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185 Cards in this Set
- Front
- Back
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which two zinc-containing heme enzymes are inactivated by lead
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aminolevulinate dehydratase
ferrochelatase |
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serves as the initiation sequence for translocation
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kozak sequence
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what happens if there is a mutation 3 base pairs upstream from AUG (start codon) in the kozak sequence
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initiation is stopped - this 3rd base pair is the key base in the sequence
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mutation of what in the B-globulin gene is associated with thalassemia intermedia
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kozak sequence
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high output cardiac failure is suggestive of what vitamin deficiency
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thiamin (B1) - wet beriberi
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what can all cells produce from fructose-6-P since not all can produce NADPH
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ribose via tranketolase and transaldolase
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what is the principle stabilizing force for secondary structure of proteins
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hydrogen bonds
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what is rRNA synthesized
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nucleolus
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most abundant amino acid in collagen molecule, every third amino acid
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glycine
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allosteric activator of gluconeogenesis that acts by increase activity of pyruvate carboxylase
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acetyl-CoA
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where do thyroid hormones bind to alter gene transcription
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receptors inside of the nucleus
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what are two mutations that can lead to Ehlers-Danlos (collagen mutation)
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lysyl-hydroxylase deficiency
pro-collagen peptidase deficiency |
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point mutation of valine for glutamic acid
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sickle cell disease
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defect in fibrillin
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Marfan's syndrome
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what recognizes stop codons
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releasing factors
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stop codons
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UAA
UAG UGA |
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what help homocysteine turn into methionine
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5-methyl THF --> THF
Methylcobalamin --> cobalamin |
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most common cause for homocystinuria
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defect in cystathionine synthetase
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what cofactor is needed to turn homocysteine to cystein
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B6
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unable to metabolize F-1-6 into G-3-P or DHAP
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Aldolase B deficiency
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cytoplasmic P bodies
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important for mRNA transcription and degredation
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Can patients still form F-6-P in essential fructosuria
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yes; even though they have deficiency fructokinase, hexokinase can be used
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One bacterial mRNA can code for several proteins - such as those necessary for lactose metabolism in E. coli
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**
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What causes galactose to be converted to galactitol
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aldose reductase
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hypoglycemia and increased NADH/NAD ratio
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too much EtOH consumption
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what inhibits gluconeogenesis, seen in alcoholics
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increased NADH
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why mature erythrocytes lose the ability to synthethasize heme
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because they lose their mitochondria which is necessary for the first and final three steps in heme synthesis
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why are patients with homozygous B-thalassemia assymptomatic at birth
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because they mainly have HbF - no B globulins are found in this
Only HbA is affected |
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associated with excessive ingestion of egg whites
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biotin deficiency
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acts as a CO2 carrier for carboxylase enzymes
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biotin
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what three enzymes need biotin for their carboxylase action
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pyruvate --> oxaloacetate
acetyl-CoA --> malonyl-CoA propinoyl-CoA --> methylmalonyl-CoA |
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acts as a signal for a-chains of collagen to enter the RER where proline and lysin are hydroxylated
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N-terminal contains a signal peptide
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where are the N and C terminus cleaved on the pro-alpha chain yielding a collagen monomer
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ECM
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what enzyme cross-links collagen and elastin monomers
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lysyl oxidase
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ketogenic amino acids
