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Genes and Proteins

Investigation 2 – PreLab









A statistical geneticist develops software to perform genetic analysis, for example, quantitative trait loci mapping.


This Investigation is designed to help you to answer the following Focus Question:

  • Can mutations in DNA cause changes in an organism? 

Note: This question is located in your SDR at the beginning and end of the Investigation.



As a class, read the Background(s) in the Investigation. When finished, discuss the following concepts as a class:

  • Mutations in DNA can cause changes in the amino acid sequence of a protein.
  • A protein that is produced when there are no mutations in the gene is called the wild-type protein.
  • Mutant proteins are caused by a change in the DNA that codes for the protein.
  • Proteins fold in a certain way to perform a function. Part of the function of many proteins is to bind or attach to another molecule.
  • Most proteins have a binding site or an active site. A binding or active site is the place where the protein binds or attaches to another molecule. These sites are made of specific amino acids, and their structure is important in helping the protein function properly.
  • Amino acids can be symbolized as a single letter or by a three-letter abbreviation of the name. For example, A or Ala for Alanine.


  • There are no Key Terms introduced in Investigation 2.


  • Complete the Recall section in your SDR.                                                       
  • What are the effects of mutations?
  • Do all mutations in DNA have an effect on protein structure?
  • Do all mutations have an effect on protein function?
  • In this Investigation, you will explore whether changes in amino acid sequence always cause changes in function.
  • Play the video below. Remember to follow along with your SDR and make any notes that you think might be helpful in the lab.
  • After the video, divide into lab groups to discuss strategy for the lab. For example, you may assign certain group members to perform specific functions during the lab.

Note: The purpose of the video is to allow you to anticipate the laboratory experience you will soon encounter. You should leave this PreLab session with a firm idea of what to expect and how to perform in the lab.

Note: Homework is posted below the video.


You should review the Investigation and video in preparation for the Lab.