Aim: What TWO cell processes make life on Earth possible? Do Now: HW: Textbook pages 222-227; #1-5 in complete sentences! READ CAREFULLY Castle Learning “HW #10 – if not completed!

“It's not easy bein' green…” but it is ESSENTIAL for LIFE on EARTH!

Two Important Cell Processes

Two Chemical Reactions Make Life Possible Photosynthesis: Converts SOLAR energy into chemical energy stored in the bonds of glucose. Cell Respiration: Releases energy stored in glucose and creates high-energy ATP used to do work.

Using "light" energy to "put together" glucose The Origin of the Word… Photo – “light” Synthesis – “putting together” Using "light" energy to "put together" glucose

Photosynthesis title, definition and equation. 7

WHY ARE PLANTS GREEN?

Electromagnetic Spectrum and Visible Light Gamma rays Infrared & Microwaves X-rays UV Radio waves Visible light Wavelength (nm)

WHY ARE PLANTS GREEN? Different wavelengths of visible light are seen by the human eye as different colors. Micro- waves Radio waves Gamma rays X-rays Infrared UV Visible light Wavelength (nm)

The feathers of male cardinals are loaded with carotenoid pigments The feathers of male cardinals are loaded with carotenoid pigments. These pigments absorb some wavelengths of light and reflect others. Reflected light Sunlight minus absorbed wavelengths or colors equals the apparent color of an object.

Why are plants green? Reflected light Transmitted light

THE COLOR YOU SEE IS THE COLOR REFLECTED Chloroplasts contain PIGMENTS (chlorophyll) that absorb the sun’s energy and use it to create glucose Light

AIM: How are plants able to transform SOLAR energy into CHEMICAL energy? Do you recall? Which organelle is the site of autotrophic nutrition? What are the two raw materials necessary for a plant to perform photosynthesis? The screen you are looking at appears green – what does that mean in terms of the light being reflected vs. absorbed by the screen?

THE BASICS: Autotrophs perform photosyn. And include most plants, some bacteria and protists (algae) Capable of synthesizing organic materials from inorganic raw materials Ultimate source of energy = Sun (c) Euglena (d) Cyanobacteria (b) Kelp (a) Mosses, ferns, and flowering plants

6 CO2 + 6 H2O → C6H12O6 + 6 O2

THE BASICS: Organelle: Occurs in the CHLOROPLAST Raw materials: Carbon dioxide & Water Products: Glucose & Oxygen gas Plants use some Glucose for their own energy– and store excess as STARCH

AIM: What are the two reactions that make up photosynthesis? DO NOW: Using the diagram at the right– what are the raw materials? What are the products? What is the source of energy? What types of molecules (not shown here) are involved in speeding up the reactions involved in photosynthesis? HW: Photosynthesis Handout

THE BASICS: Enzymes (protein catalysts) speed this reaction up Plants obtain CO2 from atmosphere & water from soil and precipitation Composed of 2 separate reactions: The light reaction The light-independent reaction (dark)

The Structure of the Chloroplasts Leaves contain the most chloroplasts Chloroplast contains: STROMA, a fluid filling the space in the chloroplast – Dark Reaction occurs here GRANA, stacks of THYLAKOIDS – Light Reaction occurs here The THYLAKOIDS contain pigments: Chlorophyll a - green pigment that captures light for photosynthesis Chlorophyll b and c Carotenoids

http://www.youtube.com/watch?v=Wi60tQa8jfE&feature=related Stack of Pancakes Surrounding Space

The Light and Dark Reactions: LIGHT REACTION: splits water molecule using sun’s energy and releases OXYGEN GAS By-product: Produces ATP & NADPH (to be used in the dark reaction) LIGHT-INDEPENDENT REACTION (Dark Reaction): uses by-products from first reaction and carbon dioxide to produce SUGAR

What are the gas bubbles produced by the plant What are the gas bubbles produced by the plant? Which of the 2 reactions produced these bubbles, the light or the dark?

THE 2 REACTIONS OF PHOTOSYNTHESIS 1. What molecule is split using the energy of the sun to create oxygen gas? 2. What does the plant do with excess sugar that is made? 3. What is the product of the Dark Reaction? 4. Within which organelle do both the light and dark reactions occur? 5. What are the two raw materials necessary for the process of photosynthesis? 6. What is a scientific name for organisms that are capable of performing photosynthesis

TAKE A LOOK AT THE DIFFERENT PIGMENTS SHOWN HERE!

