Photosynthesis Edwin P. Davis, M.Ed. Biology - Chapter 8
Cells Biology - Chapter 8
Cells Biology - Chapter 8
Plant & Animal Cells Biology - Chapter 8
Photosynthesis Biology - Chapter 8
Photosynthesis – Chapter 8 Biology - Chapter 8
Time Line Jan Ingenhousz Joseph Priestley Jan van Helmont Experiment to see if plants grew by taking material out of soil. He measured the amount of soil then planted a seed and let it grew. After 5 years, he measured the weight of the soil and found it was the same as the original weight. Water and Carbon Dioxide account for the weight of the plant. Carbon from carbon dioxide is used to make sugars. Water is used to hydrate the plant. Pristley: When a lit candle is placed under a jar, it will burn out. Priestly placed a plant under the jar with the candle and waited a few days. The candle could be re-lit after a few days because the plant had produced oxygen which is necessary for fire to burn (or the candle to stay lit) Ingenhousz: Ingenhousz found that Priestley’s experiment only worked when the plant was exposed to light. Joseph Priestley Biology - Chapter 8
Significant People Helmont: trees gain most of their mass from water Priestly: plant releases oxygen Ingenhousz: water plants produce oxygen bubbles in the dark! Biology - Chapter 8
Section 8-1: Energy & Life Autotrophs: Plants and other organisms that is able to make their own food by using light energy from the sun. Plants are able to use light energy from the sun to produce food. Biology - Chapter 8
Energy & Life Heterotrophs: are organisms that cannot make their own food. Heterotrophs obtain their energy from the foods they consume. Examples: Impalas eat grasses Leopards obtain energy stored in autotrophs by feeding on animals Biology - Chapter 8
· Chemical Energy: Living things use chemical energy stored in cells and released in the form of Adenosine triphosphate (ATP). Biology - Chapter 8
Photosynthesis Photosynthesis is a process in which green plants use energy from the sun to transform water, carbon dioxide, and minerals into oxygen and organic compounds. Biology - Chapter 8
Photosynthesis Photosynthesis happens when water is absorbed by the roots of green plants and is carried to the leaves by the xylem, and carbon dioxide is obtained from air that enters the leaves through the stomata and diffuses to the cells containing chlorophyll. Biology - Chapter 8
Key Terms Photosynthesis- process by which autotrophs convert sunlight to a usable form of energy. Pigment – molecule that absorbs certain wavelengths of light (reflects others) Chlorophyll – most common photosynthetic pigment
Photosynthesis Biology - Chapter 8
Photosynthesis Biology - Chapter 8
Photosynthesis Biology - Chapter 8
Reactions of Photosynthesis Biology - Chapter 8
Photosynthesis Photosynthesis Equation: 6CO2 + 6H2O C6H12O6 + 6O2 Biology - Chapter 8
Photosynthesis The green pigment chlorophyll is uniquely capable of converting the active energy of light into a latent form that can be stored (in food) and used when needed. Biology - Chapter 8
Photosynthesis Biology - Chapter 8
Photosynthesis Biology - Chapter 8
Pigments found in plants Chlorophyll a Chlorophyll b Carotene Main pigment responsible Biology - Chapter 8
Why do plants appear green? Light is absorbed in the blue and red spectrum. Light in the green and yellow spectrum is reflected so plants look green. Biology - Chapter 8
Biology - Chapter 8
Wavelength Absorption
Vocabulary Chlorophyll: Pigment that absorbs light. 2. Chloroplast: Where photosynthesis occurs. 3. Photosystem: light-gathering units found in thylakoid membrane. 4. Thylakoid: Photosynthetic membrane 5. Granum: Stack of thylakoids 6. Stroma: Area outside of thylakoid membrane. Biology - Chapter 8
Structure of a Chloroplast Thylakoid – “pancake”- shaped -contains chlorophyll Grana - stacks of thylakoids Stroma - gel surrounding grana
Biology - Chapter 8
Chloroplast Biology - Chapter 8
Inside a chloroplast Biology - Chapter 8
Inside a chloroplast Biology - Chapter 8
1. Light-dependent reaction: takes place in thylakoid membrane Photosynthesis takes place in the chloroplast. Happens in 2 stages: 1. Light-dependent reaction: takes place in thylakoid membrane 2. Calvin cycle: takes place in stroma The light-dependent reaction occurs in the thylakoid membranes. The Calvin cycle occurs in the stroma. Biology - Chapter 8
Light Dependent Requires light Uses light to make energy which will be used to make glucose ATP and NADPH O2 is released as a by product (waste gas) Biology - Chapter 8
Calvin Cycle Does not require light Occurs in the stroma Create glucose The Calvin cycle is often called the dark rxn or the light-independent rxn because it can occur without light being present. Biology - Chapter 8
What is the main product of the Calvin Cycle? Glucose - (6-Carbon molecule) Biology - Chapter 8
Light Dependent Reactions 1. Occurs in the thylakoid of the chloroplast. Pigments that aid in photosynthesis Chlorophyll a (major pigment) and Chlorophyll b (accessory pigment). Biology - Chapter 8
Light Dependent Reactions When chlorophyll a is hit by light, the electrons inside is elevated to a higher energy level (it is "excited"), the excited electron is then passed to a Primary Electron Acceptor. The pigments in the thylakoid space organize themselves into Photosystems. Biology - Chapter 8
Light Reactions & Calvin Cycle Biology - Chapter 8
Biology - Chapter 8
Biology - Chapter 8
Biology - Chapter 8
Biology - Chapter 8
Photosynthesis Biology - Chapter 8
Photosynthesis Vs. Chemosynthesis Biology - Chapter 8
Autotrophs Vs. Heterotrophs Biology - Chapter 8
Cellular Respiration Biology - Chapter 8
Use the following to fill in the above Venn Diagram: Cellular Respiration Photosynthesis Use the following to fill in the above Venn Diagram: heterotroph energy conversion CO2 -reactant autotroph oxygen required oxygen -waste 24 hours per day glucose-product CO2 -waste daylight glucose –reactant H2O -reactant break bonds chloroplast light chemical bond energy make bonds mitochondria glucose ATP Biology - Chapter 8