Chapter 4.1 Energy and Life

Energy is the ability to do work! What is energy? Energy is the ability to do work!

Sunlight is the main energy source for life on Earth.

1. Cells use chemical energy in the form of a chemical compound called ATP, or adenosine triphosphate. a. ATP contains: i. A 5-carbon sugar called ribose ii. A nitrogenous base called adenine iii. Three phosphate groups b. The bonds between the phosphate groups store and release energy

Energy is released when a phosphate group is removed. 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. phosphate removed

The chemical energy used for most cell processes is carried by ATP. Molecules in food store chemical energy in their bonds. Starch molecule Glucose molecule

3. ATP is the basic energy source of all cells

Organisms break down carbon-based molecules to produce ATP. Carbohydrates are the molecules most commonly broken down to make ATP. not stored in large amounts up to 36 ATP from one glucose molecule triphosphate adenosine diphosphate tri=3 di=2

c. ATP is like a rechargable battery. ADP ATP Energy Energy Adenosine diphosphate (ADP) + Phosphate Adenosine triphosphate (ATP) Partially charged battery Fully charged battery

Chemical Energy and ATP: Storing Energy Energy is stored in ATP a. ADP, adenosine diphosphate, is similar to ATP but has two phosphate groups instead of three b. When a cell has energy available, it can store small amounts by adding a phosphate to ADP making ATP

Using the energy 1. When a chemical bond between the 2nd and 3rd phosphates of ATP is broken, energy is released

Chemical Energy and ATP: Releasing Energy 2. ATP has enough energy to power a variety of cellular activities A. active transport across the selectively permeable cell membrane B. protein synthesis C. muscle contractions D. Propels flagella E. Produces light in fireflies Firefly Escherichia coli bacterium with flagella

4. ATP is a good short term energy storage that is recycled between ADP and ATP. Cells have only a small amount of ATP. It is more efficient for cells to store energy as glucose. When cells need energy they make ATP from ADP using energy from glucose.

Fats 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

ADP vs. ATP http://www.phschool.com/atschool/phbio/activities/cbd-3081/simbase.htm

C A B What is the name of the molecule above? What is the name of the part of the molecule labeled: A? ___________________________ B? ___________________________ C? ___________________________ adenine ribose 3 phospates

How does a cell get energy from this molecule? B How does a cell get energy from this molecule? By breaking the bond between the 2nd and 3rd phosphate. This releases the energy!!