Photosynthesis

Two main groups of living things: Plants Animals In science we call them…. Autotrophs Heterotrophs

How do autotrophs get their energy to make food? How do heterotrophs get their energy? Sunlight By consuming something else

How do organisms obtain most of their energy? Carbohydrates (plant material)

How do plants make carbohydrates? Photosynthesis Creates glucose molecules Glucose molecules broken down in cells to basic unit of energy  ATP

What is Energy? Ability to do work Where does energy come from? Food  Glucose molecules C 6 H 12 O 6 = glucose

Living things use chemical energy stored in food Energy is stored as  ATP Adenosine Triphosphate

ATP powers cell activities like: Active transport Protein synthesis Muscle contractions

Energy is released when bonds are broken between phosphates – becomes ADP (Adenosine Diphosphate) ADP can be recharged to ATP by adding a phosphate = stored energy

ATP vs. ADP ATP is like a fully charged battery ADP is like a half charged battery

Photosynthesis Plants use energy from sunlight to convert water and CO 2 into high-energy carbohydrates and oxygen

Equation for photosynthesis 6CO 2 +6H 2 O  C 6 H 12 O 6 + 6O 2 Carbon dioxide + water  sugars + oxygen light

Photosynthesis is divided into two parts: Light Dependent Reaction (needs sun) Light Independent Reaction OR Calvin cycle

Why are plants green? What does chlorophyll do? Chlorophyll in chloroplasts Traps energy from sunlight

Light H2OH2O Oxygen CO 2 C 6 H 12 O 6 1 st reaction: light required 2 nd reaction : no light required

Quick Quiz What is the name of the main energy- storing compound in living organisms? What are the two reactions of photosynthesis? ATP Light Dependent and Light Independent (or Calvin Cycle)

What are the two things required in the first reaction? What is required for the second reaction? What are the products of photosynthesis? Light Energy and Water Carbon dioxide Oxygen and Glucose

Reason: The beakers closer to the light should produce more oxygen bubbles because light is required for the 1 st part of photosynthesis in which water is split and oxygen is released

Reason: Oxygen is produced during the first stage of photosynthesis; carbon dioxide is USED during the second stage; hydrogen from the water is USED in the second stage to form carbohydrates; nitrogen is not produced/used in photosynthesis The picture shows the results of a demonstration using the simple water plant Elodea. When the setup was placed in strong light, a space gradually appeared above the water in the graduated cylinder containing the plant. The gas in the space above the water was mostly -