(GNG) conversion to pyruvate or CAC intermediates to make glucose.
direct conversion to Acetyl CoA to enter CAC or undergo FA synthesis. Carbons never make it to glucose via GNG (2 carbons lost in CAC).
Branched chain AAs
Isoleucine, Leucine, and Valine (40 percent of skeletal muscle AAs). Significant energy source in skeletal muscles, heart, kidney, and brain. Turned into BCKA by BCKD.
Maple syrup disease
BCKD (branched a-keto acid dehydrogenase) defective. Autosomal recessive disease. Accumulation of BCAAs (branched chain amino acids) and their corresponding BCKAs.
Consist of phenylalanine, tryptophan, and tyrosine. All contain ring structures. Phenylalanine are considered essntial AAs. Ring structures absorb light near the UV spectrum. Found in lens of eye to filter out UV radiation.
____ is the synthesis f catecholamines from tyrosine. Results in epinephrine, norepinephrine, dopamine, and DOPA.
most common clinically encountered inborn error of amino acid metabolism. Autosomal recessive. Hyperphenylalaninemia (plasma Phe > 1000 um) resulted from defective phenylalanine metabolism => impaired cognitive development and function => lack of tyrosine => lack of neurotransmitters => mental retardation, seizure, microcephaly, growth retardation.
Autosomal recessive disease resulted from defective homogentisic acid oxidase (catabolism of Phe and Tyr). Charactarised by homogenistic aciduria (black urine), ochronosis, and arthritis. Not life threatening
Sulfur containing AAs
Cysteine and Methionine
Sulfur containing AA which Forms disulfide bond by interacting with itself, important role in protein stabilization. Tertiary structure is most likely stabilized by this bond.
sulfur containing AA that is a major methyl donor.
triple helix structure. Repeating sequence (Gly-x-y). X often proline; y often hydroxyproline or hydroxylysine. Hydroxylation by prolyl hydroxylase and lysyl hydroxylase and VITAMIN C cofactor. glycine, proline, and Lysine needed for _______ formation
heterogeneous group of generalized connective tissue dissorders. Skine hyperelasticity and joint hypermotility.
________ ehlers-danlos syndrome (type 6) is an autosomal recessive disease w/ a deficiency in pro-collagen lysyl hydroxylase. Occular problems: more fragile, high myopia, retinal detachment, keratoconus.
protoporphyrin IX has a Fe2+ center. Most common prosthetic group for hemoglobin, myoglobin, cytochromes, and catalase.
accumulation of bilirubin in the body => yellowing of skin and sclera. Caused by increased production (hemolysis => sickle cell) or decreased excretion due to liver damage (cirrhosis, heparitis) or bile duct obstruction (regurgitation into bloodstream).
High starch diet with low amount of protein.
Low protein and caloric uptake.
pKa > pH
When _____ the AA will be protonated.
pKa < pH
When _____ the AA will be deprotonated.
term meaning electrically neutral concentration with both COO- and NH3+ present.
____ pKa for COOH ~ 2, and ____ = pKa for NH2 ~ 9
pH is maintained around 7.4. This is done by the absorption of CO2 by hemoglobin => H2CO3 <=> H+ HCO3- <=> H+ buffered by Hb => lowers the affinity for oxygen in the peripheral tissues; increasing affinity in lungs. Alternate is Formation of Hb-carbamate (15 percent) (both pathways do this). Hb acts as the buffer for blood.
______ happens when HB buffers H+ after CO2 absorption causing a lowered affinity for oxygen and therefore release.
accumulation of ketone bodies or lactic acids => increased H+ => increased CO2 => have to breath more.
if the lungs fail to expel CO2 => increased CO2 => have to breath more
during hypervention (decreased CO2) => not enough H+ => have to breath less (brown bag).
Induced fit model
substrate bindin induces a conformational change in the active site leading to further enzyme substrate interactions and brings catalytically active groups to the substrate.
structurally unstable requiring higher free energy state. The formation of the _______ is rate-limiting in the overall reaction.
the free energy difference between substrate and transition state.
maximum velocity of the reaction acheived by the system after it has reached a certain amount of substrate. Part of Michaelis-Menton model
Km (Michaelis constant)
amount of substrate to reach half of vmax
inverse of Michaelis-Menton model which makes it linear.
______ inhibitors are structurally related to the normal substrate. Binds to the active site, non covalent, reversible. Vmax unchanged; Increases Km
_____ inhibitors binds to a site other than the active site of an enzyme. Has equal affinity for free enzyme or enzyme substrate complex. Substrate binding is unaltered, but ESI complex cannot form products. Non covalent, reversible. Reduces vmax. Km unchanged.
transfer hydrogen between a substrate and coenzyme
enzyme that transfers a group from one molecule to another
cleaves bonds by the addition of water
remove a group non hydrolytically, forming a double bone
interconvert positional, geometric or optical isomers
couple the hydrolysis of a phosphoanhydride bond to the formation of a bond.