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277 Cards in this Set
- Front
- Back
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How many amino acids make up mammalian proteins?
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20
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How do amino acids connect to make proteins?
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Peptide bonds
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What is the basic structure of an amino acid?
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Amino group + Carboxylic acid group
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What are the four classes of AA side chains?
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Nonpolar
Uncharged polar Acidic Basic |
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What AA have nonpolar side chains?
|
Tryptopham
Proline Isoleucine Methionine Phenylalanine Valine Alanine Glycine Leucine |
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What AA have uncharged polar side chains?
|
Tyrosine
Threonine Glutamine Asparagine Cysteine Serine |
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What AA have acidic side chains?
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Aspartic acid
Glutamic acid |
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What AA's have basic side chains?
|
Histidine
Arginine Lysine |
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What are the essential AA's?
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Methionine
Isoleucine Leucine Lysine Trypotophan Threonine Histidine Valine Phenylalanine |
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What is the Henderson-Hasselbalch equation?
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pH= pKa + log (A-/HA)
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How does the Henderson Hasselbalch equation pertain to AA's?
|
when pH is greater than the pKa the carboxyl group loses its proton (COO-); at pH values less then the pKa, the amino group gains a proton
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What is physiologic pH?
|
7.35-7.45
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What is acidotic?
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Less than 7.35
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What is alkalotic pH?
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Greater than 7.45
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For AA's with uncharged side chains, what is their overall charge?
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Neutral at physiologic pH (COO- and NH3+)
|
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At acidic pH, what is the charge of an AA with an uncharged side chain?
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Positive (NH3+)
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At alkalotic pH, what is the charge of an AA with an uncharged side chain?
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Negative (COO-)
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What are 3 characteristics of the peptide bond?
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1. Lack rotation around the bond
2. Planar 3. Uncharged, but polar |
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What does primary structure of a protein mean?
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Linear sequence of AA's
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What is the secondary structure of a protein?
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Regular arrangement of AA's (3D structure)
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What are the 2 most common types of secondary protein structures?
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Alpha Helix
Beta Sheet |
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|
2 proteins in the body that are primarily alpha helical?
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Hgb
Keratin |
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2 properties of an alpha helix?
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Stabilized by H-bonds
Each turn of helix contains about 4 AA's |
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Which AA's disrupt an alpha helix?
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Proline (kink)
Charged AA's (basic/acidic) Bulky (Tryptophan) Branch at beta C (Valine, Isoleucine) |
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What is the difference between alpha helix and beta sheet?
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Alpha helix has one peptide chain (beta has 2 or more)
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What are the forms that a beta sheet can take on?
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Parallel
Anti-parallel |
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Which beta sheet form gives more stability?
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Anti-parallel
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Name a protein like structure composed of beta sheets?
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Amyloid
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In what disease processes is amyloid deposited within the body?
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Alzheimer
Downs Chronic Hemodialysis |
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What does tertiary structure of a protein mean?
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Interactions of primary sequence
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Name 4 types of interactions that cooperate in stabilizing the tertiary structure of a protein?
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1. van der Waals
2. Hydrophobic 3. H bonds 4. Ionic |
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What is the quaternary structure of a protein?
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Arrangement of many subunits in a protein (dimeric)
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What is the quaternary structure of Hgb?
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Heterotetramer (4 globular subunits)
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What is protein denaturation?
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Unfolding and disorganization (secondary and tertiary disrupted)
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What causes denaturation of a protein?
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Heat
Organic solvents Acid/bases Heavy metals |
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What are the two most abundant hemeproteins in humans?
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Hemeglobin
Myoglobin |
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What is the difference between Hgb and myoglobin?
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Hgb made up of 4 subunits and less affinity for O2 (myoglobin has 1 subunit)
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What is heme?
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Complex of protoporphyrin IX and Fe2+
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What enzyme catalyzes the rate limiting step of heme synthesis?
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Aminolevulinate (ALA) synthase
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How does lead cause microcytic, hypochromic anemia and porphyria?
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Inhibits ALA synthase and ferrochelatase
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What is methemooglobin?
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Hgb with iron oxidized to 3+
(cannot bind O2) |
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What are common causes of methemoglobin production?
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Environmental agents (nitrates)
Pharmaceuticals (local anesthetics) Metabolic Def (methemoglobin reducatase def) |
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What reduces methemoglobin (Fe3+) to Hgb (Fe2+)?
