Lets get it started
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Post by Lets get it started on Sept 6, 2006 23:00:46 GMT -5
Please post the question and the multiple choice options in this thread.
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Post by Kevin Gamett on Sept 8, 2006 4:08:36 GMT -5
12. Which of the following acid/conjugate base pairs has the highest buffering capacity at pH 7.0?
a. Lactic acid/lactate ion, pKa = 3.86
b. Monobasic phosphate/dibasic phosphate, pKa = 6.86
c. Imidazole, imidazolium ion, pKa = 6.1
d. Acetic acid/acetate ion, pKa = 4.76
e. Bicarbonate ion/carbonate ion, pKa = 10.25
Answer below - - -
B
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Post by Nick on Sept 9, 2006 12:35:31 GMT -5
All of the following enzymes use acid-base catalysis as a mechanism of enhancing the rate of the reaction EXCEPT:
a) Lysozyme
b) Carbonic anhydrase
c) Chymotrypsin
d) Carboxypeptidase
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Post by Nick on Sept 9, 2006 12:52:46 GMT -5
High levels of which of the following are tested for the determination of broken bones?
a) Hydroxylysine
b) Hydroxyproline
c) Creatinine
d) Phospho-enol-pyruvate (PEP)
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chad
New Member
Posts: 6
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Post by chad on Sept 9, 2006 22:17:22 GMT -5
One would find all of the following interactions stabilizing an enzymes quaternary structure except:
A) Hydrogen bonding
B) Disulfide bonds
C) Ionic links
D) hydrophobic interactions
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Post by jcartinella on Sept 10, 2006 10:48:02 GMT -5
Here's good practice for determining the AA sequence of a protein segment:
Analysis revealed that a peptide contained the following AAs:
val, lys, ala, met, met, phe, cys, his, arg, ile
Two cycles of Edman degradation gave first met then ala
Trypsin digest gave three fragments:
(met, arg, ile), (lys, ala, val, met), and (his, phe, cys)
CNBr treatment gave three fragments:
(met), (cys, arg, phe, his), and (val, lys, ala, met, ile)
Chymotrypsin digest gave two fragments:
(his) and (the 9 other AAs)
Determine the AA sequence of the peptide.
(answer will be posted on the answer message board)
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chad
New Member
Posts: 6
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Post by chad on Sept 10, 2006 12:10:28 GMT -5
Which of the following is responsible for increasing the activation energy of the following reaction ATP + H2O => ADP +Pi?
A) Ca++
B) ATP dismutase activity
C) A low [ATP] conc.
D) A lower temperature
E) Presence of glucose
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chad
New Member
Posts: 6
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Post by chad on Sept 10, 2006 12:33:47 GMT -5
Which of the following molecules has a largely negative delta G due to the effects of tautomerism?
A) Thiol-esters
B) Guanidium phosphates
C) Enoyl phosphates
D) Esters
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Post by Nick on Sept 10, 2006 14:45:18 GMT -5
If you perform an Edman’s degradation and get lysine, tyrosine, and arginine on a TLC plate, what is most likely the amino terminal amino acid?
a) Lysine
b) Tyrosine
c) Arginine
d) Proline
e) None of the above
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Post by Nick on Sept 10, 2006 15:05:05 GMT -5
What makes the brain so efficient in absorbing a large portion of blood glucose?
a) Vmax/Km is higher in the brain
b) the BB isozyme has a higher affinity for glucose
c) it has more GK than other tissues
d) it has more HK than other tissues
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Post by sohini on Sept 10, 2006 20:53:49 GMT -5
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Post by sohini on Sept 10, 2006 20:55:29 GMT -5
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Post by ccharles on Sept 10, 2006 23:01:36 GMT -5
What does Vitamin A and physiological salts help to re-form?
a. alpha helixes
b. LDH
c. Collagen fibrils
d. beta sheets
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