18 - Wednesday, October 5, 2011 Lecture 18 Announcements:...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Wednesday, October 5, 2011 Lecture 18 Announcements: Have a prelim conflict for Thursday 10/20? Meet briefly after class today to determine the date/time for the make-up prelim. (This meeting has now occurred. The make-up exam will be Sunday 10/23 from 1 - 3:30PM. Room to be announced. Send Prof. F. an e-mail! You MUST send an e-mail, describe your conflict, then you get onto “the list”) Every student having a conflict must e-mail the prof BEFORE the Fall Break to verify the conflict (which class; what time that exam); Are you a predental student? You might be interested in the Cornell Predental Society. General Body Meeting TODAY, Wed 10/5 at 4:45PM in G73 MVR. Monday's lecture: conventions for illustration of mechanism of an enzyme-catalyzed rxn step-by-step mechanism of chymotrypsin why proteins require non-amino acid components Today's lecture: Page 140 Control of metabolism. Control is via enzymes, and the control is exerted at two levels: First, is the enzyme there? i.e. control of enzyme concentration. Second, is the enzyme active? Enzyme regulation p. 141 In an adult, about 300 grams of protein are synthesized each day, and about 300 grams of protein are degraded each day in a person who is not growing or shrinking rapidly. Thus, controlling synthesis and controlling degradation are both important. I. Control of enzyme concentration A. Control of Enzyme Synthesis: 1. Make more or make less mRNA. This means control RNA transcription by RNA polymerase. 2. Modify the mRNA that has been transcribed. For example, some mRNA must be "spliced" together to form the mature message-- this is under control by a huge protein + RNA complex termed the Spliceosome.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 4

18 - Wednesday, October 5, 2011 Lecture 18 Announcements:...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online