July 28th xam - Doubts

[k3nshin]

So instead of making different threads i thot i would just start one in which i will keep adding my doubts

Characteristic of exergonic reactions
dec entropy
inc enthalpy
dec enthalpy
neg free energy change (ans)
pos free energy change

I disagree with the key....I think it should be positive free energy change....energy is released in the environment....also, wouldnt decreased enthalpy be also a choice??

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[HupHolland]

So instead of making different threads i thot i would just start one in which i will keep adding my doubts

Characteristic of exergonic reactions
dec entropy
inc enthalpy
dec enthalpy
neg free energy change (ans)
pos free energy change

I disagree with the key....I think it should be positive free energy change....energy is released in the environment....also, wouldnt decreased enthalpy be also a choice??

No, the key is correct. Free energy (delta G) describes spontaneity. A negative free energy means the reaction is spontaneous; a positive free energy means the reaction in non-spontaneous.

Exergonic reactions release energy, thus do not require energy to proceed and can therefore occur spontaneously.

-Hup!

 

[k3nshin]

Thanx HupHolland!

I have v.small amount of time left....I'm especially weak in biochem....should i do the released papers or the kaplan qbank for biochem?? which one is better in ur opinion?? i have done 3 released biochem papers till now...

Some1 plz reply fast....i gotta study biochem full day tmrw...thanx!

 

[HupHolland]

Thanx HupHolland!

I have v.small amount of time left....I'm especially weak in biochem....should i do the released papers or the kaplan qbank for biochem?? which one is better in ur opinion?? i have done 3 released biochem papers till now...

Some1 plz reply fast....i gotta study biochem full day tmrw...thanx!

I suggest the released papers. My exam in on the 24th and I'm working through the papers now. My roommate took the exam last week and said there were a fair amount of repeats (10%).

-Hup!

 

[k3nshin]

I suggest the released papers. My exam in on the 24th and I'm working through the papers now. My roommate took the exam last week and said there were a fair amount of repeats (10%).

-Hup!

Thanx a lot...u hv even less time than me....goodluck buddy
Do post a feedback in general how the test was

 

[tinna]

I suggest the released papers. My exam in on the 24th and I'm working through the papers now. My roommate took the exam last week and said there were a fair amount of repeats (10%).

I have also my exam on 24th. I am also doing released papers second time. Any suggestion that can help me during my exam ? I hope 24th would be a nicer day in our lives. Wishing u best of luck.

 

[docasrpa]

are u guys doing recent released exams or going back to 7o s papers also.
any input will be appreciated.

 

[k3nshin]

I'm starting from the recent ones and doing as many as possible....i know i dnt have time to do it all....

 

[HupHolland]

thanks! I've been preparing for 3 weeks or so- I hope it is enough.

-Hup!

 

[njsmahal]

i agree. the free energy change is of the system. so negative means the reaction was exergonic as the system is now in lesser energy state

 

[k3nshin]

Heart Disease subjective to Infective endocardiis secondary to bacteremia from oral microrgs
a. Tetralogy of fallot
b. congenital AS
c. PDA
d. VSD
ANS- b,c and d
can any1 explain?

Seeding/transplantation likely in carcinoma of
a. Skin
b. Ovary
c. Tongue
d. Stomach
e. Large bowel
Ans. b,d,e
Why cant it be skin or tongue? isnt seeding the same as metastasis which is common in cancers like squamous cell carcinoma??

Aerosol from operative dental procedure has predominance of..
G(+) bacteria(ans)
Spirochete and rod forms
G+ bacterias are common in oral env bt when u talk abt operative procedures involving caries wouldnt it be spirochete n rods since thats wuts predominates in caries??

 

[sindu]

hi
i think answer is all the above for the first question i mean all heart disorders, organnisms try to conc on defective areas of heart.
3. it is caries the gram positive are more, spirochetes are more in anug and chronic infections.

 

[k3nshin]

hi
i think answer is all the above for the first question i mean all heart disorders, organnisms try to conc on defective areas of heart.
3. it is caries the gram positive are more, spirochetes are more in anug and chronic infections.

Yes ofcourse!! i got the listgarten zones confused with caries...thanx

 

[k3nshin]

Where is urine MOST osmolar in kidney?
Ans....Loop of Henle

Shouldnt it be Collecting ducts as its supposed to increase in osmolarity as it travels down the kidney..?