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lysin
leucine |
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which two amino acids would not raise blood lactate levels in patients with pyruvate dehydrogenase deficiency
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lysine
leucine |
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what is the cofactor for the conversion of phenylalanine --> tyrosine and tyrosin --> DOPA
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BH4
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what resynthesizes BH4 from BH2
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dihydrobiopterin reductase
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what causes propionic acidemia
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propinoyl-CoA carboxylase deficiency
propinoyl-CoA **--> methylmaonyl-CoA --> succinyl-CoA |
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what is propinoyl-CoA derived from
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odd-numbered fatty acids and some amino acids
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what forms aminolevulinic acid
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succinyl-CoA + glycine + pyridoxal phosphate (cofactor)
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young person who lives in an older house that develops anemia
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think lead poisoning which blocks ALA dehydratase and ferrochelatase
*build up of ALA and protoporphyrin IX |
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which end of the tRNA binds amino acid
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3' end
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what sort of acidosis is seen in patients in septic shock with tissue hypoxia
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lactic acidosis secondary to impaired oxidative phosphorylation from decreased oxygen
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binds intracellularly and is transported to the nucleus where it alters gene expression for gluconeogenesis
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cortisol
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what upregulates expression of lac operon in E. coli
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presence of lactose which increases cAMP
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used to remove RNA primer and damaged DNA
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5' - 3' exonuclease
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contains 5' - 3' exonuclease activity, 3' - 5' exonuclease activity, and 5' - 3' polymerase activity
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DNA polymerase I
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decrease in what results in increased ALA synthase activity
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heme
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increase in what two molecules are responsible for acute abdominal pain and neurologic symptoms seen in some phorphyrias
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Aminolevulinic acid
porphobilinogen |
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disease associated with abnormal nucleotide mismatch repair
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hereditary non-polyposis colon cancer
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why is F-1-P the most rapidly metabolized for use in glycosis
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because it bypasses PFK-1 (rate-limiting step in glycosis)
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what forms N-acetylglutamate
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acetyl-CoA + glutamate --> N-acetylglutamate + CoA
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what forms carbamoyl phosphate
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CO2 + NH4 + 2ATP + N-acetylglutamate
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x-linked recessive disorder caused by a defect in HGPRT
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Lesch-Nyhan syndrome
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leads to failure of purine salvage pathway causing increased uric acid and de novo purine synthesis
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Lesch-Nyhan syndrome (HGPRT defect)
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enzyme associated with:
hypoxanthin --> IMP guanine --> GMP |
HGPRT
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De novo purine synthesis
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ribose-5-P --> PRPP --> 5-phosphoribosylamine --> IMP --> AMP or GMP
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PPRP aminotransferase
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PRPP --> 5-phosphoribosylamine
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what converts IMP into GMP and AMP respectively
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IMP + GTP --> GMP
IMP + ATP --> AMP |
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debranching enzyme deficiency
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Cori disease
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associated with hypoglycemia, hypertriglyceridemia, ketoacidosis, and hepatomegaly with dextrin-like accumulates
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Cori disease
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secondary lactase deficiency
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occur after viral gastroenteritis or other diseases that damaged intestinal epithelium
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removes improper base-pair nucleotide during replication while checking for errors
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3' - 5' exonuclease
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bisphosphoglycerate mutase
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converts 1,3 - BPG --> 2,3 - BPG
found in erythrocytes |
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what do the nitrogens of urea come from
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1. NH3 used to make carbamoyl phosphate
2. aspartate |
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urea cycle
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carbamoyl phosphate + ornithine --> citrulline + (aspartate) --> argininosuccinate --> (fumarate) + arginine --> urea + ornithine
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where do fumarate and aspartate join in addition to the urea cycle
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TCA cycle
fumarate --> malate --> oxaloacetate --> aspartate (via transamination) |
