Term
| Where do reducing equivalents from NADH enter the electron transport chain? |
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Definition
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Term
| What is oxidized to make energy? |
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Definition
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Term
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Definition
LEO
Transfer of high energy electrons to a compound where electrons have lower energy |
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Term
| What ultimately happens to high energy electrons? |
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Definition
| They are transferred to O2 to make water |
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Term
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Definition
| Tendency for a species to gain electrons |
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Term
| Electron movement reductant/oxidant? |
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Definition
From reductant to oxidant.
Reductants are oxidized.
Oxidants are reduced. |
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Term
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Definition
| Reducing equivalents are transferred from one compound to another. |
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Term
| What does the oxidation half of the reaction do with reducing equivalents? |
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Definition
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Term
| What does the reduction half of a redox reaction do with reducing equivalents? |
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Definition
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Term
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Definition
| Difference in reduction potential between the oxidant and reductant |
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Term
| Relationship of Delta E and Delta G? |
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Definition
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Term
| Nutrients and Oxygen E values? |
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Definition
Nutrients=Negative Ered
Oxygen=Positive Eox |
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Term
| Where do the oxidation reaction take place? What catalyzes them? |
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Definition
Mitochondria
Catalyzed by TCA cycle. |
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Term
| What does the out membrane of the mitochondria do? |
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Definition
| Allow small molecules and some proteins to freely pass |
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Term
| What does inner membrane of mitochondria do? |
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Definition
| Very impervious to all charged molecules |
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Term
| Where are the elctron transfer chain complexes located? |
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Definition
| Inner membrane of mitochondria |
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Term
| Mitochondrial matrix is located where? What is inside it? |
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Definition
Within the inner membrane
Location of pyruvate dehydrogenase, TCA cycle enzymes and fatty acid oxidation enzymes |
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Term
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Definition
NADH->NAD+H++2e-
1/2O2+2H++2e-->H20
Sum:
O2+NADH->NAD+H++H20 |
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Term
Which is more oxidized, carbs or fats?
How does this effect the energy released? |
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Definition
| Fats. Less energy released from carbs |
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Term
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Definition
| Make reducing equivalents from NADH, UQH2, or FADH2. Pass these through reactions, donate reducing equivalents to O2 |
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Term
What is reduced in the ETC?
What makes this happen? |
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Definition
HADH
UQH2
FADH2
Happens when nutrients are oxidized by TCA cycle fatty acid oxidation, PDH |
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Term
| What releases energy in relation to NADH, UQH2, and FADH? |
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Definition
| These are storage for the reducing equivalents, and they release energy when they are oxidized |
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Term
| What is the energy released from steps in the ETC used for? |
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Definition
| Pump protons from inner mitochondrial space to cytosol |
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Term
Proton motive force?
What does it represent |
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Definition
Charge separation, more positive on the outside. B/c protons are pumped out.
Represents stored energy |
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Term
| ATPase location? What does it do? |
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Definition
Inner mitochondrial membrane.
Couples ATP synthesis to proton transfer down the gradient (out to in) |
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Term
| Complex 1 of ETC name, reaction, delta G, overall protons? |
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Definition
NADH dehydrogenase
NADH+UQ->NAD+UQH2
DeltaG=-70
Four protons out/NADH |
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Term
| Complex 2 of ETC name, reaction, delta G, overall protons? |
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Definition
Succinate Dehydrogenase (part of TCA cycle)
Succinate+UQ->Fumarate+UQH2
DeltaG=-2
No protons, not exergonic |
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Term
| Complex 3 of ETC name, reaction, delta G, overall protons? |
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Definition
Cytochome Bc1 complex
UQH2+2Cyt C (Fe3+)->UQ+2CytC(Fe2+)
DeltaG=-37
Two protons out/UQH2 |
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Term
| Complex 4 of ETC name, reaction, delta G, overall protons? |
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Definition
Cytochome C Oxidase
4CytC(Fe2+)+O2+4H+->4 CytC(fe3+)+2H2)
DeltaG=-110
4 Protons/H2O produced
Terminal End |
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Term
| What enzymes donate reducing equivalents to UQ Pool to make UQH2 |
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Definition
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Term
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Definition
| Ultimately used by complex 3 to reduce cyt. C |
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Term
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Definition
FAD and FMN (2 e Carriers)
UW
Iron Sulfur Clusters (1e carrier) |
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Term
What molecules do cytochromes/complex 3 contain?
