Passage: There are 20 amino acids that make up proteins. With three bases per codon, there are 64 possible codons. This is more than enough to code for the 20 amino acids plus start and stop signals. You can see how to translate the genetic code in Figure below . Start at the center of the chart for the first base of each three-base codon. Then work your way out from the center for the second and third bases. Answer: 20
How many different amino acids make up proteins.