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NADH-methemoglobin reductase
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Why is methemoglobin used to prevent cyanide poisoning?
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Avidly bind cyanide ion (CN-) so sequesters it
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Where is myoglobin often present in the body?
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Heart and skeletal muscle
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Where in the body is Hgb found?
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RBCs only
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What is the function of Hgb?
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Transport O2 from the lungs to the caps of body tissues
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What are the main types of Hgb??
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Hgb A
Hgb F Hgb A2 Hgb S Hgb C |
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What does Hgb F consist of?
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Two alpha chains
Two gamma chains |
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What are the 2 forms of Hgb?
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Taut (deoxy)
Relaxed (oxy) |
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What does cooperative binding mean in regard to Hgb?
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Binding of O2 at one heme group inc the O2 affinity of the remaining heme groups
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Does myoglobin bind O2 in the same way that Hgb does?
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No cooperative binding in myoglobin (1 subunit)
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What is the significance of the sigmoidal shape of O2 dissociation curve?
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Allows Hgb to carry and deliver O2 efficiently from site of high O2 to sites of low O2
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What is the significance of the plateau portion of the curve?
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Pul caps, where O2 binds readily to Hgb
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What is the significance of the steep portion of the curve?
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Systemic caps, where O2 is unloaded to tissues efficiently
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What does a R shift in the O2 dissociation curve signify?
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Improved O2 delivery to tissues
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What does a L shift in the O2 dissociation curve signify?
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Improved O2 extraction in the lungs
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What variables shift the Hgb oxygen dissociation curve to the R?
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Inc CO2
Dec pH Inc 2,3-DPG Inc Exercise Inc Temp |
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How is the CO2 carried in the body?
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Transported as bicarb ion
Carbamate bound to Hgb |
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What reaction does carbonic anhydrase catalyzae?
|
CO2 + H2O -> HCO3- + H+
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What is the Bohr effect?
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H+ conc on the affinity of Hgb O2
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How is the Bohr effect significant in O2 transport?
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pH is high in the lungs: Hgb high affinity for O2
pH is low in the tissues: Hgb low affinity for O2 |
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Where is 2,3-BPG created?
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In glycolysis cycle from 1,3-BPG to 3-Phosphoglycerate
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Does fetal Hgb or adult Hgb have a higher affinity for O2?
|
Fetal (dissociation curve shifted to the left)
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What are the minor forms of Hgb?
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Hgb A2
Hgb A1c |
|
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What disease process is Hgb A1c important in?
|
DM (glucose glycosylates Hgb)
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What are hemoglobinopathies?
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A family of disorders- structurally abnormal Hgb, synthesis of insufficient quantities of Hgb, both
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What are the constituents of sickle cell Hgb?
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Two normal alphas and two mutant beta globin chains
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What is the mutation of the beta-globin chain in sickle cell Hgb?
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Glutamate replaced by valine (position 6)
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What happens when RBCs sickle?
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Deform and block the flow of blood in capillaries (anoxia)
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What are some complications of sickle cell anemia?
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Aplastic crisis (parovirus B19)
Autosplenectomy Vaso-occlusive painful crisis Splenic sequestration crisis Avascular necrosis of the femoral head |
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Sickle cell anemia is more prevalent in what ethnic group?
|
African Americans
|
|
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What findings do you see on x-ray in individuals with sickle cell anemia?
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Crew cut (due to marrow expansion)
Fish vertebral bodies |
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What are some variables that increase the sickling of RBCs?
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Dec O2
Inc CO2 Dec pH Inc 2,3-BPG Dehydration |
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Sickle cell heterozygotes have an advantage over nonsickle individuals in the presentation of what disease?
|
Malaria
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Name some potential treatments for individuals with sickle cell anemia?
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Hydroxyurea (inc Hgb F)
BM transplant Hydration O2 |
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What mutation causes Hgb C?
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Beta globin chain (glutamate is replaced by lysine) at position 6
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What mutation produces Hgb SC?
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One beta globin gene has sickle cell mutation and the other has C disease mutation (painful crisis milder than SS)
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What is the common complication of Hgb SC disease?
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DVTs
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What are thalassemias?
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hereditary hemolytic disease in which an imbalance in the synthesis of globin chain occurs
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What is an alpha thalassemia?