Electron carrying #/motility? |
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Definition
Heme.
One electron carrier. Mobile. |
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Term
Heme cofactors?
Characteristics of each |
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Definition
Heme A,B,C
Difference in substituents
B=hemoglobin/myoglobin
C=covalently attached to cysteine
A=polyisopreme chain attached |
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Term
| How is H2O produced in complex 4? |
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Definition
Four electron reduction of O2.
O2 is the 'terminal acceptor'
Cytochrome C oxidase utilizes 2 hemes and 2 copper sites |
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Term
| Inhibitors of the ETC do what? |
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Definition
Block oxigen reduction by 4.
Blocks proton pumping
NO ATP, death |
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Term
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Definition
Prevent oxidation of NADH and UQH2, other reactions keep going.
Less ATP made. NADH builds up inhibits dehydrogenase reactions.
Pyruvate->Lactate to get NAD+ |
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Term
| How many kJ required to pump one H+ out? |
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Definition
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Term
| How many protons total are pumped out/NADH |
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Definition
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Term
| If complex 1 inhibited, how many total protons? |
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Definition
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Term
| What differences are alose made by the H+ gradient in mitochondria? |
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Definition
Change in pH
Change in voltage |
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Term
| Delta pH/voltage values in respiring mitochondria? |
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Definition
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Term
| How is electron transfer through the chain regulated? |
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Definition
Respiratory control
Normal=20 KJ; if already at 20kJ can't pump
Coupled w/ ATP synthesis; w/o ADP no O2 uptake or electron transfer |
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Term
| Respiratory control during high energy demand? |
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Definition
ATP rapidly synthesized; deplete proton gradient
ETC will respond by oxidizing NADH and reducing O2 at a high rate, in order to re-establish the proton gradient |
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Term
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Definition
Oligomycin
prevent use of the gradient, electron transfer stops, NADH oxidation; O2 reduction stopped |
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Term
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Definition
deplete proton gradient w/o makiing ATP,
NADH still oxidized and O2 reduced at a high rate
Ex.2,4DNP |
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Term
What enzyme uses the ETC to make ATP from ADP+P?
Location? |
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Definition
ATPsynthase
Inner mitochondrial membrane |
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Term
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Definition
F0=membrane bound protein channel
F1=into the matrix and contains 3 alpha and 3 beta subunits |
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Term
| Where is the ADP+P binding site in the ATP ase? |
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Definition
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Term
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Definition
Fo domain rotates as protons move from cytosol inward.
This rotation cases conformational change of F1 domain
At each 1/3 rotation each B unit changes conformation
Beta subunits cycle from tight to open to loose |
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Term
| Tight, Open, Loose conformation of Beta Subunits? |
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Definition
Tight-ATP bound tight
Open-exchanges ATP for ADP
Loose-ADP+P bound loosely |
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Term
| What happens when the gamma subunit is facing in the ATP synthase? |
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Definition
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Term
| How many protons flow back through per ATP molecule made? |
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Definition
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Term
| How many ATP are made per NADH? |
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Definition
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Term
| If complex one of ETC is skipped how many ATP made per NADH? |
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Definition
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Term
| Shuttle systems to get reducing equivalents from cytosol into the mitochondria? |
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Definition
Glycerol Phosphate Shuttle
Malate Shuttle |
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Term
| Glycerol Phosphate Shuttle |
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Definition
| Uses cytosolic NADH to reduce dihyroxy acetone phosphate to G3P Then uses membrane bound enzyme to oxidize G3P back to dihydroxy acetone phosphate and reduce UQ to UQH2 Net reaction is cytosolic NADH is converted to UQH2 so some energy is lost (b/c UQH2 has more positive reduction potential than NADH) |
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Term
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Definition
Uses cytosolic NADH to reduce oxaloacetate to malate.
Malate enters themitochondria where it is oxidized back to oxaloacetate along with NAD being reduced to NADH
Net reaction is cytosolic NADH is converted to NADH inside the mitochondria
No energy is lost, in contrast to the glycerol phosphate shuttle. |
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Term
| Non shivering thermogenisis |
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Definition
Uses uncoupling protein (UCP) to form short circuit in mitochondria.
