Fireflies

Photuris pyralis

Beetle or Fly?

• Beetle

The firefly light is called a "cold light" because it produces no heat.

• Each species has a unique signal, and females of some species thereby locate males of other species and eat them.

• A female Photuris sp. ready to devour a prey male. These femme fatales use flash signals to lure in males of other species by imitating their females' flash patterns.

• The insect controls the emission of light by regulating the amount of air supplied to the cells (photocytes).

• A lot like the glow-in-the dark sticks at Halloween

Mating Fireflies

GLOWWORMSGLOWWORMS

• These, along with firefly larvae, are often called glowworms.

Luciferin

• Used as a bio indicator of life

Needs ATP

• As a cofactor• The luciferin-luciferase chemical

reaction has been used for years to measure the amount of ATP produced in cells and by various chemical reactions.

Role of membranes?

• Many enzymes that control a cell’s chemical reactions are located in membranes.

• Control the substances that go in and out of a cell.

Making light Step 1

luciferinluciferin + ATP ------------->

luciferyl adenylate + PPi

PPi = pyrophosphate

enzyme

Making Light Step 2• luciferyl adenylate + O2 -------------

> oxyluciferin +AMP + lightlight

• Light is given off and the oxyluciferin and AMP are released from the enzyme's surface.

Ever seen a glow-in-the dark mushroom?

• Recently, the gene (section of DNA coding for the protein) for the luciferase enzyme has been isolated, placed in the genes of other organisms