for flexibility.

Answer 4

used for silk soft and flexible filaments made of beta conformation no cross-links

Answer 5

tendons, connective tissues, organic bone matrix high tensile strength without stretch made of collagen triple helix – hydroxylysine (unique) cross-links  structure = function

Answer 6

hair, feathers, and nails tough, insoluble protective structures of varying hardness and flexibility made of alpha helix, cross-linked by disulfide bonds

Answer 7

examples: enzymes, transport proteins, molar proteins, regulatory proteins, immunoglobulins etc alpha helices, beta sheets, beta turns can all be found the different secondary structures are - compact conformation - folding provides structure diversity general rule: - bury nonpolar amino acid R-groups - distant segments may come together, but not the norm - optimize the number of weak interactions

Answer 8

myoglobin! binds iron and O2 and is found in muscles related to hemoglobin but has a higher affinity for O2 general rules: the hydrophobic R groups are buried made of alpha helices connected by loops made of 153 amino acids it is a porphyrin ring and has iron at its center heme is it a prosthetic group a prosthetic group is a nonprotein group forming part of or combined with a protein. a proximal histidine group is attached to the iron, a distal histidine group hovers near the opposite face

Answer 9

they are secondary structures!

Answer 10

Purify the protein Crystallize the protein Collect diffraction data (light bending) Calculate electron density Fit residues into density

Answer 11

Pros: - No size limits - High resolution - Well-established Cons: - Difficult for membrane proteins - The crystal form may not represent the protein in solution or in the cell - Not dynamic (cannot determine how the protein interacts with things)

Answer 12

Steps Grow the protein with a NMR-active isotope (usually of Carbon-13) Purify the protein Collect NMR data Assign NMR signals Calculate the structure

Answer 13

Pros: - No need to crystallize the protein - Dynamic studies possible - Interaction with ligands Cons: Difficult for insoluble proteins Works best with small proteins Nuclear Magnetic Resonance

Answer 14

Globular Proteins are associated with Motifs Motifs are stable arrangements of several secondary structure elements All alpha-helix All beta-sheet Combination These are sometimes considered supersecondary structures Motifs can be found as reoccurring structures in numerous proteins Motifs can be found as reoccurring structures in numerous proteins examples of secondary structures that can be found in motifs: twisted beta-sheet alpha alpha corner beta alpha beta loop beta barrel

Answer 15

You can find small motifs as a part of large motifs People have determined the structure of so many proteins, so we must organize. Two classes of organization are shown here.

Answer 16

can be found in globular proteins Domains are relatively stable, independently folded regions within the tertiary structure of a globular protein Each domain may encompass one or more motifs and have the same combination of motifs (EF-hand) Domains having more than 30% of their amino acid sequence in common normally adopt the same folding pattern. A single protein can have several domains with each domain performing a different function (e.g., enzymatic, docking, regulatory, pore, membrane anchoring, etc)

Answer 17

Results from the association of two or more polypeptide subunits into a larger functional cluster These polypeptide subunits associate into a larger functional cluster via side chain – side chain and side chain – polypeptide backbone interactions what drives quaternary association: Stability: reduction of surface to volume ratio Genetic economy and efficiency (using quarternary structure makes our genome more efficient) Bringing catalytic sites together Cooperativity (biological function may be regulated by complex interactions of multiple subunits)

Answer 18

Contain protein segments that lack a definable structure. Or, the entire protein The protein can remain in a primary structure indefinitely; or it may have a domain that can interact with other molecules, but the rest of the protein will remain disordered. Possibly 1/3 of all human proteins fit this designation.

Answer 19

Proteostasis is Protein Stability;Proteostasis is the constant level of the active set of proteins in a cell. Proteins can exist in native conformation, or other conformations; flexibility is important Maintaining proteostasis is a complex process, involving: synthesis, folding, unfolding, degradation, modification, etc

Answer 20

Most protein’s function depends on its 3D-structure. To be active a protein must be correctly folded (native conformation) The order of amino acids can help determine what this 3D conformation will be Loss of structural integrity and function/activity is called denaturation Proteins can be denatured by: 1. Strong acid or base 2. Organic solvents 3. Detergents 4. Reducing agents 5. Salt concentration 6. Heavy metal ions 7. Temperature 8. Mechanical stress

Answer 21

Proteins fold to the lowest-energy (most stable) conformation in the microsecond to second-time scales. It is not a “search” The direction is biased towards thermodynamically and sterically possible conformations Nonpolar inside, polar outside! (we’ve gone over this Folding of secondary structures can occur at multiple sites at the same time. Then, secondary structures interact to find the lowest energy minima (conformation) Folding often begins before protein synthesis is complete!

