Steps of Photosynthesis Factors that Affect Photosynthesis http://www.world-builders.org/lessons/less/les4/photo.html

What is Photosynthesis? A process that converts light (solar) energy into stored (chemical) energy in the form of food molecules like glucose or starch Process used by AUTOTROPHS like plants and algae to make food for all living organisms.

Where does photosynthesis take place? Inside the mesophyll (middle) of leaves in organelles called Chloroplasts.

Anatomy of a Chloroplast Inside the chloroplast Pigment called Chlorophyll is found inside the thylakoid membranes (causes plants to look green). Stroma - an aqueous liquid outside the thylakoid membranes Grana - the stacks of thylakoids

Structure of chloroplast Grana stacks of thylakoids Stroma enzyme rich solution Thylakoid membrane place where chemical reactions takes place Chlorophyll green pigment that absorbs solar energy

2 Stages of Photosynthesis 1. Light Dependent Stage Light Independent Stage or Calvin Cycle

Light Dependent Stage: Takes place in the thylakoid membrane Energy is captured from sunlight. Through a series of many enzyme reactions, light energy is converted to chemical energy which is stored in the forms of ATP and NADPH.

Light Independent Stage/Calvin Cycle: Takes place in the stroma of the chloroplast. The stored energy in ATP and NADPH from the Light Dependent Stage along with CO2 is used to produce high energy sugars (carbohydrates).

What does photosynthesis require? Sunlight – source of energy Chlorophyll, the green pigment that captures light energy. Water Carbon dioxide

6H2O + 6CO2 C6H12O6 + 6O2 The photosynthesis equation WATER + CARBON  GLUCOSE + OXYGEN DIOXIDE Review conservation of matter Say: In Atmosphere Lesson 4, you learned about chemical reactions. Question: What is an example of a chemical reaction? Answer: (Accept all correct answers. One chemical reaction that students may have learned about was that hydrogen gas and oxygen gas combine to make water vapor.) Question: When a chemical reaction takes place, does the amount of matter change? Answer: The amount of matter does not change during a reaction. The number of atoms stays the same, but they change location and recombine to form new substances. Say: You can see that during a chemical reaction, just like during the water cycle, the amount of the substances involved does not change. Today, we will be looking at another cycle that is important to human survival.

Summary of Photosynthesis 6CO2 + 6H2O + sunlight  C6H12O6 + 6O2 What are the reactants (needed) for photosynthesis? http://www.phschool.com/ What are the products (made) of photosynthesis?

Types of Organisms Energy

ENERGY Energy is the ability to do work ATP (adenosine triphosphate) is the main energy-storing molecule used as currency in living things ATP ADP AMP Energy Energy Pi Pi

Types of Organisms Autotrophs Make their own food Heterotrophs Obtain energy from the food they consume or absorb

Cellular Respiration Mitochondria Cellular Respiration (Aerobic) Glycolysis Kreb’s Cycle Electron transport chain Fermentation (Anaerobic) http://www.world-builders.org/lessons/less/les4/respire.html

What is Cellular Respiration? A process that converts stored (chemical) energy in food molecules like glucose into energy (ATP) Process used by BOTH AUTOTROPHS & HETEROTROPHS to release energy from food they have made, absorbed, or consumed.

Where does respiration take place? Inside the mitochondria of every living organism

What does cellular respiration require? Glucose – source of stored energy Oxygen – aerobic process Mitochondria, the organelle that converts glucose into ATP.

There are 2 types of Cellular Respiration: Aerobic (with oxygen) Anaerobic (without oxygen)

There are 3 steps in Aerobic Cell Respiration: 1. Glycolysis Krebs cycle 3. ETC: Electron Transport Chain

Glycolysis: takes place in the cytoplasm (cell spends 2 ATP) does not require oxygen Glucose is converted to 2 Pyruvates 4 ATP’s produced (2 paid back to cell) Krebs Cycle: takes place in the mitochondria 2 Pyruvates converted to Acetyl-CoA CO2 is produced along with NADH and FADH2 2 more ATP’s are made Electron Transport Chain: also takes place in mitochondria Electrons are used to make optimum number of ATP molecules (32 – 34)

ANAEROBIC: Fermentation When NO oxygen (anaerobic) is present, what do organisms do with the glucose (food)?! ANAEROBIC: Fermentation Alcoholic Fermentation Yeasts and microorganisms use this to produce CO2 and alcohol Causes bread dough to rise and used to make alcohol Lactic Acid Fermentation Prokaryotes use this to produce CO2 and lactic acid Lactic acid build up during vigorous exercise causes pain and burning sensation in your muscles. These organisms are used to make cheese, yogurt, buttermilk, pickles, sour cream, sauerkraut, and kimchi

6H2O + 6CO2 C6H12O6 + 6O2 The cellular respiration equation C6H12O6 + 6O2 6H2O + 6CO2 + ATP GLUCOSE + OXYGEN  WATER + CARBON +ENERGY DIOXIDE How is this chemical reaction similar or different when compared to photosynthesis? 6H2O + 6CO2 C6H12O6 + 6O2 WATER + CARBON  GLUCOSE + OXYGEN DIOXIDE

COMPARING THE PROCESSES Photosynthesis In photosynthetic organisms like some bacteria, plant-like protists (Euglena) & all plants Requires CO2 Occurs in the chloroplasts Cellular Respiration Use oxygen  aerobic respiration No oxygen  anaerobic respiration like lactic acid fermentation or alcoholic fermentation All plants,animals, fungi, and animal-like protists Occurs in the mitochondria

Cyclic Relationship The products of photosynthesis are the reactants for aerobic cell respiration and vice versa. sunlight CO2 food Discuss the carbon cycle in more detail using the Carbon Cycle Diagram. Note to Teacher: Carbon dioxide is removed from the atmosphere during photosynthesis. As a part of the geological carbon cycle discussed in this lesson, you could have a discussion or have students investigate the carbon that is stored in all living things. Plants and other producers remove carbon dioxide from the atmosphere during photosynthesis. They use this carbon to build their bodies. This could be used to address the misconception that plants are mainly made of water and substances in the soil. You could trace the carbon from the atmosphere to the plants (stored as part of the plant and as food) to the consumers that eat the plants until it is eventually returned to the Earth during decomposition or added back to the atmosphere during respiration. The burning of fossil fuels like oil and gasoline returns the biological carbon stored in the Earth back into the atmosphere. The biological cycle is considered the “short-term” cycle. The geological cycle is considered “long-term.” The biological and geological carbon cycles are actually two parts of the same cycle. Discuss with students how the balance of carbon dioxide occurs. Question: How do you think a balance of carbon dioxide occurs? Answer: (Allow students to share their ideas.) Say: Think back to our discussion on cycles at the beginning of this lesson. Carbon dioxide is part of the cycle called the carbon cycle. Question: What do you think the carbon cycle does for the amount of carbon dioxide in the atmosphere? Answer: (Allow students to share their ideas. Students should conclude that carbon dioxide must be both trapped and released in order to keep the level of carbon dioxide in the atmosphere balanced.) Question: Does the amount of carbon change during the carbon cycle? Explain your answer. Answer: No, the amount of carbon does not change during the carbon cycle. The carbon changes form and location, but it is not created nor destroyed. H2O O2 H2O

6CO2 + 6H2O + sunlight  C6H12O6 + 6O2 Cyclic Relationship Photosynthesis 6CO2 + 6H2O + sunlight  C6H12O6 + 6O2 Cellular Respiration C6H12O6 + 6O2  6CO2 + 6H2O + ATP