fermentation
When oxygen is present, the Krebs Cycle and then the Electron transport chain follow glycolysis. When oxygen is not present, a different pathway follows glycolysis. The combination of glycolysis and the different pathway is called fermentation.
Glycolysis
fermentation
Glycolysis is a metabolic process that normally occurs whether or not oxygen is present. It is the first step in cellular respiration and involves the breakdown of glucose to produce energy in the form of ATP.
Glycolysis is a process in eukaryotic cells that will proceed normally whether oxygen is present or absent. Glycolysis breaks down glucose to produce ATP, the cell's energy currency, and occurs in the cytoplasm. It does not require oxygen and is the first step in both aerobic and anaerobic respiration pathways.
This statement is incorrect. The final product of glycolysis is not oxygen, but rather pyruvate, along with a net gain of two ATP and two NADH molecules. Glycolysis occurs in the cytoplasm and does not require oxygen, making it an anaerobic process. Oxygen is involved in aerobic respiration, which occurs after glycolysis if oxygen is present.
In the absence of oxygen after glycolysis, muscle cells will produce lactic acid through the process of fermentation. This allows the cells to regenerate NAD+ needed for glycolysis to continue in the absence of oxygen.
Cellular Respiration
the Krebs cycle, which is followed by the electron transport chain
No - glycolysis is anaerobic (it does occur in the presence of oxygen).
Glycolysis literally means "splitting sugars." Glucose, a six carbon sugar, is split into two molecules of a three carbon sugar. In the process, two molecules of ATP and two "high energy" electron carrying molecules are produced. Glycolysis can occur with or without oxygen. In the presence of oxygen, glycolysis is the first stage of cellular respiration. Without oxygen, glycolysis allows cells to make small amounts of ATP. This process is called fermentation.
It is false that if oxygen is present in a cell, pyruvic acid in glycolysis enters the chloroplasts. The pyruvic acid enters the mitochondria if oxygen is present in a cell.