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alpha globin chain is dec or absent (less than 4)
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How many different types of alpha thalassemias are there?
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4
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What are the different types of alpha thalassemia?
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Silent carrier (1 of 4)
Alpha thalassemia trait (2 of 4) Hgb H dx (3 of 4) Hgb Bart/Hydrops fetalis (4 of 4) |
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What is beta thalassemia?
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Synthesis of beta globin chain is dec (less than 2)
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How many different types of beta thalassemia are there?
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2
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What are the different types of beta thalassemia?
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Minor (1 of 2)
Major (2 of 2) |
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In what geographical regions is alpha thalassemia most prevalent?
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Asia and Africa
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In what geographic region is beta thalassemia most prevalent?
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Mediterranean
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What type of Hgb is increased in beta thalassemia?
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Hgb F
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What is the treatment for beta thalassemia major?
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Blood transfusions
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What is the complication of blood transfusions in beta thalassemia?
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Cardiac failure bc of secondary hemochromatosis
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Characterize the anemia associated with thalassemia?
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Microcytic hypochromic anemia
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What sign on x-ray is indicative of thalassemia?
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Crew cut
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Name the CT proteins found throughout the body?
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Collagen
Elastin Keratin |
|
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What are the CT proteins located in the body?
|
Collagen and elastin are in sclera, cornea, and bv walls
Keratin is in skin and hair |
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What is the most abundant protein in the body?
|
Collagen
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What is the structure of collagen?
|
Three polypeptides (alpha chains) in a triple helix
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What is the sequence of AA in the triple helix of collagen?
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Gly-X-Y
(X and Y can be proline, hydroxyproline, or hydroxylysine) |
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What vitamin is required for the synthesis of collagen?
|
Vit C (hydroxylation)
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Def of Vit C is referred to as what dx?
|
Scurvy
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Name common physical findings ass. with Scurvy?
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Swollen gums
Easy bruising Anemia Poor wound healing Weakness |
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|
How is collagen synthesized?
|
Prolyl and lysyl residues are hydroxylated via prolyl hydroxylase in the ER (procollagen) in extracellular space procollagen is cleaved to tropocollagen which aggregates to fibrils
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What characteristic linkage reinforces the structure of collagen?
|
Covalent cross linking of Lys and hydroxylys
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Where is collagen type I located?
|
Bone
Tendon Skin Dentin Fascia Cornea |
|
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Where is collagen type II located?
|
Cartilege
Vitreous body Nucleus Pulposus |
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Where is collagen type III located?
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Reticulin fibers (skin)
BV Uterus Fetal tissue Granulation tissue |
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Where is collagen type IV located?
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Basement memebrane
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Where is collagen type X located?
|
Epiphyseal plate
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Name 3 dx which result in dysfunctional collagen synthesis?
|
Scurvy
Ehlers-Danlos OI |
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Name several signs of Ehlers-Danlos?
|
Hyperextensible skin
Tendency to bleed (bruise) Hypermobile joints |
|
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What significant vascular pathology is ass. w Ehlers Danlos?
|
Intracranial berry aneurysms
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What is the most common mode of inheritance for OI?
|
Auto Dom
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What are some signs and symptoms of OI?
|
Multiple fractures
Blue sclerae Hearing loss (middle bone malform) Dental probs |
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OI may often be confused with what suspicion?
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Child abuse
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Which type of OI is fatal?
|
Type II
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What autoimmune dx is due to antibodies against the basement membrane?
|
Goodpasture
|
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Describe the clinical manifestations of Goodpasture?
|
Lungs-coughing blood, diff breathing
Kidneys-hematuria, burning urniation |
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What genetic disorder prevents the proper production of the basement membrane?
|
Alport
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Describe the clinical manifestations of Alport?
|
Kidneys- nephritis and hematuria
Ears- hearing loss Eyes- ocular lesions |
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Which serum protein inhibits elastin degradation?
|
alpha-1-antitrypsin (inhibits neut elastase)
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Where is alpha-1-antitrypsin produced?
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Liver by monocytes and macrophages
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What dx are ass. w alpha-1-antitrypsin deficiency?
|
Emphysema
Liver damage (cirrhosis, cholestasis) |
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What are enzymes?
|
Protein catalysts that inc the rate of chem rxn wo being altered in the process
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6 properties of enzymes?
