Molecular Biology Flashcards
Parietal Cells
Found in stomach. Produce HCL and Intrinsic Factor
HCL
Degrades protein, activates pepsinogen
Chief Cells
Found in stomach. Produce pepsin
Endopeptidase
Degrades protein to peptide
G Cell
Found in stomach. Produces gastrin (blood stream)
Mucus Cell
Found in stomach. Secretes Mucus and HCO3 to protect the stomach lining
Enteropeptidase/Enterokinase (brush border)
Found in duodenum. Activates trypsinogen -> trypsin, which in turn activate proteases to hydrolyze protein.
Hyperchlorhydria
Zollinger Ellison syndrome. Gastrin secreting tumor
HYPOchlorhydria
Pernicious Anemia. Autoimmune destruction of parietal cells. B12 deficiency
Cystic Fibrosis
Decrease pancreatic enzymes. Mutation in CFTR
Hartnup disease
Defect absorbing neutral AA. Decrease in Tryptophan and Niacin (Pellagra like manifestations) Photosensitivity.
Cystinuria
Defect in dibasic AA absorption (Cysteine). Cysteine stones - Kidney stones
H2 Blocker
Treats HYPOchlorydria
Glucogenic AA Degradation
Alanine -> Pyruvate -> Glucose
TCA Intermediates
Ketogenic Degradation of AAs
Lysine -> Acetyl CoA -> Ketone Bodies
Purely Ketogenic Amino Acids
Leucine & Lysine
Glucogenic & Ketogenic Amino Acids
Isoleucine, Phenylalanine, Threonine, Tryptophan & Tyrosine
Transamination
Catalyzed by aminotransferases/transaminases. Pyridoxal Phosphate (B6) - cofactor. Transfers alpha amino group from one carbon skeleton (amino acid) to another (α-keto acid, which becomes an amino acid). Can not be done to lysine or threonine.
Trans-deamination
Transaminate L-amino acids to generate glutamate, which can then be oxidatively de-animated to to form α-ketoglutarate and ammonia.
Excretion from Intestines
NH3 -> directly to Portal system (Liver) (Periportal)
Excretion from Liver
Urea / Protein (synthesis) to transport nitrogen
Excretion from Muscle
Breaks down branched chain amino acids (BCAAs)
Form Alanine -> transport NH3 to liver
Form Glutamine -> transport NH3 to kidneys