Starch Hydrolysis Test Quiz and Flashcards

Questions and Answers

What is starch?

A large carbohydrate molecule with hundreds or thousands of glucose subunits.

What is the enzyme used in starch hydrolysis?

Amylase

What is the medium used in the Starch Hydrolysis Test?

Starch Agar plate

How can you see starch on the Starch Agar Plate?

You add iodine to the plate after incubation. Signup and view all the answers

What does a positive starch hydrolysis test look like?

The iodine remains its original amber color around the bacteria. Signup and view all the answers

What does a negative starch hydrolysis test look like?

The iodine turns a dark blue/black complex with intact starch. Signup and view all the answers

What does a positive starch hydrolysis test mean?

It means that the bacteria have the enzyme amylase. Signup and view all the answers

What does a negative starch hydrolysis test mean?

It means that the bacteria do not have the enzyme amylase. Signup and view all the answers

What are the steps of a Starch Hydrolysis Test?

<ol> <li>Use a loop to streak each organism in a single line on the Starch Agar Plate. 2) Incubate the plate at 37C till next class. 3) Obtain the incubated plates. 4) Coat the surface of each agar with Gram's iodine. 5) Observe and record.</li> </ol> Signup and view all the answers

What is the reagent used in the starch hydrolysis test?

Gram's iodine Signup and view all the answers

Study Notes

Starch Hydrolysis Test Overview

Starch is a large carbohydrate composed of numerous glucose subunits that require breakdown for bacterial utilization.
Amylase is the enzyme responsible for hydrolyzing bonds between glucose units, facilitating starch digestion by bacteria.

Medium and Procedure

The test is conducted on Starch Agar plates, which contain starch that dissolves completely in water, making it clear.
Iodine is used to visualize starch presence after incubation; it forms a dark blue/black complex with intact starch while remaining amber where starch is broken down.

Interpretation of Results

A positive Starch Hydrolysis test shows an amber color around bacteria after iodine application, indicating the presence of amylase.
A negative test appears dark blue/black, signifying intact starch and the absence of the amylase enzyme.

Test Steps

Streak organisms in a straight line on the Starch Agar Plate.
Incubate at 37°C until the next class.
After incubation, coat the agar surface with Gram's Iodine and observe the results.

Key Reagents

Gram's Iodine serves as the reagent to detect the presence of starch on the agar plate.

Description

Explore essential concepts related to the Starch Hydrolysis Test through these informative flashcards. Learn about starch, the enzyme amylase, and the overall process of starch breakdown by bacteria. Perfect for students studying microbiology or biochemistry.