G1SG2

10+ Year Member
5+ Year Member
May 2, 2008
1,454
2
Status
Pre-Medical
Chloramphenicol is an antibiotic with an extremely lipid-soluble molecular structure. It binds to the large subunit of 70S ribosomes and prevents peptidyl transferase activity. Chloramphenicol is effective against almost all bacteria; however, it is considerably toxic to humans. This is most likely because chloramphenicol:

A. is able to diffuse into the mitochondria and affect mitochondrial protein synthesis
B. is able to diffuse into the nucleus and block transcription of rRNA.
C. affects both human and bacterial ribosomes
D. disrupts the cell membrane

Which would you pick???
 

wanderer

10+ Year Member
5+ Year Member
Dec 14, 2008
1,979
29
Status
Medical Student
Chloramphenicol is an antibiotic with an extremely lipid-soluble molecular structure. It binds to the large subunit of 70S ribosomes and prevents peptidyl transferase activity. Chloramphenicol is effective against almost all bacteria; however, it is considerably toxic to humans. This is most likely because chloramphenicol:

A. is able to diffuse into the mitochondria and affect mitochondrial protein synthesis
B. is able to diffuse into the nucleus and block transcription of rRNA.
C. affects both human and bacterial ribosomes
D. disrupts the cell membrane

Which would you pick???
C is ridiculous and can be ruled out. It is extremely lipid soluble so D might be plausible but not very likely. I would pick A since peptidyl transferase activity (and thereby polypeptide elongation) is affected, but not actual production of those ribosomes (thereby ruling out B).
 

capn jazz

10+ Year Member
7+ Year Member
Aug 29, 2006
1,529
9
Status
Medical Student
I really like A since mitochondria are derived from prokaryotes and would thus have prokaryote ribosomes.
 
OP
G

G1SG2

10+ Year Member
5+ Year Member
May 2, 2008
1,454
2
Status
Pre-Medical
I picked D. For some reason, I kept thinking about transcription in mitochondria and wasn't really thinking about mitochondrial translation :scared:
 
May 8, 2009
289
1
Status
Pre-Medical
Chloramphenicol is an antibiotic with an extremely lipid-soluble molecular structure. It binds to the large subunit of 70S ribosomes and prevents peptidyl transferase activity. Chloramphenicol is effective against almost all bacteria; however, it is considerably toxic to humans. This is most likely because chloramphenicol:

A. is able to diffuse into the mitochondria and affect mitochondrial protein synthesis
B. is able to diffuse into the nucleus and block transcription of rRNA.
C. affects both human and bacterial ribosomes
D. disrupts the cell membrane

Which would you pick???
I would pick A

A. Its possible because its lipid soluable and since mitochondria is derived from prokaryotes its possible it uses some of the same ribosomes
B. i don't think this is the answer because the protein binds rRNA not DNA, it would have to bind DNA and also have a nuclear import sequence to get into the nucleus
C. Human ribosomes are 80s so no
D. Disrupts cell membrane, no, if its soluable it will just diffuse through.
 

Doodl3s

7+ Year Member
Jun 17, 2009
404
14
NorthEast
Status
Fellow [Any Field]
A for sure... the only other maybe WAS b, then i read TRANSCRIPTION, NOT TRANSLATION.... ribosomes have nothing to do with transcription, so B's out.