Quiz I Lab Review

Hypotheses –
1. Identify the by-products of aerobic and anaerobic respiration in yeast.
2. The effects of freezing on aerobic respiration of peas.
3. Rate of oxygen consumption in room thawed peas and peas.

YEAST AND GLUCOSE
How –
Yeast can break down glucose therefore, it was mixed, causing Glycolysis to happen. The end product of Ethanolic Fermentation in Yeast is water and carbon dioxide (CO2)

Culture set up, with tube coming out of it, heated, produced ethanol, yellow precipitate. YELLOW precipitate indicates presence of ethanol.

White precipitate tells us CO2 is being produced.

In the experiment we took 4 test tubes
1. Number 1 to 4
2. Add Iodine to each****KOH **
3. Add NAOH sodium hydroxide to each NAOH **** NAOH sodium hydroxide
4. Add Sample in each
a. Tube 1 - distilled water
b. Tube 2– Water and 95% ethanol
c. Tube 3 – Anaerobic culture
d. Tube 4 – Control (already done)

WAITED 5 Minutes
Then Mixed
1. If ethanol is present it will react with the iodine to form (iodoform)
2. Tube 3 with the anaerobic culture should have turned Yellow Precipitate
Yellow Precipitate*** Yellow Precipitate***** Yellow Precipitate = Ethanol
Yellow Precipitate ***IODOFORM***** = Ethanol
IODOFORM ***Yellow Precipitate*** Yellow Precipitate*** IODOFORM