ACADEMIC SPEECH - BIOCHEMISTRY
Cellular respiration can be broken down into 3 phases.
The first one is glycolysis, which is the breakdown of glucose. This can occur with or
without oxygen. If we don’t have oxygen, then we go over to fermentation, producing
lactic acid or ethanol. But if we have oxygen then we can proceed with the Krebs
cycle and then we proceed to the electron transport chain.
The whole purpose of cellular respiration is to generate energy in the shape of ATPs,
or adenosine triphosphate composed of adenine + ribose + 3 phosphoryl groups.
This groups have high energy bonds. If we break one of this bonds, the electron are
free and are going to release energy. So one of the phosphate grous is going to
popp off and we’ll have ADP, adenosindiphosphate (with just 2 phosphoryl groups.
Glycolysis is the first step in the breakdown of glucose to extract energy for cellular
metabolism. Glycolysis consists of an energy-requiring phase followed by an
energy-releasing phase.
What is glycolysis?
Glycolysis is a series of reactions that extract energy from glucose by splitting it into
two three-carbon molecules called pyruvates. Glycolysis is an ancient metabolic
pathway, meaning that it evolved long ago, and it is found in the great majority of
organisms alive today
Highlights of glycolysis
Glycolysis has ten steps, we’re gonna firstly highlight the key steps and principles
without tracing the fate of every single atom.
Glycolysis takes place in the cytosol of a cell, and it can be broken down into two
main phases: the energy-requiring phase and the energy-releasing phase.
● In the energy-requiring phase, the starting molecule of glucose gets
rearranged, and two phosphate groups are attached to it. The phosphate
groups make the modified sugar, now called fructose-1,6-bisphosphate,
unstable, allowing it to split in half and form two phosphate-bearing
three-carbon sugars. Because the phosphates used in these steps come from
ATP, two ATP molecules get used up. The three-carbon sugars formed
