Topics for the paper
Emergence of order
Self replicating systems
Self Assembling systems
Patterns in Organisms
The logarithmic spiral
Chemical Evolution (Prebiotic Equation)
Due BEFORE the last class
Paper is 2000 words
Looking at the helix, there is an overall dipole moment
there is a slight negative charge at the carboxyl end and the + at the NH end
Some suggest that the dipole moment of the alpha helix helps polarize the active site.
Hydrogen bonds serve as springs along the helical axis
this makes long keratins springy (think of hair)
people’s hair become curly or straight depending on the humidity One side of the helix might have hydrophobic region, the other side is hydrogen bonding to water.
Some helix we can see part of it being exposed to aqueous environment.
In some others we see a helix completely surrounded by hydrophobic environment.
We can predict which helixes are as such
Name each amino acid (100degrees apart)
Then look at each amino acid, and you can see part of the helix is hydrophobic and the other is hydrophilic
When helices have both hydrophilic and hydrophobic it’s called amphipathic
Beta Plated Sheet
Just like alpha helix, beta sheet soaks up all the hydrogen bonds that aren’t being used by water.
It’s when two amino acid strands run antiparallel N to C
The hair pins make these antiparallel strands
Sequences can also run in parallel if an entire loop comes back and runs C to C
Antiparallel beta structure
Notice how the carbonyl carbons and amide nitrogen are oriented, hydrogen bonds facing each other.
This cannot be continued forever, because at the end of the sheets there are no more amino acid sequence
But that is okay because t