Answer 22

another protein that promotes correct folding Hsp70 (Heat Shock Protein 70) family protects unfolded proteins from denaturation and aggregation Chaperonins promote correct folding Isomerases make sure we have the correct stereochemistry PDI – Protein disulfide isomerase PPI – Peptide prolyl cis-trans isomerase

Answer 23

normally misfolded proteins are fixed (rendked) or degraded defects n any of the ceeluar systems may affect the degree of protein misfolding

Answer 24

The native (correctly folded) β-amyloid is a soluble globular protein which is critical for neuronal growth, survival, and post-injury repair In Alzheimer’s disease, bet amyloid is clipped from the cell membrane, fragmented, and then, it misfolds This misfolding promotes aggregation Correctly folded helices are lost, and peptides form β strands, β helices, and β sheets  now insoluble These insoluble plaques collect around the neurons and disrupt their environment and connectivity

Answer 25

Parkinson’s Disease, Lewy-Body Dementia: misfolded α-synuclein forms aggregates  Lewy Bodies Huntington’s Disease: genetic mutation that increases CAG repeats (increases #of amino acids) causes misfolding and aggregation  neuronal death

Answer 26

a molecule that is reversiibily bound to a receptor specific location on protein protein flexibility is important for induced fit regulation is important for binding enzyme comes into contact with a substrate and catalytic (active) site binding is via noncovalent forces that dictate protein structure which allows for interactions to be transient

Answer 27

High specificity can be explained by the complementary nature of the binding site and the ligand Molecular complementarity: size, shape, charge, hydrophobicity Lock and key model: proteins and ligands have a rigid interaction with each other Proteins are FLEXIBLE! Induced Fit Model: both the ligand and theprotein can change conformations uponbinding; makes binding site more complementary to the ligand

Answer 28

Illustrating Protein Function Through Oxygen Binding O2 is critically important (obvs), but poorly soluble Transition metals (esp. Fe) can transport O2 but can damage cells So there is a need to sequester Fe How? Heme! Heme is a prosthetic group – a porphyrinring complex with an iron ion (Fe2+) Binds oxygen reversibly Oxygen binds via heme as amino acidscannot bind oxygen 6 coordination sites: 1-4 (nitrogen),5 (amino acid), 6 (oxygen)

Answer 29

Myoglobin is a compact globular protein composed of a single polypeptide chain (153 amino acids in length) Mainly α helices; there are 8. Also some intrinsically disordered regions (flexibility) Carries and stores oxygen (poorly soluble)for muscles Contains a heme prosthetic group Histidines interact with heme and O2 Sterically inhibits oxygen from bindingperpendicularly to the heme plane (specific!) Shaped/folded to form a “cradle” thatnestles the heme prosthetic group -----Protects iron from oxidation (free radicals  bad!)

Answer 30

In free heme, carbon monoxide (CO) binds 20,000x better than O2 In Mb, heme binds CO only 40X better than O2 The protein structure acts as a gate. The effect of histidine (His E7), forces ligands to bind at an angle. Significantly improves O2 vs CO binding

Answer 31

Keq = [products]/[reactants] Ka = [PL]/[P][L] Kd = [P][L]/[PL] high Kd means that there is more products which is [P] [L], so that means that the ligand would rather be dissociated from the receptor because t has a low affinity for for it low Kd means that there is more reactants which is [PL], so that means that the ligand would rather be associated from the receptor because t has a high affinity for for it use eqn of Kd to understand affinity!!!!!!!!!!! Kd = 1/Ka

