Term
| Chediak - Higashi syndrome |
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Definition
Chediak-Higashi syndrome is a microtubule polymerization defect resulting in decreased fusion of phagosomes and lysosomes
SYMPTOMS = recurrent pyogenic infections, partial albinism, and peripheral neuropathy |
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Term
| Kartagener's syndrome (cause, symptoms) |
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Definition
Kartagener's syndrome is caused by immotile cilia due to dynein arm defect.
SYMPTOMS = male and female infertility, bronchietasis, recurrent sinusitis (associated with situs inversus) |
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Term
| Disease resulting from defect in type I collagen: |
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Definition
Osteogenesis Imperfecta is a Type 1 collagen disorder.
Type 1 collagen accounts for 90% of the bodies collagen - used in bone, skin, tendon, dentin, fascia, cornea, and late wound repair. |
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Term
| Disease resulting from type III collagen defect: |
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Definition
Ehlers - Danlos (III = D) is caused by a defect in type III collagen.
Type III collagen = Reticulin - used in skin , blood vessels, uterus, fetal tissue, and granulation tissue |
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Term
| Disease caused by defect in type IV collagen: |
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Definition
Alport Syndrome is caused by a defect in type IV collagen.
Type IV collagen = used in basement membranes and basal lamina |
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Term
| Orotic aciduria (inheritance pattern, symptoms, treatment) |
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Definition
Orotic aciduria is an autosomal recessive dz.
SYMPTOMS: Increased orotic acid, normal ammonia levels, megaloblastic anemia (without response to B12 or folic acid). and failure to thrive.
Don't confuse with OTC deficiency (an X-linked recessive dz) - characterized by increased orotic acid AND increased ammonia.
TX for orotic aciduria: oral uridine administration (normally is synthesized from orotic acid) |
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Term
| Adenosine deaminase deficiency causes what disease? |
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Definition
Adenosine deaminase deficiency causes SCID = severe combined immunodeficiency dz. (ex: bubble boy).
Rxn catalyzed be adenosine deaminase:
>> adenosine --> inosine (part of the purine salvage pathway, inosine can be made into a nucleic acid (GMP or AMP) or can be broken down into uric acid)
A deficiency in adenosine deaminase causes excess ATP and dATP. |
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Term
| Lesch - Nyhan syndrome (inheritance, defective enzyme/ pathway, symptoms) |
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Definition
Lesch Nyhan syndrome is an X-linked recessive dz caused by defective purine salvage - due to absence of HGPRT. This results in excess uric acid production (more stuff gets broken down than recovered) and increased de novo purine synthesis (due to lack of salvage).
Fxn of HGPRT:
>> hypoxanthine --> IMP (inosinic acid) - a precursor for AMP.
>> Guanine --> GMP - a precursor for IMP.
** remember - both GMP and AMP are needed to make nucleic acids
SYMPTOMS: retardation, self-mutilation, aggression, hyperuricemia (--> gout), choreoathetosis |
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Term
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Definition
| Uses ATP to add high energy phosphate group onto substrate. |
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Term
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Definition
| adds inorganic phosphate onto substrate without using ATP |
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Term
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Definition
| removes phosphate group from substrate |
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Term
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Definition
| Dehydrogenase oxidizes the substrate (transfers H- from substrate to acceptor like NAD+ or FAD) |
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Term
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Definition
| Carboxylase: transfers CO2 groups with help of biotin |
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Term
| Rate limiting step of: Glycolysis |
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Definition
The rate limiting step of glycolysis is: Phosphofructokinase-1 (PFK-1) -
>> converts fructose-6-phosphate (F6P) --> fructose-1,6-bisphosphate (F-1,6-BP)
** note: F6P is also the end product of the HMP shunt pathway. |
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Term
| Rate limiting step of: Gluconeogenesis |
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Definition
The rate limiting step of gluconeogenesis is Fructose-1,6 - bisphosphatase.
>> fructose-1,6-bisphosphate --> fructose-6-phosphate (reverse function of phosphofructokinase-1) |
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Term
| Rate limiting step of: TCA cycle |
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Definition
The rate limiting step of the TCA cycle is: Isocitrate dehydrogenase.
