MBB 400a/700a
Problem Set #1
1. Assume that the dimensions of a single E. coli cell are scaled
up to the size of East Rock (the big natural landmark you can see from
looking north out the window of Bass). You may estimate the height=300
feet and the diameter=600 feet. What would be the size (diameter)
of the following cellular components? What other objects are of a
similar size (i.e. a baseball)?
Ribosome
tRNA molecule
Water molecule
Small protein (20 kD)
Large protein (200 kD)
Now assume that a Eukaryotic cell is the size of East Rock. What
is the thickness of the cell membrane? What is the relative size
of an E. coli cell?
2. You have a 20 residue polypeptide in an a-helix
conformation and a 20 residue polypeptide in a b-sheet.
Which is longer and what are the approximate lengths of each?
3. Estimate how many small proteins can fit inside a ribosome.
You may assume both are spherical and estimate the diameters. Show
your work.