Answer:
Glucose
Step-by-step explanation:
There are two types of respiration:
1. Aerobic respiration
2. Anaerobic respiration
Aerobic respiration
It is the breakdown of glucose molecule in the presence of oxygen to yield large amount of energy. Water and carbon dioxide are also produced as a byproduct.
Glucose + oxygen → carbon dioxide + water + 38ATP
Anaerobic Respiration
It is the breakdown of glucose molecule in the absence of oxygen and produce small amount of energy. Alcohol or lactic acid and carbon dioxide are also produced as byproducts.
Glucose→ lactic acid/alcohol + 2ATP + carbon dioxide
This process use respiratory electron transport chain as electron acceptor instead of oxygen. It is mostly occur in prokaryotes. Its main advantage is that it produce energy (ATP) very quickly as compared to aerobic respiration.
Steps involve in anaerobic respiration are:
Glycolysis
Glycolysis is the first step of both aerobic and anaerobic respiration. It involve the breakdown of one glucose molecule into pyruvate and 2ATP.
Fermentation
The second step of anaerobic respiration is fermentation. It involve the fermentation of pyruvate into lactic acid or alcohol depending upon the organism in which it is taking place. There is no ATP produced in this step, however carbon dioxide is released.