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AS
Catalytic Substrate specific Uses cofactors Activity can be regulated Located in specific areas |
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Does the enzyme change the chemical equilibrium of a rxn?
|
No (faster by dec energy of activation)
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Name the factors that can affect the rate of enzymatic catalysis of an enzyme?
|
Substrate conc
pH Temp |
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What is the effect of temp on the rxn velocity?
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Inc with temp until a peak velocity is reached and then declines
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What is the effect of substrate conc on rxn velocity?
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Inc with inc substrate conc until max velocity is reached
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What is V max?
|
Max velocity at which an enzyme can catalyze a rxn
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What is the effect of pH on enzymatic activity?
|
Extremes denature
Preference of ionized and unionized state of specific enzymes and substrates |
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What is the Michaelis-Menton equation?
|
Vi= Vmax(Sub conc)/(Km+sub conc)
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What does the Michaelis-Menten equation represent?
|
Relationship between initial rxn velocity and sub conc
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What are the three assumptions of the Michaelis-Menten equation?
|
Sub conc is greater than enzyme conc
ES does not change with time Only initial velocities are assumed |
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What is Km?
|
It is equal to the substrate conc at which the reaction velocity is equal to 1/2 Vmax
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What does a small Km imply?
|
High affinity of the enzyme for the substrate
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What does a large Km imply?
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Low affinity of the enzyme for the substrate
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Does hexokinase have a large or small Km?
|
Low Km (in most tissues)
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Does glucokinase have a large or small Km?
|
High Km (liver and pancreas)
|
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What is meant by the term 0 order reaction?
|
Velocity of reaction is constant and independent of substrate conc.
|
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What enzymes showcase zero order reaction kinetics?
|
Alcohol dehydrogenase
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What is meant by the term first order reaction?
|
The reaction is directly proportional to the amount of substrate (linear relationship)
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How does a competitive inhibitor inhibit an enzymatic reaction?
|
Competes with substrate for AS on an enzyme
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Can the effect of a competitive inhibitor be overcome by increasing the amount of substrate?
|
Yes
|
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What is the effect of a competitive inhibitor on the Michaelis-Menten equation?
|
Inc apparent Km
(Vmax constant) |
|
|
How does a noncompetitive inhibitor inhibit an enzymatic reaction?
|
By binding to an allosteric site
|
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Can the effect of a noncompetitive inhibitor be overcome by increasing the amount of substrate?
|
No
|
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What is the effect of a noncompetitive inhibitor on the Michaelis-Menten equation?
|
Dec Vmax
(Km constant) |
|
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How does a mixed inhibitor inhibit an enzymatic reaction?
|
By binding to an allosteric site outside of the AS
|
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What is the effect of a mixed inhibitor on the Michaelis-Menten equation?
|
Inc Km
Dec Vmax |
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How does an uncompetitive inhibitor inhibit an enzymatic reaction?
|
By binding to the ES complex at the allosteric site
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What is the effect of an uncompetitive inhibitor on the Michaelis-Menten equation?
|
Both Vmax and Km change
|
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Which is the only class of inhibitors that binds to the enzymatic AS?
|
Competitive Inhibitors
|
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|
What is the treatment for ethylene glycol poisoning?
|
Ethanol (competitive inhibitor of alcohol dehydrogenase)
Fomepizole |
|
|
What can be a manifestation of ethylene glycol poisoning?
|
Kidney failure (oxalate crystallizes)
|
|
|
What is the treatment for methanol poisoning?
|
Ethanol (competitive inhibitor of alcohol dehydrogenase)
|
|
|
What can be an early manifestation of methanol poisoning?
|
Blindness (optic neuropathy bc of formaldehyde and formic acid)
|
|
|
Name the methods the body uses to regulate enzyme activity?
|
Allosteric reg
Covalent modification Cofactors Induction/repression of enzyme synthesis |
|
|
Describe the mechanism behind allosteric regulation?
|
An effector binds to the enzyme at an allosteric position that alters the activity of the enzyme
|
|
|
Allosteric regulation of enzymatic activity is ass. with what type of substrate-velocity curve?
|
Sigmoidal (positive cooperation)
|
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What is the effect of a positive effector on the Michaelis-Menten equation?
