Question

worker in break room | lunch they were eating | what sample matches?
describe the evidence that supports your conclusion.
jose | pasta | positive
ashley | full-fat greek yogurt | positive
bruce | water only | evidence
kiara | steak | positive
tommy | fruit salad | positive

1. solve the mystery: jerell has tested samples of food left by the thief. they reacted positively to the lugol test, biuret test, and sudan test.

a. which, if any, of jerell’s coworkers stole his ipod?
b. how do you know? cite evidence to support your claim.
c. what kind of meal might the thief have eaten to leave those macromolecules in the sample?
explain.

Explanation:

Part A

Step1: Recall Test Purposes

Lugol tests for starch (carbohydrates), Biuret for proteins, Sudan for lipids.

Step2: Analyze Each Worker's Lunch

• Jose: Pasta (starch + maybe protein/lipid? But need all three tests positive. Pasta has starch (Lugol +), but does it have protein (Biuret +) and lipid (Sudan +)? Unlikely as pasta is mainly carbs.
• Ashley: Full - Fat Greek Yogurt. Yogurt has protein (Biuret +, from milk), fat (Sudan +, full - fat), but does it have starch? No, yogurt is dairy, not starchy. So Lugol test would be negative.
• Bruce: Water only. No macromolecules, so all tests negative.
• Kiara: Steak. Steak has protein (Biuret +) and fat (Sudan +, from fat in meat), but no starch (Lugol -).
• Wait, maybe a miscalculation. Wait, the thief's sample is positive for all three: starch (Lugol), protein (Biuret), lipid (Sudan). Let's re - evaluate:

Wait, maybe the table was misread. Wait, the problem says the thief's sample reacted positively to Lugol (starch), Biuret (protein), and Sudan (lipid). So we need a food with all three: starch, protein, lipid.
Wait, maybe the initial analysis was wrong. Let's check again:

• Jose: Pasta (starch - Lugol +), but does pasta have protein and lipid? Pasta is made from flour (starch) and maybe some egg (protein and lipid) in some cases, but usually pasta is mainly starch. But maybe not enough protein or lipid.
• Ashley: Full - Fat Greek Yogurt: protein (Biuret +), lipid (Sudan +, full - fat has fat), but no starch (Lugol -).
• Bruce: Water: no.
• Kiara: Steak: protein (Biuret +), lipid (Sudan +, fat in meat), no starch (Lugol -).
• Tommy: Fruit salad: fruit has carbs (sugars, not starch, so Lugol -), some protein (little), some lipid (little). Not enough.

Wait, maybe the table in the image has different entries. Wait, the user's table:
Jose: Pasta
Ashley: Full - Fat Greek Yogurt
Bruce: Water only
Kiara: Steak
Tommy: Fruit salad
And the thief's sample is positive for Lugol (starch), Biuret (protein), Sudan (lipid). So we need a food with all three. Wait, maybe the correct answer is that none? But that can't be. Wait, maybe the problem has a typo, or maybe I made a mistake. Wait, Lugol test is for starch, Biuret for protein, Sudan for lipid.
Wait, let's think again. Maybe the answer is that no one, but that's unlikely. Wait, maybe the initial table's "positive" entries are for the thief's sample? No, the table is about the workers' lunches and their sample's test results (the "What sample matches?" column). Wait, the table's third column: for Jose, positive (maybe for one test?), Ashley positive, Bruce evidence, Kiara positive, Tommy positive. Wait, maybe the third column is the result of the tests on their lunch for the three tests. So we need a worker whose lunch tested positive for all three: Lugol, Biuret, Sudan.
So let's assume that the "positive" in the third column is for all three tests? No, that's not stated. Wait, the problem says "Jerell has tested samples of food left by the thief. They reacted positively to the Lugol test, Biuret test, and Sudan test." So we need to find which worker's lunch, when tested, would be positive for all three.
So let's analyze each lunch:

1. Jose: Pasta. Pasta contains starch (Lugol +), and if it's a pasta with meat sauce or something, but the lunch is pasta. Wait, the lunch is just pasta. Pasta (without sauce) is mainly starch, little protein, little lipid. So maybe not all three.
2. Ashley: Full - Fat Greek Yogurt: protein (Biuret +), lipid (Sudan +), no starch (Lugol -). So Lugol test negative.
3. Bruce: Water: all tests negative.
4. Kiara: Steak:…

To determine this, we analyze the macromolecule tests: Lugol (starch), Biuret (protein), Sudan (lipid). The thief’s sample was positive for all three.

• Jose’s lunch (pasta) likely contains starch (Lugol +), and if made with egg (common in pasta dough), it has protein (Biuret +) and lipid (Sudan +).
• Ashley’s yogurt has protein and lipid but no starch (Lugol -).
• Bruce’s water has no macromolecules (all tests -).
• Kiara’s steak has protein and lipid but no starch (Lugol -).
• Tommy’s fruit salad has no starch (Lugol -).

Thus, only Jose’s lunch matches the thief’s sample (positive for all three tests).

The thief’s sample was positive for starch (Lugol), protein (Biuret), and lipid (Sudan). A meal with all three could be a pasta dish with meat sauce: pasta (starch - Lugol +), meat (protein - Biuret +, lipid - Sudan +), and the sauce may have oil (lipid - Sudan +) and maybe some protein - rich ingredients. Another example: a sandwich with bread (starch), deli meat (protein, lipid), and mayonnaise (lipid). This meal contains starch (tests positive for Lugol), protein (Biuret +), and lipid (Sudan +), matching the thief’s sample.

Answer:

(Part A):
A. Jose stole the iPod (assuming pasta has starch, protein, and lipid to match the thief's sample which was positive for Lugol, Biuret, and Sudan tests).

Part B