Answer 32

the amount of O2 bound to Mb increases with O2 concentration as the [O2] increases sufficiently, the amount of binding reaches a maximum value and this is called saturation fraction saturation is the fraction (or half) of the protein that is bound to the ligand Y or theta = [PL]/[Ptotal] slope of the curve (how quickly we reach saturation) depends upon the affinity of the concentration steep slope = high affinity not so steep slope = low affinity

Answer 33

Kd = [P][L]/[PL] originally Kd = [P]/[PL] ([L]) If the [PL] = [P] then [P]/[PL] = 1 and the concentration of free ligand [L] equals Kd Kd = 1 [L] For 50% saturation, Kd = L Kd = [L] at which half of the available ligand-binding sites are occupied, so when P binds half of the L

Answer 34

theta is the fraction saturation which is [PL] = [Ptotal] which is occupied binding sites over the total protein eqn: theta = [L]/Kd + [L] if [L] = 0 then theta equals 0 if [L] >> Kd then theta equals 1 f [L] << Kd then theta equal 1/2 as the Kd gets smaller (binding is tigher) the binding curve is steepere

Answer 35

Agonist – a compound that causes a physiological response Antagonist – a compound that interferes with the physiological action of another compound

Answer 36

as partial pressure so pO2 How well does myoglobin bind oxygen here?- very very well, indicated by the steep slope, so even a little bit of O2 is enough tot bind half of the ligands and then to saturate it to cause a plateau at 13 kPa, there is a plateau which means that there is saturation and almost all of the ligands are bound at 4 kPa, there is a forming plateau so there is almost saturation Mb is not a good transporter because it has a very very hgh affinity for O2 so it does not want to let it go Carries and stores oxygen (poorly soluble)for muscles Our body prefers to use hemoglobin rather than myoglobin as the oxygen carrier in the bloodstream. This is because hemoglobin not only binds oxygen weakly but more importantly binds oxygen cooperatively.

Answer 37

Myoglobin (Mb) 1 subunit O2 storage 1 heme group Hemoglobin (Hb) 4 subunits – 2α and 2β O2 transport 4 heme groups

Answer 38

tense state more stable in absence of O2 Lower affinity for O2 tense state no O2 bound salt bridges makes it rigid salt bridges are ionic interactions between the R groups of the Hb Salt bridges are broken when the O2 binds to the heme groups, makes it more relaxed

Answer 39

Relaxed state more stable in the presence of O2 higher affinity for O2 O2 bound Beta subunits interact salt bridges make it rigid Salt bridges are broken when the O2 binds to the heme groups, makes it more relaxed Relaxed state = fewer interactions, more flexible, higher affinity for O2

Answer 40

Recall that Hb has 4 O2 binding sites Hb is an allosteric protein: having more than one conformation; binding at one site affects the affinity of another site) This opens the door for something called cooperativity With the binding of each O2 molecule, (which changes the conformation of the binding subunity from T to R), the affinity of the whole protein for O2 increases. Positive Cooperativity: binding of a ligand increases the binding affinity of subsequent ligand Negative Cooperativity: binding of a ligand decrases the binding affinity of the subsequent ligand

Answer 41

sigmoidal because Hb has a low affinity for O2 Hb binds O2 cooperatively One binding site  hyperbolic Mb has only 1 binding site for O2 and this has a hyperbolic curve Mb can’t be cooperative. Why? One binding site. Hb has a sigmoidal curve. Reflects a transition from low-affinity to high-affinity binding. This makes Hb highly sensitive to changes in [O2].

Answer 42

Physiologically, Hb must bind O2 efficiently in the lungs (pO2 ~ 13.3 kPa) Hb must release O2 in tissues (pO2 ~ 4 kPa) Effective transport requires the ability to pick something up and drop if off. Therefore, affinities must change. Binding is much more sensitive to changes in oxygen concentration Other ligands bind Hb and change its oxygen-binding properties  Regulation! Hb is ALLOSTERIC!

