Chapter 5: Cellular Respiration What are some types of energy we use everyday? Living things require chemical energy stored within their food to function.

Food Energy When cells break down food into energy, some is converted into heat, and the rest is changed to chemical energy. The process by which cells convert food into energy is called cellular respiration.

AC or DC current? Energy derived from food is not given off in a great burst…how come? Our cells would die!!! Instead, the energy is stored in high energy bonds…

Bond, Phosphate Bond. The compound that stores chemical energy in living things is called adenosine triphosphate (ATP). ATP is made of: 1) 1 Adenine 2) 1 Ribose 3) 3 Phosphates

Déjà vu all over again? Adenine, ribose, and phosphate? Where have we seen these things? Adenine and phosphate are both found in DNA, and ribose is the sugar in RNA!!! This is just an example of how organisms recycle.

Let’s look at ATP!!!

3 - 1 = ? Notice that when ATP transfers a phosphate group (and hence energy) it becomes ADP (adenosine diphosphate) This energy transfer is called phosphorylation!!!

Recap to date… Phosphorylation

ATP doesn’t grow on trees does it? Well, trees are made of cellulose, a complex carbohydrate, so… The main source of energy is GLUCOSE!!! 1 glucose molecule can make 36ATP!!!

Again, all of this energy is not released all at once…there are a series of small steps along the way. Each step is regulated by enzymes, and involves the transfer of electrons… As electrons are transferred, two processes occur…

Energy transfer… Electrons carry energy with them, so each time an electron is transferred, energy is as well… If an atom is oxidized, does it gain or lose energy? LOSE!!! What if you’re reduced? GAIN!!!

Why do we knead to know this? Well… Cellular respiration occurs in multiple steps, called a biochemical pathway. At various points on the pathway, electrons are transferred to carriers…

Electron Carriers… There are two electron carriers involved in the breakdown of glucose into energy: NAD+ and FAD Each of these can accept a pair of electrons and H atoms…