Chapter 8 - Photosynthesis Plant – multicellular eukaryotes that do photosynthesis. “stationary animals that eat sunlight”

Adenosine Triphosphate (ATP) One of the most important compounds that cells use. Stores and releases energy - adenosine triphosphate (ATP). ATP consists of adenine, a 5-carbon sugar called ribose, and three phosphate groups.

Adenosine Triphosphate (ATP) Adenosine diphosphate (ADP) has two phosphate groups instead of three. ADP does not contain as much energy as ATP. Another P is added to ADP to form ATP. Cells release the energy stored in ATP by breaking the bonds between the second and third phosphate groups.

Uses of ATP Powers protein pumps in the cell membrane Powers cilia and flagella Power for synthesis of proteins Powers proteins that contract muscles Provides cell energy

How could a small seed become a giant tree? Heterotroph – obtains energy from food it consumes Autotroph – uses energy from the sun to produce food Photosynthesis - autotrophs convert the energy from sunlight to produce high-energy carbohydrates (glucose)

Autotroph or Heterotroph

Photosynthesis CO 2 + H 2 O C 6 H 12 O 6 + O 2 LIGHT Carbon Dioxide Water Glucose Oxygen

Photosynthesis Takes place in the chloroplast Thylakoids – saclike photosynthetic membrane in the chloroplast Grana – stacks of thylakoids Stroma - the region outside of the thylakoid membranes

Photosynthesis (Overall) Light CO 2 H2OH2O Chloroplast LIGHT REACTIONS (in thylakoids) CALVIN CYCLE (in stroma) NADP + ADP +P ATP NADPH OSugar Electrons Light Dark

Factors Affecting Photosynthesis Shortage of water Temperature Photosynthesis is controlled by enzymes that work best between 0 C and 35 C. Light Intensity More light increases rate of photosynthesis

Chapter 9: Cellular Respiration 9-1 Chemical Pathways

Chemical Energy and Food Cellular respiration happens slowly and in many steps. If all the energy was release in one step... Most would be lost as light and heat! Cellular respiration breaks down glucose molecules and banks their energy in ATP

Chemical Energy and Food The two equations are exact opposites! PHOTOSYNTHESIS ___________ + _________ + ___________ → _______________ + __________ CO 2 H2OH2OC 6 H 12 O 6 O 2 _____________ + _________ → ________ + __________ + __________ CELLULAR RESPIRATION C 6 H 12 O 6 O2O2 CO 2 H 2 O

Overview of Cellular Respiration Occurs in three main steps Step 1: Glycolysis Occurs in the cytoplasm Breaks down glucose producing a small amount of ATP Step 2: Krebs cycle Takes place in the mitochondria Completely breaks down glucose, produces a small amount of ATP Provides third stage of cell respiration with electrons Stage 1 Stage 2 Stage 3

Overview of Cellular Respiration Cellular respiration Step 3: Electron Transport Chain (ETC) Occurs in the mitochondria Uses the energy released from electrons to produce ATP Stage 3

Overview of Cellular Respiration NADH FADH 2 GLYCOLYSIS Glucose Pyruvate (Electron Transport Chain) Substrate-level phosphorylation Oxidative phosphorylation Mitochondrion and High-energy electrons carried by NADH ATP CO 2 Cytoplasm Substrate-level phosphorylation Step 1 Step 2 Step 3 Krebs Cycle

Mitochondria Structure Has a double membrane, with an intermembrane space between the two layers. Cristae are folds of the inner membrane The matrix is the innermost compartment, which is filled with a gel-like fluid. Krebs Cycle occurs in the matrix. ETC occurs on the inner membrane.

Organize your thoughts Working in pairs at your tables please address the following: What is the chemical equation for photosynthesis (reactants/products) What is light? How does it play a role in photosynthesis? Write down everything that you already know about photosynthesis. Lastly, what is it that you don’t understand about plants or photosynthesis?

Green Solar Cells 1. What is responsible for the various shades of green in plants? 2. What is the function of the stroma lamellae? 3. What evidence supports the theory that chloroplast were once invasive cells? 4. How is excess food stored? 5. How does the author define photosynthesis?

Light CO 2 H2OH2O Chloroplast LIGHT REACTIONS (in thylakoids) CALVIN CYCLE (in stroma) NADP + ADP +P ATP NADPH OSugar Electrons Photosynthesis – Light and Dark Reactions LightDark

Dark Reaction (Calvin Cycle) 7._______ 6._______ 1._______ 4._____________ 3.___________ 2._______________ 5._____________

Homework (for Thurs. 12/9): 1.In text read pgs In 8.2 assessment on pg 234 answer question #1,2 and 3 all parts of each question

Using the light reaction diagram: On your own, describe the four steps of the light reaction in your own words. Use complete sentences.

In pairs: 1.See if you can write the chemical equation for photosynthesis (inputs and outputs) 2.What is the organelle in plant cells that is most involved with photosynthesis 3.Explain why this organelle captures energy 4.If you had to summarize light (from the sun or from a bulb) in one word what would it be?

Light Reaction Type of Transport = Type of transport = H+ Concentration =