The Basics Photosynthesis and Cell Respiration

Sunlight Powers Life Certain organisms convert energy from sun to chemical energy in food… –S–S–S–Some make food themselves AUTOtrophs producers (photosynthesis) –S–S–S–Some rely on others for food HETEROtrophs consumers ALWAYS starts with the sun Regardless of Photosynthesis or Respiration

Working Together The p pp products of photosynthesis are the chemical ingredients for cellular respiration The p pp products of cellular respiration are the chemical ingredients for photosynthesis

ATP is ENERGY! Adenosine Tri Phosphate ATP = Adenosine Tri-Phosphate -Energy needed for cellular work ATP  ADP + P + energy Energy released used in metabolic activity PPP Di ENERGY

ATP Cycle ATP continuously converted to ADP as cells do work… but cant use ADP…ATP continuously converted to ADP as cells do work… but cant use ADP… Recycles!Recycles! Page 144

Photosynthesis Direct from the sun

The stages of Photosynthesis The Light Dependent Reaction 3 stages Stage 1: Energy is captured from sunlight Done by leaves –C–Contain chloroplasts, chlorophyll (green pigment) »A»Absorbs blue and red, reflects yellow and green

Stage 2Stage 2 Light energy converted into chemical energy Stored in ATP and NADPH (e- carrier) Light NRG ADP ATP NADP+ NADPH Chemical NRG The stages of Photosynthesis The Light Dependent Reaction

Stages of Photosynthesis: Light Independent Reaction –Step 3 NRG stored in ATP and NADPH powers formation of organic compounds (sugars) by using CO2 End products of photosynthesis ARE: Sugar (organic compound) and Oxygen ATP Oxygen

Light Reaction and Calvin Cycle

Reflection Activity why plants grown in shaded areas produce larger leaves than those grown in direct sunlight?

Why Do Leaves Turn Autumn Colors? Tree and plant leaves contain pigments that give them their color. Three pigments are involved in fall color:· Chlorophyll (a & b) — gives leaves their green color. Carotenoids —yellow, orange, brown colors Anthocyanins — give the red and purple colors. During the growing season, most tree leaves are green because they are full of chlorophyll. Leaves turn different colors in the fall because chlorophyll a & b are not being made! As these pigments dissipate out of the leaves the accessory pigments (other colors) become v vv visible.

change fall So…Why do leaves change colors in the fall ? Leaves turn different colors in the fall because chlorophyll a & b are not being made! As these pigments dissipate out of the leaves the a aa accessory pigments (other colors) become v vv visible.

Photosynthesis Review 1.Is it direct or indirect? 2.What is “Stage 1” a)Where is this happening? b)What pigment absorbs the light energy? 3.What is “Stage 2” a)What is the name of the chemical energy? b)What is “carrying” the electrons? 4.What is “Stage 3” a)What 2 things power the formation of sugar? b)What is the name of the final sugar made? c)What else is made at the end besides sugar?