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132 Cards in this Set
- Front
- Back
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Amino Acid precursors to catecholamines, melanin, T3/T4
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Phenylalanine and Tyrosine
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Amino Acid component of collagen
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Glycine and Proline
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Amino Acid precursor to Serotonin and Melatonin
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Tryptophan
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Amino Acids that accumulate in Maple Syrup Urine Disease
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Isoleucine, Leucine, Valine (I Love Vermont)
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Amino Acid component of Histones
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Arginine and Lysine
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Amino Acid precursor to Urea and Nitric Oxide
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Arginine
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Amino Acid pH buffer of RBC's
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Histidine
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First Amino Acid synthesized in all proteins
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Methionine (AUG start codon)
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Amino Acid component of disulfide bonds
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Cysteine
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Amino Acid precursor for gluconeogenesis
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Alanine
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Amino Acid carrier of NH3
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Glutamine
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Stimulatory Amino Acid that is a precursor for an inhibitory neurotransmitter
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Glutamate (synthesized to GABA)
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Positively Charged Amino Acids (have amino group)
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Lysine, Arginine, and Histidine
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Negatively Charged Amino Acids (have carboxyl groups)
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Glutamate, Aspartate
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Essential Amino Acids (10)
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BCAA (Ile, Leu, Val)
Positive (Lys, Arg, His) 1st AA (Met) Trp, Thr, Phe |
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Competitive inhibitor's effect on Km and Vmax
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Km is increased (Decreased affinity)
Vmax is unchanged |
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Non-Competitive inhibitor's effect on Km and Vmax
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Km is unchanged
Vmax is decreased |
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Statins effect the enzyme ______ by _______ inhibition
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HMG CoA Reductase, competitive
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Methotrexate effects the enzyme ______ by ______ inhibition
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Dihydrofolate Reductase, non-competitive
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Name the enzyme and Protein Kinase of the cAMP Second Messenger Pathway
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Enzyme = Adenyl Cyclase
Protein Kinase = A Gs subunit is stimulated by B receptors and activates Adenyl Cyclase Gi Subunit is stimulated by A2 receptors and inhibits Adenyl Cyclase |
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Name the enzyme and protein kinase involved in the PIP2 second messenger pathway
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Enzyme - Phospholipase C
Protein Kinase - C Gq subunit stimulates Phospholipase C using the second messengers DAG, IP3, and Ca2+ Stimulated by Epi and Vasopressin |
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Name the enzyme and protein kinase involved in the cGMP second messenger pathway
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Enzyme - Guanyl Cyclase
Protein Kinase - G No G-subunit used Stimulated by ANF and NO |
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How do growth factors transduce signals inside the cell?
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They use Tyrosine Kinase
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What enzymes require Thiamine (Vit B1)
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Pyruvate Dehydrogenase
A-ketoglutarate Dehydrogenase Transketolase |
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What are the symptoms of a thiamin deficiency?
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Wernicke's (ataxia, opthalmoplegia)
Korsakoff's (confabulation, psychosis) Wet Beri-Beri (cardiac failure --> dilated cardiomyopathy) Dry Beri-Beri (Peripheral neuropathy) |
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What are the symptoms of Niacin deficiency?
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Pellegra: Diarrhea, Dementia, Dermatitis (and Death)
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What other nutritional deficiency can cause Pellegra? (Other than Niacin)
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Tryptophan (diets based on corn)
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What enzyme is dependent of Folic Acid?
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Thymidylate synthase (involved in purine synthesis)
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What type of patients develop Folic Acid deficiency?
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Alchoholics and pregnant women
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What are symptoms of Folic Acid deficiency?
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Megaloblastic anemia
Homocystinemia w/ risk of deep vein thrombosis and atherosclerosis Neural tube defects |
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What enzymes are dependent on cyanocobalamin? (Vit B12)
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Methylmalonyl CoA Mutase
Homocysteine methyltransferase |
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What are some causes of Vit B12 deficiency?
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Pernicious anemia
Resection of ileum Chrohn's/UC Vegans Infection w/ D. latum |
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What are the symptoms of Vit B12 deficiency?
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Megaloblastic anemia
Progressive peripheral neuropathy due to deposition of odd chain FA in myelin sheath |
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What enzymes use Vitamin B6?
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Aminotransferases: AST and ALT
g-Aminolevulinate synthase (involved in heme synthesis) |
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What is the most common cause of a Vitamin B6 deficiency?
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Isoniazid therapy to treat TB
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What are the symptoms of a vitamin B6 deficiency?
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Sideroblastic anemia, cheilosis, stomatitis
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What are the symptoms of a Riboflavin deficiency?
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Corneal neovascularization
Cheilosis or stomatitis Magenta colored tongue |
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What enzymes use Ascorbic acid (Vit C)?
