Term
| What are the other three names for the TCA cycle? |
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Definition
| Kreb’s Cycle, Citric Acid Cycle, Tricaboxylic Acid Cycle |
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Term
| List 8 intermediates in order and how many carbons each one has |
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Definition
| Citrate (6C), Isocitrate (6C), a-Ketoglutarate (5C), Succinyl CoA (4C), Succinate (4C), Fumarate (4C), Malate (4C), Oxalloacetate (4C) In essence start with 6 C |
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Term
| What's the other name for CoA? |
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Definition
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Term
| What two TCA conversions give off CO2? |
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Definition
| Isocitrate to a-Ketoglutarate a-Ketoglutarate to Succinyl CoA |
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Term
| TCA cycle net rxn (12, 6 & 6) |
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Definition
| Acetyl CoA + 3NAD+ + FAD + GDP + Pi + 2H2O → 2CO2 + CoASH + 3NADH + 3H+ + FAD(2H) + GTP |
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Term
| Practice Drawing Pyruvate and Lactate |
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Definition
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Term
| How does CO2 leave the body? |
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Definition
| Binds to hemoglobin in the blood (15% travels through blood) and exits through the lung capillaries due to a higher concentration of CO2 in the blood than the atmosphere. |
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Term
| Practice Drawing Figure 20.1 on page 362 (a rough sketch of the TCA cycle) |
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Definition
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Term
| Practice drawing an acetyl group |
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Definition
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Term
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Definition
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Term
| What is the function of CoA? |
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Definition
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Term
| What are the 5 cofactors that apply to a-keto acid dehydrogenation and what is the role of each one? Also, what two molecules does this apply to? |
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Definition
| Applies to a-ketoglutarate and pyruvate B1- helps with the decarboxylation 2 Lipoic acid- helps with the attachment to CoA and helps with the oxidation B5- coA needed for the attachment to CoA B2- FAD- helps with the oxidation B3- NAD+ final acceptor of the electrons |
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Term
| Name the B vitamin that must be obtained from the diet for the body’s synthesis of CoASH |
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Definition
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Term
| Name the 8 enzymes of the TCA cycle in order |
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Definition
| Citrate Synthase, Aconitase, Isocitrate dehydrogenase, a-ketoglutarate dehydrogenase, succinate thiokinase, succinate dehydrogenase, fumarase, malate dehydrogenase |
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Term
| What is the only dehydrogenase that makes FAD(2H) instead of NADH? |
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Definition
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Term
| Practice drawing succinate to fumarate drawing from fig 20.3 p. 364 |
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Definition
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Term
| FAD (stands for) Practice Drawing FAD schematic and remember which part the 2H's attach |
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Definition
| Flavin Adenine Dinucleotide attach to 2 different Nitrogens on Flavin |
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Term
| NAD (stands for) Practice Drawing NAD schematic and remember which part the H attaches |
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Definition
| Nicotinamide Adenine Dinucleotide 3 parts Top Nicotinamide Part Ribose with phosphate in between AMP on bottom |
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Term
| Vitamin from which your body can make nicotinamide adenine dinucleotide |
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Definition
| Nicotinic Acid or NIACIN is the vitamin that can make Nicotinamide |
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Term
| Name the essential amino acid from which your body can make nicotinamide adenine dinucleotide |
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Definition
| Tryptophan can be made into Niacin which is then made into NAD |
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Term
| From malate to oxaloacetate which H leaves as a hydride and which one as a proton? |
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Definition
| OH H+ leaves malate as a proton, the lone H is a hydride ion (two electrons) H:- that attaches to NAD to make NADH |
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Term
| Draw a-Ketoglutarate and explain why it is an a-keto acid |
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Definition
| COO- CH2 CH2 C=O COO- a-keto acid because it has a ketone on the alpha position and 2 carboxylic acid groups |
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Term
| What three things happen to a-keto glutarate by a-keto dehydrogenase and pyruvate by PDC? What happens to its hydrogen? |
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Definition
| Gets oxidized, decarboxylated, and gets attached to coA Doesn't lose an H+ |
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Term
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Definition
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Term
| What cofactor assists in a reaction catalyzed by an alpha-keto acid dehydrogenase? |
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Definition
| TPP (Thiamine Pyrophosphate) |
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Term
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Definition
| Not a protein but assists a reaction nonetheless (since the word is used so broadly) |
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Term
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Definition
| Pyruvate Dehydrogenase Complex Pyruvate Dehydrogenase (PDH) |
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Term
| Describe differences in the permeabilities of the two membranes towards most small molecules |
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Definition
| Inner membrane is highly impermeable (requires protein carrier); outer membrane permeable |
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Term