 

[sindu]

hi

it loop of henle because there counter current multiplier acts and increases water to ions ratio where as in collecting duct adh acts and there ions are absorbed so osmolarity is decreased.

 

[k3nshin]

hi

it loop of henle because there counter current multiplier acts and increases water to ions ratio where as in collecting duct adh acts and there ions are absorbed so osmolarity is decreased.

Osmolarity is the measure of solutes in a solution right....so if water to ions ratio is increased, shouldnt osmolarity decrease?? Sorry i have the whole osmolarity concept messed up in my head...may be u could help clear it up...
Although i do remember that the countercurrent system acts to concentrate urine...
lol, i dnt knw wut to think n wut not to think....m really confused on this one...plz help!!

 

[k3nshin]

Another question...

Is there any difference between epithelium of sulcular epi and junctional epithelium??
I recall that one of them has n one doesnt...sumthing like that....n that the presence of retepegs is a sign of inflammation in one of them...plz clarify which one is which

 

[k3nshin]

When is the mandibular second premolar's occlusal surface square and when is it pentagonal?
I know it has to do with one of the forms.....y,u,h
which is more common? One of the papers had pentagonal for the answer when i thot it was square....so i geuss pentagonal more common?

 

[k3nshin]

Wut tooth has a dip in the cervical line?
was it the primary mandibular second molar? on the buccal side?

 

[de297]

Where is urine MOST osmolar in kidney?
Ans....Loop of Henle

Shouldnt it be Collecting ducts as its supposed to increase in osmolarity as it travels down the kidney..?

actually the urine is most osmolar in the medulla or in the tip of loop of henle.(upto 1200)
am just mentioning this so that u know what to answer if loop of henle is not given in the answer choices.
osmolarity is the measure of molecules in a solution.

the urine that reaches loop of henle is isotonic,after initial absorption in proximal tubule.the descending portion of loop is permeeable to water.so u can imagine that water is reabsorbed here.so that leaves us with increased Na when compared water,isnt it?that makes it hyperosmolar.
the ascending limb of the loop is impermeable to water.so instead of water being reabsorbed,na is reabsorbed n it becomes hypotonic.
the distal tubule further reasorbs na by action of aldosterone.
hope this helps.

 

[de297]

Another question...

Is there any difference between epithelium of sulcular epi and junctional epithelium??
I recall that one of them has n one doesnt...sumthing like that....n that the presence of retepegs is a sign of inflammation in one of them...plz clarify which one is which

sulcular epi is continuous with gingival epi while junctional epi is thin,non keratinised n lacks rete pegs.

 

[k3nshin]

Thanx de297!!

any1 know the cervical dip question?

 

[k3nshin]

Haemodynamics of flow in the tooth pulp are most likely analogous to those in the
Heart
Lungs
Cranium(ans)
liver
gut

kindly enlighten me....

 

[k3nshin]

The subliminal fringe of a motor neuron pool is a useful concept in explaining the phenomenon of
direct inhibition
reciprocal innervation
central facilitation(ans)
monosynaptic conduction

wth is subliminal fringe and central facilitation??
cudnt find on wiki either...

 

[k3nshin]

Main function of plasma globulins
maintain colloid osmotic pressure
provide the body with both natural n acquired immunity(ans)

y not colloid osmotic pressure?? afterall if thats not maintained haemodynamics will be affected much before theres a need to provide an immunity to any infection....

 

[njsmahal]

Main function of plasma globulins
maintain colloid osmotic pressure
provide the body with both natural n acquired immunity(ans)

y not colloid osmotic pressure?? afterall if thats not maintained haemodynamics will be affected much before theres a need to provide an immunity to any infection....

albumins are responsible for colloidal osmotic pressure.
if question was about plasma prt then both would be the answer

 

[njsmahal]

if a neuron is near another one say X is near Y and X is stimulated. its found that Y also gets excited. this property of being excited even if the neuron is not excited is subliminal fringe. here Y is in subliminal fringe of X
so the answer is cental facilitation

 

[njsmahal]

Haemodynamics of flow in the tooth pulp are most likely analogous to those in the
Heart
Lungs
Cranium(ans)
liver
gut

kindly enlighten me....

the unique thing about pulp blood supply is that 1st, it has no collaterals and secondly it is enclosed by rigid walls.
only cranium has rigid walls with capillaries without collaterals. hence the answer
hope it helps

 

[k3nshin]

thanx njsmahal!!

here's more

Seeding/transplantation likely in carcinoma of
a. Skin
b. Ovary
c. Tongue
d. Stomach
e. Large bowel
Ans. b,d,e
Why cant it be skin or tongue? isnt seeding the same as metastasis which is common in cancers like squamous cell carcinoma??

