Wednesday, February 11, 2009

Lab 10: Constructing an Amylase Evolutionary Tree

Amylase is an enzyme in human saliva that breaks down starch. If you chew a piece of plain white bread, eventually, it will start to taste sweet. What's going on here? Well, amylase is breaking down the starches (a storage polysaccharide) and releasing the sugars. What does this have to do with evolution?

Scientists can look at evolutionary relationships based not only on homologies but also by using protein sequences; after all amino acids are the genotypes which make proteins which display phenotypes. In this lab you will be constructing an evolutionary tree by comparing amino acid sequences in amylase. The biggest thing to remember in this lab is:


What does that mean? It means take your time, because one little careless mistake will throw off the rest of your data.

Does what you are learning in the lab have any real-world connections? YES! For homework:

Part One: Read Understanding Phylogenies, make sure you click "next" at the bottom of the page, so you get to "Understanding Phylogenies (2 of 2)."

Part Two: Read Evolutionary Evidence Takes The Stand and write a 3-2-1 using COMPLETE SENTENCES. 3 Things you learned, 2 things you have questions about and 1 thing you would like to learn more about.

This is due the next time class meets.

No comments: