* Exercises A through C in this document are based on the following resource: Hood-DeGrenier, J. (2015). Genetics Society of America Peer-Reviewed Education Portal (GSA PREP): 2015.004 Exercise A:...

Extracted text: * Exercises A through C in this document are based on the following resource: Hood-DeGrenier, J. (2015). Genetics Society of America Peer-Reviewed Education Portal (GSA PREP): 2015.004 Exercise A: Amino Acid Functional Groups Figure 1 below shows one of the 20 amino acids that make up proteins. Recall that carbon can form four covalent bonds. Amino acids consist of a central carbon, called the a-carbon, that is bonded to four different chemical groups. corboxylic group H C. Amino E earbon CH2 OH group Figure 1. Structure of an amino acid Siae Chain/ R group


Extracted text: Answer the below questions in your own document. 1. On the amino acid shown in Figure 1, label the a-carbon. 2. The a-carbon of each of the 20 amino acids is bonded to one hydrogen atom, one amino group, one carboxyl group, and one R group (more on that below). You should recognize the amino and carboxyl groups from our discussion of functional groups in organic molecules. Circle and label* the amino group and the carboxyl group in Figure 1. *Note: our goal in this question, and in similar questions throughout this lab, is for you to be able to identify specific structures. You can do this circling/labeling in whatever way is easiest for you. You might want to draw the structures on a piece of paper, or use a computer program (like Powerpoint, Photoshop, Paint, Preview, etc.) to draw on these images. Whatever is easiest for you! 3. The last bond an a-carbon in an amino acid makes is to an R group,or side- chain. Circle and label the R group in Figure 1. Figure 3.2 on page 81 of your textbook shows the structures of all 20 amino acids. They are categorized into 4 chemical groups: nonpolar, uncharged polar, acidic, and basic. 4. Using the three groups you identified in Figure 1 as a reference, what is the only thing that is different about each of the 20 amino acids? 5. Look at the amino acids in each of the four groups and compare them to the ones in the other groups. Figure out rules that describe what the members of each group have in common so that you will be able to identify the chemical group for each of the 20 amino acids if you are shown its structure. Record your rules in a table similar to the one shown below. Chemical Group Rules Describing Membership in this Group