Term
| How is a human metabolism similar to a fire? |
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Definition
They both have the same general equation:
Carbon source + O2 -> CO2 + H2O + energy |
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Term
| How much ATP is made in the body in one day in terms of weight? |
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Definition
| About the same amount as body weight |
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Term
| Why is ATP unstable and therefore a source of energy? |
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Definition
| The phosphate groups repel each other |
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Term
| Where does glycolysis take place? |
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Definition
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Term
| Where does the Krebs cycle take place? |
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Definition
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Term
| Where does the Electron Transport chain take place? |
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Definition
| On the innermembrane of the mitochondria |
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Term
| Describe the gradient formed during the ETC. Where is it? |
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Definition
| High proton concentration inside mitochondrial innermembrane space, lower concentration in the matrix |
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Term
| How is the proton gradient for the ETC basically formed? |
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Definition
| Electrons are carried through protein complexes that end up reducing O2 to H2O. This energy is used to pump protons into the innermembrane space. |
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Term
| Under what sort of conditions does mitochondrial O2 consumption increase? |
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Definition
Any condition that would compromise the proton gradient
Ex. Uncouplers, ATP synthase issues, membrane destruction |
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Term
| What does the Krebs cycle start with? |
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Definition
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Term
| What is the only molecule that gets "used up" in the Krebs cycle? |
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Definition
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Term
| From what is Acetyl CoA derived? |
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Definition
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Term
| How many reactions in the Krebs cycle reduce coenzymes? |
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Definition
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Term
| Describe brown adipose tissue and why it uses a lot of O2 |
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Definition
Brown adipose tissue is used for thermoregulation (babies have a lot of it)
Mitochondria is designed for heat generation, not ATP synthesis. Uncouplers are present that lead to increased O2 consumption without making ATP. |
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Term
| Why, basically, do uncouplers increase the rate of O2 consumption? |
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Definition
| Uncoupling proteins are designed to bring H+ back into the innermembrane space without making ATP. Therefore, O2 is consumed, but no ATP is produced. |
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Term
| Is O2 consumption based on ATP production? |
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Definition
Not necessarily.
O2 consumption is directly based on electron and H+ transport rate, not ATP production. |
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Term
| What is the mobile carrier of carbons between glycolysis in the cytosol and Krebs in the mitochondria? |
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Definition
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Term
| Where is pyruvate converted to Acetyl-CoA? |
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Definition
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Term
| What is the enzyme that converts pyruvate to Acetyl-CoA? |
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Definition
| Pyruvate dehydrogenase, a huge enzyme |
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Term
| What are some inhibitors of pyruvate dehydrogenase? |
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Definition
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Term
| What are the products of the pyruvate DH reaction? |
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Definition
| Acetyl CoA, CO2, and 1 NADH |
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Term
| What are the net products of the Krebs cycle? |
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Definition
| 2CO2, GTP, 3NADH, 1 FADH2 |
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Term
| What are some vitamins that are needed for the Krebs cycle? |
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Definition
| Thiamine (vitamin B1) in TPP, Riboflavin in FAD, Niacin in NAD, Pantothenate in CoASH, Lipoic acid |
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Term
| What enzymes in the Krebs cycle have a large -ΔG? |
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Definition
Citrate synthase
Isocitrate dehydrogenase
α-ketoglutarase dehydrognease |
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Term
| What is notable about citrate synthase? |
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Definition
| Large -ΔG, forms C-C bond |
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Term
| What is notable about isocitrate dehydrogenase? |
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Definition
Large -ΔG, 2 isoforms
One isoform makes NADH, one isoform makes NADPH |
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Term
| Generally speaking, what is the difference between the use of NADH vs NADPH? |
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Definition
NADH is used for the ETC
NADPH is used for anabolic and antioxidative reactions |
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Term
| What is notable about α-ketoglutarase dehydrognease? |
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Definition
| Large -ΔG, mechanically similar to pyruvate dehydrogenase |
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Term
| What is notable about succinyl-CoA synthase? |
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Definition
| It catalyzes the reaction in the Krebs cycle that makes an ATP |
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Term
| What is notable about Succinate dehydrogenase? |
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Definition
|
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Term
| What is notable about Malate dehydrogenase? |
