PHOTOSYNTHESIS Autotrophic Process Plants and plantlike organisms make

PHOTOSYNTHESIS • Autotrophic Process: Plants and plant-like organisms make their energy (glucose) from sunlight. • Stored as carbohydrate in their bodies. • 6 CO 2 + 6 H 2 O + sunlight C 6 H 12 O 6 + 6 O 2

Catalyst: 1. Write the chemical equation of Photosynthesis in words. 2. What physical signs can you see in plants that indicates the use of glucose?

Why is Photosynthesis important? Makes organic molecules (glucose) out of inorganic materials (carbon dioxide and water). It begins all food chains/webs. Thus all life is supported by this process. It also makes oxygen gas!!

Photosynthesis-starts ecological food webs!

Photo-synthesis means "putting together with light. " Plants use sunlight to turn water and carbon dioxide into glucose. Glucose is a kind of sugar. Plants use glucose as food for energy and as a building block for growing. Autotrophs make glucose and heterotrophs are consumers of it.

Photosynthesis sunlight Carbon dioxide + water absorbed by chlorophyll glucose + oxygen 6 CO 2 + 6 H 2 O + energy C 6 H 12 O 6 + 6 O 2

Plant Cells

The photograph below is an elodea leaf X 400. Individual cells are clearly visible. The tiny green structures within the cells are chloroplasts this is where photosynthesis happens.

Stomata This opening how plants exchange gases! Check it! Can you name the two important gases that go in and out of the leaves? Why are the stomata located on the underside of leaves?

PHOTOSYNTHESIS • Absorbing Light Energy to make chemical energy: glucose! • Pigments: Absorb different colors of white light (ROY G BIV) • Main pigment: Chlorophyll a • Accessory pigments: Chlorophyll b and Carotenoids • These pigments absorb all wavelengths (light) BUT green!

Catalyst: Write your answers in the catalyst paper from last week. Identify the independent & dependent variable. • A scientist want to study the diversity of soil bacteria found during different months of the year. • Guinea pigs are kept at different temperatures for 6 weeks. Percent weight gain is recorded. • 3. An investigator hypothesizes that the adult weight of a dog is higher when it has fewer littermates.

PHOTOSYNTHESIS • Why do we see green? • Green color from white light reflected NOT absorbed • Chloroplast: organelle responsible for photosynthesis • Chlorophyll: located within Chloroplast • Green pigment

Chloroplast Pigments • Chloroplasts contain several pigments – Chlorophyll a – Chlorophyll b – Carotenoids – Xanthophyll Figure 7. 7

Visible light is only a small part of the electromagnetic spectrum (all forms of light).

• LIGHT behaves as if it were composed of "units" or "packets" of energy that travel in waves. These packets are photons. • The wavelength of light determines its color.

Oxygen and Sugar!

PHOTOSYNTHESIS • 2 Phases • Light-dependent reaction • Light-independent reaction • .

AN OVERVIEW OF PHOTOSYNTHESIS • The light reactions convert solar energy to chemical energy Light Chloroplast • Produce ATP & NADPH • The Calvin cycle makes sugar from carbon dioxide – ATP generated by the light reactions provides the energy for sugar synthesis – The NADPH produced by the light reactions provides the electrons for the reduction of carbon dioxide to glucose NADP +P Light reactions Calvin cycle

Steps of Photosynthesis Step 1. Light Reaction • Light hits reaction centers of chlorophyll, found in chloroplasts • Chlorophyll vibrates and causes water to break apart( Photolysis) • Oxygen is released into air • Hydrogen remains in chloroplast attached to NADP to form NADPH

How the Light Reactions Generate ATP and NADPH Primary electron acceptor Energy to make Primary electron acceptor NADP 3 2 Light Ele ctr on tra nsp o rt c Light hai n Primary electron acceptor 1 Reactioncenter chlorophyll Water-splitting photosystem 2 H + 1/2 NADPH-producing photosystem

• Two types of photosystems cooperate in the light reactions Photon ATP mill Water-splitting photosystem NADPH-producing photosystem

PHOTOSYNTHESIS • Light-dependent reaction (LIGHT Reaction) • Energy lost along electron transport chain • Lost energy used to recharge ATP from ADP • NADPH produced from e- transport chain • Stores energy until transfer to stroma • Plays important role in light-independent reaction • Total byproducts: ATP, NADP, O 2

PHOTOSYNTHESIS • How did we get O 2 as a byproduct? ! • Photolysis: replaces lost electrons by splitting water

Catalyst: • Briefly explain how ATP and NADPH is formed at the end of the light rxn.

PHOTOSYNTHESIS • Light-independent reaction (Dark Reaction)/Calvin Cycle • Does not require light • Occurs in stroma of chloroplast • Requires CO 2 • Uses ATP and NADPH ( from Light reaction) as fuel to run • Makes glucose sugar from CO 2 and Hydrogen

Catalyst • In what 4 ways is the light independent reaction different from the light reaction? • (Note: think about reactant/s, site of occurrence, products, source of energy)

Catalyst: Copy and fill in the answers Phases of Photosynthesis Reactants Light Reaction Water Calvin Cycle ATP, NADPH, CO 2 Products Site of reaction ( specific)

(and other organic molecules

Summary—Light Dependent Reactions a. Overall input light energy, H 2 O. b. Overall output ATP, NADPH, O 2.

Summary—Light Independent Reactions a. Overall input CO 2, ATP, NADPH. b. Overall output glucose.

PHOTOSYNTHESIS • What affects photosynthesis? • Light intensity: as light increases, rate of photosynthesis increases

PHOTOSYNTHESIS • What affects photosynthesis? • Carbon Dioxide: As CO 2 increases, rate of photosynthesis increases

PHOTOSYNTHESIS • What affects photosynthesis? • Temperature: • Temperature Low = Rate of photosynthesis low • Temperature Increases = Rate of photosynthesis increases • If temperature too hot, rate drops

CHEMOSYNTHESIS • The process by which bacteria uses energy from inorganic substances are used to make sugars

Check it! 1. The process that uses the sun’s energy to make simple sugars is _______. A. B. C. D. Cellular respiration Glycolysis Photosynthesis Photolysis

Check it! 2. The function accomplished by the lightdependent reactions is _______. A. B. C. D. Energy storage Sugar production Carbon fixation Conversion of sugar

Catalyst: 1. What gases pass through the stomata? 2. What effect would a closed stomata have on photosynthesis?

Classwork: 1. Read annotate “Biological drawings” 2. Draw a PLAN DIAGRAM of the structures observed during the lab on the space provided. Make sure to : a. all the organelles visible b. stomata c. Guard cell d. Plant cell 3. Answer the analysis questions in complete sentences 4. Write a conclusion ( CER format)

Conclusion: • The distilled water. caused the egg to swell Data shows that the egg increased by 3. 2 g after being soaked in distilled water. This is because the egg was sitting in a hypertonic solution( more solutes outside of the egg)The concentration gradient between the egg and its environment caused water molecules to diffuse into the egg through the membrane.

Conclusion • The syrup caused the egg to shrink. The data shows a significant decrease in the eggs mass by 6. 2 grams after 3 days. This is because of the concentration gradient between the egg and the syrup ( the syrup has more solutes than the egg) causing the environment to be hypertonic. Since water is more concentrated inside the egg, it diffused outside causing the egg to shrink.