Bio Flashcards
Can bacteria do post-transcriptional modifications? What is the effect on proteins if post-transcriptional modifications are not able to occur?
Bacterial cells CANNOT do post-transcriptional modifications of mRNA, and therefore cannot remove introns. If introns are not removed, then the proteins won’t fold correctly
What are the two reasons that enzymes bind to the major grooves vs the minor grooves in DNA sequences?
By binding the major grooves, there is more space to access the bases AND it allows for enzymes to establish a more clear pattern of H-bonding to be able to properly recognize sequences.
What’s the effect does Mg2+ have on DNA? What’s the effect of Urea on DNA? What’s the effect of dilute NaOH on DNA?
Mg2+ has a stabilizing effect on DNA and is essential in PCR. It sometimes might even prevent complete DNA denaturation, thus being problematic for PCR. Urea interferes with H-bonding, which disrupts the double helix structure and may lead to separation. NaOH denatures DNA.
What happens in Western blotting?
Western blotting includes a denaturation step that separates any bound monomers.
What level of protein structure is H-bonding involved in?
H-bonding is involved in creating alpha helices and beta-pleated sheets in SECONDARY structures
How do prokaryotes and eukarotes differ in translation?
Prokaryotes have several release factors in translation vs. only one in eukaryotes. This may be due to prokayotes being polycistronic = 1 mRNA has many genes on it
What is the size of prokaryotic and eukaryotic ribosomes?
“Prokaryotic ribosomes have overall sizes of 70S, with individual subunits of 50S and 30S. Eukaryotes have overall size of 80S, with individual 40S and 60S subunits.
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What is the difference between euchromatin and heterochromatin?
EUchromatin is LOOSELY packed chromatin vs heterochomatin is tightly packed chromatin. EUrope= chill, loosely packed
What is the function of centrioles? What is the function of centromeres?
Centrioles are protein structures that act as an “organizational center” where spindle fibers originate. Centromeres have kinetochores on them where the mitotic spindles can attach to.