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Definition
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Term
| How does NADH get from the cytosol to the mitochondria |
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Definition
Through shuttles:
Glycerol-3-phosphate shuttle and malate-aspartate shuttle |
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Term
| For any general metabolic reaction, where could you find regulation points? |
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Definition
| Entry points, exergonic steps, branch points, and substrate supply |
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Term
| Why does Calcium activate the Krebs cycle? |
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Definition
Because ATP is needed for Ca-ATPase in muscles
95% of ATP produced is used for that purpose |
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Term
| What is notable about aconitase? |
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Definition
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Term
| What directly activates pyruvate dehydrogenase? |
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Definition
| The phosphorylated pyruvate dehydrogenase complex |
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Term
| What are some inhibitors of pyruvate dehydrogenase? |
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Definition
ATP, NADH, Acetyl CoA, Fatty acids
(just think about what logically would inhibit) |
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Term
| What are some activators of pyruvate dehydrogenase? |
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Definition
ADP/AMP, Calcium, Pyruvate, CoA, NAD+
(just think about what logically would activate) |
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Term
| Describe "substrate channeling" |
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Definition
| Krebs cycle enzymes are physically linked so the substrates move through quickly and with more regulation |
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Term
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Definition
Replenishment of Krebs cycle intermediates
Ex. Pyruvate carboxylase converts pyruvate to oxaloacetate |
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Term
| Describe thiamine pyrophosphate |
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Definition
| A coenzyme in pyruvate dehydrogenase that cleaves C-C bonds |
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Term
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Definition
| A coenzyme in pyruvate carboxylase that forms C-C bonds |
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Term
| What does a (+) E(v) indicate? |
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Definition
| The element wants to accept electrons |
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Term
| What kind of E(v) value does O2 have? What sort of E(v) value does NAD+ have? |
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Definition
| O2 has a very (+) E(v) value, NAD+ has a (-) value |
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Term
| What forms FMNH2 in the electron transport chain? |
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Definition
| The electrons given off from NADH |
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Term
| What forms FADH2 for the electron transport chain? |
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Definition
| Succinate dehydrogenase (converting succinate to fumarate) |
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Term
| From where does Coenzyme Q get electrons? |
|
Definition
FMNH2,
FADH2,
Glyceraldehyde-3-phosphate
β-oxiation flavoprotein |
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Term
| Describe the path of electrons in the electron transport chain from Coenzyme Q to the final electron acceptor |
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Definition
| Coenzyme Q -> Complex III -> Cytochrome C -> Complex IV -> O2 -> H20 |
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Term
| Are the complexes in the electron transport chain as simple as they appear in the diagrams? |
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Definition
No, the complex are complex. :)
There are many subunits and actually over 40 redox reactions in the ETC |
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Term
| Give four examples of an electron transport chain inhibitor |
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Definition
| Roterone, antimycin A, CN-, CO |
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Term
| What is the result of an electron transport chain inhibitor? |
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Definition
All molecules become reduced upstream, all molecules become oxidized downstream.
No proton gradient, no ATP= death |
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Term
| Describe mitochondria DNA |
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Definition
It has its own genome, but very limited.
Can only make 13 proteins
Susceptible to genetic diseases |
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Term
| How many electrons can Ubiquinone/Coenzyme Q carry? |
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Definition
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Term
| List three electron carriers in the electron transport chain |
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Definition
- Ubiquinone/Coenzyme Q
- Cytochromes
- Iron-sulfur proteins
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Term
| Describe the structure of ATP synthase |
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Definition
F1 unit makes ATP with α, β,and γ subunits
F0 unit is the proton transporter submerged in the lipid bilayer which rotates |
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Term
| Describe what the α, β,and γ subunits in ATP synthase do |
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Definition
α and β change configuration, each with a catalytic site
γ stalk touches the active sites and makes the Enzyme-ATP complex less stable so ATP can be removed |
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Term
| What is the H+ proton gradient energy ultimately used for? |
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Definition
| Removal of ATP from ATP synthase |
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Term
| What are four regulators Dr. Szwedna listed for Oxidative Phosphorylation? |
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Definition
Thermodynamic
Energy charge
Protein inhibitor IF1
Uncoupling Proteins |
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Term
| List some functions of mitochondria |
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Definition
Choose from:
ATP synthesis, gluconeogenesis, thermogenesis, Amino acid production/consumption, Ureagenesis, prophryrin biosynthesis, apoptosis, Ca++ hoarding, free radical production |
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