|
Dec Km (inc affinity)
|
|
|
What is the effect of a negative effector on the Michaelis-Menten equation?
|
Inc Km (dec affinity)
|
|
|
What is meant by the term homotropic effector?
|
Substrate itself serves as an effector
|
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What is meant by the rem heterotropic effector?
|
The effector is a molecule other than the substrate
|
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Describe the mechanism behind covalent modification.
|
Bond another molecule to the enzyme to alter the enzymes activity (usually phosphate groups)
|
|
|
Describe the effect of covalent modification on the activity of glycogen phosphorylase and glycogen synthase?
|
Glycogen phosphorylase inc activity
Glycogen synthase dec activity |
|
|
Name several enzymes whose activity is mostly altered via the induction or repression of enzyme synthesis?
|
Cytochrome P450
Glycolytic enzymes HMG-CoA reductase |
|
|
What is a cofactor?
|
Small molecule essential for the action of an enzyme
|
|
|
List several enzymes that utilize cofactors?
|
Pyruvate Dehydrogenase
Alpha Ketoglutarate Dehyrdrogenase Pancreatic lipase |
|
|
What symptoms are ass. with PKU?
|
Inc phenylalanine causes mental retardation, impairment of brain development, fair skin, eczema, musty body odor
|
|
|
What is the enzyme disturbance in PKU?
|
Dec phenyalanine hydroxylase
Dec BH4 (Dec producation of tyrosine) |
|
|
What substances are found in inc amounts in the urine of those with PKU?
|
Phenylketones (phenyllactate, phenylpyruvate, phenylacetate)
|
|
|
When is PKU screened?
|
At birth
|
|
|
PKU is inherited in what pattern?
|
Auto Rec
|
|
|
What is the treatment for PKU?
|
Dec Phe and Inc Tyr in the diet
|
|
|
What is maternal PKU?
|
Mother's uncontrolled hyperphenylalaninemia leads to mental retardation and defects of the fetus at birth (organogenesis 3-8 wks)
|
|
|
Describe the pathophysiology behind maple syrup urine disease?
|
Degradation of branched AA's (Isoleucine, leucine, valine) is blocked (alpha ketoacids in the blood inc)
|
|
|
What is the deficient enzyme in maple syrup urine disease?
|
Branched chain keto-acid dehydrogenase (thiamine cofactor)
|
|
|
What are the symptoms of maple syrup urine disease?
|
Mental retardation
Edema White matter demyelination Hyperglycemia Death |
|
|
What is the pathophysiological processes that can result in albinism?
|
Def of tyrosinase
Defective tyrosine transporters Lack of NCCs migration |
|
|
What is the role of tyrosinase?
|
Tyrosine to melanin
|
|
|
What is the role of melanin?
|
Pigment
|
|
|
Which important pathology is ass. w dec melanin?
|
Inc susceptibility to sunburns (squamous cell carcinoma)
|
|
|
Describe the pathophysiology behind homocystinuria?
|
Defective cystathionine synthase or methionine synthase
|
|
|
Describe the two forms of homocystinuria?
|
Def cystathionine or methionine synthase
Dec affinity for PLP (B6) |
|
|
What is the treatment for homocystinuria?
|
Inc cysteine and dec methionine in the diet
Inc B6 (PLP) |
|
|
What are the symptoms of homocystinuria?
|
Marfan-like body
Mental retardation Osteoporosis Thrombolytic episodes |
|
|
What physiological defect is found in cystinuria?
|
Defective renal tubular AA transporter for Cystine, Ornithine, Lysine, and Arginine
|
|
|
What are the major symptoms ass. w cystinuria?
|
Cystine stones in the kidneys (yellow-brown)
|
|
|
What is the treatment for cystinuria?
|
Acetazolamide (alkalinize urine)
|
|
|
What is the deficient enzyme in alkaptonuria?
|
Homogentistic acid oxidase
|
|
|
Most common genetic error of AA transport?
|
Cystinuria
|
|
|
Homogentistic acid oxidase is utilized in the degradation of which AA?
|
Tyrosine
|
|
|
What are the symptoms of alkaptonuria?
|
Dark urine and CT (onchronosis)
Rarely athralgias |
|
|
What causes urine and CT to be dark in alkaptonuria?
|
Homogentistic Acid accumulates forming polymers
|
|
|
What is deficient in cystathioninuria?
