Lab 11: Carbohydrate Metabolism

Vocabulary flashcards for lab 11 carbohydrate metabolism lecture.

Streak Plate

A method used to isolate bacteria and allow them to grow into a colony.

Colony

A mass of identical bacteria.

Colony Morphology

Characteristics of a bacterial colony such as color, size, shape, and texture.

Gram Stain

A process used to identify the type of cell wall a bacteria has (gram-positive or gram-negative) and to determine cell shape.

Gram-positive Bacteria

Bacteria with a specific type of cell wall that retains the crystal violet stain in the Gram stain procedure.

Gram-negative Bacteria

Bacteria with a cell wall that does not retain the crystal violet stain in the Gram stain procedure, appearing pink or red after counterstaining.

Cocci

Spherical-shaped bacterial cells.

Bacilli

Rod-shaped bacterial cells.

Spiral Bacteria

Spiral-shaped bacterial cells.

Biochemical Profile (Enzyme Profile)

A profile of all the different enzymes or biochemical reactions that a bacteria can perform, used to identify unknown bacteria.

Metabolism

All the biochemical reactions that occur within a cell, including anabolic and catabolic reactions.

Carbohydrate Metabolism

The process of breaking down different types of carbohydrates to produce ATP, often resulting in acidic waste products.

ATP

The readily usable form of energy for a cell.

Phenol Red

A pH indicator that is red at pH 7.4, turns yellow in acidic conditions, and pink in alkaline conditions; used to detect sugar utilization by bacteria.

Durham Tube

A small inverted test tube placed in a glucose tube to collect gas produced during glucose fermentation.

Starch Hydrolysis

A test to determine if bacteria can break down starch using the enzyme amylase; detected using iodine.

Iodine

An indicator used to detect the presence of starch; turns black in the presence of starch.

Methyl Red (MR) Test

A test to determine if bacteria produce acidic waste products when metabolizing glucose; methyl red is red in acidic conditions and yellow in basic conditions.

Voges-Proskauer (VP) Test

A test to determine if bacteria convert acidic waste products into neutral waste products during glucose metabolism.

Citrate Utilization Test

A test to determine if bacteria can use citrate as a sole source of carbon; bromthymol blue is the pH indicator, turning blue in basic conditions (positive result).

Bromthymol Blue

A pH indicator used in the citrate utilization test; green at neutral pH, yellow at acidic pH, and blue at basic pH.