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274 Cards in this Set
- Front
- Back
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what are 3 serine proteases? where are they produced?
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- trypsin
- chymotrypsin - elastase - produced in the pancreas |
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Enzymes contain an _______, which usually a crevice on the surface of the enzyme.
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- active site
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what kind of residues do each of the following bind: chymotrypsin, trypsin, elastase
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- chymotrypsin: binds bulky hydrophobic residues
- tyrpsin: binds positively charged residues (arginine, lysine, histidine) - elastase: small residues (glycine, alanine, valine) |
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what is the catalytic machinery of serine proteases?
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- serine + oxyanion hole
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The ______ residues are not the same as substrate-binding residues
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- catalytic
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what is the catalytic triad in serine proteases? which aa is made reactive?
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- Histidine, Aspartate, Serine
- this triad makes serine unusually reactive |
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what is the mechanism of serine proteases?
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1) serine attacks substrate to make a tetrahedral transition state
2) the oxyanion in the tetrahedral transition state is stabilized by the oxyanion hole 3) when tetrahedral transition state resolves it breaks the peptide bond = acyl-enzyme intermediate 4) attack by water cleaves bond w/ rest of peptide & enzyme is regenerated |
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the oxyanion formed during the transition state of serine proteases is stablized by ______ bonds in the ____________
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- hydrogen bonds
- oxyanion hole |
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Serine protease mechanism: substrate --> ________ state --> _________ intermediate --> enzyme regeneration
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- tetrahedral transition state
- acyl-enzyme intermediate |
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spontaneous reactions have a _______ delta G, non-spontaneous have a ________ delta G
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- negative
- positive |
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what is the formula for ΔG? what is it sensitive to?
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- ΔG = ΔH - TΔS
- sensitive to concentration of reactants and products |
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what is ΔG⁰? formula?
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- standard conditions, certain temperature, 1M concentration
- ΔG = ΔG⁰ + RTlnQ - R is a constant |
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formula for Q?
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- [products] / [reactants]
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what is ΔH? ΔS?
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-ΔH is heat produced (calories)
- ΔS related to change in concentration (entropy) |
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at equilibrium, ΔG = what? what is Q called at equilibrium? what does it tell you?
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- 0
- Keq - concentration of products & reactants at equilibrium |
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at equilibrium what does the formula for ΔG⁰ become? Therefore, the information content of ΔG⁰ & Keq is _____ at a given temperature
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- 0 = ΔG⁰ + RTlnQ
--> ΔG⁰ = -RTlnKeq - identical |
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what are 4 difference b/w chemical & biochemical reactions?
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1) reactions in body not at equilibrium (except in death)
2) reaction can be driven by reducing product concentration 3) non-standard conditions (hinder accurate prediction of ΔG from ΔG⁰) 4) some processes do not take place in solution, but are solid phase reactions |
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The free energy of activation is called ΔG‡. The _________ the ΔG‡, the slower the reaction.
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- larger
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Stabilization of the __________ by a catalyst lowers the __________, thus increasing the attainment of equilibrium. The catalyst does not change the _________ of substrate or product and does not alter the ________.
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- transition state
- activation barrier - free energy - equilibrium ratio |
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Food, or fuel, is degraded to smaller molecules with the release of energy, a process known as _________. Reactions that require the input of energy are called _________ reactions.
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- catabolism
- anabolic |
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There are ____ possible bond cleaves that release energy with ATP. So enzymes _____ NTP hydrolysis to peptide bond synthesis. How much energy does each bond cleavage release?
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- two
- couple - releases about -13 kcal/mole (about -7 kcal/mole per bond) --> therefore it is functionally irreversible |
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what is glutamine synthesis from glutamate an example of?
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- enzymes coupling reactions to ATP
- need to add NH3 --> to do so use common intermediate (phosphorylate glutamate) then replace PO3 with NH3 |
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what is enzyme velocity? why do you use the beginning of the curve? why does it stabilize off at the top?
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- amount of product formed per unit time
- use initial velocity b/c it is linear --> as time goes on you might run out of substrate or product might inhibit enzyme activity |
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at low [S], [S] <<<< _____ therefore the reaction is ______ order. That is, proportional to the concentration of __________.
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- Km
- first - substrate |
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At high [S], [S] >>>> _____, the velocity of the reaction is ______ order, constant and independent of ________ concentration.
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- Km
- zero - substrate |
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when [S] = 0, V = ____.
when [S] is infinite, V = ______. when [S] is equal to Km, V = _____. |
- 0
- Vmax - 1/2 Vmax |
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The Km is equal to the ________ concentration at _______.
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- substrate
- 1/2 Vmax |
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if you damage enzyme and therefore if you need to get more substrate to get to 1/2 Vmax what happens to your Km? If low substrate concentration gets you to 1/2 Vmax what does this mean about Km?
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- large Km
- small Km |
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why does Michaelis-Menten not require pure enzymes?
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- because enzymes are specifi
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large Km reflects what? small Km reflects what?
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- large: low affinity of enzyme for substrate
- small: high affinity of enzyme for substrate |
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how do you measure enzyme?
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- velocity is proportional to amount of enzyme present
- be at saturating amounts of substrate |
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how do you measure substrate?
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- low substrate levels best b/c velocity directly proportional to amount of substrate
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in many cases, substrate concentration fluctuates near _____, controlling the activity
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- Km
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is the Km ever negative?
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- no
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formula for lineweaver-burk plot? what is the x axis? y axis? x intercept? y intercept? slope?
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1/v = (Km/Vmax) 1/[S] + 1/Vmax
- x axis: 1/[S] - y axis: 1/V - x intercept: -1/Km - y intercept: 1/Vmax - slope: Km/Vmax |
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as enzyme concentration increases does Vmax change? Km?
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- Vmax increases
- Km does not change |
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The equilibrium constant (Keq) and ΔGº are ________ and have the same information, they describe reactions
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- CONSTANTS
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The Km measures [substrate] needed for _____% activity
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- 50%
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appearance of alanine transaminase (ALT) in the blood is indicative of what?
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- liver damage or viral hepatitis
- another example of this is low level of alpha-1-antitrypsin |
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zymogen
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-inactive protein precursor
- active site blocked until proteolytic cleavage on specific chain |
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what happens in the blood clotting cascade? what kind of enzyme are these examples of?
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- prothrombin --> thrombin
- thrombin cleave fibrinogen --> fibrin - zymogens |
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fibrinogen cleaved by ________ turns into ________. These form the initial clot with _______. _______ makes the final clot.
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- thrombin
- fibrin monomers - sticky ends - crosslinking |
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prothrombin: cleavage sites & what it turns into
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- cleavage sites: 274 & 323
- without clip at 323 it is prethrombin - with both clips it is thrombin |
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thrombin is a ______ protease (however what residues within it differ?).
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- serine
- isoleucine & aspartate are the critical H-bond formation residues |
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when thrombin is activated by a proteolytic clip, what critical bond is formed?
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- Isoleucine16 is brought into contact with aspartate 194
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where is prothrombin? what does it complex with? how does the GLA domain sit on the membrane (ie what is it dependent on & also what vitamin)? how is it activated?