|
Cystathionase
|
|
|
What reaction does cystathionase catalyze?
|
Formation of cysteine and alpha ketobutyrate from cystathionine
|
|
|
What is the deficient enzyme in histidinemia?
|
Histidase
|
|
|
What reaction does histidase catalyze?
|
Histidine to urocanate
|
|
|
What are the symptoms of histidinemia?
|
Often asymptomatic, may have mental retardation
|
|
|
Describe the pathophysiology behind histidinemia?
|
Inc levels of histidine in the urine and blood
|
|
|
What is the inheritance pattern of histidinemia?
|
Auto Rec
|
|
|
What type of emphysema is ass w. alpha 1 antitrypsin def?
|
Panacinar
|
|
|
What are the 3 major classes of carbs?
|
Monosaccharides
Dosaccharides Polysaccharides |
|
|
What is the simplest carb?
|
Monosaccharide
|
|
|
What is the major fuel source for the brain?
|
Glucose
|
|
|
What are the major metabolic pathways of the brain?
|
Glycolysis
AA metabolism |
|
|
What cells do not contain mitochondria and thus rely only on glycolysis for E production?
|
Erythrocytes
|
|
|
What type of tissue stores, synthesizes, and mobilizes TGs?
|
Adipose tissue
|
|
|
Which metabolic pathway does fast twitch muscles use for fuel?
|
Glycolysis
|
|
|
Which metabolic pathway does slow twitch muscles use for fuel?
|
TCA cycle
Beta oxidation |
|
|
Name the family of glucose carrier proteins that transport glucose into the cell?
|
GLUT
|
|
|
What glucose transporter is used by the liver?
|
GLUT 2
|
|
|
What glucose transporter is used by muscle?
|
GLUT4
|
|
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Which one of the glucose transporters is sensitive to insulin?
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GLUT4
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What is the mechanism of action of insulin on GLUT4?
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Facilitates movement of the transporter to the cell membrane
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What glucose transporter is located on the brush border membrane of both intestinal and kidney cells?
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GLUT2
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GLUT2 is coupled to the transport of what ion to provide E for glucose transport?
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Na+
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In most tissues, glucose is trapped in the cell by phosphorylation by what enzyme?
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Hexokinase
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What inhibits hexokinase?
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Feedback inhibition by its product glucose-6-ph
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In the liver, glucose is phosphorylated by what enzyme?
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Glucokinase
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What is the major distinction between hexokinase and glucokinase?
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Glucokinase has a higher Km
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Does glucokinase or hexokinase prevent hyperglycemia following a carb-rich meal?
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Glucokinase
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Which two organs express glucokinase?
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Liver
Pancreas |
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Describe the kinetics of glucokinase?
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High Km and high Vmax
No feedback inhibition by gluc-6-ph |
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Describe the kinetics of hexokinase?
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Low Km and low Vmax
Feedback inhibition by gluc-6-ph |
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What is the effect of insulin on glucokinase?
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Induces synthesis of glucokinase
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Name two functions of glycolysis?
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Degrade glucose to generate ATP
Provide building blocks for other rxns |
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How much ATP is consumed per mole of glucose that undergoes glycolysis?
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2 moles
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How much ATP is generated per mole of glucose that undergoes glycolysis?
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4 moles
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What is the net generation of ATP per mole of glucose that undergoes glycolysis?
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2 moles
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What is the major regulatory enzyme in glycolysis?
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Phosphofructokinase I (PFK-1)
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Name the 3 enzymes of glycolysis that catalyze virtually irreversible reactions?
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Hexokinase
PFK-I Pyruvate kinase |
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What reaction does PFK-I catalyze?
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Fructose-6-Ph-->Fructose 1,6-bisphosphate
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Name the positive allosteric regulator of PFK-I
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AMP
Fructose-2,6-bisphosphate |
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Name allosteric inhibitors of PFK-I
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Citrate
ATP |
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What reaction does PFK-II catalyze?
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Fructose-6-Ph-->Fructose-2,6-bisphosphate
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In what organ is PFK-II not regulated by phosphorylation?
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Muscle
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Is the activity of PFK-II a sign of a fed or fasting state?