Brown adipose tissue
Infants |
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Term
| When is insulin released from the pancreas? |
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Definition
| When glucose concentration in the bloodstream is high. |
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Term
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Definition
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Term
| What does insulin activate? |
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Definition
Things that use glucose.
Glycolysis, Glycogen Synthesis, Fatty Acid Synthesis |
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Term
| What does insulin inhibit? |
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Definition
Things that produce glucose
Gluconeogensis, Glycogenolysis |
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Term
| Glucagon. What does it do. Relation to insulin. |
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Definition
Controlling hormone when glucose in blood stream is low.
Opposite effect of insulin |
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Term
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Definition
| Glucogon's has opposite effects than insulin |
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Term
| Insulin effect of glucose uptake by cells. |
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Definition
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Term
| What regulatory enzymes does glucose increase synthesis/activity of? |
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Definition
| Glucokinase and Pyruvate kinase |
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Term
| What helps transport glucose into cells? |
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Definition
|
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Term
| Is glucose transport independent or dependent on insulin? |
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Definition
Both. Most of the time independent
Miscle and adipose dependent. glut 4 |
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Term
| Regulatory steps of glycollysis. |
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Definition
| Glucokinase, PFK-1, Pyruvate kinase |
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Term
| Glucokinase vs. Hexokinase |
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Definition
Glucokinase=liver
Sigmoidal kinetics (Hyperbolic)
Greater activity during fed state (both)
Gluocose used only during fed state (both) |
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Term
Phosfructokinase-1
Inhibit; Activate? |
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Definition
Key regulatory step in glycolysis.
ATP and citrate
Activated by AMP and fructose 2,6 Bisphosphate |
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Term
| What controls concentration of 2,6 BP? |
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Definition
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Term
| What makes Fructose 2,6 BP? Describe. |
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Definition
Phosphofructoinase-2 (PFK-2.)
Bifunctional:Kinase AS &Phosphatase AS but only one functions at a time
Insulin activates Kinase AS (increases synthesis of Fructose 2,6 BP, activeates PFK-1 and glycolysis)
Glucagon activates Phosphataase AS (removes PFK-1 and slows down glycolysis.) |
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Term
Pyruvate Kinase
Activated,inhibited |
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Definition
Induced by insulin
Activated by F 1,6 BP (feet forward)
Inhibited by ATP
Regulated by phosphorylation also |
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Term
| Phosphorylation activity of pyruvate kinase |
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Definition
Phosphorylated form is inactive
Glucagon stimulates kinase that inactvates
Insulin stimulates phosphatase |
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Term
| What is PDH the main control point of? |
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Definition
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Term
| PDH regulation is based on? |
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Definition
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Term
| What is the secondary thing that regulates PDH activity? |
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Definition
Reversible phosphorylation.
NOT controlled by hormones |
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Term
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Definition
Not controlled by hormones
Phosphorylated form is inactive
Kinase stimulated by NADH and Acetyl CoA
Kinase is inhibited by ATP, NAD, CoA, Pyruvate |
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Term
| What regulates TCA cycle? |
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Definition
| Energy state of the cell. |
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Term
What step is allostericaly regulated in the TCA cycle?
Activated/Inhibited |
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Definition
isocitrate dehydrogenase
Activated by ADP
Inhibited by ATP, NADH |
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Term
| What does a high energy state do to dehydrogenase enzymes of the TCA cycle? |
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Definition
| Slow activity of these dehydrogenases by limiting substrate availability and shifiting delta G toward a + value |
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Term
| What is coupled with TCA cycle? |
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Definition
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Term
| What does a high rate of ATP synthesis do to rate of NADH? |
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Definition
| Increases oxidation by ETC, which stimulates TCA cycle to produce more NADH |
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Term
| Anaplerotic reactions of TCA cycle? |
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Definition
Add intermediate compounds to the cycle
Stimulate activity if oxaloacetate limiting. |
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Term
| Most important anaplerotic reaction? |
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Definition
| Pyruvate carboxylase, makes oxaloacetate from pyruvate and CO2 |
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