M1 Biochem Enzymes - FA Only Flashcards

Question

Adenylsucinate Synthase - Function/Pathway/Regulation/Co-Factor

Answer 1

Function - Converts IMP to AMP Pathway - Purine Synthesis Regulation - Activated by GTP and Inhibited by ATP Co-Factors - Aspartate + GTP

Answer 2

Function - Restores THF which provides the 1-Carbons for Purine + TMP Production Pathway - Multiple (Including Nucleotide Synthesis) Disorder - Target of Methotrexate - DHFR Analog to prevent THF regeneration

Answer 3

Function - Salvage of Adenine and PRPP to AMP Pathway - Purine Salvage Co-Factors - Needs PRPP

Answer 4

Function - Salvage of Hypozathine and Gaunine to IMP and GMP Pathway - Purine Salvage Co-Factors - PRPP Disorder - Lesch-Nyhan Syndrome - HGPRT Deficiency - XR - Hyperuricemia + Gout + Pissed Off (Self-mutilation) + Retardation + DysTonia --------- Treatment - Allopurinol (GMP/IMP is the problem)

Answer 5

Function - Converts Adenosine to Inosine (for conversion to IMP) for degradation Pathway - Purine Degradation Disorder - ADA Deficiency - AR - Can't break down dATP and ATP - Massive pools of ATP inhibit nucleotide synthesis - Decreases lymphocyte count and causes SCID (leads to infant death)

Answer 6

Function Converts Hypoxanthine to Xanthine and Xanthine to Uric Acid (Second step is rate limiting) Pathway - Purine Degradation Disorder - Blocked by Allopurinol

Answer 7

Function - Converts to dexoxy state for DNA synthesis (activated in G1/S Phase) Pathway - Nucleotide Synthesis Co-Factor - NADPH Disorder - Target of Hydroxyurea

Answer 8

Function - Rate Limiting Step in Pyrimidine Synthesis - Forms the start of the base (Orotic Acid) to link with PRPP - Uses Glutamine + Aspartate Pathway - Pyrimidine Synthesis Regulation - Activated by ATP and PRPP and Inhibited by UTP/CTP

Answer 9

Function - Combines Orotic Acid + PRPP - Forms UMP Pathway - Pyrimidine Synthesis Disorder - Orotic Aciduria - Excess Orotate + Anemia - Treat with UMP/CMP

Answer 10

Function - Builds dTMP from dUMP (dUMP forme from either dCMP or UTP) Pathway - Pyrimidine Synthesis Co-Factor - Folate (THF) Disorder - 5-Fluorouracil (5-FU) Inhibits it prevent TMP formation - Prevents DNA Synthesis - Anti-cancer drug

Answer 11

Function - Rate Limiting Step - Converts Glucose-6P to Ribulose-5P + CO2 + 2NADPH Pathway - HMP Shunt Regulation - Insulin Activates (Dephos.) + NADPH Inhibits Co-Factor - NADP+ Disorder - XR - Favaism - No HMP - No Glutathione Restoration - Oxidative Damage + Hemolytic Anemia - Classes (I-IV with I being most severe) African = III vs. Mediterranean (II) Disorder Causes - Sulfa Drugs + Antimalarials (Primaquine) + Fava Beans

Answer 12

Function - Converts Ribulose-5P to Glyceraldehyde-3P + Fructose-6P + Ribose-5P Pathway - HMP Shunt Co-Factor - B1 (Thiamine) Deficiency - Wernicke-Korsakoff - Can't use TPP - Ataxia + Confusion + Optha

Answer 13

Function - Restores Glutathione after it reduces a peroxide to prevent free radical damage Pathway - Oxidative Burst/HMP Pathway Regulation - NADPH Co-Factor - Uses NADPH to NADP+ and Requires Selenium

Answer 14

Function - Converts Citrate from Mito. into Acetyl CoA and Oxaloacetate in the Cytoplasm (Citrateleaves due to high energy/inhibited Isocitrate DH) Pathway - Fatty Acid Synthesis Co-Factor- Requires ATP

Answer 15

Function - Rate Limiting Step of FA Synthesis - Converts Acetyl CoA to Malonyl CoA Pathway - Fatty Acid Synthesis Regulation - Insulin + Citrate Activate vs. Glucagon + Palmitoyl CoA Inhibit Co-Factors - ABC Carboxylase - ATP + Biotin + CO2

Answer 16

Function - Elongates Fatty Acids (After Malonly CoA) 2 Carbons at a time Pathway - Fatty Acid Synthesis Co-Factors - NADPH + Pantothenic Acid (B5)

Answer 17

Function - Removes Acetyl CoA's from Fatty Acids Pathway - Fatty Acid Degradation Co-Factor - Uses ATP

Answer 18

Function - Rate limiting step of the Carnitine Shuttle to bring Acyl CoA into the Mito. for B-Oxidation Pathway - Fatty Acid Degradation Regulation - Inhibited by Malonyl CoA (Activates synthesis + inhibits degradation) Disorder - Deficiency - Relatively rare + commonly associated with hypoketotic + hypoglycemia + high levels of blood carnitine + hepatomegaly

Answer 19

Function - Same as CPT1 - Caratine Shuttle - Inner mitochondrial membrane vs. outer + not rate limiting Pathway - Fatty Acid Degradation Regulation - None Disorder - 3 Forms - Adult (Skeletal Muscle/Fatigue/Pain) //////// Severe Infantile Multi-system Form - (Onset in the first 6-24 months of life - Hypoketotic Hypoglycemia + Hepatomegaly + Cardiomyopathy) ////// Neonatal Lethal - Symptoms within hour of birth + respiratory failure + seizures + cardiomegaly

Answer 20

Function - Removes the Acetyl CoA for use in the Mito. Pathway - Fatty Acid Degradation Disorder - MCAD vs. LCAD vs. SCAD - AR - Hypoketotic + hypoglycemia + hyperammoneia due to liver damage + limited gluconeogenesis

Answer 21

Function - Begins the Urea Cycle (in Mito.) as the Rate Limiting Step - Creates the first major substrate taking NH3 from Glutamate Pathway - Urea Cycle Co-Factors - Uses 2 ATP + CO2 + N-Acetylglutamate (From Arginine) Regulated - N-Acetylglutamate is the regulatory co-factor - Levels correspond with Arginine levels (High Protein = High Urea Need = High Arginine = High N-Acetylglutamate

Answer 22

Function - Adds the Aspartate in the Urea Cycle (Cytoplasm) to add the second N for release Pathway - Urea Cycle Co-Factor - 1 ATP

Answer 23

Function - Final Step of the Urea Cycle - Releases Urea + Restores Ornithine for use in further cycles Pathway - Urea Cycle

Answer 24

Function - Converts Homocystine (After using SAM from Methionine) bak to Methionine Pathway - Amino Acid Carbon Chain Elimination Co-Factor - B12

Answer 25

Function - Converts Homocystine to Cystine or Serine (2 Step Process) Pathway - Elimination of Amino Acid Carbon Chains Co-Factor - Pyridoxine (B6)