Answer 43

homotropic means the same ligands heterotropic means different ligands Hb binds CO2 Hb binds O2 & CO2 at different sites binding one reduces the affinity for the other high [CO2] raises the [H+] in circulation: - our RBCs have Hb and O2 from lungs - the O2 binds to Hb - Hb releases O2 to tissues

Answer 44

Hb binds H+ Binds at different binding site from O2 & CO2 The [CO2] influences the [H+]: H+ is formed when CO2 reacts with Hb or H2O CO2 + H2O <-> H2CO3 <-> H+ + HCO3 when Hb binds H+, its affinty for O2 decreases Hb is the main buffer system in RBCs the affinity of Hb for O2 is inversely proportional to amount of H+ & CO2 bound consequences are the Bohr effect - Peripheral tissues: high [CO2] and [H+]: low affinity - lungs: low [CO2] & [H+]: high O2 affinity

Answer 45

2,3-bisphosphoglycerate plays an important role in adaptation to high altitudes (low O2 partial pressure) BPG binds to Hb at a site far from the O2 binding site stabilizes the T state of Hb (low affinity for O2

Answer 46

At altitude pO2 decreases BPG regulates the affinity of Hb for O2 It has its own binding site BPG is an allosteric modulator Stabilization of the T state decreases the affinity of Hb for O2. So Hb is Less willing to bind and less willing to *hold* onto O2 so oxygen gets dropped off The concentration of BPG varies in response to our altitude above sea level. At altitude, since less oxygen is bound to Hb, that allows for BPG to fit into its binding site

Answer 47

Initially, at a lower pO2 (altitude), in the lungs, the affinity of Hb for O2 is reduced at altitude, there is a higher Kd so O2 has a low affinity for Hb (or vice versa) and does not bind very well, Kd is 8mM, maybe because there is less O2 at sea level the Kd is 5mM which is less than 5 and says that at sea level there is a higher affinity for Kd Within hours of being at altitude, the concentration of BPG increases from 5 mM to 8 mM the curve is looking more hyperbolic showing that there is an increased affinity for O2, BPG brings that back up to sea level – levels. What does BPG do to the binding curve?- Makes it more hyperbolic, BPG shifts the oxygen saturation curve to the right  Hb has less affinity for O2  allowing it to release oxygen to the tissues (more than it did before) Physiologically, what is happening? - Hb is gaining less affinity for O2 so it can drop it off at the tissues

Answer 48

Affinity for O2 in the lungs is reduced slightly, but in peripheral tissues more significantly; so, even though less is bound initially, more of it is released in the peripheral tissue; result: ~ 37% of bound O2 is delivered to peripheral tissue!

Answer 49

if [Protein] = [protein + ligand] then you can say y50% of L its bound the answer is 4.0 x 10^-9 because. this is when the [protein] = [protein + ligand]

Answer 50

Catalysts: change rate of reaction without a net change of itself. So: they increase reaction rates without being used up; do not alter equilibrium (Keq)

Answer 51

a substance produced by a living organism that acts as a catalyst to bring about a specific biochemical reaction. Vast majority of biological catalysts are globular proteins globular protein interact via side-side chain interactions, h-bonding, ionic interactions and have subunits, domains and motifs

Answer 52

Substrate: substance acted upon (specific!) Product: results Active Site: location in the enzyme where thereaction occurs

Answer 53

Enzymes Increase Reaction Rates by lowering the activation energy Without enzymes, biochemical reactions are slow. This is a good thing. Enzymes can increase reaction rates (depending on the reaction) up to 1017 X faster than the uncatalyzed reaction!

Answer 54

E+ S <-> ES <-> transition state <-> EP <-> E + P Many enzymes act in the forward and reverse reactions; helping the reaction reach equilibrium (but not affecting equilibrium, only rate) Interactions between enzyme and substrate at the active site  binding affinity

Answer 55

regulated by: pH Temperature [enzyme] [substrate] [cofactors/coenzymes] (stay tuned) 1/3 of all known enzymes require metal ions(metalloenzymes) Holoenzyme: apoenzyme (inactive) +cofactor/coenzyme/metal ion (prosthetic group) Coenzymes are often vitamins and essential toour diet. Enzymes can be regulated: enzymes can beactivated (phosphorylated) or inactivated (de-)

Answer 56

the minimum amount of energy that colliding molecules have in order for a chemical rxn to take place In biochemistry, activation energy is this is free energy of activation ∆G‡ on a graph, Ea is the difference between energy levels of the ground state and the transition state (typically higher energy than both ground states) The rate of a reaction relates to activationenergy. A higher ∆G‡ corresponds to a slowerreaction. ∆G is the energy difference between the substrateand product! NOT CHANGED BY ENZYME

Answer 57

decreasing ∆G‡

Answer 58

∆G (substrate and product) is not changed by an enzyme The free energy difference between the substrate and the transition state ∆G‡ is changed by an enzyme Reaction rates are set by the activation energy. The activation energy “hill”, therefore, is the rate-limiting step! A catalyst reduces the activation energy of a reaction! ∆G‡ is the amount of energy needed to convert 1 mol of the substrate from the ground state to the transition state

Answer 59

transition state

Answer 60

The more molecules reaching the transition state means the more likely product forms, meaning the faster the reaction rate to reach equilibrium. Enzymes bind the transition state BEST (more weak interactions). Induced fit andmolecular complementarity

Answer 61

Enzyme-catalyzed reactions begin with the substrate enteringthe active site to form the enzyme-substrate complex This is mediated by shape and weak, noncovalent interactions Induced fit leads to both enzyme and substrate shape changes. This increases noncovalent interactions (desolvation - strip away H2O - Entropy?) Enzymes act as catalysts because of their ability to: 1. Bring substrate(s) and active sites together: proximity effect 2. Hold substrate(s) at the exact distance and exact orientation necessary for the reaction: orientation effect 3. Provide acidic, basic, or other types of groups required for catalysis: catalytic effect 4. Lower the energy barrier by inducing strain in bonds in the substrate molecule: energy effect

Answer 62

General acid-base catalysis: proton donation/removal by an acid/base lowers free energy of the transition state Covalent catalysis: acceleration through transient formation of an enzyme-substrate bond Metal ion catalysis: metal ions In reality, many enzymes use a combination of these strategies participate in the reaction mechanism

Answer 63

Acid catalysis: proton transfer from an acid lowers the free energy of the reaction’s transition state Base catalysis: proton removal by a base lowers the free energy of the reaction’s transition state Amino Acids: Glu, Asp, Lys, Arg, Cys, His, Ser, Tyr

Answer 64

Metal ions bound to the enzyme Metal ions: help orient the substrate for the reaction Stabilize negative charges Mediate oxidation-reduction reactions

Answer 65

If we understand how enzymes catalyze reactions, we can determine how to inhibit or stimulate them. Key Factors Affecting Rate: concentrations of enzyme ([E]) and substrate(s) ([S]) The maximum achievable reaction rate is proportional to the concentration of the limiting reactant [E].

Answer 66

nonallosteric means only 1 binding site The initial reaction velocity (V0) is the rate at which substrate is consumed or product (molarity/time) is formed at the START of the reaction The maximum velocity, (Vmax) is wherethe rate plateaus looks like Kd Note: Vmax is not an inherent propertyof an enzyme. It depends on reaction conditions  [E] At low [S], V0 increaseswith an increase in [S]. At higher [S], V0 increases by smaller and smaller amounts in response to increased [S]. The rate never exceeds a maximum rate, Vmax

Answer 67

Km is a constant; it is intrinsic to the particular enzyme-substrate pair. For a given enzyme, each substrate has its own Km Small Km indicates tight binding (curve shifted to the left) High Km indicates weak binding (curve shifted to the right) Km is the [S] at which half of the enzyme molecules have their active sites occupied with S and are generating ES. Km is the [S] at which V0 = ½ Vmax

Answer 68

promote the formation of a transition state lower the activation energy increase the magnitude of the rate constant for both the forward and reverse reactions, as the enzyme catalyzes both reactions. cannot change the delta G (which is also equilibrium)

Answer 69

[S] Vo Vmax Km

Answer 70

The substrate concentration at which half of the enzyme active sites are bound by substrate! Km is the [S] that generates a rate of 1/2 Vmax Vo = (Vmax)([S])/(Km + [S]) graph looks like a hyperbola

Answer 71

Sometimes we want reactions to stop, so we inhibit enzymes Alternatively, if you know a lot about the enzyme’s structure, one can rationally design an inhibitor to fit the active site (target-based design). Many drugs, and toxic agents, act by inhibiting enzymes!

