The overall mechanism of cellular respiration<span> involves four subdivisions: glycolysis, in which glucose molecules are broken down to form pyruvic acid molecules; the Krebs cycle, in which pyruvic acid is further broken down and the energy in its molecule is used to form high-energy compounds such as NADH.
Source: </span><span>Cellular Respiration - Cliffs Notes</span>
Essential amino acids refer to the eight amino acids the adult body needs, which they cannot be synthesized correctly or at all.
The essential amino acids must be obtained from food such as proteins (meats, seafood, milk, eggs, etc).
Solution
Cut open an onion.
Use forceps to peel a thin layer of epidermis from the inside.
Lay the layer of epidermis on a microscope slide.
Add a drop of iodine solution to the layer.
Carefully place a coverslip over the layer.
Observe it under a microscope to see onion cells.
The correct answer should be (d) The Krebs cycle
After Glycolysis, the Krebs cycle begins in the matrix of the mitochondrion.