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- on the membrane surface
- complexes with factor X (enzyme) & factor V - gamma-carboxylation of glutamate allows calcium to bind & exposes hydrophobic residues (can interact w/ surface) --> dependent on vitamin K - factor X does double cleavage to release soluble thrombin |
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how does warfarin work?
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- vitamin K analog = interferes with clotting
- gamma-carboxylation dependent on vitamin K - poorly carboxylated prothrombin does not bind well to surface = reduced coagulation |
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thrombin interacts with the irreversible inhibitor ________. a drug that promote the binding of this to decrease coagulation is _______.
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- antithrombin
- heparin |
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what enzymes to neutrophils release in the lungs? what is the normal inhibitor to this? what happens when it is defective? what happens in smoking? how do you treat it?
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- elastase
- alpha-1-antitrypsin or alpha-1-antiproteinase - defective: unregulated elastase activity (destroys elasin) = emphysema - smoking oxidizes Met residue on alpha-1-antitrypsin --> elastase cleaves elastin --> scarring/emphysema - treat with IV of alpha-1-antitrypsin |
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what residues on a protein can be phosphorylated? example MAP kinase?
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- serine, threonine, tyrosine
- can change the charge & maybe expose active site of enzyme - in MAP kinase - phosphorylation leads to 1000x increase in catalytic activity (increases substrate binding) |
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where do competitive inhibitors bind? how do they affect the Km? Vmax?
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- bind to substrate binding site
- raise Km - do not change Vmax - one ex. is when product chemically resembles substrate |
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where do non-competitive inhibitors bind? what kind of inhibition is it? what do they do to Km? Vmax? They can be _____ or ______.
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- bind in location other than active site (allosteric inhibition)
- don't change Km - lower Vmax - they basically reduce the amount of enzyme present - reversible or irreversible |
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in a competitive inhibitor, what happens to Km when you increase amount of inhibitor? non-competitive Vmax?
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- increase Km
- more inhibitor = decreased Vmax (b/c effectively decreasing amount of enzyme) |
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______ is an irreversible inhibitor of serine proteases. why is it the basis for nerve gases/insecticides?
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- DIFP
- inactives Ach esterase (aka nerve poison) |
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_________ enzymes are even more sensitive to changes in substrate concetration. what does an increase in [S] do? These enzymes do not follow Michaelis-Meten kinetics.Binding is said to be _________
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- allosteric
- [S] increase = increase in velocity - cooperative |
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Allosteric enzymes are usually at the beginning of a dedicated reaction pathway because they are sensitive to __________. How does aspartate transcarbamoylase illustrate this? what does it do? what regulates it?
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- feedback inhibition
- aspartate trascarbamoylase: joins carbamoylphosphate + L-aspartate --> carbamoyl-L-aspartate --> makes pyrimidines - sensitive to NEGATIVE feedback from CTP & POSITIVE from ATP |
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how does the RB gene (protein) work? what kinases are involved?
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- two hits to render it inactive (either hereditary or spontaneous)
- binds E2F & keeps it inactive until phosphorylated by Cyclin D or E & CDKs phosphorylate it - once phsophorylated becomes inactive & E2F free to go turn on genes for S phase |
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_____ RB binds _____ E2F. Once phosphorylated by CDKs ___ or ____, RB is _____ and E2F is ______ and goes and turns on genes for S phase. What happens in the absense of pRB?
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- active
- inactive - D or E - inactive - active - in absence E2F is always on & cell growth is abnormal |
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pRB is a ___________ associated with what cancers?
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- tumor suppressor
- retinoblastoma |
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p53 is a __________ associated with what cancers?
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- tumor suppressor
- sarcomas, carcinomas |
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_______ stabilizes p53 and allows it to bind DNA. _____ is an important target gene it turns on. This gene does what? what happens in the absence of p53?
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- phosphorylation
- p21 - p21 halts cell cycle by binding Cyclin/CDK complex --> allows time to repair DNA before S phase - p21 can also inhibit replication forks by binding with PCNA - in absence p21 never turned on & damaged DNA is replicated - also without p53 can't undergo apoptosis |
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NF1 is a ________ associated with what cancers?
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- tumor suppressor
- associated with neuroblastoma |
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APC is a _________ associated with what cancers?
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- tumor suppressor
- colon, stomach cacncer |
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BRAC 1 is a _________ associated with what cancers?
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- tumor suppressor
- breast cancer |
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difference between tumor suppressors & oncogenes?
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- tumor suppressors: 2 mutations needed (AR), breaks
- oncogenes: 1 mutation needed (AD), gas |
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many ______ code for proteins involved in pathways that relay growth-stimulating signals from outside the cell into the nucleus
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- proto-oncogenes
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what is PDGF an example of?
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- signal transduction, receptor that penetrates the plasma membrane & has tryrosine kinase activity
- phosphorylation of Tyr residues allows interactions w/ other members in cascade |
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how does simian sarcoma (sis) alter cell growth? example of what?
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- encodes part of PDGF & enduces signal transduction
- oncogene |
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what happens with mutant form of epidermal growth factor? example of what?
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- constantly stimulates growth even in absence of EGF (ErbB/HER2)
- oncogene |
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how does mutant ras work? example of what?
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- when GTP is bound it's active
- has GAP (GTPase activing protein) & hydrolyzes GTP to GDP to turn off - mutation makes it always on - oncogene |
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NF1 contains a what? therefore it is though to be associated with what?
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- contains a GAP domain
- thought to be associated with RAS |
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what goes wrong with c-fos & c-jun? what are they? what do they bind? example of what?
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- Fos & Jun bind to AP1 sites and cause transient growth
- they are transcription factors - in mutated cells there is continuous growth - oncogenes |
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Myc is a transcription factor that regulates expression of ____% of all genes. Binds to enhancer sequences (E-boxes) that recruit ________. what happens in mutated forms? example of what?
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- 15%
- HATs (histone acetyltransferases) - mutated form leads to upregulation of genes - oncogene |
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what happens in Burkitt's lymphoma?
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- Myc (chromosome 8) translocated to genes encoding antibodies (chromosome 2, 14, 22)
- Myc constituitively expressed in cells with immunoglobulin chains |
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there can be excessive or inappropriate expression of _________ in diverse malignancies
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- cyclins
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how does SV40 T-antigen work on Rb & p53?
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- viral protein complexes with p53 & pRB
- E2F always on & no one checking DNA |
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The _____ domain of the papillomavirus binds p53 and induces _______. The ____ domain binds pRB.
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- E6
- induces proteolysis - E7 |
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What are the 6 capabilities for tumorigenesis (SSILEM)?
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1) self-sufficiency in growth signals: RAS
2) sustained angiogenesis: VEGF 3) insensitivity to anti-growth signals: pRB 4) limitless replicative potential: telomerase 5) evasion of apoptosis: p53 6) metastasis |
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the anomeric carbon can react with ______ or ______ to create a __________ bond
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- alcohols or other sugars
- glycosidic |
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what is maltose made up of? lactose? sucrose?
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- maltose: glucose-glucose
- lactose: galactose-glucose - sucrose: fructose-glucose |
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amylose is a polymer of what? what are the linkages? amylopectin?
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- glucose alpha(1-->4 linkage)
- amylopectin is branched version w/ alpha(1-->6) every 12 residues |
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glycogen is a polymer of what? what are the linkages?
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- glucose polymer, alpha(1-->4) linkages with branching every 8-10 residues with alpha(1-->6)
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glycosaminoglycans (GAGs) are repeating _________ with a _____ charge. It can also be ______ which adds additional negative charge.
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- disaccharides
- negative - sulfated |
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each sugar is _____ for enzymatic polymer synthesis or transfer by sugar nucleotide formation
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- activated (with UDP)
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difference b/w amylose & cellulose in terms of linkage?
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- amylose: alpha(1-->4)
- cellulose: beta(1-->4) |
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difference between enzymatic & non-enzymatic conjugation of glucose?
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- enzymatic requires UDP-glucose
- non-enzymatic (HbA1C) just requires glucose |
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except for _______, enzymatic protein glycosylation is for secreted proteins or domains facing extracellularly
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- O-GlcNac
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N-linked residues are attached to what amino acid? O-linked?
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- N-linked = asparagine
- O-linked = threonine or serine |
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a different _______ is required for each step of carbohydrate chain synthesis They are all _________.
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- enzyme
- transferases |
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how are O-linked sugars added? N-linked?
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- O-linked are added one at a time on the threonine or serine residue
- N-linked are built to 14 residues on the protein Dolichol phosphate then transfered to asparagine |
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N-linked sugars are made on _________ which is a ______. where is this assembled?
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- dolichol phosphate
- lipid - ER |
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what is the site of principal modification of glycosylation?
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- golgi
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________ are part of the matrix and found in places like cartilage b/c they are hydrated and provide coushioning.
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- proteoglycans
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Proteoglycans usually consist of a core protein __-linked to a ______
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- 0-linked
- GAG |
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why are type O individuals more prone to ulcers?
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- H-pylori binds structures that look like type O sugars
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the avian influenza virus epidemic was due to what?
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- a virus being able to recognize avian alpha(2-3) linkages and mutations to human alpha(2-6) linkages
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White cells have _______ ligand & _______ receptor. Endothelial cells have _____ ligand & ______ receptor.
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- P-selectin ligand
- L-selectin receptor - L-selectin ligand - P-selectin receptor |
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a defect in fucosylation leads to what? leads to what phenotype?
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- leukocyte adhesion deficiency II (LAD II)
- bombay phenotype - can't recruit white cells when you need them, exceptionally prone to infection |
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which food source gives you the most energy? protein, fat or carbs
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- fat (9Kcal/g)
- both protein + carbs are about 4 |
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what are the end products of alpha-amylase breaking down amylopectin? what kind of linkages can he break down?
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- maltotriose
- maltose - alpha-limit dextrins - breaks down 1-->4, can't break down 1-->6 |
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what are the brushborder enzymes (GASLIM)?
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- glucoamylase
- alpha-amylase (soluble) - sucrase - lactase - isomaltase - maltase |
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what does lactase breakdown/products? sucrase? alpha dextrinase (isomaltase)? glucoamylase? alpha amylase?
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- lactase: lactose --> galactose + glucose
- sucrase: sucrose --> fructose + glucose - alpha dextrinase (isomaltase): alpha limit dextrins --> glucose - glucoamylase: malto-oligosaccharides made by alpha amylase --> glucose - alpha amylase: glycogen --> alpha limit dextrins & malto-oligosaccharides |
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what happens in intestinal lumen on lactose intolerance person?
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- lactose gets acted on by bacteria generating lactic acid & fatty acids --> creates osmotic gradient & H20 flows out of intestinal cell
- H2 generated - watery diarrhea! |
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UNDIGESTED ________ `ARE MAJOR COMPONENTS OF DIETARY FIBER
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- POLYSACCHARIDES
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_____ and _____ are transported by simple diffusion in the intestine. _____, ______ and ______ (on basolateral side) are transported by facilitated diffusion. _____ and _____ are transported by active transport.
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- arabinose & xylose
- manose, fructose & glucose - galactose & glucose |
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Glut4 is found where? is it responsive to insulin? what about glut2? insulin responsive? SLGLUT1 is found where? insulin responsive?
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- glut4: white blood cells, fat & muscle --> responsive to insulin
- glut2: liver & pancreatic beta-cells --> not responsive to insulin -slglut1 found in intestines & kidney --> responsive to insulin |
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How does insulin stimulate receptor function in muscle, fat and white blood cells?
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- glut4 normally inside cells, insulin increases number of receptors on the membrane
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after carb ingestion, glucose peaks around _______ minutes and returns back to baseline around _______ mins.
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- peaks 30-40, baseline @ 120
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high glycemic index foods stimulate _____ insulin secretion, whereas complex carbs tend to have ____ GIs.
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- high
- low |
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what is the effect of diabetes on blood glucose levels?
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- diabetics start higher, stay higher, come back to baseline slower
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why are glucokinase & hexokinase isozymes?
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- they are different enyzmes that catalyze the same reaction
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_______ can phosphorylate other hexoses, while ______ is specific for glucose. __________ is restricted to liver and pancreatic b cells,
while _________ are ubiquitous. ________, but not _________, are inhibited by G6P. |
- Hexokinases
- glucokinase - Glucokinase - hexokinases - Hexokinases - glucokinase |
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who has a lower Km: glucokinase or hexokinase? what stimulates gene transcription and synthesis of glucokinase?
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- hexokinase (0.1mM Km)
- glucokinase (10mM Km) - insulin |
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what happens with MODY? is it associated with obesity/high lipid levels?
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- defect in glucokinase gene or transcription factors
- type II diabetes, AD - NOT associated with obesity or high lipids |
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how does glucokinase regulate insulin secretion?
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- when glucose taken into cell & phosphorylated by glucokinase then glycolysis happens
- energy created phosphorylates potassium channel depolarizing cell --> open calcium channels & vessels with insulin fuse with membrane & are released |
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Red Cells Lack ______ So They Depend on Glycolysis for ATP Production
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- Mitochondria
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glucose --> G6P by ________. G6P --> F6P by ______. F6P --> F16BP by ______. F16BP --> G3P by _______. (isomerization between G3P & DHAP by ______). G3P --> 13BPG by ________. 13BPG --> 3PG by _______. 3PG -->2PG by ______. 2PG --> PEP by _______. PEP --> pyruvate by ______.
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- hexokinase
- phosphoglucose isomerase - phosphofructokinase I - aldolase - triosephosphate isomerase - glyceraldehyde 3 phosphate dehydrogenase - 3 phosphoglycerate kinase - phosphoglycerate mutase - enolase - pyruvate kinase |
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which steps of glycolysis use ATP? which make ATP?
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- hexokinase & PFK1 use ATP
- phosphoglycerate & pyruvate kinase make ATP |
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what does G3P dehydrogenase use? what is its substrate? product?
