Chemical Energy & Trophs How do different organisms obtain and use energy to survive in their environment?

How do Organisms get carbohydrates? 1. Autotrophs: make their own carbohydrates using inorganic compounds Phototrophs: use the sunlight for E source Chemotrophs: use chemicals for E source 2. Heterotrophs: eat other organisms for carbs Describe the relationship between autotrophs and heterotrophs.

Cellular Energy Cells must convert carbohydrates into a form of energy they can use. Cells cannot directly use carbohydrates for energy Analogy: cannot use Canadian money in the US. You have to convert it first.

Cellular Energy Cells use carbohydrate’s energy to make ATP ATP (adenosine triphosphate): molecule used to carry chemical energy Carries energy in its bonds

Cellular Energy The energy from ATP can power different kinds of work in the cell. (a) Mechanical work (b) Transport work (c) Chemical work Low concentration of solute ATP ADP + P ADP + P ATP ADP + P ATP Chlamydomonas Flagella Enzyme Substrates Product High concentration of solute Figure 4.12

How does ATP Release Energy? Energy is released when the last phosphate group is removed (bond is broken). ATP becomes ADP

How does ADP become ATP? Carbohydrates and other foods consumed by the body contain energy. When they are broken down, energy is released and is used to reattach a phosphate to ADP, turning it back into ATP. Occurs in the mitochondria

ATP is like a Rechargeable Battery