Biology Forum › Molecular Biology › Are these right?–won’t take long..
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- November 3, 2007 at 4:16 am #8493biology_06erParticipant
Had an exam yesterday and would just like to know if I am right in a few MCQs…I have just written out the ones I chose:
affinity chromatography is a purification technique that:
separates proteins according to size
explots an unique property of a protein
separates proteins according to their hydrophilicity
involves ion-exchange chromatography
results in protein samples that are denaturedcellulose acetate electrophoresis indicates that albumin:
is -vely charged
is +vely charged
is a minor component of serum
is a basic protein
has a PI close to the ph of the electrophoresis bufferthe rate of enzyme catalyzed rxns is usually determined by measuring the initial rate of rxns because:
only the initial rate is simply related to the initial substrate concentration
enzyme rxns are always fast
at equlibrium the absorption of light will continue to increase
otherwise the light absorption will go off the scale
the initial rate is always the slowestPapain incubated with EDTA:
Activates enzyme activity by binding divalent metal cationshave no effect on enzyme activty
activate enzyme activty by modifying the casein substrate
inhibit enzyme activty by binding divalent metal cations
inhibit enzyme activty by binding divalent metal cationsWhen acid is added to the rxn: ethanol + Nad+ <–> acetaldehyde + NADH + H+ the following is expected to happen:
Increases the conc. of NADHinteraction between cibacron blue and albumin is considered:
Hydrophobicwhen the liver enzyme alcohol dehydrogenase oxidizes ethanol an increase in the absorbance of the solution occurs at 340nm. This is because:
NADH is produced during the rxnIn the lab where the enzyme papain is investigated, it was preincubated prior to assay to:
ensure that the reactive site cysteine was in the reduced formI know there is heaps of q’s but any1 that can tell me if they are wrong/right will be great…I just wanna make sure I have got the marks for these so having the ans. to this post will be MOST appreciated!!
Thanks you to whoever answers!!
b_06er - November 3, 2007 at 4:25 am #77415MichaelXYParticipant
You have a good memory, I can never remember questions in that detail after a test.
- November 3, 2007 at 10:03 am #77419biology_06erParticipant
haha i wish i had a good memory then I would do better on exams!…we actually get to take the paper home 😛
- November 3, 2007 at 3:57 pm #77422MrMisteryParticipantquote biology_06er:Had an exam yesterday and would just like to know if I am right in a few MCQs…I have just written out the ones I chose:
affinity chromatography is a purification technique that:
separates proteins according to size
explots an unique property of a protein
separates proteins according to their hydrophilicity
involves ion-exchange chromatography
results in protein samples that are denaturedThe correct answer is "explots an unique property of a protein". The technique used to separate according to size is gel filtration chromatography.
quote :apain incubated with EDTA:
Activates enzyme activity by binding divalent metal cationshave no effect on enzyme activty
activate enzyme activty by modifying the casein substrate
inhibit enzyme activty by binding divalent metal cations
inhibit enzyme activty by binding divalent metal cationsEDTA binds metal ions through amine and carboxyl groups. However, i don’t think papain has metal prosthetic groups. You can look that up and you will have your answer.
quote :When acid is added to the rxn: ethanol + Nad+ <--> acetaldehyde + NADH + H+ the following is expected to happen:
Increases the conc. of NADHMy guess is it would increase the rate of the backwards reaction, as the added H+ will increase the concentration of products.
Don’t know the answers to the others, or i consider your answers correct.
Cheers.
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