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- Pi, NAD+
- substrate is G3P, product is 13BPG |
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pyruvate is converted to lactate which takes two _____ and converts them to ______
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- NADH
- NAD+ |
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G6P can make ______ for storage or go to Pentose-5-phosphate and make _____ or ______.
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- glycogen
- NADPH or nucleotides (ribose?) |
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DHAP can be converted to what?
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- phosphatidic acid --> either triacylglycerols or phospholipids
- aka USED FOR LIPID SYNTHESIS |
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1,3BPG generates 2,3BPG a regulator of ________ by the enzyme _______.
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- hemoglobin
- bisphosphoglycerate mutase |
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3PG can be converted to which amino acid? what are the 3 steps? what other glycolytic intermediate can make amino acids?
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- serine
- oxidation --> transamination --> dephosphorylation - pyruvate |
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how does G3P dehydrogenase show negative cooperativity?
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- enzyme is more or less buffered from changes in substrate concentrations
- resists changes to [substrate] |
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NAD is derived from what? what does it accept? do cells have higher [NAD+] or [NADH]?
|
- derived from vitamin B3
- absorbs 2e- & 1H+ - higher [NAD+] |
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pellegra
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- niacin deficiency
- 4Ds: dimentia, dermatitis, death, diarrhea |
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________ regenerates NAD+ by converting pyruvate to lactate
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- lactate dehydrogenase
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what are the 3 regulated steps in glycolysis? this is because they are _____ from equilibrium
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1) hexokinase
2) PFK1 3) pyruvate kinase - far |
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disease associated with glucokinase: _______, pyruvate kinase: _______
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- MODY
- warburg effect: cancer cells have elevated levels of glycolysis - b/c of pyruvate kinase expressed in cells |
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hexokinase is inhibited by ______. PFK1 is activated by _____, inhibited by _____ & ______. pyruvate kinase is activated by ______.
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- G6P
- AMP - ATP & citrate (meaning high Acetyl CoA) - F16BP (feed forward) |
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F26BP is made by ______. how does this regulate glycolysis?
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- PFK2
- F26BP is positive allosteric regulator of PFK1 therefore turning on glycolysis |
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how is PFK2 regulated?
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- hormonally
- insulin: signals well fed state = enzyme dephosphorylated & acts as kinase to make F26BP --> start glyoclysis (acts as a synthetase - kinase) - without insulin: phosphorylated & turns into phosphatase to make F26BP into F6P --> decrease glycolysis |
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deficiencies in glycolysis mainly affect _____ & _____. it is limited by ____. requires the coenzyme ____. Net yield of ___ ATP/mole of glucose.
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- RBC, skeletal muscle
- Pi - NAD+ - 2 |
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2-F-Deoxyglucose (PET) is an inhibitor for _______. Arsenate for _______. Fluoride for ______.
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- hexokinase
-G3P dehydrogenase - enolase |
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Glucose is converted to sorbitol via _________. This can then be converted to fructose by __________. These conversions are of particular interest in the ______ & __________.
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- aldol reductase
- sorbitol dehydrogenase - seminal vesicles - eye |
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what does sorbitol have to do with retinopathy in the eye?
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- aldol reductase is slower than sorbitol dehydrogenase therefore glucose --> sorbitol and it build up in the eye
- causes osmotic pressure |
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In fructose metabolism: fructose is converted to _____ by _____. _____ cuts this substrate into _____ & _______. Both of these substrates can be converted to ________, how?
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- F1P
- fructokinase - aldolase B - DHAP & glyceraldehyde - G3P - DHAP by triosephosphate isomerase - glyceraldehyde by glyceraldehyde kinase |
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where does fructose enter glycolysis?
|
- enters at G3P
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essential fructosuria
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- defect in fructokinase
|
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hereditary fructose intolerance & why is it bad
|
- defect in aldolase B
- build up for F1P sequesters phosphate & stops glycogen breakdown & glucose synthesis |
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Mannose metabolism: Mannose is converted to _________ by ________. This is then converted to ________ by _______.
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- Mannose-6-phosphate
- hexokinase - Fructose-6-phosphate - phosphomannose isomerase |
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where does mannose enter glycolysis?
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- fructose 6 phosphate
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to metabolize galactose 1 phosphate you need to make __________
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- UDP-glucose
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galactose metabolism: galactose --> _______ by _______. UDP is then transferred from ______ to it by _________. UDP-galactose is then changed into ________ by ________. _______ then acts on this molecule to remove the UDP and make it _________. This is then converted to _________ by __________.
|
- galactose-1-phosphate
- galactokinase - UDP-Glucose (leaving Glucose-1-phosphate) - Galactose-1-phosphate-uridylyl transferase - UDP-glucose - epimerase - Galapcose-1-phosphate-uridydyl transferase - Glucose-1-phosphate - Glucose-6-phosphate - phosphoglucomutase |
|
|
where does galactose enter glycolysis?
|
- glucose-6-phosphate
|
|
|
instead of turning into galactose-1-phosphate, galactose can also turn into _________ via ______.
|
- galactitol
- aldol (aldolase) reductase |
|
|
UDP-galactose can be converted into UDP-glucose, _______ & __________
|
- lactose
- glycoprotein/lipid |
|
|
galactokinase deficiency & what conversion affected
|
- deficiency in galactokinase
- minor problem - conversion of galactose --> galactose-1-phosphate |
|
|
classic galactosemia & what conversion affected
|
- defect in galactose-1-phosphate-uridylyl transferase
- serious - galactose-1-phosphate --> UDP-galactose (using UDP-glucose making glucose-1-phosphate) |
|
|
epimerase deficiency & what conversion affected
|
- deficiency in epimerase
- UDP-galactose --> UDP-glucose - rare |
|
|
UDP-glucose can be converted to __________ to be conjugated to bilirubin and drugs, why would it do this?
|
- UDP-glucuronic acid
- do this to make the molecules more polar and therefore more excretable |
|
|
alcohol is converted to ________ by ________. If you are a chronic alcoholic _____ is also developed to help this conversion.
|
- acetaldehyde
- alcohol dehydrogenase - MEOS (CYT P450) |
|
|
alcohol metabolism: alcohol --> _______ by ______. _______ ---> _____ by _________. Acetate can then either cause ________ or be turned into _______ by _________.
|
- acetaldehydge
- alcohol dehydrogenase - acetaldehyde --> acetate by alcohol dehydrogenase 2 - acidosis - acetyl Coa by Acetyl CoA synthetase |
|
|
wernicke korsakoff
|
- thiamine deficiency from chronic alcoholism
|
|
|
high levels of NADH can do what to gluconeogensis?
|
- inhibit gluconeogenesis (stop malate --> oxaloacetate)
- keep making lactate b/c so much NADH |
|
|
high levels of NADH do what to triglyceride?
|
- stimulates triglyceride formation
- make DHAP --> glycerol-3-phosphate --> triglycerides - stop fatty acids from breaking down into acetyl CoA |
|
|
with high levels of NADH you get increased _______, decreased ________ and metabolic ________.
