Lesson 6: Introduction to Enzymatic Assays

Vocabulary flashcards covering key enzymatic assays and bacterial profiling concepts from Chapter 1 through Chapter 5.

Oxidase Test

A qualitative test used to determine the presence or absence of cytochrome c oxidase activity in bacteria, producing a purple color change within $20\,\text{seconds}$ if positive.

Cytochrome c

A component of the electron transport chain found in aerobic bacteria, such as Pseudomonas.

Catalase Test

A qualitative differential test that determines the presence or absence of catalase by checking for bubble formation upon the addition of hydrogen peroxide.

Catalase

An enzyme vital for bacterial survival in oxygen-rich environments that breaks down hydrogen peroxide to prevent the formation of toxic oxygen radicals.

Coagulase Test

A qualitative test that determines the presence or absence of coagulase, an enzyme that plays a role in blood clot formation by precipitating or coagulating plasma.

Coagulase Reacting Factor (CRF)

A factor that binds with coagulase to interact with fibrin, leading to the formation of blood clots.

Lipase Test

A qualitative test conducted on spirit blue plates to detect the presence or absence of lipase based on a zone of clearance or color reduction.

Lipase

An enzyme that hydrolyzes triglycerides, also referred to as fatty acids or lipids.

Qualitative Test

A non-quantitative assay that yields a yes-or-no result based on visual cues, such as bubble formation, precipitation, or color change.

Staphylococcus aureus

A Gram-positive bacterium that is positive for both catalase and coagulase, using coagulase to form a fibrin protective coat against antibodies and phagocytosis.

Staphylococcus epidermidis

A Gram-positive staph bacterium that is positive for catalase but negative for coagulase activity.

Streptococcus

A spherical Gram-positive bacterium that is catalase negative, differentiating it from Staphylococcus species.

Pseudomonas

An aerobic, Gram-negative bacterium that does not ferment lactose and is positive for oxidase activity.

Escherichia coli (E. coli)

A Gram-negative bacterium that ferments lactose and is negative for oxidase activity.

Bacillus subtilis (B. subtilis)

A bacterial species that is lipase positive and hydrolyzes fatty acids to create a zone of clearance on spirit blue plates.