Terminology

-Lactalbumin - Protein that, when bound to galactosyltransferase, converts it to the enzyme lactose synthase.
Amino Acids - Molecules, such as alanine, containing an amino group on the carbon adjacent to a carboxyl group. The building blocks of proteins.
Anaplerotic Reactions - Pathways which provide molecular intermediates for the citric acid cycle. A term that literally means 'to build up intermediates.'
Bacitracin - Antibiotic that kills bacteria by interferring with peptidoglycan synthesis by inhibiting conversion of undecaprenol pyrophosphate to undecaprenol phosphate (Figure 16.20).
Dolichol Phosphate - The lipid upon which oligosacchardies for N-linked glycoproteins are assembled (Figure 16.17)
Endergonic - In a nonisolated system, a process that is accompanied by a positive change in free energy (positive G) and therefore is thermodynamically not favored.
Exergonic - In a nonisolated system, a process that is accompanied by a negative change in free energy (negative G) and therefore is thermodynamically favored.
Glucogenic - Amino acids which can be converted to oxaloacetate.
Gluconeogenesis - Biosynthesis of carbohydrate from three and four carbon precursors, generally noncarbohydrate in nature (Figure 16.1, Table 16.1).
Glucose-Alanine Cycle - A process parallel to the Cori cycle in which pyruvate in peripheral tissues undergoes transamination to alanine, which is returned to the liver and used for gluconeogenesis. This pathway is important to help tissues dispose of toxic ammonia during protein degradation
Glycoconjugates - Macromolecules containing covalently bound oligosaccharide chains.
Glycogen - A polymer of glucose units linked -1,4 with numerous branches linked -1,6. Is the primary glucose storage form in animals (Figure 16.9).
Glycogen Storage Diseases - Medical condition causes by deficiencies in enzymes of (or related to) glycogen metabolism (Table 16.2).
Hypoglycemia - A potentially dangerous decrease in blood glucose levels.
I-cell Disease - Rare congenital disease in which lysosomal function is defective due to problems with transport of N-linked glycoproteins. The problem arises because a glycosyl transferase that generates mannose-6-phosphate is defective, causing lysosomal enzymes to be transported outside of the cell.
Lactam Ring - A four membered ring of penicillin that opens during reaction with the bacterial transpeptidase, forming a cross link with the enzyme.
N-linked Glycoproteins - A glycoprotein in which the oligosaccharide is joined to protein via the structure shown in Figure 16.16.
O-linked Glycoproteins - A glycoprotein in which the oligosaccharide is joined (most commonly) to protein via an N-acetylgalactosamine-serine (or threonine) linkage.
Peptidoglycans - Components of the bacterial cell wall that consist of polymeric chains of amino sugars cross-linked by oligopeptide chains, to form a huge three dimensional network (Figure 9.25).
Polysaccharides - Long polymers of monomeric carbohydrate units used for energy storage and structural integrity of cells.
Proteoglycans - Glycoproteins rich in carbohydrate (50% or more) containing sulfated polysaccharides or sialic acid.
R 2C 2 - A description of the subunit composition of cAMP-dependent protein kinase. The R is a regulatory subunit that inhibits the catalytic subunit (C) when it is bound to it. cAMP causes the R subunits to become unbound from the C subunits, activating the enzyme.
Reciprocal Regulation - A type of regulation of catabolic and anabolic pathways where the mechanism(s) that inactivate one pathway, activate the other. This prevents both pathways from being active simultaneously (Figure 16.7).
Sugars - Also known as saccharides. Molecules having the general structure (CH 2O)n. Glucose and galactose are common ones.
Transpeptidation - Reaction involving cleavage of one peptide bond, which provides the energy needed to drive the formation of another peptide bond. Occurs in cross-linking of peptidoglycan strands of the bacterial cell wall (Figure 16.21).
Triacylglycerols - Also known as fats or oils, these molecules are composed of glycerol esterified to three acyl groups.
Undecaprenol Phosphate - Lipid carrier containing 11 isoprenoid units with a phosphate at the end. The phosphate accepts the N-acetylmuramylpentapeptide moiety in bacterial peptidoglycan synthesis. To this complex, five glycyl residues are added from glycyl tRNA. The complex may also be the form that is transferred through the lipid bilayer (Figure 16.20).
Vancomycin - Antibiotic that kills bacteria by interfering with peptidoglycan synthesis by inhibiting transfer of the peptidoglycan from undecaprenol pyrophosphate to its acceptor. Figure 16.20
Vitamin B 12 - A necessary coenzyme for propionate to be converted to succinyl-CoA, on its gluconeogenic pathway.