|
- triglyceride formation
- gluconeogenesis - acidosis |
|
|
if someone gets poisoned by methanol what will alcohol dehydrogenase turn it into? what can you treat them with?
|
- formaldehyde
- treat them with ethanol b/c it will out compete methanol for alcohol dehydrogenase |
|
|
what is the pathway for antifreeze (ethylene glycol) poisoning?
|
- ehtylene glyol --> glycoaldehyde (via alcohol dehydrogenase)
- glycoaldehyde --> glycolic acid (via alcohol dehydrogenase) - glycolic acid --> acidosis |
|
|
What are the 4 fates of pyruvate?
|
1) lactate
2) acetyl CoA (oxidative decarboxylation) 3) oxaloacetate (carboxylation) 4) alanine (transamination) |
|
|
How many NADH, ATP, GTP, FADH2 do glycolysis, PDH & TCA make? between how many ATP are made?
|
- glycolysis: 2NADH, 2ATP
- PDH: (NADH) x2 - TCA: (3NADH, FADH2, GTP) x2 - 32-38 ATP |
|
|
______ takes place in the cytoplasm & _____ in the Mito matrix. ______ is the molecule of glycolysis transported from the cytosol into the mito matrix
|
- glycolysis
- TCA - pyruvate |
|
|
what is the active site on acetyl CoA (ie where is the acetyl group added)
|
- SH group on beta-mercapto ethylamine which is where the acetyl group is added
|
|
|
PDH: E1 is ________. E2 is ________. E3 is ________. what is the mechanism? Remember how to regenerate FAD.
|
- E1: pyruvate dehydrogenase
- E2: dihydrolipoyl acetyltransferase - E3: dihydrolipoyl dehydrogenase - 1) decarboxylate the pyruvate --> 2) transfer to thioester on lipoate --> condense w/ HSCoA --> 3) regenerate lipoate using FAD --> FADH2 --> need to change NAD+ --> NADH to regenerate FAD |
|
|
_______ is the coenzyme on E1 of PDH. What does it do? Where is it derived from?
|
- thiamine pyrophosphate
- decarboxylates pyruvate - derived from vitamin B1 (thiamine) |
|
|
wernicke's encepalopathy (wernicke-korsakoff) & beri beri are derived from what deficiencies? difference b/w wet & dry beri beri?
|
- thiamine (b1)
- wet beri beri - CVD complications - dry beri beri has involuntary eye movements - happens where white rice is predominant |
|
|
_____ is the active arm on E2 of pyruvate dehydrogenase. This is a target for what kind of poisoning? what does it have to hold the acetyl group? where does it transfer the acetyl group? the electrons?
|
- lipoate
- trivalent arsenic (any enzyme with lipoate is a target for this) - has a thioester (S-S) - acetyl group transferred to CoA - electrons to FAD on E3 |
|
|
where does E3 of pyruvate dehydrogenase transfer its electrons? where is FAD derived from?
|
- transfers them from FADH2 --> NAD+ to make it NADH
- FAD is derived from vitamin B2 (riboflavin) |
|
|
how is PDH regulated by phosphorylation?
|
- when it is phosphorylated it is inactive --> ATP, acetyl CoA, NADH all turn on kinase that turns OFF PDH2 (aka negative feedback inhibition)
- when it is unphosphorylated it is active --> insulin, ADP, Ca2+, pyruvate, CoASH, NAD+ all turn on phosphatase that ACTIVATES PDH |
|
|
Leigh's disease & how do you treat?
|
- deficiency in PDH
- seizures, lactic acidosis - poor prognosis - treat by giving thiamine (vitamin B1), high-fat, low-carb diet recommended |
|
|
Acetyl CoA can be made from what 3 things? what are it's 4 fates?
|
- made from: pyruvate, fatty acids, amino acids
- made into: energy, fatty acids, cholesterol/steroids, ketone bodies |
|
|
Citrate is made from ______ & _____ by ______. Then converted to isocitrate by ______. Then converted to alpha-ketoglutarate by ______. What is made here? Then converted to Succinyl coA by _____, what is made here? Then converted to succinate by ______, what is made here? Then converted to Fumarate by ______, what is made here? Then converted to malate by _______, then converted to oxaloacetate by _________, what is made here?.
|
- oxaloacetate & acetyl CoA by citrate synthase
- aconitase - isocitrate dehydrogenase., makes CO2 & NADH - alpha-ketoglutarate dehydrogease, makes CO2 & NADH - succinyl CoA synthetase, makes GTP - succinic acid dehydrogease, makes FADH2 - fumarase - malate dehydrogenase |
|
|
what enzymes in the krebs cycle make NADH? GTP? FADH2?
|
- NADH: isocitrate dehydrogenase, alpha ketoglutarate dehydrogenase, malate dehydrogenase
- GTP: succinyl-CoA synthetase - FADH2: succinic acid dehydrogenase |
|
|
trivalent arsenic targets what enzymes?
|
- G3P Dehydrogenase
- PDH - alpha-ketoglutarate dehydrogenase |
|
|
_____ is exported from the mitochondria to allow fat synthesis & inhibit glycolysis. what enzyme in glyoclysis is it targeting?
|
- citrate
- targeting PFK1 |
|
|
what enzymes in the TCA cycle are stereospecific?
|
- aconitase
- fumarase |
|
|
Citrate can turn into _______ & _____. Alpha-ketoglutarate can turn into _______. Succinyl-CoA turns into ______. Oxaloacetate can turn into _________.
|
- Fatty acids & sterols
- glutamate & amino acids - heme - aspartate |
|
|
Pyruvate can be made into malate by _________. pyruvate can be made into oxalacetate by _____. PEP can be made into oxaloacetate by _________. Glutamate can be turned into alpha-ketoglutarate by _________.
|
- malic enzyme
- pyruvate carboxylase - PEP carboxykinase - glutamate dehydrogenase |
|
|
The PPS has two important products: _____ used for nucleotide synthesis, ______ used to reduce glutathione, synthesize FA, NO, steroids/sterols, detoxify drugs
|
- ribose-5-phosphate
- NADPH |
|
|
What are the oxidative steps of the PPS? Which steps make NADPH?
|
1) G6P --> 6phosphoglucono-alpha-lactone via G6P dehydrogenase --> 6 phosphogluconate via lactonase
2) 6 phosphogluconate --> ribulose-5-phosphate via 6-6-gluconate dehydrogenase - G6P dehydrogenase makes NADPH (oxidation) - 6-p-gluconate dehydrogenase makes NADPH (oxidation & decarboxylation) |
|
|
difference b/w NAD+ & NADP+? what are the relative ratios in the cell?
|
- there is a phosphate at bottome of NADP+ which makes it recognized by different enzymes
- NAD+ & NADPH are kept high in cells vs. NADH & NADP+ |
|
|
______ is needed when making fatty acids to saturate the double bonds. It is also needed in arginine conversion to citrulline & NO
|
- NADPH
|
|
|
what happens in the second non-oxidative phase of PPS? ie what are the carbon skeletons arranged into?
