Cellular Respiration Explained with Simple Animations

Glycolysis occurs in the cytoplasm of the cell, beginning with a single glucose molecule.The process begins with an investment of two ATP molecules, which are converted to ADP.Glycolysis involves ten distinct chemical reactions, each catalyzed by specific enzymes.During these reactions, electrons are transferred to NAD+ molecules, converting them to NADH.The glucose molecule is split into two pyruvate molecules.The process produces a net gain of two ATP molecules, after accounting for the initial investment.These pyruvate molecules will continue to the next stage of cellular respiration in the mitochondria.Inside the mitochondrial matrix, pyruvate from glycolysis undergoes an important transformation.Pyruvate is converted into acetyl-CoA, releasing carbon dioxide and producing NADH in the process.Acetyl-CoA then enters the citric acid cycle, also known as the Krebs cycle, a series of eight chemical reactions.As the cycle progresses, it generates several important products. For each glucose molecule, the cycle turns twice, producing six NADH molecules.It also produces two FADH₂ molecules.And directly generates two ATP molecules through substrate-level phosphorylation.The cycle continuously turns, breaking down acetyl-CoA and generating energy carriers that will power the electron transport chain.These high-energy electron carriers, NADH and FADH₂, will now move to the inner mitochondrial membrane for the final stage of cellular respiration.The electron transport chain is located in the inner mitochondrial membrane.NADH and FADH2 deliver high-energy electrons to the chain.As electrons flow through the protein complexes, their energy is used to pump protons from the matrix into the intermembrane space.This creates a proton gradient across the membrane, with a higher concentration of protons in the intermembrane space.The protons then flow back through ATP synthase, driving the production of ATP from ADP and inorganic phosphate.Through oxidative phosphorylation, this process generates approximately thirty-four ATP molecules per glucose molecule, making it the most efficient stage of cellular respiration.And that completes our journey through cellular respiration, showing how cells efficiently extract energy from glucose!