>> Isocitrate --> alpha-ketoglutarate (+ produces NADH) |
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Term
| Rate limiting step of: Glycogen synthesis |
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Definition
The rate limiting step of glycogen synthesis is: Glycogen synthase
>> adds UDP-glucose to chain of glucose molecules |
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Term
| Rate limiting step of: HMP Shunt |
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Definition
The rate limiting step of the HMP Shunt pathway is: Glucose-6-phosphate dehydrogenase (G6PD)
>> G6P (glucose-6-phosphate) --> 6-phosphogluconolactone (1st step of HMP shunt) |
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Term
| Rate limiting step of: De novo pyrimidine synthesis |
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Definition
| The rate limiting step of the de novo pyrimidine synthesis pathway is Carbamoyl phosphate synthetase II |
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Term
| Rate limiting step of: De novo purine synthesis |
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Definition
| Glutamine - PRPP amidotransferase |
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Term
| Rate limiting step of: Urea Cycle |
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Definition
| Carbamoyl phosphate synthetase I |
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Term
| Rate limiting step of: Fatty Acid Synthesis |
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Definition
| Acetyl-CoA carboxylase (ACC) |
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Term
| Rate limiting step of: Fatty Acid Oxidation |
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Definition
| Carnitine acyltransferase I |
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Term
| Rate limiting step of: Ketogenesis |
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Definition
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Term
| Rate limiting step of: Cholesterol synthesis |
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Definition
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Term
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Definition
Glucogenic: Met, Val Arg, His
Glucogenic/ ketogenic: Ile, Phe, Thr, Trp, Tyr
Ketogenic: Leu, Lys |
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Term
| Acidic and Basic Amino Acids |
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Definition
Acidic: Asp, and Glu - both are negatively charged at body pH
Basic Arg, Lys, and His. - His is uncharged at body pH and Arg is the most basic. |
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Term
| Glucose-6-Phosphate Dehydrogenase Deficiency |
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Definition
** X linked recessive disorder - most common human enzyme deficiency; more prevalent among blacks. Conveys some malarial resistance.
Histology: see Heinz bodies (oxidized Hg precipitates within RBCs) and Bite Cells (result of macrophages removing heinz bodies from RBCs in spleen) |
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Term
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Definition
| Autosomal Recessive defect in fructokinase. A benign, asymptomatic condition |
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Term
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Definition
Autosomal Recessive deficiency in aldolase B.
Result = Fructose - 1- phosphate accumulates causing a decrease in available phosphate = inhibits glycogenolysis and gluconeogenesis
Symptoms: hypoglycemia, jaundice, cirrhosis, vomiting
TX: decease intake of both fructose and sucrose (remember sucrose = fructose + glucose) |
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Term
| 4 enzymes involved in metabolism that require Thiamine (Vitamin B1) as a cofactor) |
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Definition
1) pyruvate dehydrogenase (pyruvate --> acetyl CoA)
2) alpha-ketoglutarate dehydrogenase (alpha-ketoglutarate --> succinyl CoA)
3) Transketolase (HMG shunt)
4) Branched Chain AA dehydrogenase |
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Term
| Alkaptonuria (onchronosis) |
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Definition
Relatively rare benign dz - caused by autosomal recessive deficiency of Homogentistic acid oxidase (involved in degradation of Tyr to Fumarate).
Symptoms: brown sclera, dark connective tissue, and may have arthralgias because the excess homogentistic acid is toxic to cartilage. |
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Term
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Definition
Autosomal recessive deficiency of phenylalanine hydroxylase (or due to deficiency of tetrahydrobiopterin cofactor)
Treatment: decrease phenylalanine and increase Tyrosine in diet. (Tyrosine becomes essential)
Symptoms: mental retardation, growth retardation, seizures, fair skin, eczema, and musty body odor (due to disorder of aromatic amino acid metabolism) |
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Term
| Albinism (molecular causes) |
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Definition
Variable inheritance -
1) AR form: caused by deficiency in Tyrosinase (cannot synthesize melanin from Tyr)
2) Can also be caused by defective Tyrosine transporters (see decrease in Tyr which caused less melanin) |
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Term
| Synthetic processes that occur within Mitochondria |
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Definition
1) Beta-oxidation of Fatty Acids
2) Ketogenesis
3) TCA/ Citric Acid Cycle
4) Parts of the Urea Cycle (specifically carbamoyl phosphate synthetase and ornithine transcarbamoylase)
5) Pyruvate carboxylation (initial step in gluconeogenesis - converting pyruvate to oxaloacetate).
