11/13 Turn in ATP lab Go over ATP HW Photosynthesis Notes Photo. Vocab (due by end of class) Quick review (What's not done is HW)

Bio NOTES: Photosynthesis We know from previous lessons that all living things need energy in order to survive, and that food provides the source of energy. But…where does the food come from? Food is made by producers, such as plants and algae. Photosynthesis = process where plants use energy from the sun to make their own food Plants are also known as autotrophs because they make their own food by the process of photosynthesis. Producers capture energy from sunlight to make their own source of chemical energy!

Chemical Equation vtDjWw

In plants, chlorophyll is found in organelles called chloroplasts. Plants contain pigments that absorb sunlight and trap energy. The most common pigment is chlorophyll, which gives plants their green color. Plants also contain red and orange pigments such as carotene that absorb light in other regions of the spectrum. The spectrum of visible light Energy from the sun travels to Earth in the form of light. Sunlight is a mixture of different wavelengths of light – many of these are visible to your eyes.

Plants absorb red and blue light from the sun to make food during photosynthesis Plants don’t need green light to make food, so it is reflected – which is why plants are green! So…the best wavelengths of light for plant growth are red and blue while the worst wavelength of light for plant growth is green. nce/virtual_labs/LS12/LS12.html

Inside the chloroplast Photosynthesis occurs in chloroplasts. There are two major parts of a chloroplast: - grana (thylakoids) - stroma ● grana (thylakoids) - saclike membranes arranged in stacks - contains pigments - first part of photosynthesis occurs here ● stroma - region outside the thylakoid membranes - second part of photosynthesis occurs here

Light-Dependent Reactions The light-dependent reactions capture energy from sunlight. - takes place in thylakoids - water and sunlight are needed. -Water is absorbed through the roots - chlorophyll absorbs light energy - energy (ATP) is transferred along thylakoid membrane then to light-independent reactions - oxygen is released

Light-Independent Reactions The light-independent reactions make sugar. - takes place in the stroma - needs carbon dioxide from atmosphere - uses energy (ATP) from light-dependent reaction to build a sugar in a cycle of chemical reactions * Also called the Calvin cycle

C 6 H 12 O 6 granum (stack of thylakoids) thylakoid sunlight 1 six-carbon sugar 6H 2 O 6CO 2 6O 2 chloroplast energy stroma (fluid outside the thylakoids) 6CO 2 + 6H 2 O + sunlight  C 6 H 12 O 6 + 6O 2 The equation for the overall process is:

Factors affecting Photosynthesis ● Water - shortage can slow or even stop photosynthesis - plants living in dry areas have a waxy coating to prevent water loss ● Temperature - enzymes used in photosynthesis function best between 0°C and 35°C - high or low temps slow down or stop photosynthesis ● Intensity of light - increasing light intensity increases the rate of photosynthesis - plants eventually reach their maximum rate of photosynthesis

Summary of Photosynthesis Light Reactions Inputs: Light Water Outputs: ATP Oxygen (O2) OCCURS IN THYLOKOID Dark reactions (Calvin cycle) Inputs: ◦ ATP ◦ CO2 Outputs: ◦ Glucose OCCURS IN THE STROMA

Summary Light reactionsCalvin Cycle Thylakoid Stroma Glucose

Let’s review… Light-dependent reactions Light-independent reactions

What materials come into the chloroplast that are used in the light-dependent reactions?

What material comes into the chloroplast that is used by the Calvin Cycle?

What material moves out of the chloroplast from the light-dependent reactions?

What materials move out of the chloroplast from the Calvin Cycle?

What materials move from the light- dependent reactions to the Calvin Cycle?

What materials move from the Calvin Cycle back to the light-dependent reactions?

11/13 Turn in ATP lab Go over ATP HW Photosynthesis Notes Photo. Vocab (due by end of class) Quick review (What's not done is HW)