Yeast is Beast What is Yeast Yeast are

Yeast is Beast!

What is Yeast? • Yeast are single-celled fungi • A living organism • Related to the other fungi including: – edible mushrooms – common baker's yeast used to leaven bread – molds that ripen blue cheese; molds that produce antibiotics

Is yeast an autotroph or a heterotroph? Make a prediction in your notebook!

Tiny Organism- Long Name • The scientific name is Saccharomyces cerevisiae • It means "sugar-eating fungus".

Is yeast an autotroph or a heterotroph? The scientific name tells you!

Heterotroph Tell why.

How does yeast use energy ? • Yeast cells digest food to obtain energy for growth (heterotroph) • Their favorite food is sugar – sucrose (beet or cane sugar), – fructose and glucose (found in honey, molasses, maple syrup and fruit) – maltose (derived from starch in flour).

Aerobic Respiration • C 6 H 12 O 6 + 6 O 2 → 6 CO 2 + 6 H 2 O + heat • Occurs in the presence of Oxygen • How does this connect to the Carbon Cycle?

Anaerobic Respiration • Occurs without Oxygen • Fermentation is anaerobic respiration • Yeast goes through fermentation

Alcoholic Fermentation • produces useful end products, pyruvic acid, carbon dioxide (gas) and ethyl alcohol • These end products are released by the yeast cells • yeast ferments the sugars available from the flour and/or from added sugar

Design an Experiment • How is anaerobic respiration affected by variables? • How does carbon cycle through organic matter (yeast)? • How is the carbon cycle in yeast affected by variables? • What tools do you need?