6) Acetaldehyde dehydrogenase (2nd step in alcohol breakdown - zero order kinetics - converts acetylaldehyde to acetate producing NADH in the process)
7) initial and final parts of Heme synthesis |
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Term
| Lead poisoning - see build up of two substances which are: |
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Definition
Delta aminolevulinic acid and protoporphyrin
Delta aminolevulinic acid is synthesized by combining glycine and succinyl-CoA - the process requires B6 (pyridoxal phosphate) as a cofactor. |
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Term
| Pyruvate Dehydrogenase - fxn and cofactor and what happens in deficiency |
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Definition
post - Glycolysis enzyme. (therefore is located in the mitochondria)
Converts pyruvate --> acetyl CoA = irreversible step.
COFACTOR = B1 (Thiamine)
DEFICIENCY = build up of lactic acid --> lactic acidosis |
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Term
| Pyruvate Carboxylase (fxn, cofactor, location) |
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Definition
Converts -- pyruvate --> oxaloacetate (Gluconeogenesis - located in mitochondria)
IRREVERSIBLE
COFACTOR = Biotin (also requires ATP and is activated by acetyl - CoA) |
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Term
| Ornithine Transcarbamoylase (OTC) (fxn, deficiency) |
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Definition
Key enzyme in urea cycle, located in mitochondria
>> ornithine + carbamoyl phosphate --> citrulline
DEFICIENCY => carbamoyl phosphate build up and is converted to orotic acid. Most urea cycle disorder, X-linked recessive. See increased orotic acid in blood and urine + hyperammonemia. |
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Term
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Definition
Enzyme in HMP shunt. HMP shunt = main source of NADPH, key for reductive rxns.
LOCATION = cytosol
>> Ribulose-5-Pi (+ B1) --> Ribose-6-P + G3P + F6P
COFACTOR = B1 (thiamine) |
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Term
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Definition
| aka Complex II in electron transport chain |
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Term
| HMG - CoA (3-hydroxy-3methylglutaryl-CoA) |
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Definition
| Located in mitochondria, key to ketogenesis - there is a lyase and synthase. |
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Term
| Galactokinase (fxn, deficiency) |
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Definition
>> galactose --> galactose-1-P (req. ATP)
DEFICIENCY = mild (AR) dz, galactose appears in urine and blood, infantile cataracts.
Cataracts due to build up of galactitol - a polar breakdown product of galactose that can be trapped within cells. |
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Term
| Galactose 1-phosphate Uridyl transferase (fxn, deficiency, tx) |
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Definition
>> Galactose-1-P + UDP-glucose --> UDP-galactose + Glucose-1-P
DEFICIENCY: Classic galactosemia, an AR condition. Get damage from byproducts of high galactose levels (specifically galactitol --> cataracts). Symptoms = FTT, jaundice, infantile cataracts.
TX: exclude galactose and lactose from diet |
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Term
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Definition
>> Galactose --> Galactitol
** Galactitol = polar product, builds up when there are deficiencies in the galactose metabolism pathway. Can build up in cells causing bilateral cataracts. |
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Term
| Fabry Disease (symptoms, enzyme, accumulation product) |
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Definition
SYMPTOMS: peripheral neuropathy, angiokeratomas (dark, red, non-blanching macules and papules), CV/renal dz
Deficient Enzyme: alpha-galactosidase A
Accumulation of: Ceramide trihexosidase |
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Term
| Leber Hereditary Optic Neuropathy |
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Definition
A mitochondrial myopathy (can only be transmitted by mother)
SYMPTOMS: acute loss of central vision, "ragged red" fibers on microscopy. |
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Term
| X-linked Recessive Disorders |
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Definition
Pneumonic: Be Wise, Fool's GOLD Heeds Silly Hope
1) Bruton's agammaglobulinemia
2) Wiscott-Aldrich syndrome
3) Fabry's dz
4) G6PD deficiency
5) Ocular albinism
6) Lesch-Nyhan
7) Duchenne's muscular dystrophy (and Becker's)
8) Hunter's syndrome
9) Hemophilia A and B |
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