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from what amino acid can niacin (B3) be endogenously made from
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tryptophan
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3 D's in naicin deficiency
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dermatitis
dementia diarrhea |
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glucose-6-P dehydrogenase
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G-6-P --> 6-phosphogluconate
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oxidize iron in hemoglobin from Fe2+ to Fe3+ forming methemoglobin
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nitrites
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classic galactosemia
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G-1-P uridyltransferase deficiency
G-1-P --> UDP-galactose |
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located outside the nucleosome but help package nucleosome into more compact structure
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Histone H1
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where are enhancers/repressors of gene transcription located
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anywhere upstream, downstream, or within transcribed gene
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where are promoter regions typically located
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25 or 70 bases upstream of transcription site
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what binds transcription factors and RNA polymerase
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promoter region
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where is the TATA box and CAAT box located respectively
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TATA - 25 base pairs upstream
CAAT - 70 base pairs upstream |
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associated with changing the rate of gene transcription and can be located anywhere along the DNA
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enhancers/repressors
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what vitamin supplementation should be given to children with measles from an area deficiency
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Vitamin A
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sphinogmyelinase deficiency leading to accumulation of sphinogmyelin
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Niemann-Pick disease
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associated with loss of motor skills, hepatosplenomegaly, hypotonia, and cherry-red macula
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Niemann-Pick disease
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hexosaminidase A deficiency with Gm2 ganglioside accumulation
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Tay-Sachs disease
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alpha-L-idurinidase deficiency with mucopolysaccharidosis
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Hurler syndrome
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glucocerebrosidase deficiency with glucocerebrosides accumulation in phagocytes
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Gaucher
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two glycogen storage diseases and their respective enzyme deficiencies
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Von Gierke - G-6-phosphatase deficiency
Pompe - lysosomal a-1,4-glucosidase deficiency |
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associated with ceramide trihexoside accumulation with angiokeratomas and renal failure
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Fabry disease - a-galactosidase A deficiency
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heritable connective tissue disease with abnormal collagen
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Ehlers-Danlos
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associated with elastin disorder due to defective fibrillin
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Marfan syndrome
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why can't erythrocytes use keton bodies as fuel
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lack mitochondria and thiophorase
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what allosterically activates muscle phosphorylase and glycogen phosphorylase at the same time
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increased intracellular calcium - activates phosphorylase kinase
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ceramidase deficiency leading to accumulation of ceremide in neurons and skin granulomas
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Farber disease
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arylfulfatase A deficiency causing sulfatides to accumulate leading to destruction of myelin
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metachromatic leukodystrophy
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converts F-1-6 --> DHAP or glyceraldehyde
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Aldolase B
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deficiency in homogentisate oxidase leading to accumulation of homogentisic acid
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alkaptonuria - darkening of urine if allowed to undergo oxidation
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what pathway is blocked in alkaptonuria
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breakdown of tyrosin --> fumarate
homogentisate oxidase is part of this pathway |
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differentiate detection of each: northern, southern, western, and southwest blot
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northern - mRNA
southern - DNA western - protein southwest - DNA-bound proteins |
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induces damage via DNA double-strand fractures and formation of oxygen free radicals
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exposure to radiation
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leads to thymine dimers on DNA strands
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UV radiation
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used to detect amount of a certain protein in body fluids
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ELISA
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what are two general ways to get gout
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increased purine synthesis - PRPP synthetase mutation
decreased degredation or "salvage" or purines - HGPRT defect |
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inhibits chemotaxis of neutrophils by preventing microtubule formation - used in acute gouty arthritis
