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81 Cards in this Set
- Front
- Back
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describe the inner mitochondrial membrane
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large surface area, high protein content
contains respiratory electron carriers, ATP synthase |
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describe teh outer mitochondrial membrane
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prosin, DNA form mother, symbiosis of bacteria and eukaryote
freely permeable to small molecules and ions |
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what happens in the mitochondrial matrix?
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pyruvate dehydrogenase complex
citric acid cycle enzymes fatty acid beta oxidation enzymes amino acid oxidation enzymes DNA, ribosomes ATP, Ca |
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which complex does NOT pump protons across the membrane?
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complex II
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what is ubiquinone?
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a chemical, NOT a protein.
fat-soluble, rests in inner membrane. |
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how many electrons can ubiquinone accomodate?
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1 or 2
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where does ubiquinone transfer electrons?
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from complex 1 or 2 to 3
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what are cytochromes?
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proteins with heme prosthetic groups
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how many electrons can cytochromes accept at a time?
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1
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what property allows cytochromes to be studied?
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absorb visible light
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what form is iron found in cytochromes?
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"non-heme" iron, not in prophyrin ring
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what kind of biding make the prosthetic groups of proteins?
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cysteine binding
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how many elecrons can iron transfer?
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1
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where are these iron proteins found?
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inner membrane
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how many complexes are associated with the inner membrane?
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4
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which complex has copper?
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IV
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what is another name for complex IV?
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cytochrome oxidase
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What is another name for complex I?
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NADH dehydrogenase
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how many electrons can complex I process at a time?
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2
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what does complex I do?
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converts NADH to QH2 (ubiquinone)
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Where does the NADH that enters complex I come from?
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TCA cycle, amino acid oxidation, and fatty acid oxidation
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what does complex II collect?
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lower energy electrons
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where does NADH come from that enters complex II?
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glycolysis, TCA cycle
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where does FADH2 that enters complex II come from?
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fatty acid oxidation
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what is different about complex II than the other complexes?
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does not transfer protons to intermembrane space
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what is complex III also known as?
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cytochrome b-c1
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how many subunits/dimers are in complex III?
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11
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what does complex III do?
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transfers electrons from ubiquinone to cytochrome c
and pumps protons to intermembrane space |
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where is complex III located?
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along the outer part of IMS
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why is complex III known as the "step-down transformer"?
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it accomodates the switch between the two-electron carrier ubiquinone and the one-electron carriers, cytochromes. 4 protons are translocated per pair of electrns passing through complex III to cytochrome c
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what happens when an electron is transferred through complex III?
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QH2 is oxidized to Q, and two molecules of cytochrome c are reduced
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what is another name for complex IV?
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cytochrome oxidase
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how many subunits does complex IV have?
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13
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what does complex IV do?
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takes electrons from cytochrome c to oxygen to yield water
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how many protons does complex IV pump into the inter-membrane space?
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4
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what is the source of the majority of cellular oxidative stress? (ROS formation)
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complex IV
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why is ROS formed in complex IV?
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oxygen is held between Fe/Cu centers--O2 must wait for 4 electrons to form water
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which subunit is smaller than the others?
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cytochrome c
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which complex has copper associated with it?
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complex IV
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what do all prosthetic groups have?
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iron
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what are the subunits of ATP synthase?
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F0 and F1
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what is the purpose of ATP synthase?
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generate ATP
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what powers ATP synthase?
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proton gradient
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how many positions does ATP synthase have?
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3
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what are the positions of ATP synthase?
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1. empty, no ATP
2. ADP + Pi 3. ATP bound |
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which cytochrome is an apoptosis trigger?
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cytochrome c
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how many NADH and FADH2 are made in the citric acid cycle?
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2 FADH2, 6 NADH
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what punches chemical "holes" in the membrane stopping ATP synthesis, but not electron flow?
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venturicidin or oligomycin
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which chemical blocks F0?
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oligomycin
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what blocks complex IV?
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cyanide
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what happens when DNP is added?
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respiration continues without ATP synthesis
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where does cyanide inhibit electron transfer?
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cytochrome oxidase
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where does carbon monoxide inhibit electron transfer?
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cytochrome oxidase
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where does antimycin block electron transfer?
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from cytochrome b to cytochrome c1
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where does rotenone inhibit electron transfer?
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prevents electron transfer from Fe-S center to ubiquinone
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where does oligomycin inhibit ATP synthease?
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inhibits F0 and CF0
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how does DNP uncouple phosphorylation from electron transfer?
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hydrophobic proton carriers
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how does valinomycin uncouple phosphorylation from electron transfer?
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K ionophore
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what is the symporter of the inner mitochondrial membrane?
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phosphate translocase
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what sit he antiporter of the inner mitochondrial membrane?
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adenine nucleotide translocase
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what drives oxidative phosphorylation?
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pyruvate (catabolism), acetyl CoA (fatty acid synthesis), and GNG oxaloacetate
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what associates with complex I?
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malate
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where does cellular oxidative stress come from?
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mitochondrial mismanagement of oxygen reduction
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how do superoxide radicals form?
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partial oxygen reduction
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what are examples of ROS?
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O2, H202, HO, HO-
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how can cells react to ROS?
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neutralizes, repairs protein, reduces proteins to regenerate anti-oxidant capacity.
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what are ROS neutralizers?
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-mitochondrial superoxidedismutase(Mn-SOD) catalase
peroxiredoxin(Prx)--glutathione peroxidase(GPx) |
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what is resonsible for protein repair against ROS?
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thioredoxin
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what are reducing proteins to regenerate antioxidant activity?
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glutathione reductase, thiroredoxin reductase
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what are consequnces of diabetes oxidative stress?
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blindness, kidney failure, heart disease, stroke, neuropathy
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what happens to cellular oxidative stress in hyperglycemia?
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high intracellular glucose, overstimulation of OxPhos.
Complex III shuts off, QH2 builds up, ROS forms |
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what happens to GAPDH in hyperglycemia?
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GAPDH inhibition causes buildup of glycolytic intermediates
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what happens with a buildup of glucose?
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oxidative stress and compromised antixoidant capacity
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what happens with F6P buildup?
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altered gene expression
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what happens with glycerol-3-phosphate buildup?
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altered cell signaling and gene expression and ECM dysfunctions.
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what happens with DHAP buildup?
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altered inflammation and vessel reactivity and clotting
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hyperglycemia leads to:
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oxidative stress
altered gene expression altered cell sigaling. altered inflammaion |
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what actions are caused by hyperglycemia physiologically?
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Change in capillaryl arterial tone Inappropriate vessel growth
Vascular occulsion Actiavtion of inflammation Increased ROS Compromised inflammatory cell recruitment ECM matrix alterations |
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what does defective oxidative phosphorylation do in pancreatic b cells?
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blocks insulin secretion
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what does HIFa do?
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hypoxia induced factor reduces ROS production
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how are implants different in diabetics?
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potential to corrode is greater
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