Energy & ATP

1. Energy & ATP Mrs. Stewart Honors Biology Central Magnet

2. Chemical Energy and ATP • The main chemical compound that cells use to store and release energy is called ATP (adenosine triphosphate)

3. Adenosine Triphosphate • All energy must eventually be in the form of ATP in order for it to be used for cell metabolism. • ATP is the energy "currency" of the cell. • Why?

4. ATP is the onlysource of energy that the • body can use. • Stored energy (e.g. fat, glycogen, creatine • phosphate) must first be converted to ATP • before the body can actually use it. • You bring 50 loads of laundry to a laundromat. • It will only take quarters. • It costs $5 in quarters per load • There is a change machine at the laundromat. • Are you going to carry $250 in quarters?

5. Laundromat Human Systems Quarters ATP $1 Glycogen, Blood Glucose $100 Stored Fat Visa Checkcard Protein

6. Storing Energy • ATP holds energy in the bond between the second and third phosphate group • ATP is like a fully charged battery • Stores enough energy for 8-12 seconds of intense exercise. Energy

7. Think – Pair – Share Q: How is the energy in ATP released? A: Break bond between the 2nd and 3rd phosphates

8. ATP vs. ADP • ATP – has all 3 phosphate groups • Fully charged battery • Brief energy storage • Can remove a phosphate group to release energy and form ADP • ADP – has only 2 phosphate groups • Partially charged battery • Can add a phosphate group to make ATP

11. ATP Availability • Most cells only have enough ATP for a few seconds of activity • Why? • Not good at storing energy over the long term • Glucose stores 90 times the chemical energy of ATP • Cells generate ATP from ADP as needed by using the energy in foods (like glucose)

12. $1 = glycogen/glucose • Glycogen/glucose is like having dollar bills that can be broken down to quarters in a change machine. • Much greater capacity ($1) than carrying quarters. • The human body stores ~350 g of glycogen, not enough to sustain long duration of exercise or a period of time without food.

13. $100 = Stored Fat • Fat stores are the energy sources for rest and prolonged activity at lower levels of exertion. • Breaking down fat is a SLOW process. Just like getting change for the $100 bill (in quarters) would take a while, mobilizing fat stores to be used to meet cellular energy demands also takes longer than using glucose or ATP.

14. VISA = Protein • When either carbohydrate intake or overall energy intake is low; proteolysis (the breakdown of protein – mostly from lean muscle) provides energy for biologic work. • VISA: using protein as energy supplements the ATP, glycogen and fatty acids that provide the majority of the ATP.