Cinnamon, Chocolate Chip - Yeast Bread Lab

Cellular Respiration

C6H12O6 + O2 → CO2 + H2o + ATP
Process occurs in the Mitochondria
Why is it important in bread making: When yeast becomes activated, it undergoes cellular respiration. The yeast will undergo anaerobic respiration called alcoholic fermentation; the yeast will produce CO2 as well as alcohol. During alcoholic fermentation, the yeast creates Co2 which allows the bread to rise. However, as the food (sugar) that feeds our yeast run out our yeast will start to die and the bread will start to deflate. In general cellular respiration in the yeast is what allows our bread to rise.
Where do plants fall into this (wheat in the bread)

Wheat used for making flour has a lot of glucose. When kneading dough the glucose will form a structure that is responsible for capturing the gas (CO2) released from the yeast.

Anaerobic Respiration vs Aerobic Respiration

Lactic Acid Fermentation (Humans) - Produces lactic acid which causes muscles to feel fatigued and painful
Alcoholic Fermentation (Yeast) - Produces alcohol and CO2

Lactic Acid fermentation occurs in human cells while alcoholic fermentation occurs in plant and yeast cells. Both processes are examples of anaerobic respiration.

Alcohol fermentation is important in bread making because it changes the dough from a rough dense mass into a smooth, extensible dough with good gas holding properties; which you want when making bread.

CO2 Cycle

During bread making, in order for the bread to rise, CO2 must be released by the yeast via cellular respiration. In real life this CO2 would be released into the atmosphere and be available for plants to use.

Design rationale for recipe

Yeast is a type of fungi that undergo cellular respiration under ideal conditions. This process is what allows the bread to rise.

Warm water (between 120-130 degrees) is what will activate the yeast, and allow it to start undergoing cellular respiration.

Flour has a lot of gludin and glaidin, which mixed with water will form glucose. When kneading dough the glucose will form a structure that is responsible for capturing the gas (CO2) released from the yeast.
Also there is a lot of starch in flour, and when an enzyme in the flour reacts with that starch a sugar is released. The yeast will feed on this sugar.

Salt is used to hold on to the carbon dioxide that is created during anaerobic fermentation, and helps to strengthen the dough.

Fats such as oil and butter are used to keep the dough from getting too elastic. A bread with lots of elasticity will be really chewy, and not soft.

The sugar will help to feed the yeast and keep them alive as they undergo cellular respiration.

Recipe Reflection

How successful was your recipe? Reflect on research, ingredient choice and results

Our recipe was really successful. We ended up finding a recipe that made our bread soft, and not dry. We decided to add sugar, cinnamon, and chocolate chips last minute, but in the end those ingredients made our bread sweeter, and therefore better tasting. If we had to change anything, we would allow for the bread to rise for longer because we noticed that the bottom of the loaf was a lot denser than the top, and we think by letting the bread rise for longer the yeast could release more CO2 and make the bread even fluffier.

Recipe: