BioSec 2012: Elizabeth

Elizabeth's BioSec Notes

(Organized by class dates) Brain dumps, useful insights, points of confusion, it's all here.

Jan 25

Class readings:

Chapter 2: Origins of Life Chapter 3: Selection, Biodiversity, and Biosphere

In-class notes:

• Chemistry Review
  • energy difference between reactants and products in a chemical reaction
  • however, you need an input of energy to begin the reaction
• a catalyst changes (lowers the energy needed to reach the intermediate state, making the reaction more likely to take place
  • the catalyst is unchanged in the process
• Biological catalysts are enzymes (proteins) that hold the reactants and situate them in such a way that the reaction can happen more easily
  • enzymes move the reactants around
  • enzymes can have crystalline structure
• cell logic is built on pattern-matching
  • enzyme is looking for the reactants that fit its receptors
• ATP: Adenosine Triphosphate
  • energy carrier/source for cells
  • universal resource, used by all cells
• ADP: Adenosine Diphosphate
  • similar to ATP, but has one fewer phosphate group
  • has lower energy than ATP
  • the cell expends energy to turn it into ATP
  • then the cell breaks up the ATP to use the stored energy
• Eukaryotic cells vs. Prokaryotic cells
  • in eukaryotic cells, the genetic sequence isn't simply copied from DNA to RNA. Instead, parts of different sequences are picked and chosen and edited into proteins.
  • this means that a lot of the information in the DNA is there to control and regulate how parts are edited and assembled.
• Because of how evolution works (building on what already worked), understanding how a system works is equivalent to understanding its history, and why it is the way it is.
  • however, it can be hard to know where stuff came from, and what came first

Feb 1

Class readings:

Chapter 6: Cellular Respiration Chapter 7: Photosynthesis

In-class notes:

Both chapters address how cells make ATP and other byproducts.

• not a lot of discussion about how the two processes fit together (I mean, photosynthesis is the more important because it creates the glucose for cellular respiration to use?)
• much of the in-depth chemistry was confusing
• In Ch 7, I didn't fully understand the last section about photorespiration and how plants avoid it
  • what is the problem, really?
  • I understand that the C4 cycle resolves it

Possible application-y thoughts

• both photosynthesis and cellular respiration involve a lot of cyclical processes (like loops, I suppose) that transform one product into another
• the cellular structure model seems like it could be applied to computers (and is similar to what exists), but maybe the metaphor could be extended to be larger?
• what would ATP map to in the computer world? Information output?
• It seems that the processes are finely tuned so that most of the by-products (except energy lost in heat) get used - is there a moral in that story?