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47 Cards in this Set
- Front
- Back
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What are the nine hydrophobic amino acids?.... why are these important
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glycine, alanine, valine, leucine, isoleucine, proline, phenylalanine, tyrosine, tryptophan.... These amino acids will most likey be used in the N-terminus of the secreted protein, such as insulin, or membrane or organelle protein
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What are the 6 nonpolar, amino acids with aliphatic side chains?
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glycine, alanine, valine, leucine, isoleucine, proline
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What re the 3 amino acids with aromatic side chains ?
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phenylalanine, tyrosine, tryptophan
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What is the smallest amino acid?
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glycine
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Which amino acids will disrupte the alpha helixes of membranes?
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glycine, because it is so small... proline , because it’s R group is attached to it’s amino group.
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What are the amino acids with branched chains?... Why are these important?
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Leucine... Isoleucine... Valine... These amino acids require BRANCHED CHAIN DEHYDROGENASE which is DEFICIENT IN MAPLE SYRUP URINE DISEASE
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What is the difference between penylalanine and tyrosine?
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OH group is on the aromatic ring of tyrosine, while it is absent on phenylalanine
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What is the only amino acid with a phenol group
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tyrosine
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What is tyrosine a precursure of?
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thyroid hormone, catacholamines, melanin
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What is needed for the conversion of tyrosine to catachole?
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addition of another OH group to the already present phenol on the tyrosine?
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What is tryptophan used for?
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major procurer of serotonin, and is used for NAD and NADP synthesis
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What are the hydrophilic amino acids?
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lysine, arginine, histidine, aspartate, glutamate, serine, threonine, cysteine, methionine, asparagine, glutamine
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Which amino acids have positively charged R groups?
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lysine, arginine, histidine
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Which amino acids have negatively charged R groups?
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aspartate glutamate
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Which amino acids have polar, uncharged R groups?
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serine, threonine, cysteine, methionine, asparagine, glutamine
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What gives the positively charged amino acids their charge?
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an extra amino group
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Which amino acids would be abundant in histones?
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lysine and arginine because it is a positively charged protein
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Where is the amino group on lysine?
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it is on the very end of the R group…this position is known as the epsilon position
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Why is the epsilon position on amino acid important?
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it is on the epsilon amin o group of lysine that glycosylation of hemoglobin occurs
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What gives the negatively charged R groups their negative charge?
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Their side chains contain an extra carboxylic acid group
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What is the significance of both negatively charged amino acids?
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Aspartate and glutamate are both excitatory neurotransmitters in the CNS………………….glutamate is also a precursor of GABA.
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Which amino acid is notorious for being a great physiological buffer?
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histidine
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Which amino acids contain S in their side chains?
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cysteine and methionine
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Which amino acids has an SH at the end of its side chain and why is this important?
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cysteine….it is pmportant because it is between these SH group that disulfide bonds between proteins are made…..this SH group on cysteine in the protein glutathione which mops up free redicals
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Which amino acids have an extra OH group in the side chain?
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serine, threonine
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What is the importance of the OH groups on the proteins?
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These are sites where posttranslation al modification can perform glycosylation and phosphorylation of protein.
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What medication is given to people experiencing free radical damage, such as Tylenol or acetomeniphen overdose?
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N-acetylcysteine
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What is the importance of methionine?
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it is a key methyl group donator and thus is a main component of the SAM enzyme.
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What is the name of the proteins that wraps up free radicals in cells and what is this due to?
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glutathione mops up free radicals and it is due to the SH bonds on cysteins amino acids in the protein
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What are some key reactions of the SAM protein?
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methylation of norepinephrine to epinephrine……………..or adding a methyl to the guanine to form the methyl guanine cap.
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What is the importance of asparagine and glutamine?
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These proteins have H2N on the end of their R group and thus allow N glycosylation of the end of their side chains
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What is the importance of glutamine?
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it can detoxify ammonia due to the activity of glutamine synthetase
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What is the pK value for the amino group on amino acids?
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9
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What is the pK value for the acid group on amino acids?
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2
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What are the positively chargesd amino acids and what is the pK of their extra amino group?
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arginine = 13... Lysine = 10... Histadine = 6.5
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What are the negatively charged amino acids and what is the pK of their extra acid groups?
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Aspartate = 4... glutamate = 4
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What is an isoelectric point of a molecule?
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this is the oint at which the pH and PK is balanced and there is no overall charge on the molecule , and thus it will not migrate the positive or negative electrode
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What is a characteristic of asprin and how is this used?
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asprin is a weak acid and thus is order to make it more water soluble, the urine is alkalized and that asprin gains a charge and dissolves in water. When a weak acid is in acid, it is uncharged, and thus not soluble in water, but if the weak acid is in basic solution it will lose it H+, gain a neg. charge and thus become soluble.
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What is a quick way to find the approximate pK?
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average the two closest pKs.
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Why is histidine such a good buffer?
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it has the third pK at a value of 6.5
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What are the important intracellular buffers?
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Proteins (due to histidine R groups).... Phosphate.... Organic phosphates
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What is an important extracellular buffer?
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bicarbonate, the most important buffer
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What are the ten essential amino acids?
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PVT TIM HALL ………Phenylalanine…………Valine………….. Tryptophan…... Threonine…………Isoleucine ……Methionine ……….Histidine.... Arginine………..Leucine…….Lysine
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What of the essential amino acids are only required during period of growth?
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Arginine
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What is a negative nitrogen balance?
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When the losses exceed the amount of nitrogen input.
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What is the main parameter of the energy of a reaction?
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delta G….negative delta G means that there is an energy loss and thus it is spontaneous….but tells nothing at all about the rate
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What are the parameters of the rate of a reaction?
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Km and Vmax
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