And Cellular Respiration 3.2 Cellular Energy: Photosynthesis And Cellular Respiration Complete Cornell Notes on the following power point, due Monday 11/27 (Summarize what you already know, explain what you don’t! Happy Thanksgiving!

Energy and ATP Energy and ATP A. Life depends on energy but where does this energy come from? B. Energy is stored in the chemical bonds of molecules.

Energy and ATP These molecules release energy when their chemical bonds are broken and store energy when chemical bonds are made. Compounds that store energy include: ATP, NADH, NADPH

Adenosine Triphosphate ATP (adenosine triphosphate) ATP is made of three parts: 1) ribose 2) adenine 3)three phosphates (adenine and ribose are bonded together to form adenosine)

Adenosine Triphosphate An ATP molecule releases chemical energy whenever a bond holding a phosphate group to the molecule is broken. This creates a new molecule ADP (adenosine diphosphate). Energy ATP (3 phosphates) ADP (2 phosphates)

Adenosine Triphosphate 2.Releasing Energy: Energy that is released by breaking apart phosphate groups in ATP can be used to power cell activities. 1. Stored Energy: Energy is stored in chemical bonds. The phosphate bonds in ATP are especially useful for storing energy. ATP Energy for cells Energy from food 3. Energy Depleted: ADP has less chemical energy than ATP. 4. Making ATP: Energy released by other chemical reactions can be used to bond a phosphate group to ADP, making ATP. ADP + P

Adenosine Triphosphate The energy released by converting ATP into ADP can be used by cells to do work.   Energy = ability to do work! Cells generate a continuous supply of ATP by attaching a phosphate to ADP.

Cellular Respiration Makes ATP This energy storing molecule is made in the Mitochondria during a process called cellular respiration.  

Where does the glucose for Cellular Respiration come from?

Photosynthesis II. Photosynthesis A. Energy from Sunlight Photosynthesis - the process by which autotrophs (plants) convert sunlight into a usable form of energy. (Food!!!)

Photosynthesis Autotrophs that perform photosynthesis require pigments to trap the energy in light. The most common photosynthetic pigment is chlorophyll.

Photosynthesis Chlorophyll is a green pigment that absorbs violet, blue, and red light. These wavelengths of light are necessary for photosynthesis

Photosynthesis Autotrophs also contain other pigments called accessory pigments. (yellow,red,orange)

Chloroplasts B. Chloroplasts In many organisms chlorophyll and other pigments are located in specialized organelles inside the cell. These are called chloroplasts.

Chloroplasts A photosynthetic cell may contain several thousands chloroplasts. Inside this tiny organelle is where photosynthesis takes place.

Chloroplasts Inside the chloroplasts are stacks of disk shaped structures called grana. The individual disk shaped structures are called thylakoids.

Chloroplasts Chlorophyll is housed inside of the thylakoids. Inside the thylakoids, hundreds of chlorophyll molecules and other pigments are organized into units called photosystems.

The Big Picture C. The Big Picture The process of photosynthesis can be summed up by the following chemical equation.  6CO2 + 6H2O+ energy  C6H12O6 + 6O2 Reactants Products (glucose)

The Big Picture

The Big Picture In this equation the sugar glucose is a product. The energy stored in glucose can be used later during cellular respiration to produce ATP.

Two Cycles D. Two Cycles Light-dependent reactions - Photosynthesis begins when light is absorbed by the grana in the chloroplast. This starts the light dependent reactions: - Takes place in the thylakoid membranes 1. Water is split into hydrogen ions (H+), electrons, and oxygen (O2) 2. Oxygen diffuses out of the chloroplast 3. ATP and NADPH are produced

Two Cycles Calvin Cycle – construction of carbohydrates from CO2 - Takes place in the stroma This follows the light dependent reactions. The products ATP and NADPH are used in the Calvin cycle. The Calvin cycle requires an input of CO2 to make sugars. One glucose molecule is built for every six CO2 molecules that enter the cycle.

Two Cycles

Why is Photosynthesis Important? IV. Why? Plants use glucose for growth, they create molecules such as cellulose by linking chains of glucose molecules. Most plants store glucose as starches. Starches are found in plant foods such as wheat and potatoes.

Why is Photosynthesis Important? When heterotrophs consume autotrophs they breakdown starches to glucose and use the energy in glucose for their own energy and structural needs.

Reflection Questions 1. Why is ATP important for cells? 2. What is photosynthesis? Does it store or release energy? 3. What are autotrophs and why are they important? 4. What is the formula for photosynthesis? Is it balanced? 5. Describe the 2 cycles that make up photosynthesis.