Friday, September 9, 2011
1. Mean score for each quiz,
23.3 sd 6.6
23.1 sd 5.7
21.8 sd 7.6
Regrade policy: submit written (
, NOT ORAL
purple Re-Grade Folder
at front of classroom.
You will have
the quizzes are returned to submit a quiz for re-grading.
If you do not pick up your quiz today at the end of lecture, you can find your quiz at
the Reserve Desk of the Bio Center, 2
floor of Stimson.
Quiz 2 on Wed 9/14 will cover lectures 5, 6, and 7.
Policy reminder: If you missed
Quiz 1 (or if you miss any quiz for any reason) you are eligible to take the make-up quiz
on Wed 11/30 (which will cover the lectures from 11/14 – 11/21).
No graphing calculators are allowed during quizzes and other exams in this course.
If you are using one during the quiz, you will receive a score of 0, and you cannot drop
PyMOL assignment #2: Secondary Structures.
Steric Hindrance of a Polypeptide Chain
" and "
Secondary Structures in Proteins
Any interested students: Today, Friday 9/9 at 2:55PM in Comstock B108, "Should I
apply to medical school this year?!”
Ramachandran Maps; every point within these maps is a
can never be observed because of steric hindrance;
Characteristics of the
-helix, including amphipathic helices
The allowed regions of rotation occur within the range
-60 to -150 and
+90 to +180 .
These angles make the polypeptide chain in a
extended, in contrast to the more compact
Repetition of these
values leads to a structure with an average length of the
sheet found in proteins of approximately 6 residues, or about 20 Angstroms in length.
All possible hydrogen bonds are made, but for the beta sheet these H-bonds are
strands, not within one strand
In representations of protein structure, a strand of
-sheet is indicated by an arrow,
pointing from amino toward carboxyl direction of this piece of polypeptide.
-sheet strands “run in opposite directions” with
one strand having the direction “amino
carboxyl” and the strand next to it “carboxyl
Hydrogen bonds are formed between C=O and NH of peptide bonds on