- Respiration Lab

10 pts. each for Prelab and In-Class Lab

Cellular respiration is the general term which describes all metabolic reactions involved in the formation of usable energy from the breakdown of nutrients. In living organisms, the "universal" source of energy is adenosine triphosphate (ATP). Read the Respiration background material from Bio 113. For a more in-depth explanation, there is some additional background information covering Respiration to be found here.

The summary reaction for respiration is shown below:


The first step of cellular respiration is Glycolysis, the breakdown of glucose (a six-carbon sugar) to form two molecules of pyruvate (3 Carbons). Glycolysis takes place in the cytoplasm of the cell. The resulting pyruvate molecule may pass through one of several pathways, depending on the organism in question. In some organisms, such as yeast, fermentation occurs. In other organisms, aerobic respiration occurs. After completing the lab, you should be familiar with the general reactions and products of aerobic respiration and fermentation.

Alcoholic Ferementation


One of the more familiar fermentations is conversion of glucose to ethanol to form alcoholic beverages. After the formation of pyruvate, ethanol is formed by two simple reactions. First, CO2 is removed from pyruvate to form acetaldehyde. Then acetaldehyde is reduced by NADH to form Ethanol. Below, we will measure the rate of carbohydrate fermentation by Yeast by measuring the CO2 produced. We will examine the process at two different temperatures.

0.5 pts./blank: