MLS 2213 UNIT 11; HEME DERIVATES TEST
Binds to iron and is involved in iron transport throughout the body
Transferrin
Describe the difference between heme and haemoglobin
Heme: protoporphyrin ring + Fe
Hemoglobin: Heme + 4 globulin chains
Common globulin chains
alpha (𝞪), beta (𝛃), delta (𝛅), and gamma (𝞬)
Site of iron absorption
Small intestine
Iron in what form is toxic to the tissues?
Unbound
Ferritin: Function? Iron form? Location?
Function: storage form of iron
Form: Ferric form (3+)
Location: Liver
Functional form of iron primarily in the blood
Ferrous (2+)
Porphyrins
Class of pigments whose molecules contain a flat ring of four linked
heterocyclic groups (possibly with a central mental ion)
Porphyrias
(purple in greek)
Diseases caused by enzyme deficiencies in the heme production
pathway
A black inorganic compound formed from heme when RBCs are lysed
and exposed to air. (Can be a treatment for some porphyrias)
Hemin
Primary Porphyrias
Porphyria Cutanea Tarda, Acute Intermittent Porphyria, Erythropoietic
Porphyria, ALA-Dehydratase Deficiency
Porphyria Cutanea Tarda: Deficiency? Best test to order? Defined by?
, Deficiency: Uroporphyrinogen Decarboxylase
Best test to order: Serum porphyrin
Defined by: Blistering
Acute Intermittent Porphyria: Deficiency? Best test to order? Defined by?
Deficiency: PBG Deaminase
Best test to order: urine porphobilinogen
Defined by: blistering and nerve impairments
Erythropoietic Porphyria: Deficiency? Increase in? Defined by?
Deficiency: Ferrochelatase
Increase in: total erythrocyte protoporphyrin
Defined by: blistering
Enzyme deficiency affecting the rate-limiting step in porphyrin synthesis
ALA-Dehydratase Deficiency
ALA-Dehydratase Deficiency: Results in? Confounded by? Presenting
symptom?
Results in: accumulation of delta-aminolevulinic acid
Confounded by: lead poisoning
Presenting symptom: abdominal pain
Secondary Porphyrias
Lead poisoning, hereditary tyrosinemia, liver disease, iron deficiency
anemia
Inhibits most enzymes in the synthetic pathway
Lead poisoning
Causes elevated levels of succinylacetone leading to elevated levels of
d-Aminolevulinic Acid
Hereditary tyrosinemia
Causes a problem synthesizing heme
liver disease
Leads to an increase in heme production and Erythrocyte protoporphyrin
Iron Deficiency Anemia
Binds to iron and is involved in iron transport throughout the body
Transferrin
Describe the difference between heme and haemoglobin
Heme: protoporphyrin ring + Fe
Hemoglobin: Heme + 4 globulin chains
Common globulin chains
alpha (𝞪), beta (𝛃), delta (𝛅), and gamma (𝞬)
Site of iron absorption
Small intestine
Iron in what form is toxic to the tissues?
Unbound
Ferritin: Function? Iron form? Location?
Function: storage form of iron
Form: Ferric form (3+)
Location: Liver
Functional form of iron primarily in the blood
Ferrous (2+)
Porphyrins
Class of pigments whose molecules contain a flat ring of four linked
heterocyclic groups (possibly with a central mental ion)
Porphyrias
(purple in greek)
Diseases caused by enzyme deficiencies in the heme production
pathway
A black inorganic compound formed from heme when RBCs are lysed
and exposed to air. (Can be a treatment for some porphyrias)
Hemin
Primary Porphyrias
Porphyria Cutanea Tarda, Acute Intermittent Porphyria, Erythropoietic
Porphyria, ALA-Dehydratase Deficiency
Porphyria Cutanea Tarda: Deficiency? Best test to order? Defined by?
, Deficiency: Uroporphyrinogen Decarboxylase
Best test to order: Serum porphyrin
Defined by: Blistering
Acute Intermittent Porphyria: Deficiency? Best test to order? Defined by?
Deficiency: PBG Deaminase
Best test to order: urine porphobilinogen
Defined by: blistering and nerve impairments
Erythropoietic Porphyria: Deficiency? Increase in? Defined by?
Deficiency: Ferrochelatase
Increase in: total erythrocyte protoporphyrin
Defined by: blistering
Enzyme deficiency affecting the rate-limiting step in porphyrin synthesis
ALA-Dehydratase Deficiency
ALA-Dehydratase Deficiency: Results in? Confounded by? Presenting
symptom?
Results in: accumulation of delta-aminolevulinic acid
Confounded by: lead poisoning
Presenting symptom: abdominal pain
Secondary Porphyrias
Lead poisoning, hereditary tyrosinemia, liver disease, iron deficiency
anemia
Inhibits most enzymes in the synthetic pathway
Lead poisoning
Causes elevated levels of succinylacetone leading to elevated levels of
d-Aminolevulinic Acid
Hereditary tyrosinemia
Causes a problem synthesizing heme
liver disease
Leads to an increase in heme production and Erythrocyte protoporphyrin
Iron Deficiency Anemia
