Yeast Metabolism Lab

Yeast Metabolism LabMrs. Zimmerman10/22/10

Photosynthesis

Respiration

Cellular RespirationC6H12O6 + 6 O2 6 CO2 + 6 H2O + energy

YeastUnicellularEukaryotic (like us)Kingdom FungiHetero-trophic (like us)Can produce energy anaerobically (without O2)-> called FermentationSaccharomyces cerevisiae

Alcoholic FermentationSome organisms, including yeast, can create energy without oxygen, but produce the toxin ethanol as a by-product.

Beer and wineBread

Alcoholic Fermentation

What happened there?The alcohol gets burned off when bread bakes, which is why its ok to eat.

Back to the labIndependent variableDependent variable

HypothesisMake a prediction about which treatment will produce the most carbon dioxideYeast + water? *ControlYeast + glucose?Yeast + Splenda?

Graphing your resultsWATERGLUCOSESPLENDACircumference of Balloon (cm)

Photosynthesis: the process by which a cell captures energy from sunlight and uses it to make food (sugars).*Respiration: process by which cells obtain energy from glucose (cells break down simple food molecules such as sugar and release the energy they contain).*Respiration: process by which cells obtain energy from glucose (cells break down simple food molecules such as sugar and release the energy they contain).

Respiration is required for metabolism!!The oxidation of carbohydrates is one of the most common ways organisms generate ATP

What could we measure if we wanted to know how much respiration is going on????

Today we are studying cellular respiration in yeast!!*NOT the same organism that causes yeast infections. (that is Candida albicans).*Yeast eats sugar and excretes carbon dioxide gas and ethyl alcohol. Those little bubble of carbon dioxide are what make all of the little holes in risen bread and therefore what causes bread dough to turn from an elastic compressed ball of flour and water into a warm, fragrant, loaf of bread. The alcohol produced is what gives the bread its flavor and this flavor can be modified by fermenting the yeast in different ways.*Control: the part of an experiment to which you compare the results of other tests (test WITHOUT the independent variable)*