EnergyAutotrophs & Heterotrophs | ATP |

Photosynthesis & Respiration Overview

Learning Objectives• Define autotroph and heterotroph• Explain the use of energy-carrier molecules

such as ATP• Compare and contrast photosynthesis and

respiration

Energy

• Flows through ecosystems

• Originates from sun

• Transferred between organisms

• Leaves ecosystem as motion and heat

Energy

• Heterotroph – an organism that must acquire energy by consuming other organisms

• Autotroph – an organism that is able to capture energy from the environment and store it in the chemical bonds of organic molecules– Photosynthesis – Chemosynthesis

Autotrophs & Heterotrophs

• Chemosynthetic organisms use chemicals instead of sunlight as an energy source– Bacteria and archaea– Bacteria in hydrothermal vents oxidize hydrogen

sulfide gas

– Some discovered in other ocean environments and hot springs on land

Autotrophs & Heterotrophs

• Organisms use chemical energy from food (carbohydrates)

• Breaking down carbohydrate bonds releases energy

• Stored in energy-carrier molecule (ATP)• Adenosine triphosphate (ATP) – the energy-

carrier molecule used to power cellular processes

ATP

– Stores energy in the chemical bonds between its three phosphate groups

• ATP stores energy in chemical bonds between phosphates

ATP

– Creates sugars

• Chemical equation for photosynthesis 6CO2 + 6H2O + energy C6H12O6

+ 6O2

carbon dioxide + water + energy glucose + oxygen

Photosynthesis & Respiration

– Allows autotrophs to store solar energy

• Photosynthesis – the chemical reaction that capturesenergy from sunlight and stores it in the chemical bonds of organic molecules

• Cellular respiration – the chemical reaction used by living

• Chemical equation for respirationC6H12O6 + 6O2 6CO2 + 6H2O +

energyglucose + oxygen carbon dioxide +

water + energy

Photosynthesis & Respiration

cells to release energy from organic molecules– Stores energy within

ATP– Energy released as

work and heat– Energy powers cellular

activities

Photosynthesis• Only performed by

autotrophs• Uses solar energy

to create high-energy sugars

• Uses carbon dioxide, water, and solar energy to create sugar and oxygen

Respiration• Performed by

autotrophs and heterotrophs

• Converts energy in sugars into energy within ATP

• Uses sugar and oxygen to create carbon dioxide, water, and ATP

Photosynthesis & Respiration

Photosynthesis & Respiration

Learning Objectives• Define autotroph and heterotroph• Explain the use of energy-carrier molecules

such as ATP• Compare and contrast photosynthesis and

respiration

Energy