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Prolyl and lysyl hydroxylases (collagen synthesis)
Dopamine hydroxylase (catecholamine synthesis) |
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What are the symptoms of Vit C deficiency?
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Scurvy: bleeding gums, poor wound healing, hemorrhage, painful glossitis, anemia
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What is the function of cholecalciferol? (Vit D)
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Normalize serum calcium levels (increases bone resorption and increases Ca receptors in gut)
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What is the function of carotene? (Vit A)
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Retinoic acid and retinol act as growth regulators
Retinal is important in rods and cones for vision |
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What clotting factors use Vitamin K?
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Clotting Factors II, VII, IX, X
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What anticoagulant factors use Vitamin K?
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Protein C and S
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What is the function of Vitamin E?
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Antioxidant, protects membrane lipids from peroxidation
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What is marasmus?
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Deficiency in ALL calories
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What is Kwashiorkor?
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Severe protein deficiency. Patients have large abdomen due to lack of albumin and may also have enlarged liver
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What is the enzyme responsible for the final step of Vitamin D synthesis? (25-Vit D --> 1, 25 Vit D)
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1a-Hydroxylase (induced by increased PTH due to hypocalcemia)
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Explain the process of Vit D synthesis?
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Vit D3 can be made in the skin via UV light or obtained from the diet. Vit D3 is converted to 25-Vit D in the liver and then to 1,25-Vit D in the proximal renal tubules of the kidney
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What are the symptoms of Vit A deficiency?
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Night blindness, metaplasia of corneal epithelium, dry eyes, bronchitis, pneumonia
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What enzyme is dependent on Vit K?
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g-Glutamyl Carboxylase
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What are the symptoms of Vit K deficiency?
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Prolonged bleeding, easy bruising, potentially fatal hemorrhagic disease?
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How does Warfarin work?
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Blocks the Vit K dependent enzyme g-Glutamyl Carboxylase
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What is the effect of Vit K deficiency on PT and bleeding time?
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Bleeding time = normal
PT = increased |
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What is the effect of Vit C deficiency on PT and bleeding time?
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Bleeding time = increased
PT = normal (lack of collagen in Vit C deficiency results in inability to form platelet plug) |
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What are some causes of Vit K deficiency?
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Prolonged antibiotic use
Fat malabsorption Breast fed newborns |
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What 2 types of cells are insensitive to insulin?
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Brain and RBCs
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What hormones oppose the action of insulin?
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Glucagon
Epinephrine Cortisol Growth hormone |
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What is the effect of insulin on GLUT 4 receptors?
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Insulin increases the number of GLUT 4 receptors in muscle and adipose tissue
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What are the 3 metabolic precursors for gluconeogenesis?
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Alanine
Glycerol Lactate |
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What is the rate limiting enzyme of glycolysis?
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Phosphofructokinase-1 (PFK-1)
Convert Fructose-6-P to Fructose-1,6-bisP + = Insulin, Fructose-2,6-bisP, AMP - = Glucagon, ATP, Citrate |
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What happens in Pyruvate Kinase deficiency?
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Inability to convert PEP to Pyruvate
Increase PEP Increased 2,3 BPG --> Decreased oxygen binding of hemoglobin 2nd MCC of genetic hemolytic anemia (1st is G6PD deficiency) |
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How does insulin stimulate the rate limiting step in glycosis, PFK-1?
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Insulin indirectly induces PFK-1 by activating the PFK-2 enzyme which converts some Fructose-6-P to Fructose-2,6-P which in turn activates the PFK-1 enzyme
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What is the difference between Glucokinase and Hexokinase?
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Both of these enzymes are used to phosphorylate glucose and trap it in the cell. Glucokinase is found in the liver and has a higher Km in comparison to Hexokinase which is found in the most tissues
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What are the 3 irreversible enzymes in glycolysis?
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1. Hexokinase/Glucokinase (Converts Glucose to Glucose-6-P)
2. PFK-1 (Converts Fructose-6-P to Fructose-1,6-P) 3. Pyruvate Kinase (Converts PEP to Pyruvate) |
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What are the symptoms of Lactate deficiency?
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Diarrhea, bloating, cramps, vomiting, dehydration
Lactase is the enzyme responsible for the reaction: Lactose --> Glucose + Galactose In the gut, bacteria ferment Lactose causing symptoms |
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What enzyme converts Galactose to Galactisol? What happens when this reaction occurs?
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Enzyme = Aldose Reductase
This occurs when Galactose levels increase in the blood and Galactisol is deposited in the lens of the eye causing swelling and cataracts (Similar to Sorbitol in diabetes) |
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What are the symptoms of a Galactokinase deficiency?
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Cataracts early in life
Galactosemia Galactosuria (Galactose --> Galactose-1-P) |
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What are the symptoms of a Galactose-1-P Uridyl Transferase deficiency?