|
1) ribulose-5-phosphate is converted to either ribose-5-phosphate via isomerase
OR converted to xyulose-5-phosphate via epimerase |
|
|
How can xyulose-5-P be converted to G3P & ribose-5-P to sedoheptulose-7-P? What cofactor is used?
|
- transketolase transfers 2 carbon units using thiamine
|
|
|
Sedoheptulose-7-P can be converted to Erythrose-4-P & G3P to Fructose-6-Pusing what?
|
- transaldolase transferring 3 carbon units
|
|
|
Ribulose-5-P --> Ribose-5-P via _____. Ribose-5-P --> Sedoheptulose-7-P via ________. Sedoheptulose-7-P --> Erythrose-4-P via _____.
|
- iosmerase
- transketolase - transaldolase |
|
|
Ribulose-5-P --> Xyulose-5-P via ________. Xyulose-5-P --> G3P via ______. G3P --> Fructose-6-P via _______.
|
- epimerase
- transketolase - transaldolase |
|
|
The end products of the PPS are ____ pentose-phosphates & __ triode-phosphate & ___ hexose-phosphate
|
- 3-pentose-phosphate (2 xyulose-5-P & 1 ribose-5-P)
- 1 triose-P (G3P) & 2 hexose-P (2 fructose-6-P) |
|
|
what do you do if: NADPH=ribose? Ribose > NADPH? NADPH >>> Ribose? NADPH > ribose?
|
- NADPH=ribose: run the shunt normally
- ribose > NADPH: run non-oxidative portion of shunt via rearrangement of C skeletons from glycolysis - NADPH >>> ribose: run pathway to glycolytic intermediates --> gluconeogenesis --> G6P - NADPH > ribose: run pathway normally |
|
|
____________, the first committed step, is rate limiting of the PPS. how is it inducible by insulin? what is the allosteric negative feedback?
|
- Glucose-6-P dehydrogenase
- inducible by insulin b/c insulin wants to stimulate fat production so need NADPH - NADPH is neg. allosteric inhibition |
|
|
how does actual V vs. Vmax compare with G6P dehydrogenase?
|
- high Km for substrate when low [ ]
- low Ki for inhibitor when high [ ] - therefore reaction is VERY SLOW under biological conditions |
|
|
__________ uses NADPH to reduce Met Hb 3+ back to 2+
|
- Met Hb reductase
- when Hb goes from 2+ --> 3+ it releases an O2- |
|
|
O2- + H2O = ________. Haber-weiss reaction? Fenton reaction? Both of these processes generate _________.
|
- H2O2
- Haber weis = H2O2 + O2- = OH- + H2O + O2 - fenton reaction: H202 + O2- (from oxidation of Hb) = OH- + OH- - hydroxy radicals |
|
|
chronic granulomatous disease (CGD)
|
- defect in NADPH oxidase - therefore can't generate H2O2 to kill bacteria
|
|
|
NADPH produced by _________ maintains the supply of reduced glutathione needed to destroy peroxide._____ is also responsible for maintaining the intracellular environment in a reduced state so that disulfide bonds in proteins stay reduced.
|
- glucose-6-P dehydrogenase
- Glutathione |
|
|
_______ converts superoxide --> hydrogen peroxide. ______ converts H2O2 to water turning G-SH into ______. how does it become reduced again?
|
- superoxide dismustase (SOD)
- Glutathione (GSH) peroxidase - G6P dehydrogenase generates NADPH - GSSG - GSSG reductase takes GSSG --> GSH by oxidizing NADPH --> NADP |
|
|
how do glucose meters use peroxidase & glucose oxidase?
|
- glucose --> gluconic acid via glucose oxidase
- in this process reduces hydrogen peroxide --> water |
|
|
what are heinz bodies in G6PDH deficiency? what else do you see with this condition?
|
- precipitated Hb b/c can't reduce disulfide bonds formed b/w molecules
- see dark urine, low RBC count, RBC w/ inclusion bodies, elevated reticulocyte count, low Hb, elevated bilirubin |
|
|
why do you get dark urine in G6PDH deficiency? why low count RBC? why high bilirubin? reticulcytes indicate what? This helps with what parasite?
|
- b/c excreting Hb
- b/c hemolysis - b/c bilirubin is breakdown product of heme - indicate there is active erythropoiesis in the bone marrow - helps fight malaria |
|
|
Blood entering the liver is ____ [glucose] in the portal vein whereas exiting the liver is _____ [glucose] in the hepatic vein.
|
- low
- high |
|
|
________ sustains blood glucose for a few hours after a meal. _______ sustains blood glucose for many days in the absence of carbohydrate intake.
|
- Glycogen
- Gluconeogenesis |
|
|
What are the different steps in gluconeogenesis vs. glycolysis?
|
- pyruvate --> oxaloacetate (via pyruvate carboxylase)
- oxaloacetate --> PEP (via PEPCK) - F16BP --> F6P (via F6BPhosphatase) - G6P --> Glucose (via G6Phosphatase) |
|
|
precursors for gluconeogenesis: _______ via pyruvate, ______ via pyruvate, ______ via glycolytic intermediates
|
- lactate
- amino acids (alanine) - glycerol |
|
|
transamination reactions: _______ to alanine. _____ to aspartate. ______ to glutamate.
|
- pyruvate
- oxaloacetate - alpha-ketoglutarate |
|
|
Where does glycerol enter the gluconeogenesis pathway? What does this mean if you have a defect in PEPCK?
|
- DHAP
- you could use glycerol instead of pyruvate & alanine b/c those would not produce an increase in glucose |
|
|
Which tissues do glucogenesis?
|
- liver and kidneys
|
|
|
What are 2 ways that gluconeogenesis deals with the mito location of pyruvate & pyruvate carboxylase (ie how do you get oxaloacetate into cytoplasm)?
|
- oxaloacetate --> malate using NADH --> malate then transported out of mito --> oxaloacetate using NAD+ generating NADH
- oxaloacetate --> aspartate (using alpha-ketoglutarate & glutamate) - aspartate shunted out of mito --> oxaloacetate (regenerating glutamate) |
|
|
what coenzyme does the pyruvate carboxylase enzyme use? what does it do?
|
- biotin
- adds a CO2 |
|
|
Where is G6Phosphatase located? how do you get G6P in? glucose/Pi out?
|
- located in the ER
- transporters get them in and out |
|
|
Gluneogenesis is expensive process: Pyruvate carboxylase uses _____, PEPCK uses _______, 3PG kinase uses ________, G3P dehydrogenase uses _______
|
- 2 ATP
- 2 GTP - 2 ATP - 2NADH |
|
|
What activates pyruvate carboxylase? What inhibits pyruvate dehydrogenase?
|
- Pyruvate carboxylase: activated by Acetyl CoA
- PDH: inhibited by NADH, ATP |
|
|
How does F16BPhosphatase help to regulate gluconeogenesis?
|
- turned on by low AMP, decreased F26BP, increased citrate
|
|
|
In general, ______ inhibits most gluconeogenesis pathways, where as _______ activates them.
|
- insulin
- glucagon |
|
|
glucagon has no receptors in _______ therefore it cannot do what?
