Chap 11 Quiz Flashcards
Zymogens
inactive form of enzymes (aka proenzymes)
Pancreatic Enzymes
proteases that cleave peptide linkages
Peptidases
enzymes that cleave peptides into smaller amino acids or small peptides
Protein digestion begins in the
Stomach; Pepsin
Small intestine enzyme
Trypsin
Pancreas/small intestine enzyme
Chymotrypsin
Amino acid absorption
From the intestine to the blood
Biological Roles of A.A.
- Neurotransmitters
- Metabolic intermediates
- Allosteric Regulators
- Metabolism of other A.A.
Transamination (an amino group)
a-keto acid <-aG -> A.A.
A.A. <-aT-> a-keto acid
Oxidative Deamination
A.A. <–> a-keto acid
(H2O + NAD+)
Transamination defined
Process in which ammonia can be removed from an amino acid
The amine transferred to an a-keto acid produces
new amino acid and a-keto acid
Alanine Transaminase
Enzyme that transaminates pyruvate to the amino acid, alanine
Alanine transaminase occurs in the
Muscle
Alanine then travels from the muscle to
Liver
After alanine is at the liver it is transaminated to ____ from _____
glutamate;
a-ketoglutarate
Oxidative Deamination Defined (involves a-keto acid)
the process in which the amine is removed from ammonia
*Oxidative deamination generates
NADH/H+
Glutamate is commonly used and interconverted to
a-ketoglutarate
Glucose-Alanine Shuttle (in muscle)
Metabolic process through which nitrogenous wastes generated in muscle are transferred to pyruvate generating alanine; alanine transported to the liver where it is deaminated and pyruvate is used for gluconeogenesis
Alanine is deaminated to
Pyruvate used for gluconeogenesis
Urea Cycle Defined
metabolic pathway that generates urea from carbamoyl phosphate
Function of Urea Cycle
to detoxify and dispose of ammonia
What 2 subcellular compartments does urea cycle occurs in
Mitochondrial matrix (first two)
Cytosol (remaining steps)
Carbamoyl Phosphate
Compound created from ammonia in order to reduce ammonia levels in the blood
Amino acid categorization
Glucogenic & Ketogenic
2 carbon skeleton
Ketone bodies –> Acetyl-CoA
3 carbon skeleton
pyruvate
4 carbon skeleton
oxaloacetate
Xenobiotics
molecule the body recognizes as foreign
Xenobiotic metabolism
process by which the body detoxifies and eliminates foreign molecules
Xenobiotic metabolism creates more
water-soluble molecules
Phase 1 of Xenobiotic metabolism
1) Oxidation or cleavage
2) Xeno. becomes hydrophilic
3) Products are metabolically active
Phase 2 of Xenobiotic metabolism
Conjugation to larger molecules such as glutathione or glucuronic acid
Ammonotelic
eliminate wastes as ammonia through the skin
Examples of ammonotelic animals
Insects, crustaceans, aquatic invertebrates and some fish and amphibians
Uricotelic
Synthesize uric acid and eliminates it in their waste (not technically urine)
Examples of uricotelic animals
Birds and reptiles
Glucogenic
amino acids that are broken down into products that undergo gluconeogenesis
Ketogenic
Metabolizes products into ketone bodies
(Leucine & Lysine)
Cytochrome P450 enzymes
broad family of enzyme that employ NADPH and molecular O2 to oxidatively modify substrate molecules
Monoamine Oxidases Defined
Enzymes that deactivate neurotransmitters
