Glycolysis
Glycolysis is a relatively simple process, but its mechanism is rather long. Fortunately, we do not need to memorize the intermediate molecules or enzymes involved in glycolysis for this course. However, we do need to know the input and the output of this process.
In the cytosol, 1 glucose, 2 ATP, 4 ADP, and 2 NAD+ react through a complex mechanism, and produces 2 pyruvates, 4 ATP, 2 ADP, 2 NADH, and 2 hydrogen ions. (Note that 2 inorganic phosphates are also needed, but because of their relative abundance we will not include them.)
Here's a rough outline on how the reactants become products:
1 glucose -----> 2 pyruvates
2 ATP -----> 2 ADP
4 ADP -----> 4 ATP
2 NAD+ -----> 2 NADH + 2H+
The 4 ATP molecules are produced through substrate-level phosphorylation. Since 2 ATP are put in and 4 are produced, the net gain is 2 ATP.
Glycolysis breaks glucose down into pyruvates, which can be used as fuel later in cellular respiration. It also produces 2 electron carrier NADH's and a net gain of 2 ATP. The 2 hydrogen ions are not extremely relevant to the next steps of respiration, but do note that they are produced.
An important enzyme in glycolysis is phosphofructokinase. It can be inhibited by an abundance of ATP and/or citrate and stimulated by AMP, a derivative of ADP.
Glycolysis is the most widely used metabolic system on Earth, which suggests that it also evolved very early on in biological history.
In the cytosol, 1 glucose, 2 ATP, 4 ADP, and 2 NAD+ react through a complex mechanism, and produces 2 pyruvates, 4 ATP, 2 ADP, 2 NADH, and 2 hydrogen ions. (Note that 2 inorganic phosphates are also needed, but because of their relative abundance we will not include them.)
Here's a rough outline on how the reactants become products:
1 glucose -----> 2 pyruvates
2 ATP -----> 2 ADP
4 ADP -----> 4 ATP
2 NAD+ -----> 2 NADH + 2H+
The 4 ATP molecules are produced through substrate-level phosphorylation. Since 2 ATP are put in and 4 are produced, the net gain is 2 ATP.
Glycolysis breaks glucose down into pyruvates, which can be used as fuel later in cellular respiration. It also produces 2 electron carrier NADH's and a net gain of 2 ATP. The 2 hydrogen ions are not extremely relevant to the next steps of respiration, but do note that they are produced.
An important enzyme in glycolysis is phosphofructokinase. It can be inhibited by an abundance of ATP and/or citrate and stimulated by AMP, a derivative of ADP.
Glycolysis is the most widely used metabolic system on Earth, which suggests that it also evolved very early on in biological history.