Person with Hbs and Anti-Hbs in blood has/is
Carrier(ans)
Acute disease
^^^^y cant it be acute disease also??

 

[k3nshin]

Which of the following papillae would normally be found in the buccal vestibule?
Parotid(ans)
Incisive
Fungiform
Interdental
Circumvallate
^^^is parotid DUCT and PAPPILAE the same
considering proper "pappilae" i wud've gone with interdental as thats the closest one to wut they r asking...i know that parotid duct is in the buccal vestibule, bt they askin for papillae...

 

[k3nshin]

this one i dnt really remember the question word to word, cant find it nw bt it asked...

Organic matrix of calculus made up of
no micorgs
lots of microrgs(ans)

^^^Really?? Calculus just acts to retain bacteria on its surface rather than bacteria incorporated in it....Calculus is calcified plaque(which is just crapload of bacteria) but still im confused on this one...
in one of my perio classes i was told that there was an experiment done where 19 students with calculus hdnt brushed n used only antibaccterial mouthwash to prove that calculus only plays a part in retaining bacteria on surface for periodontal disease...so as i said, it holds bact ON it bt is it MADE OF bact??
Wish i had my perio notes with the composition of calculus right now...

 

[kupra]

Person with Hbs and Anti-Hbs in blood has/is
Carrier(ans)
Acute disease

it is carrier state....as in acute disease there will be HBe antigen present in pt........i hope it help

 

[de297]

Person with Hbs and Anti-Hbs in blood has/is
Carrier(ans)
Acute disease

it is carrier state....as in acute disease there will be HBe antigen present in pt........i hope it help

hbe antigen is indicative of active viral production and infectivity.
hbs is indicative of acute and persistant infection.but since anti-hbs is present it indicates a carrier state.

 

[njsmahal]

Which of the following papillae would normally be found in the buccal vestibule?
Parotid(ans)
Incisive
Fungiform
Interdental
Circumvallate
^^^is parotid DUCT and PAPPILAE the same
considering proper "pappilae" i wud've gone with interdental as thats the closest one to wut they r asking...i know that parotid duct is in the buccal vestibule, bt they askin for papillae...

parotid papilla is just an elevation around the opening of the parodtid duct.

 

[njsmahal]

this one i dnt really remember the question word to word, cant find it nw bt it asked...

Organic matrix of calculus made up of
no micorgs
lots of microrgs(ans)

^^^Really?? Calculus just acts to retain bacteria on its surface rather than bacteria incorporated in it....Calculus is calcified plaque(which is just crapload of bacteria) but still im confused on this one...
in one of my perio classes i was told that there was an experiment done where 19 students with calculus hdnt brushed n used only antibaccterial mouthwash to prove that calculus only plays a part in retaining bacteria on surface for periodontal disease...so as i said, it holds bact ON it bt is it MADE OF bact??
Wish i had my perio notes with the composition of calculus right now...

calculus is 75-80 percent inorg and 20 percent org and bacteria is what i recall

 

[k3nshin]

thanx njsmahal, de297 n kupra!!
u guys r great....i'll keep posting questions which i dnt get....
i just feel like giving the damn exam tmrw itself...already too much info in my head!!

 

[k3nshin]

Does Cementum have incremental lines?

When u are asked to make a complimentary codon i always get confused....the codon they give is 5'>3' or 3'>5'??
normally u read from 3'>5' right??

