Explore BrainMass

Glycolyis and Cellular Respiration

Answer the following questions in a 2- to 3-page paper:

1. What is the starting molecule in glycolysis (i.e., what is being metabolized. Be specific)?
2. Define these terms: substrate, enzyme, ATP, and describe why they are important in cellular respiration.
3. What do these enzymes do, generally speaking? Would the reaction occur if they were not present? Why or why not?
4. What are the byproducts of cellular respiration? Where do these byproducts end up (in the organism AND in the environment)?

Solution Preview

Glycolysis is part of the larger metabolic pathway called aerobic respiration. Glycolysis is the process that occur in heterotrophs that converts food into energy and begins cellular respiration. It is a catabolic process that breaks down food. It begins with a glucose molecule in the presence of ADP and phosphate. Glucose is broken down into pyruvic acid. The goal of glycolysis is to break down glucose to form two pyruvates. All life on earth performs glycolysis. Glycolysis usually occur in the cytoplasm. Glycolysis produces 4 ATP's and 2 NADH, but uses 2 ATP's in the process for a net of 2 ATP and 2 NADH. The first stage of Glycolysis is known as the "priming phase" because it requires energy in form of 2 ATPs per glucose molecule. The second phase of glcolysis is known as the "pay off phase" because energy is released in the form of 4 ATPs, 2 per glyceraldehydes molecule. The end of glycolysis is two new pyruvate molecules that can be fed into the citric acid cycle if oxygen is present. Glycolysis occurs in all living cells and is primary source of Acetyl-CoA that is responsible for the majority of energy output under aerobic conditions. Glucose (6C) is broken down into 2 PGAL's ( Phosphogleraldehyde - 3 carbon molecules), that requires two ATP's. alpha-D-Glucose is phosphorylated at the 6 carbon by ATP via the enzyme Hexokinase to ...

Solution Summary

This solution of 822 words looks at the step-by-step process of glycolysis and cellular respiration. It also explains the role of enzymes, the different types of respiration and the substrates required. References used are included