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colchicine
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what decreases expression of lac operon in E. coli
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addition of glucose to media, induces decreased cAMP
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causes protein to be bigger than normal but non-functional; however, still has immune reactivity
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splice site mutation
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defect seen in thalassemias
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mutation and defective mRNA processing resulting in decreased chain synthesis
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differentiate activated and inactivated Ras protein
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activated - bound GTP
inactivated - bound GDP |
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where are very-long-chain fatty acids and phytonic acid metabolized
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peroxisomes
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what happens when there is an inability to split the bound GTP on Ras protein
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uninhibited cell proliferation and cancer could develop
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what can glycerol from breakdown of TGs be used for
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1. used to make glucose
2. phosphorylated by glycerol kinase to form G-3-P used in glycolysis |
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As hemoglobin binds more O2, what is released
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H
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young child presents with mental retardation, massive stroke, and homocystinuria; what is the deficient enzyme and its cofactor
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cystathione synthetase
B6 is the cofactor |
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most common disorder of the urea cycle, results in increased blood ammonia and orotic acid excretion in urine
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ornithine transcarbamoylase deficiency
carbamoyls phosphate + ornithine --> citrulline |
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converts heme to biliverdin
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heme oxygenase
biliverdin is green pigment seen in bruises days after injury |
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deficient in myophosphorylase leading to failure of glycogenolysis with decreased exercise tolerance, myogloinuria, and muscle pain
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McArdle's syndrome
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needed for carboxylation of glutamate residues for clotting factor production
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Vit. K
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where is conjugated bilirubin found if activated secretion into bile is deficient
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found in blood and urine secondary to passive transport from the liver to the blood
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activation of protein phosphatase-1 by insulin via tyrosine kinase leads to what
|
dephosphorylation (deactivation) of gluconeogensis and glycogenolysis
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carbamoyl synthetase II is the regulatory step for what
|
pyrimidine synthesis
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what inhitis carbamoyl synthetase II and should be given in patient with orotic aciduria
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uridine
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pyrimidine synthetasis
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carbamoyl phosphate + aspartate --> orotate --> uridine --> thymidine or cytidine
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why does HbF have increased O2 affinity
|
inability to interact with 2,3 - DPG
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due to defective a-keto acid dehydrogenase with an inability to break down branched amino acids
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maple syrup urine disease
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associated with sweet smelling urine, dystonias, and poor feeding
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a-keto acid dehydrogenase deficiency
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used to treat cyanide poisoning
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amy nitrite - converts hemoglobin into methemoglobin allowing cyanide to bind and form cyanomethomoglobin
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RNA molecule that has thymidine and dihydrouracil
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tRNA
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which two vitamins are infants deficient in if only given breast milk
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vitamin D and K
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which three enzymes is thiamine a cofactor for
|
pyruvate dehydrogenase
a-ketoglutarate /a-ketoacid dehydrogenase transketolase (part of pentose phosphate pathway) |
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what can you measure to diagnose thiamine deficiency
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erythrocyte transketolase activity
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what leads to insulin resistance
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aberrant serine and threonine residue phosphorylation by serine kinases
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what cause aberrant phosphorylation of serine and threonine residues causing insuline resistance
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TNF-a, catecholamines, glucocorticoids, glucagon
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differentiate Keq in (+)Gibss free energy and (-)Gibbs free energy reactions
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(+) - Keq < 1
(-) - Keq > 1 |
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this deficiency leads to deficient hydroxylation of proline and lysine residues on a-chain collagen monomers in the RER
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vitamin C deficiency
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code for DNA-binding transcription factors that play a role in morphogenesis
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homeobox genes
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why does HbS cause red blood cell distortion (sickle)
|
