Biology Case Study: Picture Perfect Lab

Questions and Answers

What was the Picture Perfect case about?

It was about how a textile worker could identify a stain on an old dress and how it could be removed.

What bio-related topics does the Picture Perfect case involve?

Starch/how it's removed, enzymes, cellulose.

What type of macromolecule are starch and cellulose?

Polysaccharides.

What monomer is found in starch and cellulose?

Glucose. Signup and view all the answers

Contrast the structure/function of starch with those of cellulose in plant cells.

Starch is made from glucose monomers and used for cellular fuel; cellulose is found in plant walls, made from glucose monomers with different linkages. Signup and view all the answers

What is an enzyme?

Enzymes help to speed up reactions by acting as a catalyst. Signup and view all the answers

What happens to starch molecules when amylase acts upon it?

Amylase cuts off the bond between two glucose molecules, breaking starch into simple sugars like maltose. Signup and view all the answers

Why can amylase break down amylose easier than it can break down amylopectin?

Amylopectin's branched structure differs from amylose's unbranched structure, making amylose easier to break down. Signup and view all the answers

Why didn't the textile worker have to worry about the amylase cleaning solution damaging the dress?

The dress was made of cotton, which is mostly cellulose not affected by amylase. Signup and view all the answers

When iodine was added to a test tube with starch and amylase, why did the iodine turn blue?

The amylase broke down the starch before iodine was added, so there was no starch left to react. Signup and view all the answers

What was the purpose of adding iodine to the test tubes containing starch and amylase?

To test for the presence of starch; blue color indicates starch presence. Signup and view all the answers

What did the Benedict's solution test for in the results of the lab?

Maltose. Signup and view all the answers

Which solution removed the most wallpaper in the wallpaper lab?

The substance with 0.5% amylase removed the most wallpaper. Signup and view all the answers

How did the most effective substance in the wallpaper lab remove the wallpaper paste?

The amylase broke down the bonds holding starch monomers together. Signup and view all the answers

Explain the results seen with vinegar in the wallpaper lab.

Vinegar removed 50% of the paste because acids hydrolyze starches. Signup and view all the answers

Why was it important for water to be used as a testable substance in the wallpaper lab?

Water served as a control to show it doesn't break down starch like the other substances. Signup and view all the answers

Study Notes

Picture Perfect Lab Overview

The Picture Perfect case involved a textile worker identifying and removing stains from an old dress using bio-related methods.
Key biological topics include starch breakdown, enzyme action, and cellulose structure.

Polysaccharides

Both starch and cellulose are classified as polysaccharides, which are complex carbohydrates made from multiple sugar units.

Monomer Units

Glucose serves as the monomer for both starch and cellulose, forming the building blocks of these carbohydrates.

Structural Differences

Starch consists of glucose monomers and serves primarily as a cellular fuel source.
Cellulose exists in plant cell walls, where glucose monomers are linked differently, alternating orientations of the monomers' structures.

Enzyme Function

Enzymes function as catalysts, facilitating chemical reactions without being consumed in the process.

Amylase Action on Starch

Amylase cleaves starch molecules by breaking the bonds between glucose units, resulting in simpler sugars like maltose.

Amylose vs. Amylopectin Breakdown

Amylose features a linear, unbranched structure, making it easier for amylase to degrade compared to the branched structure of amylopectin.

Effects of Amylase on Cellulose

The textile worker was unconcerned about potential damage from amylase to the dress since cotton is primarily cellulose, which has beta-linkages that amylase cannot digest.

Iodine Test Results

Iodine turned blue when added to a test tube containing starch due to the breakdown of starch by amylase prior to the test, indicating that starch had been digested.

Purpose of Iodine in the Experiment

Iodine was added to test tubes to check for starch presence, with expectations of a blue reaction in tube 1A (starch present) and a lack of color change in tube 3A (no starch).

Benedict's Solution and Sugar Testing

Positive results from Benedict's solution in tubes 2 and 4 indicated the presence of maltose, confirming that amylase hydrolyzed starch into simpler sugars.

Wallpaper Lab Results

A 0.5% amylase solution effectively removed the most wallpaper, suggesting the wallpaper paste contained starch.

Mechanism of Wallpaper Removal

The amylase solution disintegrated the bonds between starch monomers in the wallpaper paste, aiding in its removal.

Role of Vinegar in Results

Vinegar's acidic properties hydrolyzed some starch, explaining its partial effectiveness (50% removal) in the wallpaper lab.

Control of Water in the Experiment

Water was utilized as a control to demonstrate that it alone lacked the ability to break down starch, contrasting with the effects of the other solutions.

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Description

Explore the Picture Perfect case involving the identification and removal of stains on textiles. This quiz delves into important biological concepts related to polysaccharides like starch and cellulose, examining their structures and functions. Test your knowledge of macromolecules and enzymatic processes through these flashcards.