CHEM 153C Final: PROTEINS – AMINO ACIDS METABOLISM important points
23 Jun 2016
School
Department
Course
Professor
Document Summary
Protein monomeric units - peptide bonds cleaved in small intestine. Energy source (atp) (aa -> cmp and waste products to generate atp) Source of carbon and nitrogen (heme, nucleotides, amines, nucleotide. Precursors of other biological molecules (a-ketoacids; pyruvate, oaa, a-kg) => glucose / fa / ketone bodies. Degradation of keto acids to central metabolites. Generation & excretion of nitrogen waste products. Acidic ph (internal ph = ~5: protects cells from accidental lysosomal protein leakage) Functions: degrade endocytosed material, nonselective pathway: recycle vacuolar-enclosed material (autophagy) Not brain, testes, etc: muscle wastage: disuse, denervation, or traumatic injury. Regression of uterus following child birth (2 kg > 50 g in 9 days) Atp-dependent process independent of lysosomes: rheumatoid arthritis: extracellular release of lysosomal enzymes. Ubiquitin (marks proteins for degradation) - condemned proteins. 76-residue monomeric protein: ubiquitous and abundant, highly conserved identical in: E1: ubiquitin-activating enzyme: ubiquitin-coo- + e1-sh => ubiquitin-co-s-e1 coupled with atp hydrolysis. E2: ubiquitin-conjugating enzyme: ubiquitin-co-s-e1 + e2-sh => ubiquitin-co-s-e2.
