Single celled microorganism
Type of fungus
Exist on all living matter
Hundreds of different species!
We may not look much like yeast or they like us, but many of the 6,000 genes in yeast have counterparts in humans!
As a living organism, just like us, yeast needs the following to survive and flourish:
Respiration is the process by which a living organism releases energy from its food
Do you remember the difference between aerobic and anaerobic respiration?
Humans produce energy through aerobic respiration
In aerobic respiration glucose reacts with oxygen in the mitochondria of the cells to release energy.
Carbon dioxide and water are by-products of the reaction.
Glucose + oxygen carbon dioxide
+ water + energy
Anaerobic respiration occurs when oxygen is not available.
In anaerobic respiration the glucose is only partially broken down, and lactic acid is produced
Living yeast cells in the absence of oxygen are still able to use sugar as their source of food to make energy
This is known as fermentation
In this case ethanol (alcohol) is produced instead of lactic acid
Glucose carbon dioxide
+ ethanol + energy
Aerobic Vs. Anaerobic Respiration
-oxygen always required
-efficient method of respiration