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Cataracts early in life
Galactosemia Galactosuria LIVER DAMAGE MENTAL RETARDATION (Gal-1-P --> Glu-1-P) |
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What are the symptoms of Fructokinase deficiency?
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Benign
Fructosuria (Fructose --> Fructose-1-P) |
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What are the symptoms of an Aldolase B deficiency?
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Hypoglycemia, ketoacidosis, liver damage, hyperuricemia, lethargy, vomiting, kidney damage
Fructosuria Does not occur until the introduction of foods to diets (not while breast feeding) (Fru-1-P --> DHAP + G-3-P) |
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How can a Thiamine deficiency cause impaired glucose metabolism?
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Thiamine is necessary for Pyruvate Dehydrogenase to function
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What is the rate limiting step in the TCA cycle?
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Isocitrate Dehydrogenase (Citrate --> a-KG)
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What enzyme in the TCA cycle requires Thiamine?
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a-KG Dehydrogenase
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How do barbituates effect the ETC?
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Inhibit NADH Dehydrogenase (Complex I)
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How does Cyanide effect the ETC?
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Inhibits Cytochrome Oxidase (Cyto a/a3) Complex IV
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At which Complex of the ETC does NADH enter?
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Complex I (NADH Dehdrogenase)
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At which complex in the ETC does FADH2 enter?
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Complex II (Succinate Dehydrogenase)
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What are the sources of FADH2 for the ETC?
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Succinate Dehydrogenase
Glycerol Phosphate Shuttle Fatty Acyl CoA Dehydrogenase |
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What drugs can act as an uncoupler in the ETC?
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2,4 Dinitrophenol
Aspirin |
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What effect would an ETC inhibitor have on O2 consumption, intracellular NADH/NAD ratio, and ATP?
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O2 Consumption = Decreased
NADH/NAD = Increased ATP = Decreased |
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What effect would an ETC uncoupler have on ATP synthesis, O2 consumption, and NADH/NAD ratio?
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ATP synthesis = Decreased
O2 consumption = Increased NADH/NAD = Decreased |
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What are the 3 Reactive Oxygen Species (ROS)?
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Superoxide (O2-)
Hydrogen Peroxide (H2O2) Hydroxyl Radical (OH') |
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How does tissue hypoxia cause lactic acidosis?
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Lack of oxygen decreases the rate of ETC and ATP production which causes glycolysis to increase and the lack of O2 facilitates Lactate production
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What causes Cyanide poisoning?
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Burning polyurethane
Byproduct of Nitroprusside (Cyanide binds Complex IV - Cyto a/a3) |
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What are the symptoms of CO poisoning?
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Lips and cheeks turn cherry red color
Headache, N/V, tachycardia, tachypnea (Binds Complex IV - cyto a/a3) |
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What is the rate limiting enzyme of glycogen synthesis?
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Glycogen Synthase
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What hormones activate glycogen synthase?
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Insulin and glucose in the liver
Insulin in muscle |
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What hormones inhibit glycogen synthase?
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Glucagon and Epi in the liver
Epi in the muscle |
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What enzyme breaks down glycogen?
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Glycogen Phosphorylase
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What enzyme converts glucose-6-P to glucose?
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Glucose-6 Phosphatase
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What enzyme is lacking in Von Gierke's disease?
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Glucose-6-Phosphatase
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What are the symptoms of Von Gierke's disease?
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SEVERE HYPOGLYCEMIA during fasting (unable to perform gluconeogenesis or glycogenolysis)
Lactic acidosis, hepatomegaly, hyperlipidemia, hyperuricemia |
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What enzyme is deficient in Pompe's disease?
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a-1,4-glucosidase
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What are the symptoms of Pompe's disease?
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Cardiomegaly, muscle weakness, death by 2 years
Build up of glycogen like material in inclusion bodies |
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What enzyme is deficient in Cori's disease?
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Glycogen Debrancing Enzyme
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What are the symptoms of Cori's disease?
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Mild hypoglycemia, hepatomegaly
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What enzyme is deficient in McArdle's disease?
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Muscle glycogen phosphorylase
(McArdle's = Muscle) |
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What are the symptoms of McArdle's disease?
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Muscle cramps and weakness on exercise (McArdle's = Muscle)
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What enzyme is deficient in Hers disease?
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Hepatic Glycogen Phosphorylase
(Hers = Hepatic) |
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What are the symptoms of Hers disease?
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Mildy fasting hypoglycemia, hepatomegaly, cirrhosis
(Hers = Hepatic) |
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What enzyme converts Pyruvate to OAA?
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Pyruvate Carboxylase (uses Biotin)
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How does OAA generated in the mitochondria get to the cytoplasm for gluconeogenesis?
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OAA is converted to Malate in the mitochondria, and then transported into the cytoplasm and converted by to OAA
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What enzyme controls the rate of gluconeogenesis?
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Fructose-1,6-bisphosphatase
+ - Glucagon - = insulin, Fructose-2,6-bisphosphate |
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How does Acetyl CoA regulate PDH and Pyruvate Carboxylase?
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During periods of fasting, accumulation of Acetyl CoA activates Pyruvate Carboxylase and inhibits PDH
In the well fed state, acteyl CoA is shuttled into the cytoplasm via Citrate for fatty acid synthesis |
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How does alcoholism cause Hypoglycemia?
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Detoxification of alcohol produces NADH, and the increase in NADH/NAD ratio in turn inhibits gluconeogenesis
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What are the major functions of the Hexose Monophosphate Shunt?
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1. Produce NADPH
2. Source of Ribose-5-P for nucleotide synthesis |
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What are the functions of NADPH?
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1. Biosynthesis (Liver)
2. Maintenance of glutathione (RBC) 3. Bacteriacidal activity (Neutrophils) |
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What is the major enzyme of the Hexose Monophosphate Shunt?
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Glucose-6-P Dehydrogenase
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What enzyme is responsible for the interconversion of Fructose-6-P and G-3-P with Ribose-5-P? (Requires Thiamine)
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Transketolase
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What are the symptoms of Glucose-6-P Dehydrogenase deficiency?
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Most common hereditary cause of hemolytic anemia (usually following bacterial or viral infection)
Heinz bodies Chronic granulomatous Disease Can protect against Malaria Induced by fava beans |
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What enzyme hydrolyzes triglycerides to fatty acids and glycerol?
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Hormone Sensitive Lipase
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What hormones activate Hormone Sensitive Lipase?
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Epinephrine and Cortisol
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What enzyme activates fatty acids (adds acetyl group) for B-oxidation?
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Fatty Acyl CoA Synthetase
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How are fatty acids transported into the mitochondrial matrix for B-oxidation?
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Fatty acyl CoA in the outer mitochondrial matrix is attached to carnitine via Carnitine acyltransferase-1 which is shuttled into the mitochondrial matrix and then the fatty acyl CoA is released via Carnitine acyltransferase-2
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What are the products of B-oxidation?
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NADH
FADH2 Acetyl CoA |
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What enzymes are responsible for the oxidation of fatty acids?
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Fatty Acyl CoA Dehydrogenase
(LCAD, MCAD) |
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What are the symptoms of a MCAD (Medium Chain Acyl CoA Dehydrogenase) deficiency?
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Profound fasting, non-ketonic, hypoglycemia
Lethargy, coma, death Provoked by overnight fast in infant or illness that causes loss of appetite/vomiting in adult |
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What are the symptoms of Carnitine Acyl Transferase (CAT) deficiency?
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Most commonly occurs in muscle
Muscle aches, weakness Rhabdomyolysis, myoglobinuria, red urine Provoked by exercise, especially after fasting Muscle biopsy shows elevated TG in cytoplasm |
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What does the final step in B-oxidation produce for odd chain FA? (HInt: breakdown of 5C)
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Acetyl CoA (2C)
Propionyl CoA (3C) |
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What is propionyl CoA converted to for energy use?
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Succinyl CoA (intermediate of the TCA cycle and can be converted to Malate and used to generate glucose via gluconeogenesis)
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What enzymes are used to convert Propionyl CoA to Succinyl CoA?
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Proprionyl CoA Carboxylase (Biotin)
METHYLMALONYL COA MUTASE (VIT B12) |
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Name the ketone bodies?
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Acetoacetate
3-hydroxybutyrate |
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What lysosomal enzyme is missing in Tay-Sachs disease?
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Hexosaminidase A
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What substrate accumulates in inclusion bodies in Tay-Sachs disease?
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Ganglioside GM2
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What are the symptoms of Tay-Sachs disease?
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Cherry red spots in the macula
Blindness Psychomotor retardation Death < 2 years |
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What lysosomal enzyme is missing in Gaucher's disease?
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Glucocerebrosidase
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What substrate accumulates in inclusion bodies in Gaucher's disease?
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Glucocerebroside
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What are the symptoms of Gaucher's disease?
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Hepatosplenomegaly
Erosion of bones, fractures Pancytopenia |
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What lysosomal enzyme is missing in Niemann-Pick disease?
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Sphingomyelinase
(PICK your nose with your SPHINGer) |
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What substrate accumulates in inclusion bodies in Niemann-Pick disease?
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Sphingomyelin
(PICK your nose with your SPHINGer) |
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What are the symptoms of Niemann-Pick disease?
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Cherry red spots in macula
Hepatosplenomegaly Microcephaly, mental retardation Early death |
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What lysosomal enzyme is missing in Fabry's disease?
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Aryl Sulfatas
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