hydrophobic interaction among hemoglobin molecules due to valine being substituted for glutamic acid
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what dietary restriction should be implicated in patients with defective ornithine transport
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protein - decreased ammonia
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cofactor for synthesis of tyrosine, DOPA, serotonin, and NO
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BH4
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what cause compact structure of heterochromatin (transcriptionally inactive)
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methylated DNA
non-acetylated histones |
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pantothenic acid
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CoA
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phenylethanolamine-N-methyltransferase
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enzyme that converts NE --> E
*under the control of cortisol |
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synthesis of what two things utilizes NADPH produced from the HMP shunt
|
cholesterol and fatty acid synthesis
|
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increased level of what activates PFK-1
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F-2,6-BP
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what three things does increased F-2,6-BP do
|
1. activates PFK-1
2. inhibits fructose bisphosphatase-1 3. inhibits conversion of alanine --> glucose |
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what is the cofactor both aminotransferases (ALT and AST)
|
B6 (pyridoxine)
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what do aspartate and alanine donate their ammonia group to
|
a-ketoglutarate and form glutamate
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during transamination, what do alanine and aspartate turn into respectively after donation of their ammonia group
|
alanine --> pyruvate
aspartate --> oxaloacetate |
|
|
what is the enzyme order for base excision repair
|
glycosylase - generates AP site
endonuclease - cleaves 5' end lyase - cleaves 3' end DNA polymerase - adds new base ligase - fuses adjacent bases together |
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|
deletions or additions of a number of base pairs that are not a multiple of three suggest what
|
frameshift mutation
|
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what gives elastin the ability to recoil
|
cross-linking of lysine residues accomplished by lysl hydroxylase
|
|
|
what induces HbS sickling
|
anoxia, decreased pH, increased 2,3 - DPG
|
|
|
causes closure of Katp channels in B cells in the pancrease
|
increased ATP/ADP ratio
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what does increased ATP in B cells of the pancreas lead to
|
insulin release via increased intracellular calcium due to depolarization from closure of Katp channel
|
|
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what relieves abdominal pain in patient with porphyria
|
glucose administration
decreases ALA synthase |
|
|
patient presents with abdominal pain and darkening of the urine upon standing
|
indicates porphyria
|
|
|
what is needed for PCR to amplify DNA sequences
|
primers that are complementary to the regions of DNA flanking the segment to be amplified
|
|
|
restricts ketone body production because of decreased fatty acid transport into the mitochondria
|
carnitine deficiency
|
|
|
causes left shift on Hemoglobin dissociaton curve
|
increased pH
decreased temp decreased 2,3-DPG |
|
|
causes right shift on hemoglobin dissociation curve
|
decreased pH
increased temp increased 2,3-DPG |
|
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patient presents with hair loss, skin lesions, loss of taste and smell, and they are infertile
|
zinc deficiency
|
|
|
enzyme that posses reverse transcriptase activity and is expressed in stem cells and cancer cells
|
telomerase
|
|
|
contains complementary sequence to mRNA that is necessary for initiation of translation
|
16S rRNA
|
|
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patient presents with homocysteinuria and increased methionine levels in blood
|
cystathionine synthetase deficiency
|
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what is now an essential AA in patients with cystathionine synthetase deficiency
|
cysteine - cannot make from homocysteine
|
|
|
job of each RNA polymerase I, II, and III
|
I - synthesizes rRNA
II - synthesizes mRNA III - synthesizes tRNA and snRNPs |
|
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inhibits formation of dTMP
|
folate deficiency
|
|
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supplementation of what would help in folate deficiency
|
thymidine
|
|
|
hormones associated with tyrosine kinase-associated receptors and JAK/STAT signalling pathway
|
GH
prolactin cytokines |
|
|
activates LCAT (cholesterol esterification in HDL)
|
ApoA-1
|
|
|
apolipoprotein found on chylomicrons
|
ApoB-48
|
|
|
detected by extrahepatic tissue when they want to take up LDL particles
|
ApoB-100
|
|
|
activates lipoprotein lipase
|
ApoC-II
|
|
|
Used by the liver to uptake chylomicron and VLDL remnants
|
ApoE 3 & 4
|
|
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what is needed for decarboxylation of oxaloacetate to PEP
where does this come from |
GTP
formed by conversion of succinyl-CoA --> succinate in TCA cycle |
|
|
incorporates short RNA primers into replicating DNA - therefore you would detect uracil in replicating DNA
|
primase
|
|
|
defective intestinal and renal reabsorption of tryptophan leading to decreased niacin, serotonin, and melanin
|
Hartnup disease - ataxia, skin rash, loose stools
|
|
|
associated with increased ICP, dry skin, and hepatosplenomegaly
|
Vit. A overuse
|
|
|
how does streptomycin prevent protein translation
|
binds to 30S subunit and prevents initiation
|
|
|
analogous to individual subunit of hemoglobin
|
myoglobin
|
|
|
glucokinase defect would result in what
|
gestational diabetes
|
|
|
what does glucokinase do in pancreatic B-cells
|
senses amount of glucose for insulin release or not
|
|
|
single nucleotide deletion or addition
|
leads to frameshift mutation - premature stop codon or dramatic change in protein structure
|
|
|
glycogen accumulation within lysosomes
|
Pompe disease - alpha glucosidase deficiency
|
|
|
what is sorbitol converted to
|
fructose
|
|
|
what is the principal source of blood glucose after 12 to 18 hours
|
gluconeogenesis
|
|
|
hypoglycemia with decreased ketone body formation
|
suggests impaired B-oxidation
*Acetyl-CoA DH catalyzes first step of this rxn |
|
|
decreased P50 of hemoglobin results in what
|
polycythemia because decreased O2 release resulting in tissue hypoxia
|