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Fed
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Which 2 glycolytic intermediates liberate enough energy for driving ATP synthesis?
|
3-phosphoglycerate kinase
Pyruvate kinase |
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Pyruvate kinase catalyzes what reaction?
|
PEP-Pyruvate
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What covalent modification inhibits pyruvate kinase?
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Phosphorylation
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What enzyme allosterically inhibits pyruvate kinase by phosphorylating it?
|
Protein kinase A
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Allosteric inhibitors of pyruvate kinase?
|
ATP
Acetyl CoA Alannine (in liver only) |
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Name the allosteric activator of pyruvate kinase?
|
Fructose-1,6-bisphosphate
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What are the signs of pyruvate kinase deficiency?
|
Anemia
Reticulocytosis Inc 2,3-BGP |
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How is pyruvate kinase disorder inherited?
|
Auto Rec
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What is the most effective treatment for pyruvate kinase deficiency?
|
Exchange transfusions
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Which enzyme produces NADH in glycolysis?
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Glyceraldehyde-3-phosphate dehydrogenase
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How much NADH is produced per mole of glucose oxidized to pyruvate?
|
2
|
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Since erythrocytes do not contain mitochondria, what is the NADH produced in glycolysis used for?
|
To reduce pyruvate to lactate
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How is the reducing power of NADH transferred to the mitochondria?
|
Glycerol-3-Phosphate Shuttle
Malate Aspartate Shuttle |
|
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What are the possible fates of pyruvate produced in the cell?
|
Lactate
Alanine Acetyl CoA OAA Glucose |
|
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How many moles of ATP are required to generate glucose from pyruvate?
|
6 moles
|
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Under anaerobic conditions, pyruvate is converted to what molecule?
|
Lactate
|
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What enzyme catalyzes pyruvate-->lactate?
|
Lactate Dehydrogenase
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What are the 3 enzymes of the pyruvate dehydrogenase complex?
|
Pyruvate decarboxylase
Dihydrolipoyl transacetylase Dihydrolipoyl dehydrogenase |
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What reaction does the pyruvate dehydrogenase complex catalyze?
|
Pyruvate + NAD+ +CoA-->Acetyl CoA + CO2 + NADH
|
|
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What coenzymes are required by pyruvate dehydrogenase complex?
|
Thiamine (B1)
FAD (B2) NAD+ (B3) Coenzyme A (B5) Lipoic acid |
|
|
The pyruvate dehydrogenase complex is similar to what other enzyme?
|
Alpha-ketoglutarate dehydrogenase complex
|
|
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Is the pyruvate dehydrogenase complex active in the phosphorylated or nonphosphorylated state?
|
Nonphosphorylated
|
|
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What enzymes phosphorylates the pyruvate dehydrogenase complex?
|
PDH kinase
|
|
|
What molecules activate PDH kinase (inhibit PDH complex)?
|
Acetyl CoA
NADH |
|
|
What molecules inhibit PDH kinase (activate PDH complex)?
|
Pyruvate
Dec levels of ADP |
|
|
What enzyme dephosphorylates the PDH complex?
|
PDH pohphatase
|
|
|
What molecule activates PDH phosphatase (activating PDH complex)?
|
Ca2+
|
|
|
What are the major manifestations of PDH deficiency?
|
Lactic acidosis
Neurological manifestations |
|
|
What is the treatment for PDH deficiency?
|
Inc intake of ketogenic nutrients
|
|
|
For each Acetyl CoA through the TCA cycle, how many NADH are produced?
|
3
|
|
|
For each Acetyl CoA through the TCA cycle, how many FADH2 are produced?
|
1
|
|
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For each Acetyl CoA through the TCA cycle, how many CO2 are produced?
|
2
|
|
|
For each Acetyl CoA through the TCA cycle, how many GTP are produced?
|
1
|
|
|
How much ATP is produced per acetyl CoA pushed in the TCA cycle?
|
12
|
|
|
What reaction does citrate synthase catalyze?
|
OAA + Acetyl CoA --> Citrate
|
|
|
The presence of what molecule inhibits citrate synthase?
|
ATP
|
|
|
What reaction does isocitrate dehydrogenase catalyze?
|
Isocitrate + NAD+ --> alpha-ketpglutarate + CO2 + NADH
|
|
|
What molecules inhibit isocitrate dehydrogenase?
|
ATP, NADH
|
|
|
The presence of what molecule activates isocitrate dehydrogenase?
|
ADP
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