|
- muscle
- stimulate glycogen breakdown in muscle |
|
|
How does glucagon act on PFK2? how does insulin work?
|
- glucagon --> cAMP --> PKA --> phosphorylate PFK2 --> becomes a phosphatase & turns F26BP --> F6P = TURNS OFF GLYCOLYSIS & ON GLUCOGENESIS
- insulin stimulates phosphatase takes phosphate off of PFK2 --> turns into kinase --> makes F26BP = TURNS ON GLYCOLYSIS AND OFF GLUCOGENESIS |
|
|
Cori cycle
|
- lactate made in RBC & muscle is transported in blood to liver where it turns it back into glucose to send out to muscles
|
|
|
Cahill (alanine) cycle
|
- pyruvate made in muscle is transaminated to alanine --> tranported to liver --> made back into glucose to send out
|
|
|
How does high NADH/NAD+ inhibit gluconeogenesis? how does it cause acidosis?
|
- NADH inhibits malate --> oxaloacetate therefore interferes w/ gluconeogenesis
- causes acidosis b/c want to convert back to NAD+ by making pyruvate into lactate - alcohol also deprives liver of gluconeogenic substrates |
|
|
Which is more percentage of glycogen: liver or muscle? which has more weight by mass?
|
- liver has higher percentage but muscle has more total weight
|
|
|
glycogen synthesis: G6P --> G1P via _________. G1P --> UDP-glucose via __________. UDP-glucose to Glycogen alpha 1-4 via ________. Glycogen 1-4 to 1-6 via __________. The beginning are the same steps used to activate glucose.
|
- phosphoglucomutase
- UDP-glucose pyrophosphoryase - glycogen synthase - branching enzyme |
|
|
what is the regulated step of glycogen synthesis? How is it regulated? It adds molecules 1 at a time.
|
- glycogen synthase
- increased by increase in G6P, UNphosphorylated |
|
|
What happens when there is no glycogen primer?
|
- glycogen is build on a glycogenin protein
|
|
|
What is the regulated step of glycogen breakdown? What is its product? What happens when you reach a branch? What is it's product? What is the mechanism of each of their cleaving?
|
- glycogen phosphorylase, product is G1P
- debranching enzyme (transfers 3C residues to different chain), product is free glucose - glycogen phosphorylase cleaves by phosphorolysis, debranching enzyme cleaves by hydrolysis |
|
|
In liver, there is lack of _________ during glycogen breakdown, therefore the product is ______. What is the difference in muscle?
|
- F26BP
- therefore once get to G6P use G6P bisphosphatase to make free glucose for other cells - in muscle there is no G6Phosphatase therefore CANNOT get free glucose as a product --> G6P has to go through glycolysis |
|
|
How does glycogen synthesis autoregulate? What does cortisol do?
|
- increased glycogen content slows synthesis
- cortisol chronically stimulates glycogenolysis slowly |
|
|
Which form of phosphorylase is more active: a or b? How do you change b/w the two?
|
- A is more active
- B is converted to A when phosphorylated |
|
|
what is the glucagon cAMP cascade?
|
- glucagon --> G protein --> adenylate cyclase --> cAMP --> PKA
|
|
|
Glucagon cascades to activate cAMP. cAMP activates PKA how? PKA can they phosphorylate _________ making it active to phosphorylate __________ turning it from form _______ which makes more glycogen breakdown. PKA will also phosphorylate _______ which makes less glycogen synthesis.
|
- by causing dissociation of the regulatory subunits
- phosphorylase kinase - phosphorylase - b -->a - glycogen synthase |
|
|
Insulin stimulates _________ to turn phosphorylase a --> b. Glucagon stimulates _______ to turn phosphorylase b -->a. Insulin stimulates ________ to dephosphorylate glycogen synthase and make it active. Glucagon stimulates ________ to phosphorylate glycogen synthase.
|
- phosphorylase phosphatase
- phosphorylase kinase - protein phosphatase - protein kinase |
|
|
Epinephrine & nerve stimulation aka Ca2+ (only epinephrine in liver) in muscle stimulate __________
|
- glycogen breakdown
|
|
|
Glucose-6-phosphate stimulates glycogen______
& decreases_________. |
- synthesis
- breakdown |
|
|
Type I glycogen storage disease Von Gierke Disease
|
- glucose-6-phosphatase defect: Von Gierke Disease
- hypoglycemia, affects liver/kidney/intestine, decreased mobilization of glycogen (hepatomegaly), increased glycolysis, decreased gluconeogenesis |
|
|
Type II glycogen storage disease Pompe Disease
|
- Lysosomal alpha 1-4 glucosidase defect: Pompe Disease
-normal glycogen structure, can't mobilize polysaccharides |
|
|
Type III glycogen storage disease Cori's Disease
|
- Debranching enzyme defect: Cori's Disease
- hepatomegaly, glycogen increased but deposits have shorter outer branches (abnormal structure) |
|
|
Type IV glycogen storage disease Andersen's Disease
|
- Branching enzyme defect (Andersen's Disease)
- normal amount of glycogen but with longer outer branches (abnormal structure) |
|
|
Type V glycogen storage disease McArdle Disease
|
- Skeletal Muscle glycogen phosphorylase defect: McArdle Disease
- sketelal muscle affected, but liver normal, fatigue fast on exercise, no rise in lactic acid after strenuous exercise, increased level of glycogen |
|
|
Type VI glycogen storage disease Hers Disease
|
- Liver glycogen phsophorylase defect: Hers Disease
- liver affected, skeletal muscle normal, following glucagon there is no rise in blood glucose, hepatomegaly |
|
|
Type VII glycogen storage disease Tauri's Disease
|
- Phosphofructokinase defect: Tauri's Disease
- glycogen normal structure but increased in amount, fructose helps |
|
|
• The _______ mito membrane is about 50% protein and permeable to small molecules through ______ channels. The ______ membrane is about 80% protein and contains the _______ complexes & _____ synthase, _____ transporters. Is it permeable?
|
o Outer
o Porin o Inner o Ox phos (I-IV complexes), ATP synthase, ANT transporters o No |
|
|
• Does Mito DNA have any introns? What does it look like? How many compartments of the mitochondria are there?
|
o No
o Bacteria – it is circular o Four compartments |
|
|
• ______ on the outer mitochondrial membrane recognizes internal sequences. ________ on the outer mitochondrial membrane recognizes N-terminal sequences for target to _____ channels on the inner membrane.
|
o TOM 70
o TOM 20 o TIM (translocases of the inner membrane) |
|
|
• Mitochondrial protein import is a ______ dependent process
|
Energy
|
|
|
• Complex I: _________, oxidizes _____ and generates _____ ATP
|
o NADH dehydrogenase
o NADH o 3 ATP |
|
|
• Complex II: ___________, oxidizes ______ and generates _____ ATP
|
o Succinate, acetyl CoA, glycerol phosphate dehydrogenase (3 different enzymes)
o FADH2 o 2 ATP |
|
|
what are the 3 steps in ox phos?