| Give the intracellular locations of each of the following: the enzymes for glycolysis; pyruvate dehydrogenase; the enzymes for β-oxidation; the enzymes for oxidative phosphorylation |
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Definition
Glycolysis occurs in cytosol
B-oxidation enzymes found entirely in mitochondrial matrix
PDH/PDC found in mitochondrial matrix
Enzymes for oxidative phosphorylation arelocated in inner mitochondrial membrane |
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Term
| Why is succinate dehydrogenase different from all other TCA enzymes? |
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Definition
| It is embedded in the inner mitochondrial membrane |
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Term
| PDK (stands for and function) |
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Definition
Pyruvate Dehydrogenase Kinase
Deactivates PDC via phosphorylation |
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Term
| How would an increase in ADP affect PDK? |
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Definition
Slow it down
Since PDK deactivates PDC which is positive for TCA cycle ADP will stop PDK
Speed up TCA cycle |
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Term
| The effect of an increase in the concentration of pyruvate on the activity of PDC kinase? |
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Definition
Slow it down
PDC activity is needed at this point so PDK deactivating it wouldn't make sense |
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Term
| What is the effect of an increase in the concentration of calcium ion on the activity of PDC phosphatase? |
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Definition
| Activates/Increases PDC phosphatase activity |
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Term
| What is the conversion for alcohol to energy? |
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Definition
| Ethanol → acetaldehyde → acetate → acetyl coA |
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Term
| Describe and give examples of the use of TCA cycle intermediates as precursors for biosynthetic pathways (5) |
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Definition
Citrate -> Fatty Acid synthesis
a-Ketoglutarate -> AA synthesis (to NT's)
Succinyl CoA -> Heme synthesis
Malate -> Gluconeogenesis
Oxaloacetate -> AA synthesis |
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Term
| What is the function of pyruvate carboxylase? |
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Definition
| Adds a HCO3/CO2 (indistinguishable in blood) to pyruvate using ATP and cofactor biotin to form oxaloacetate |
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Term
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Definition
| Puts intermediates back into the TCA cycle without using intermediates to make them |
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Term
| Draw the chemical structure of oxaloacetate |
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Definition
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Term
| Generalize about carboxylases and carboxylation reactions |
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Definition
Caboxylases add CO2 to a molecule
Carboxylation is the addition of CO2
Decarboxylation is the removal of CO2 |
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Term
| Name the four intermediates of the TCA cycle that can be made from carbons of amino acids |
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Definition
| Succinyl CoA, Oxaloacetate (can be made from 2 dif AA pathways), Fumarate, a-ketoglutarate |
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Term
| How are the 10 H+ per pair of electrons added to the mitochondrial gradient distributed among the ETC complexes? |
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Definition
Complex 1 pumps 4H+
Complex 3 pumps 2H+
Complex 4 pumps 4H+ |
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Term
| How is acetyl CoA not anaplerotic? |
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Definition
| Acetyl CoA converts oxaloacetate to Citrate, it doesn’t create citrate |
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Term
Two sources of propionyl CoA
Propionyl CoA to Succinyl CoA requires... |
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Definition
Valine Isoleucine (made from AA's)
Odd-chain FA's
Propionyl CoA + CO2 --Carboxylase--> Succinyl CoA |
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Term
| What happens to even chained FA's as opposed to odd chained FA's? |
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Definition
Even chained FA's are broken down in B-oxidation to acetyl groups and bonded to acetyl CoA
Odd chained are too, but a propionyl group is made which is bonded to CoA which then gets carboxylated to succinyl CoA |
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Term
| Methylmalonyl CoA mutase (MCM) catalyzes... |
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Definition
| Isomerization of methylmalonyl-CoA to succinyl-CoA |
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Term
| Oxidative Phosphorylation (definition) |
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Definition
| oxidation of FADH2 and NADH, and ADP gets phosphorylated to ATP |
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Term
| What is the connection between the TCA cycle and Oxidative phosphorylation (OP)? |
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Definition
| TCA cycle gives electrons to FADH2 and NADH which are then oxidized in OP to make ADP -> ATP |
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Term
| What two roles does the ETC have? |
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Definition
| Create a H+ gradient, and give electrons to O2 to convert it to H2O |
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Term
| What requirements are there for oxidative phosphorylation (2)? |
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Definition
| Electrochemical Gradient (primarily due to H+) across intact inner mitochondrial membrane generated by ETC, presence of oxygen O2 |
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Term
| Give the alternative name for the ETC, and describe its location in a cell |
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Definition
Embedded in inner mitochondrial membrane
Alternate name: Respiratory Chain |
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Term
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Definition
TCA makes NADH's at three different locations (malate dehydrogenase, isocitrate dehydrogenase, a-ketoglutarate dehydrogenase)
B-oxidation makes many NADH's
Glycolysis produces one NADH
Pyruvate attaching to Acetyl CoA makes one NADH (which can often be used by lactate to be made back into pyruvate) |
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Term
Where does NADH donate its electron pair?
