inactive protein that requires extra peptides attached to it to be cleaved before it becomes active. Released in the stomach to digest proteins.
Proteins go into ______ Interacts with => HCl + Mucus + Pepsinogen + Gastrin => final product (chyme).
Maintains stomach pH around 2, kills bacteria, denatures protein structures held together by 'weak bonds', provides ideal environment for certain enzymes to function properly.
the final product of digested enzymes in the stomach. Mixture of partially digested proteins, enzymes, and HCl which enters the small intestine.
Lumen, Trypsinogen, Chymotrypsinogen, Procarboxypeptidase.
pancreatic enzymes released as zymogens into ____ of the small intestine: _____, ______, ______ => trypsin, chymotrypsin, carboxypeptidase.
bond formed by the condensation of the carboxyl group of one AA with the amino group of another AA. Strongest bond in protein structure. One water molecule is removed in the process.
____ protein structure: Linear order of amino acids from N terminis to C terminis formed using mRNA.
_____ protein structure: alpha helices and beta sheet formation. Provides functional site for proteins
stabilized by h bonds between amide nitrogen and carbonyl carbon of peptide bonds; essential for globular proteins. All R groups are sticking out.
stabilized in adjacently opposed stretches of the poly peptide backbone; can be parallel or antiparallel ( based on N terminis).
_____ protein structure: complete 3-d structure of the polypeptide chain; relationship of different domains to one another w/in a protein. Often final protein structure.
hydrogen bonds, hydrophobic, electrostatic, van der waals (weakest) (all weak bonds)
two or more different polypeptide chains are stabilized by the same non-covalent forces. EX Hemoglobin (2 alpha and 2 beta chains) Not all proteins have this structure
_____ is the alteration of a protein's 3-d structure caused by either ph, heat, enzymes, or agitation (stirring). Doesn't affect primary structure (except enzymes)
transfer of amino group to an alpha-keto acid. OAA as an acceptor to produce Aspartate. Pyruvate as an acceptor to produce Alanine.
removal of an amino group from an amino acid. Glutamate + Glutamate dehydrogenase => a-ketoglutarate + NH3 + NADH
linkage of Urea cycle to citric acid cycle. Fumarate (from Urea cycle) => CAC => OAA => transanimation => aspartate => Urea cycle => Fumarate
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 AA which Forms disulfide bond by interacting with itself, important role in protein stabilization. Tertiary structure is most likely stabilized by this bond.
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).
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.
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.
maximum velocity of the reaction acheived by the system after it has reached a certain amount of substrate. Part of Michaelis-Menton model
______ 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.