An Overview of Photosynthesis

Aim: Have we mastered the chemical reactions of photosynthesis? Do Now: An unknown bacterial cell is observed with a compound light microscope. Identify the structure that, if observed, would indicate that this bacteria is an autotroph. Name one organic molecule that contains carbon – name one inorganic molecule that contains carbon. HW: Photosynthesis handout

STRUCTURE OF A LEAF Leaves have large surface area for maximum absorption of sunlight Stomates: tiny openings on underside of leaf surface that allow for gas exchange and water evaporation Guard Cells: control opening and closing of stomates, assist in maintenance of HOMEOSTASIS: During DROUGHT, guard cells close stomates preventing DEHYDRATION

Stomate Guard Cell

"opening" A B controls the opening

Large Surface Area for Photosynthesis

Abiotic = nonliving part of ecosystem (ex Abiotic = nonliving part of ecosystem (ex. minerals, water, temperature)

Photosynthesis Song http://www.youtube.com/watch?v=C1_uez5WX1o The World of Plants: Photosynthesis – unitedstreaming.com

CHROMATOGRAPHY: Separating plant pigments (COLORS)

CHROMATOGRAPHY

Different Pigments Absorb Light Differently Best Overall Colors: _____________ and ____________ Worst Overall Color: _______________

PHOTOSYNTHESIS REVIEW CHECKPOINTS Within which organelle does photosynthesis occur? What are the two raw materials of photosynthesis? What are the products of the photosynthesis reaction? What types of organisms perform photosynthesis? What is the major product of the light reaction? What is the major product of the dark reaction? Where does the light reaction occur? Where does the dark reaction occur? What molecule is split in order to release oxygen gas? What is the ultimate source of energy for life on earth? What are the two most effective colors of light for photosynthesis? What is the worst color of light for photosynthesis? Provide an example of 3 organisms that are capable of photosynthesizing.

measure how much a plant is How can scientists measure how much a plant is photosynthesizing?

Methods of measuring the rate of photosynthesis. 54

FACTORS EFFECTING THE RATE OF PHOTOSYNTHESIS

plateau As amount of available CO2 increases, photosynthesis increases until a point, then it levels off. At low CO2 concentration, rate is positively correlated with concentration CO2 affects rate of photosynthesis. CO2 is the substrate in carbon fixation (Calvin cycle) – rubisco is the enzyme. 56

plateau As the amount of available light increases, the rate of photosynthesis increases - then it levels off. Light intensity affects rate of photosynthesis. 57

As temperature increases, rate of photosynthesis increases to a point… Optimum temperature Above the optimum temp., enzymes are denatured and rate drops steeply. As temperature increases, rate of photosynthesis increases to a point… Above 35 C the rate rapidly decreases… WHY??? Increased temp. gives increased energy and increased rate of photosynthesis Which enzymes are used in respiration? Temperature affects the rate of photosynthesis. Remember enzyme theory. Enzymes used in respiration: rubisco is the main one. ATP synthase can also be denatured. 58

Explain This Statement... Photosynthesis is the process by which light energy is converted into chemical energy.

__ _ ___ ___ _____________ __ _ ___ ___ _____________ ________ True or False: Photosynthesis occurs during the day-time ONLY!

__ _ ___ ___ _____________ __ _ ___ ___ _____________ ________ True or False: As the temperature increases, the rate of photosynthesis will decrease.

__ _ ___ ___ _____________ __ _ ___ ___ _____________ ________ True or False: Oxygen and water are the raw materials for the process of photosynthesis.

__ _ ___ ___ _____________ __ _ ___ ___ _____________ ________ True of False: Photosynthesis is a process performed by autotrophs in which light energy is converted into chemical energy.

__ _ ___ ___ _____________ __ _ ___ ___ _____________ ________ This term refers to the complex carbohydrate that plants store their excess sugar as?

__ _ ___ ___ _____________ __ _ ___ ___ _____________ ________ What is the least effective color of light for plants to do photosynthesis in? Why?

__ _ ___ ___ _____________ __ _ ___ ___ _____________ ________ True or False: Guard Cells are holes in the surface of a leaf which allow the passage of oxygen gas.

__ _ ___ ___ _____________ __ _ ___ ___ _____________ ________ What life process studied earlier this year includes the process of photosynthesis?

Explain the Process of Photosynthesis with regard to the following: List the raw materials needed for this process List the products made from this process State the types of organisms that do this process State the time of day that this process takes place State the type of cells (plant or animal) that are capable of this process State the importance of this process Explain how the glucose created in this process enters the cells of animals and is put to use.

What is this picture a cross section of? What are tiny openings found in the lower epidermis called? What structures are present to control the opening and closing of these “holes”? What substances are exchanged through these openings? How is the closing of these tiny openings during a drought an exmape of the plant maintaining homeostasis?

C A B Identify one substance that could be found at letter “A”. Identify the source of energy necessary to allow the chloroplast to perform photosynthesis. What types of cells, plant or animal, contain mitochondria? What are the two substances released by the chloroplast at letter “B”? What important cell process can the mitochondria perform? What is the ATP released by the mitochondria used for? What might a plant do with excess glucose produced by photosynthesis? A B

How does the structure of a leaf assist in the maintenance of homeostasis for the plant?