SAMPLE+ESSAY+ANSWER+-+CELLULAR+RESPIRATION+ESSAYS

25-Explain the process of chemiosmosis IN YOUR OWN WORDS. Make sure to include and **__underline all of__** the following terms: electron carriers, electrons, electron transport chain, oxygen, hydrogen channels, intermembranous space, matrix, hydrogen concentration, active transport, facilitated diffusion, ATP synthase, ADP and phosphate.

Chemiosmosis occurs during the last step of cellular respiration which is the ETC and it ultimately results in the production of 32 ATP per molecule of glucose. **__Electrons__** that originate from the breakdown of glucose molecules during glycolysis, are carried by __**electron carriers**__ into the __**electron transport chain**__, which is a series of proteins embedded in the inner mitochondrial membrane. __**Oxygen**__ is required for this process as it is the ultimate electron acceptor. The electrons are taken by the oxygen atoms at the end of the ETC and together with hydrogen ions they combine and water is formed. Once the electrons arrive to the ETC, they travel from protein to protein, and as they do, a small amount of energy is released. That energy is used to __**actively transport**__ positive hydrogen ions from the matrix into the intramembranous space through __**hydrogen channels**__. This process of active transport results in a really __**high concentration of hydrogen**__ ions in the __**intermembranous space.**__ Once that concentartion gradient has been built, the hydrogen ions now start to travel from the intermembranous space (where they are highly concentrated) back to the **__matrix__** (low concentration) through a protein in the membrane called __**ATP synthase**__ in a process known as __**facilitated diffusion**__. As the hydrogen ions diffuse through the ATP synthase, energy is used to bond __**ADP**__ and single __**phosphates**__ to make ATP.