EDIT: nvm i got it nw....5'>3'.....no wonder i kept gettin confused

 

[k3nshin]

The main stabilizing bond in DNA is the c=g right? (p.s. i knw its a triple bond between c n g)

im confused coz in decks they say, "a=t promotes helix stabilization in DNA bt doesnt do so in RNA"...are they just implying that theres no a=t in rna(which is obvious) or they mean to also say that a=t is the one that gives the main stability.....technically c=g is stronger

 

[k3nshin]

Which of the following describes the effect of a drug that inhibits renal carbonic anhydrase?
dec urea cleararnce
inc Tm for glucose
inc the acidity of the urine
dec the Na reabsorption in the proximal tubule(ans)

i cudnt think of any answer in this question....i jus knew that it wud decrease the acidity i geuss, coz bicarbonate wudnt be reabsorbed....the Na answer is beyond my thinkin

 

[njsmahal]

Which of the following describes the effect of a drug that inhibits renal carbonic anhydrase?
dec urea cleararnce
inc Tm for glucose
inc the acidity of the urine
dec the Na reabsorption in the proximal tubule(ans)

i cudnt think of any answer in this question....i jus knew that it wud decrease the acidity i geuss, coz bicarbonate wudnt be reabsorbed....the Na answer is beyond my thinkin

carbonic anhydrase produces protons and bicarbonate from CO2 n H2O and H+ is then used by proton pump to pump out H+ making the urine acidic as well as pumping in Na+

 

[k3nshin]

carbonic anhydrase produces protons and bicarbonate from CO2 n H2O and H+ is then used by proton pump to pump out H+ making the urine acidic as well as pumping in Na+

so that ways there shud be two answers for this one....acidity increase too

 

[njsmahal]

so that ways there shud be two answers for this one....acidity increase too

acidity would increase if it is present and as it is absent so acidity would decrease as H+ ion secretion and Na+ absorption are not happening.

 

[k3nshin]

right!

 

[missiondds]

Osmolarity is the measure of solutes in a solution right....so if water to ions ratio is increased, shouldnt osmolarity decrease?? Sorry i have the whole osmolarity concept messed up in my head...may be u could help clear it up...
Although i do remember that the countercurrent system acts to concentrate urine...
lol, i dnt knw wut to think n wut not to think....m really confused on this one...plz help!!

its pretty simple,

you are correct in the point that at looop of henle the tubular fluid actually becomes dilute but that is after it sets in the osmotic gradient for CT to concentrate the urine via ADH.
AT END OF PCT urine is isoosmotic, at end of descending loop(in medulla) its hyperosmotic, at the end of ascending loop its hyposmotic(Medulla)...( so whts the point is conc??)BUT!! the increase osmotic gradient of interstial fluid increases through this entire process... which is the sole intention of countercurrent mechanism to generate an osmotic gradient. this OG is used by CT to conc the urine. The ct has no mechanism of its own for conc of urine, and ADH is just an adjunt in the conc.

 

[missiondds]

Which of the following describes the effect of a drug that inhibits renal carbonic anhydrase?
dec urea cleararnce
inc Tm for glucose
inc the acidity of the urine
dec the Na reabsorption in the proximal tubule(ans)

i cudnt think of any answer in this question....i jus knew that it wud decrease the acidity i geuss, coz bicarbonate wudnt be reabsorbed....the Na answer is beyond my thinkin

Crbonic anhydrase inhibitors are diuretic drugs that act at the PCT.eg: acetazolamide which via inhibiting the cah enzyme in the renal pct cells inhibit na resortion causing direusis.water follows passively with na . 70% of na is resorbed in the pct. hence CAH inhibitors are ptent diuretics

 

[dreamdental]

Crbonic anhydrase inhibitors are diuretic drugs that act at the PCT.eg: acetazolamide which via inhibiting the cah enzyme in the renal pct cells inhibit na resortion causing direusis.water follows passively with na . 70% of na is resorbed in the pct. hence CAH inhibitors are ptent diuretics

 

[toothfairy21]

Does Cementum have incremental lines?

When u are asked to make a complimentary codon i always get confused....the codon they give is 5'>3' or 3'>5'??
normally u read from 3'>5' right??

EDIT: nvm i got it nw....5'>3'.....no wonder i kept gettin confused

incremental lines of salters ..... in cementum
a new dna strand is synthesise in 5'-3' direction
even synthesis of mRNA from dna occurs in 5'-3' direction

 

[k3nshin]

Thanx all of u guys!

m excited for the xam...less than 2 days left
will post a feedback surely

 

[k3nshin]

Which is more potent?
Endotoxin or exotoxin?
one of the cards in decks say exotoxin is more potent than endo, n another one says that endotoxin are HIGHLY POTENT....even i think its endotoxin.....wut say?

 

[k3nshin]

Which enzyme coils the DNA back after replication?