|
1) electron transfer from NADH (succinate, etc) to O2 --> respiratory chain (Complexes I-IV)
2) generation of electrochemical proton transmembrane potential - respiratory chain (Complexes I, III, IV, NOT II) 3) use proton motive force to synthesize ATP - ATP synthase (Complex V) |
|
|
In the mitochondrial OXPHOS system electrons flow to complexes of a ____ reduction potential to an oxidized molecule of_______ reduction potential.___ is a final acceptor of electrons.
|
- lower
- higher - O2 |
|
|
What are the 5 prosthetic groups of Ox Phos?
|
1) NADH - 2e
2) Flavin group (FAD, FMN) - 2e 3) CoQ (ubiquinone) - 2e 4) Heme (cyt b, c1, c, a, a3) - each carry 1e 5) Fe-S clusters |
|
|
What are the names of the different complexes?
|
- Complex I: NADH: CoQ Reductase
- Complex II: Succinate: CoQ reductase - Complex III: cyt c reductase - Complex IV: cytochrome oxidase |
|
|
What prosthetic groups do each of the complexes contain? Who is the only one without an Fe-S cluster? Who shuttles between complex I/II & III? III & IV?
|
- Complex I: FMN, Fe-S
- Complex II: FAD, Fe-S - Complex III: cyt b, cyt c1, Fe-S - Complex IV: cyt a, cyt a3, Cu - b/w I/II & III = CoQ - b/w III & IV = cyt c |
|
|
For the heme prosthetic groups, what oxidation state are they in? How many electrons can they hold? How is cyt a3 an exception?
|
- in Fe3+
- can hold 1e - cyt 3a has 1 axial ligand - can bind oxygen & transfer e-s directly to oxygen |
|
|
What do rotenone, amytal, piericidin A inhibit? Antimycin? CO, cyanide, azide?
|
- Complex I
- Complex III - Complex IV |
|
|
NADH generates ____ hydrogens. FADH2 generates ___ hydrogens.
|
- 10 H
- 6 H - b/c NADH feeds in w/ 4 H+ pumped at complex I whereas complex II doesn't pump (III does 4, IV does 2) |
|
|
____ subunit of ATP synthase has 5 subunits (alpha, beta, gamma, delta, epsilon), whereas the _____ subunit forms the transmembrane channel. Which portion has the catalytic subunits? where are they? How many ATPs can subunit generate?
|
- F1
- F0 - F1 has catalytic subunits at interface b/w alpha & beta - 3 ATPs per F1 subunit |
|
|
oligomycin
|
- inhibitor of ATP synthase
|
|
|
What prosthetic groups do each of the complexes contain? Who is the only one without an Fe-S cluster? Who shuttles between complex I/II & III? III & IV?
|
- Complex I: FMN, Fe-S
- Complex II: FAD, Fe-S - Complex III: cyt b, cyt c1, Fe-S - Complex IV: cyt a, cyt a3, Cu - b/w I/II & III = CoQ - b/w III & IV = cyt c |
|
|
In the glycerol phosphate shunt: _______ --> glycerol-3-phosphate, generating _____. glycerol-3-phosphate transfers it's electrons to ______ in the _____. ____ transfers the electrons to ____. Thus, no compounds move through the IMM. Is it reversible? Where does it enter?
|
- DHAP
- NADH --> NAD+ - FAD --> FADH2 - IMM - FADH2 --> CoQ --> CoQH2 - enters at Complex II |
|
|
For the heme prosthetic groups, what oxidation state are they in? How many electrons can they hold? How is cyt a3 an exception?
|
- in Fe3+
- can hold 1e - cyt 3a has 1 axial ligand - can bind oxygen & transfer e-s directly to oxygen |
|
|
In the malate-aspartate shuttle: oxaloacetate --> malate generating ______. Goes in through transporter then it is oxidized back to oxaloacetate generating ____ in the matrix. Is it reversible? What complex is it used for?
|
- NADH --> NAD+
- NAD+ --> NADH - yes reversible - used for complex I |
|
|
What do rotenone, amytal, piericidin A inhibit? Antimycin? CO, cyanide, azide?
|
- Complex I
- Complex III - Complex IV |
|
|
The rate limiting factors in ATP synthesis are ______ (rate of ATP synthesis) & _____ (rate of respiratory chain)
|
- ADP
- NADH/FADH2 |
|
|
NADH generates ____ hydrogens. FADH2 generates ___ hydrogens.
|
- 10 H
- 6 H - b/c NADH feeds in w/ 4 H+ pumped at complex I whereas complex II doesn't pump (III does 4, IV does 2) |
|
|
As a result of_______ respiration occurs at a maximal rate (no longer constrained by___ concentration) but no____ is synthesized
|
- uncoupling
- ADP - ATP |
|
|
____ subunit of ATP synthase has 5 subunits (alpha, beta, gamma, delta, epsilon), whereas the _____ subunit forms the transmembrane channel. Which portion has the catalytic subunits? where are they? How many ATPs can subunit generate?
|
- F1
- F0 - F1 has catalytic subunits at interface b/w alpha & beta - 3 ATPs per F1 subunit |
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oligomycin
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- inhibitor of ATP synthase
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In the glycerol phosphate shunt: _______ --> glycerol-3-phosphate, generating _____. glycerol-3-phosphate transfers it's electrons to ______ in the _____. ____ transfers the electrons to ____. Thus, no compounds move through the IMM. Is it reversible? Where does it enter?
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- DHAP
- NADH --> NAD+ - FAD --> FADH2 - IMM - FADH2 --> CoQ --> CoQH2 - enters at Complex II |
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In the malate-aspartate shuttle: oxaloacetate --> malate generating ______. Goes in through transporter then it is oxidized back to oxaloacetate generating ____ in the matrix. Is it reversible? What complex is it used for?
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- NADH --> NAD+
- NAD+ --> NADH - yes reversible - used for complex I |
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The rate limiting factors in ATP synthesis are ______ (rate of ATP synthesis) & _____ (rate of respiratory chain)
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- ADP
- NADH/FADH2 |
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As a result of_______ respiration occurs at a maximal rate (no longer constrained by___ concentration) but no____ is synthesized
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- uncoupling
- ADP - ATP |
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In_____ mitochondria inhibition of ATP synthesis, e.g.______, will not change the rate of respiration. Where does the energy go? What are some examples of uncouplers?
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- uncoupled
- oligomycin - energy goes to heat - FCCP, dinitrophenol, thermogenin, UCP1 (brown fat) |
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atractyloside & bongkrekic acid
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- inhibit ANT (adenonucleotide transporters)?
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how does ATP get out & ADP/Pi get into matrix?
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- ANT transporters/translocases
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what happens in mitochondria loss of impermeability of IMM? How can CsA help? When is this relevant?
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- Cyp D opens the ANT/PT pore in response to calcium
- CsA can stop CypD from opening pore even in response to calcium |
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What is the pathway of loss of IMM impermeability in stroke?
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- decreased O2 --> glutamate --> Glut-R --> Calcium --> MPT --> Cell death
- osmotic gradient makes water rush in & mito swell, inner membrane expands & rips apart outer membrane |
