PETase Enzyme Analysis

Scientific Question: Have scientists found an enzyme that breaks down PET plastic polymers?

#1 Your Claim (answers the question - 5pts)

#2 Your Evidence (data gathered from text or graphics that help you answer the question provided in the task - 5 pts)

#3 Reasoning (A justification that connects the evidence to the claim and shows why the data counts as evidence by using appropriate and sufficient scientific principles - 10 pts)

Grading Rubric:

Claim
A statement or conclusion that answers the original question.

Evidence
Scientific data that supports the claim. The data must be appropriate and sufficient to support the claim.

Reasoning
A justification that connects the evidence to the claim. It shows why the data counts as evidence by using appropriate and sufficient scientific principles.

Directions: Use the Claim/Evidence/Reasoning strategy to answer the question below. In the table on the next page, formulate a claim, use information in the graphs to provide evidence, & apply scientific principles in biology class to explain your reasoning.

Experiment setup: Plastic pollution is of major concern in our world. An area of the pacific ocean twice the size of Texas is basically a plastic soup that is getting into the food chain and choking marine habitats. For many decades, plastic, a man-made material, was considered non biodegradable, meaning it would not be broken down by natural organisms and persist in the environment for many hundreds of years.

However, in 2016 observant scientists looking around a Japanese plastic bottle recycling plant examined a substance for evidence that bacteria had developed the ability to break down PET (a common type of plastic) through enzymatic action. The scientists isolated the enzyme they thought was breaking down the plastic polymers; they called this enzyme PETase. To check whether PETase was indeed breaking down PET polymers, they put a PET film in a regular environment and then one with the PETase enzyme. The results are presented in the graph below:

Upon further investigations, other scientists tested the products of the PETase enzymatic reaction and how the reaction rate changed according to ambient temperature. The results are presented in the graph below:

In order to check if it was indeed the enzyme that was working on PET polymer molecules, they developed a model for the enzyme’s interaction with its substrate. The model is presented in the figure below:

Have scientists found an enzyme that breaks down PET plastic polymers?

What data or evidence gathered from text or graphics lead you to your claim?

What scientific principles from our unit on macromolecules and the 7 characteristics of life connects the evidence to the claim and explains why the data counts as evidence?