obesity

Lab: Identifying Nutrients
Student Guide

Prelab Information
Purpose

Explore the presence of nutrients in food using a laboratory experiment and deductive reasoning. Time

Approximately 45 minutes

Scenario

Your biology teacher found an unknown food sample in the classroom, and there are four suspects: students who have different foods for lunch.
Student

Food

Macromolecule Present

Zack

Tofu

Protein

Nicole

Salad dressing

Lipid

Christian

Jelly sandwich

Monosaccharides

Abigail

Pasta

Polysaccharides

For various reasons, your teacher strongly suspects Zack of leaving the food sample. In this lab, you will figure out who was guilty by determining which macromolecules are present in the mystery food sample.
Question

Which macromolecules are present in the mystery food sample?

Hypothesis

If the mystery food is tofu, then it will react with the reagent that indicates the presence of a protein because tofu is primarily protein.

Variables

Independent variable: presence of macromolecules, including monosaccharides, polysaccharides, proteins, and lipids
Dependent variable: color changes observed in tests

Safety
 Always wear safety goggles and a lab coat when performing an experiment.
 Keep behavior in the lab purposeful.
 Use caution when working with dyes. They may stain your clothes or body.
 Check glassware such as test tubes and beakers for cracks and chips prior to use.
 Use the right gear, such as insulated gloves and test tube tongs, when moving test tubes into and out of the boiling water bath. When handling test samples otherwise, use thinner protective gloves of latex or other suitable material.
 Report all accidents—no matter how big or small—to your teacher.
 Never eat food in a science laboratory. Contamination could cause illness.

Copyright © Edgenuity Inc.

Student Guide (continued)

Lab Procedure
Step 1: Gather Materials
Mystery Food Sample