Like this study set? Create a free account to save it.

Sign up for an account

Already have a Quizlet account? .

Create an account


a complex of ribonucleoproteins that catalyze the removal of introns from pre-mRNA


small nuclear ribonucleoprotines - part of spliceosome

snRNA; protein

snRNPs are made up of: - and -


vary in nucleotide composition

U1, U2, U4, U5, U6



binds to 5' splice site; joins prior to lariat formation; leaves prior to lariat formation


binds branch-point sequence; binds to U6


interacts with U6; leaves before splicing


no complement to snRNA or exon/intron; interacts with last base of 1st exon AND first base of 2nd exon; involved in positioning; in a complex with U6/U4


binds to 5' splice site; joins before lariat forms; stays after lariat for splicing; interacts with U4/U2; only interacts with U4 OR U2

commitment complex

_ _:U1 binds at the 5' splice site

A complex; ATP

_ _:U2 binds to the branch point in intron (A); folds the pre-mRNA; requires _

B1 complex

_ _: U6/U4/U5 bind to 5' splice site; allows U5 to interact with the last base/first base

U4; U6; U1

the spliceosome is activated, using ATP, when _ leaves the complex and _ displaces _

B2 complex

_ _: using ATP, U2 and U6 interact

C1 complex

_ _: lariat intermediate forms

C2 complex

_ _: using ATP, exons are joined and intron is removed

I complex

_ _: introns only, exons excised

Please allow access to your computer’s microphone to use Voice Recording.

Having trouble? Click here for help.

We can’t access your microphone!

Click the icon above to update your browser permissions and try again


Reload the page to try again!


Press Cmd-0 to reset your zoom

Press Ctrl-0 to reset your zoom

It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

Please upgrade Flash or install Chrome
to use Voice Recording.

For more help, see our troubleshooting page.

Your microphone is muted

For help fixing this issue, see this FAQ.

Star this term

You can study starred terms together

Voice Recording