Answer 72

Irreversible Inhibitors (inactivators) Usually cause stable, covalent alterations in the enzyme. One inhibitory molecule can permanently shut off one enzyme molecule. Often powerful toxins, but also drugs. Example: organophosphorous compounds (sarin, insecticidesmalathion and parathion) bind to and inhibit acetylcholinesterase Example: aspirin binds to and inhibits cyclooxygenase (COX) Example: penicillin binds to and inhibits transpeptidase which makes bacterial cell walls

Answer 73

Bind to, and dissociate from the enzyme (binding is easily reversed) Interact with the enzyme through noncovalent association/dissociation reactions They are often structural analogs of substrates (fit and inhibit) or products (feedback) They are often used as drugs to slow down an enzyme The fall into two major categories - Competitive - Not Competitive Uncompetitive Mixed

Answer 74

what kind of inhibitions is this can bind - the free enzyme and prevent binding of the substrate (Competitive) - The enzyme-substrate complex and prevent the SP reaction Competitive Inhibitors - Resemble the normal substrate molecule - Compete for admission into the active site Inhibitor does not affect catalysis of SP, Vmax is unchanged! Increasing the [S] favors the likelihood of S bindingto the enzyme instead of the inhibitor, I. Km shifts to the right on the graph and thus has a lower affinity

Answer 75

not permanent Dihydrofolate is a substrate used for nucleotide synthesis Cancer cells manufacture significant amounts of nucleotides necessary for rapid cell division Methotrexate (inhibitor) is used for the treatment of some cancers (high doses)and for the treatment of various immunologic diseases such as rheumatoid arthritis

Answer 76

moves km to the right and lowers the affinity Vmax stays the same Compare the top blue curve (no inhibitor) with the other lines (increased [inhibitor]) Remember Km? Vmax? Note: the presence of the inhibitor lowers andshifts the curve; affecting Km All curves will eventually reach the sameplateau, and therefore the same Vmax I is competing with S for the active site of E. If [S] is really high, it will “win” the competition forthe active site The Km has moved to the right in the presence of I, but Vmax is unchanged.

Answer 77

Lineweaver-Burk (double-reciprocal) plots can be used to distinguish types of inhibition Using the reciprocal of the Michaelis-Mententhe equation allows a more simplistic way to comparedifferent types of inhibition and easily extractkinetic values.

Answer 78

Competitive Inhibition: Increases Km; Vmax the same Competitive Inhibition: Increases Km; Vmax the same Pay attention to the slope… (Km/Vmax) The y-intercept (1/Vmax) is always the same The slope (Km/Vmax) increases with the inhibitor The x-intercept (-1/Km) shifts to the right to showan increased Km in the presence of an inhibitor.

Answer 79

Reversible Inhibitors can bind to: The free enzyme and prevents binding of the substrate (Competitive) The enzyme-substrate complex and prevent the SP reaction (Uncompetitive) Uncompetitive Inhibitors - Binds only to the enzyme-substrate [ES] complex The binding site for the inhibitor isn’t createduntil the enzyme binds the substrate Inhibition cannot be overcome by the addition of moresubstrate

Answer 80

Compare the top blue curve (no inhibitor) with the other lines (increased [inhibitor]) In uncompetitive inhibition, the inhibitorbinds only to the ES complex. This E-S-I complexdoes not go to form any product. Remember Vmax? With a decreased Vmax, by definition, the Kmmust also decrease by the same amount as Vmax Uncompetitive inhibition decreasesVmax and Km (though can be hard to see).

Answer 81

Uncompetitive Inhibition: Decreases Km and Vmax Pay attention to the slope… (Km/Vmax) The slope remains unchanged because Km and Vmax are reduced by equal amounts The y-intercept (1/Vmax) decreases The x-intercept (-1/Km) shifts to the left to showan decreased Km in the presence of inhibitor. parallel lines!

Answer 82

transition state

exam 2 biochem practice questions Flashcards

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