There are 11 players on the field per team during a soccer game. Each team has 10 field players and a goalkeeper. Formations are identified with the number of defenders, midfielders and forwards. Goalkeepers are understood positions and aren't included in the formation. Depending on the coach's style of play, there are several different formations that could be used for the spacing of players on the field.
1 Though the Krebs cycle does not directly require oxygen, it can only take place when oxygen is present because it relies on by-products from the electron transport chain, which requires oxygen. 2  The Krebs cycle is therefore an aerobic process.
When oxygen is present, acetyl-CoA is produced from the pyruvate molecules created from glycolysis. When oxygen is present, the mitochondria will undergo aerobic respiration which leads to the Krebs cycle. However, if oxygen is not present, fermentation of the pyruvate molecule will occur. In the presence of oxygen, when acetyl-CoA is produced, the molecule then enters the citric acid cycle (Krebs cycle) inside the mitochondrial matrix, and is oxidized to CO2 while at the same time reducing NAD to NADH.