Passage I

Figure 1 depicts some of the steps of protein synthesis in eukaryotes.

In yeast, the genes that are expressed at a given time depend on environmental conditions, such as the glucose concentration in the environment.

Saccharomyces cerevisiae, a type of yeast, was grown for 12 hours on a growth medium containing glucose. The transcription rates of 4 genes (Genes 1—4) were determined. The relative transcription rate (RTR) of each gene was then calculated using the following formula:

The results appear in Figure 2.

Figure 3 shows the glucose concentration of the medium during the experiment.

Figures 2 and 3 adapted from Joseph L. DeRisi, Vishwanath Riyer, and Patrick O. Brown,“Exploring the Metabolic and Genetic Control of Gene Expression on a Genomic Scale." ©1997 by the American Association for the Advancement of Science.