Where does FAD2H donate its e- pairs? |
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Definition
NADH To complex one (which then pumps 10 H+ per e- pair)
FAD2H To Complex 2/Succinate Dehydrogenase (which then pumps 6 H+ per e- pair) |
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Term
| What is the redox reaction that each complex performs? |
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Definition
Complex 1- e- pair go via CoQH2 to complex 3
Complex 2- e- pairs from FAD2H gives them to complex 3 via CoQH2
Complex 3- e- pairs from coQH2 which then gives individual electrons to
complex 4 via cytochrome c via heme in cytochrome | which then changes Cu+ to Cu+2 as it donates e- to O2 |
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Term
| What is the number of ATP's made from each cycle/glucose? |
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Definition
| Adjusted from 36-38 to 30-32 |
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Term
| What is the name for the reduced and oxidized forms of CoQ? |
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Definition
Ubiquinone(oxidized form) → Ubiquinol (reduced form)
Which can be summarized as a reduction from a ketone to an alcohol |
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Term
| Give four different sources of electrons that reduce CoQ |
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Definition
Complex 1
Glycerol 3-phosphate dehydrogenase via FAD
Succinate via FAD
EFT:Q oxidoreductase via FAD |
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Term
| FMN (stands for and function) |
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Definition
| Flavin Mononucleotide; electron carrier in complex one gives to Fe-S then to CoQH2 then to Complex 3; synthesized by riboflavin |
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Term
| What is the name of the ring around iron in a heme? |
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Definition
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Term
| Explain the process of exercise on H+ gradient maintenance (6) |
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Definition
| ATP synthase first thing to notice not enough ATP, followed by the notice of the ETC of the decrease in H+ gradient which increases the need of O2 reduction and conversion to H2O, which then changes level of NADH which then increases the speed of the -TCA cycle, in particular the dehydrogenase actions, PDC (pyruvate dehydrogenate complex) rxn, and B-oxidation- all 3 at roughly the same time. (assuming there’s enough O2) |
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Term
| Cytochrome (general definition/features) |
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Definition
| Mostly protein with a non-protein helper; has heme which carries Fe which undergoes a +3 to +2 change for carrying electrons |
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Term
| Where is Cu and what ions does it change from and to? |
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Definition
| In complex 4 Cu+ is changed to Cu+2 as it donates e- to O2 |
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Term
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Definition
| Proteins that contain a nucleic acid derivative of riboflavin |
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Term
| SdhA (stands for and part of) |
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Definition
| Succinate Dehydrogenase subunit A (derived from riboflavin making Complex 2 a flavoprotein) |
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Term
| What is the H+ to ATP ratio? (each ATP requires how many protons to be made?) |
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Definition
| 4 H+ must go through ATP synthase for every one ATP produced |
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Term
| Explain how (the mechanism by which) oxidative phosphorylation, the TCA cycle, the pyruvate dehydrogenase reaction, and beta oxidation all slow down if a cell doesn't get enough O2 (4) |
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Definition
| O2 can’t take electrons anymore so ETC won’t work/pump protons and maintain gradient, ATP synthase works as long as it can but stops, NADH level increases in matrix which then inhibits TCA cycle, PDC rxn, and B-oxidation |
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Term
| What is the function of lactate dehydrogenase? |
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Definition
Glucose → Pyruvate ←→ Lactate
Oxidize Lactate; uses NAD+ to make NADH (during oxygen reuptake/recovery) |
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Term
| Why is lactate made by cells when there's a lack of O2? |
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Definition
| For lactic acid fermentation |
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Term
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Definition
| When protons leak back into the mitochondrial matrix without going through ATP synthase |
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Term
| Describe the effects of uncoupling on O2 usage and heat production |
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Definition
| Uncoupling increases O2 consumption, and heat production |
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Term
| UCP1 (stands for, alternate name, and function) |
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Definition
| Uncoupling Protein 1 (thermogenin), works in brown adipose tissue to degrade proton gradient so ATP synthase produces more heat known as nonshivering thermogenesis |
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Term
Which enzymes catalyze redox steps in the TCA cycle?
List reactants and products for each rxn. |
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Definition
- Isocitrite dehydrogenase (isocitrite + NAD+ -> alpha-ketoglutarate + NADH)
- Alpha-ketoglutarate dehydrogenase (alpha-ketoglutarate + NAD+ -> succinyl CoA + NADH)
- Succinate dehydrogenase ( succinate + FAD -> fumarate, FAD(2H) )
- Malate dehydrogenase (malate + NAD+ -> oxaloacetate + NADH)
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Term
| List cofactors required for the alpha-ketoglutarate dehydrogenase rxn and their function. (5) |
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Definition
i. Thiamine pyrophosphate (B1): decarboxylation
ii. Lipoic acid: attachment of CoA and oxidation
iii. Coenzyme A (aka CoA, CoASH) (B5): needed for attachment of CoA
iv. FAD (B2): helps with oxidation
v. NAD+ (B3): final acceptor of electrons |
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Term
Generalize about the reactions catalyzed by alpha-keto acid dehydrogenases. |
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Definition
oxidize an alpha-ketoacid which is an acid whose alpha-carbon is a ketone.
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Term
Chemical structure of alpha-ketoglutarate |
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Definition
| Acids on both ends with a ketone and two CH2's in the middle |
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