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83 Cards in this Set
- Front
- Back
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which amino acid isn't chiral?
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glycine
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which forms of AA are naturally occurring?
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L isomers
with the exception of platypus venom... |
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where will you find D amino acids?
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in racemases
frog, mollusk, platypus venom |
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only example of L to D Isomerase
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found in platypus
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under what conditions with the peptide bond metastasize?
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in the presence of a catalyst, hydrolyzed in an aqueous environment
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which AA drugs might be useful in treating alzheimers?
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antiglutameric
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what is insulin made up of?
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two peptide chains joined together by three disulfide bonds
(THINK, sulfur containing AA must be involved yeah?) |
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which AA is a precursor of SAM?
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methionine
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why do we care about SAM
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its a methyl donating compound
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which AA absorb UV light?
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Tyrosine
Tryptophan (greatest) |
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which AA has the largest hydrophobic effect?
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phenylalanine (at pH 7)
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what are the essential AA?
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Histadine
methionine threonine valine isoleucine phenylalanine tryptophan leucine lysine |
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of the essential AA, which are the ONLY ketogenic?
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Leucine
Lysine |
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what will tyrosine metabolize into?
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dopamine
epinepherine norepinepherine Thyroid hormones |
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generally how is seratonin made?
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in gut cells, synthesized from tryptophan
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there is a deadly fruit in the caribbean that when unripe has hypoglycine-A, what does it do?
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inhibits acyl CoA dehydrogenase, the first step in breaking down ingested FA
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histadine makes up part of...
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histamine
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where do we get one carbon units for tetrahydrofolate?
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from glycine degradation carried out by glycine cleaving enzyme
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Nonketotic hyperglycinemia
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deficiency in glycine cleaving enzyme
rare and deadly in infancy |
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what is found in most kidney stones and comes from glycine?
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oxalate
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what will lead to an accumulation of homocycsteine and methionine>
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deficiency in cystathione synthase
accumulation of homocystiene is a cardiac risk factor |
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what will a defiency in cystathyoine synthase lead to?
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thinning, lenghting of bones, osteoporosis, lens dislocation, vascular thrombosis
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What is the connection between homocysteine and methionine?
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Methionine gives rise to SAM (S-adenosyl-methioninine)
SAM gives rise to SAH (homocycsteine) SAH gives rise to homocycsteine |
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maple syrup disease is a disorder of
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alpha keto acid dehydrogenase
so its not breaking down branched chain AA |
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phenylketonuria
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complete lack of phenylalanine hydroxylase-- raises phenylalanine levels by 10x
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what will you find in the urine of phenylketonuria?
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phenylpyruvate
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what are the symptoms of phenylketonuria? (PKU)
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retardation, seizures, neurologic
light complexion |
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carboxyl esterification
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used in protein synthesis
carboxyl group + alcohol + dehydrating agent |
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Amine acylation
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?
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Ninhydrin rxn
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important for peptide synthesis and AA analysis
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what is the most common non-ribosomal peptide?
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gluathione
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amanita muscaria
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cyclic non ribosomal toxic peptide
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bufo alvarius
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non ribosomal toxic peptide of the frog
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what are opiod peptide derived from
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gluten, egg, casein
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how large are food peptides?
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small, 4-8 AA
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where do endogenous opiod peptides comes from?
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larger protein that gets processed
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vasopressin
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Antidiuretic hormone
9 AA sequence acts on kidneys, regulates water raises BP synthesized in hypothalmus stored in pit gland |
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oxytocin
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related to ADH
9 AA sequence |
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oxytocin receptors
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g protein coupled receptors that require Mg2+ and cholesterol
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Glucagon
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29 AA
responds to low blood glucose tells liver to concern glycogen into glucose Vasoactive Intestinal Peptides (VIP) |
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where is glucagon produced
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in pancreas
in alpha cells of the islets of langerhans |
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secretin
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Vasoactive Intestinal Peptides (VIP)
regulates duodenal pH |
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where is secretin secreted
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as prohormone in the S cells of the duodenum in the crypts of lieberkuhn
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what three AA are found in glutathione?
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glycine
glutamine cysteine |
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which form of glutathione is an antioxidant
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reduced
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glutathione reductase
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reduces an oxidised glutathione back to its useful reduced form
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C-peptide
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type 1 diabetes: declines alongside insulin
associated with complications of: nephropathy neuropathy retinopathy |
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peptide venoms
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useful because they can reduce pain almost or as much as morphine...
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peptide bond
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betweon COO- and NH2+
primary structure |
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what stabilizes tertiary structure
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disulfide bonds
h bonds hydrophobic interactions ionic interactions |
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globin domain
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8 bundle helix, forms an active site pocket
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which AA is the problem in sickle cell anemia?
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Glu 6 is changed into a valine (valine being more hydrophobic than glu, causes the hydrophobic regions to want to polymerize (stick together))
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how the is final 3d structure of a protein reached?
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by passing through high energy states facilitated by heat shock or chaperone proteins
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AGE's
(advanced glycosylation end products) |
?
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what factors affect protein stability
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Temp
pH solvent characteristics hydrophobicity |
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Prion
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proteinacious infectious agent PrP(Sc)
transmits spongiform encephalopathies normal protein contains no beta sheets, ab.norm. has extensive sheeting |
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acidosis
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pH<7.35
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alkalosis
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pH>7.45
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intracellular pH
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7.0
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extracellular pH
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7.4
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what are the three homeostatic regulators of pH
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chemical buffer systems
respiratory emch renal mech |
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what is the slowest regulator to respond to pH
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renal, but it is the most potent- hours to days
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what are the three buffer systems
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carbonic acid/bicarbonate buffer
protein buffer phosphate buffer |
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carbonic acid(h2CO3)/bicarbonate buffer
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most important to ECF
catalyzed by carbonic anhydrase regulated by lungs and kidneys |
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Phosphate buffer
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important in ICF and Urine, proton acceptor for at pH 7
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protein buffer
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interacts with other buffers systems, ergo both ECF and ICF
hemeglobin buffer AA buffer Plasma Protein buffer |
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protein buffer pKa
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5.5-8.5
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Hemeglobin pKa
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histadine residues: pKa 7-8
Deoxy Hb is a weaker acid than oxyHb |
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respiratory acidemia
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increased CO2
decreased pH |
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respiratory alkalemia
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decreased CO2
increased pH |
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metabolic alkalemia
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increased bicarbonate
increased pH |
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metabolic acidemia
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decreased bicarbonate
decreased pH |
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which AA is the most prevalent in active sites?
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Serine
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apoenzyme
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an enzyme without its nonprotein component
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holoenzyme
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active enzyme with its nonprotein component
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activation transfer coenzyme
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forms covalent bond
tightly bound substrate activated for transfer |
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what does biotin usually attach to?
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lyseine residue
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ReDox coenzyme
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no covalent bonds
specific for type of electron transfer (H, hydride, O2) not a good catalyst without the participation of AA from active site |
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NAD and lactate dehydrogenase
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Redox coenzyme and enzyme
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how do mechanism based inhibitors participate in rxns
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they mimic a substrate in an intermediate step, includes transition state analouges
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what results in an accumulation of acetulcholine?
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sarin
malathion parathion covalently attaching to acetylcholinersterase |
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how does penicillin work?
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as a transition state analogue. GTP covalently attaches penicillin to serene in its active site
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how does allpurinol work (treatment for gout)
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inhibits xanthine oxidase b/c XO converts allpurinol into a transistion state analog oxypurinol which binds tightly to molybdenum-sulfide in the active site
ergo, decreased urate |
