4.1 chemical energy and ATP

• the chemical energy used for most cell processes is carried by ATP
• molecules in food store chemical energy in their bonds
• ATP= Adenosine Triphosphate
• Triphosphate and Diphosphate
• take in proteins, carbs, lipids, etc. in food. Break down food and store the energy released
• ATP transfers energy from the breakdown of food molecules to cell functions
  • Energy is released when a phosphate group is removed
• ADP is changed into ATP when a phosphate group is added

ATP (adenosine triphosphate)

adenine (p) --- (p) --- (p) (circles)

               \ /

                   [R] (pentagon)

|___adenosine___|

ADP (Adenosine diphosphate)

adenine (p) --- (p)

                  \ /

                     [R] (pentagon)

|____Adenosine_____|

Energy is stored when ADP adds a phosphate and goes to ATP

When used, ATP goes to ADP because it breaks the last phosphate bond and releases energy

• Carbohydrates are the molecules most commonly broken down to make ATP
  • Not stored in large amounts
  • up to 36 ATP from one glucose molecule
• Fat store the most energy
  • 80 percent of the energy in your body
  • about 146 ATP from a triglyceride
• Proteins are least likely to be broken down to make ATP
  • amino acids not usually needed for energy
  • about the same amount of energy as a carbohydrate