Photosynthesis

Law Of Conservation of Matter and Energy Matter and energy can neither be created of destroyed, only transformed.

Total amount of energy in the universe is constant-it’s stored in the bonds of matter. Potential energy =stored energy Kinetic energy= released(bonds broken)energy. (Released energy is NOT lost energy, it’s just transformed)

Chemical Reactions

2Fe + 3H 2 O-  2FeO 3 + 3H 2 A chemical reaction is a process that changes one set of chemicals into another set of chemicals by creating/breaking bonds { { Reactants Products Chemical reactions

Carbon Bonding Organic molecules are made mostly of carbon atoms. Most matter in living organisms is made of organic molecules. Use pg to answer the following QUESTION: How do carbon’s bonding properties contribute to the existence of a wide variety of biological molecules?

Carbon ANSWER: One of the most important elements found in living things Has 4 valence electrons which means it can form 4 bonds with other carbon atoms or other elements such as hydrogen (H), oxygen (O), phosphorous (P)

Redox Reactions An oxidation reduction(redox) is a reaction where electrons are transferred from one reactant to another OIL= Oxidation is loss(of electrons) RIG= Reduction is gain (of electrons)

Oxidation- an atom loses an electron Reduction- an atom gains an electron

Compare/Contrast-the energy storing molecules Question-Name all the different molecules carbon is attached to in BOTH pictures!!

Energy Currency Life/cellular processes need constant energy. ATP (adenosine triphosphate) has energy stored in covalent bonds between phosphates.

What is Photosynthesis? Photosynthesis is when autotrophs make their own food/glucose. Photosynthesis takes light energy, water, and breaks apart carbon dioxide and converts it into stored energy in glucose.

What is Photosynthesis? s/02_MH_Photosynthesis_Web/ s/02_MH_Photosynthesis_Web/

Where does Photosynthesis happen? (read) It happens inside the CHLOROPLAST, with dozens in the cells of each leaf.

What are the Parts of the Chloroplast? #1. Thylakoids—saclike photosynthetic membranes -Arranged in stacks called= #2. Granum. solution surrounding them= #3. Stroma. Chloroplast Single thylakoid Stroma Granum

A D A C B

Why are Most Plants Green? Light travels in waves. In order to capture the energy in light, plants use a main pigment called chlorophyll. This pigment reflects green light making plants look green.

Visible Light Spectrum The suns energy travels in waves The distance between waves = wavelength Different wavelengths of light are visible as different colors

ROY G BIV Longest wavelength = Least amount of energy Shortest wavelength = larger amount of energy

What colors do chlorophyll a,b absorb best? Worst? What colors do caretenoids absorb best? Worst

not absorb green-Chlorophyll does not absorb light well in the green region of the spectrum. (absorbs blue/violet best) reflected leaves-Green light is reflected by leaves, which is why plants look green.

The chlorophyll breaks down, leaving only carotenoid pigments that reflect orange, red, and yellow.. Why Do Leaves Change Color in the Fall

Why do plants look look ? Green? There is much more chlorophyll than the other pigments (the other colors are masked). In the Fall Fall, chlorophyll is broken down and the accessory pigment colors are shown shown. Why do trees lose leaves in the winter? It’s difficult to absorb H2O H2O from frozen ground so leaves drop off to save water. 8-1

Reactants of photosynthesis? Carbon Dioxide + Water LIGHT GLUCOSE Carbon Dioxide Water

Products of photosynthesis? Oxygen & Glucose LIGHT GLUCOSE Oxygen Glucose

The GOAL of photosynthesis? -Oxygen is a waste product- GLUCOSE is the goal! LIGHT GLUCOSE WASTE PRODUCT GOAL

The Equation! Word Form: Carbon Dioxide +Water Glucose + Oxygen Balanced Chemical Equation: 6CO 2 + 6H 2 OC 6 H 12 O 6 + 6O 2 Light Energy 6

What are the Reactions? Photosynthesis is 2 reactions happening simultaneously in the chloroplast! -1 st - Light Dependent Reaction. 2 nd –Calvin Cycle a.k.a. Light Independent reaction The 2 nd reaction can not happen without the first.

Chloroplast Light Calvin Cycle Light- dependent reactions Light Dependent Reaction Water molecule is split by water splitting enzyme-Oxygen is released and Hydrogen is sent to Calvin cycle

Light dependent reaction(Step 1) a.)Occurs in the thylakoids of chloroplast b.)Starts w/water (H 2 O) and sunlight light absorbed by chlorophyll molecules c.)Makes Oxygen (O 2 ),ATP energy and NADPH energy **The ATP and NADPH will be used in reaction 2

Chloroplast Light H2OH2O O2O2 CO 2 Glucose NADP + ADP + P Calvin Cycle Light- dependent reactions Calvin cycle Light Dependent Reaction

With your shoulder partner explain when/what/where happens to each of the following when they enter the thylakoids of the Light Dependent Reaction: 1.Water 2.NADP+ 3.ADP

Light- dependent Reactions Light energy is absorbed by chlorophyll molecules This light energy excites electrons (excited electrons supply energy) and boosts them to higher energy levels. The electrons “fall” to a lower energy state, releasing energy that is harnessed to make ATP

Energy Shuttling ATP: superb molecule for shuttling energy around within cells. Other energy shuttles-coenzymes (nucleotide based molecules): move electrons and protons around within the cell NADP+, NADPH NAD+, NADP FAD, FADH 2

Q: Explain why the splitting of water is important the continuation of the calvin cycle and to our survival? Provides Hydrogen the Calvin Cycle requires to make glucose and oxygen we need to breathe. Q: Explain how oxygen is generated in photosynthesis(p.117 Paragraph 5,6) Water is split in light dependent reaction, and the oxygen is released as a waste product Silently and Independently

The Calvin Cycle (light-independent) (2 nd Step) Occcurs in the stroma of the chloroplast Uses ATP from the light dependent reaction and CO 2 to produce high energy glucose

Chloroplast Light H2OH2O O2O2 CO 2 Glucose NADP + ADP + P Calvin Cycle Light- dependent reactions Calvin cycle STROMA Calvin Cycle -aka-Light Independent Reaction

Identify the reactants/products for BOTH the light reactions and the calvin cycle. Light reaction reactants =sunlight, water, NADP+, ADP Light reaction products= Oxygen, ATP and NADPH Calvin Cycle Reactants= CO2, Calvin Cycle Products= NADP+, ADP, Glucose (orgaqnic compunds) Calvin cycle energy used =ATP and NADPH

What might happen to photosynthesis if ATP were not produced in the light reactions W/O ATP calvin cycle would stop, and so would photosynthesis Relate the rate of photosynthesis to carbon dioxide levels Increase CO2=increased photosynthesis rate Which of the following is a reactant in the calvin cycle A. 02 B. CO2 C. H2O D. C6H12O6 Oxygen is produced at what point in photosynthesis? A. when CO2 is fixed B.when water is split C. When ATP is converted to ADP D. when 3-GPA is converted to G3P

Glucose is used for what? Glucose is: 1) Broken apart and used to make ATP energy(easy to use) in cellular respiration-ATP is used for active transport and protein synthesis. 2) Chained together to make the plants body-(cellulose for cell walls) 3.) Stored as starch(another carb- ex.=potatoes) to be used later

Factors Affecting Photosynthesis 1) Light Intensity in light = ____ in the rate of photosynthesis 2)Temperature – best between 0 C and 35 C If the temperature is too high/low, this changes the shape of the enzymes involved in photosynthesis. 3) Carbon Dioxide Levels in CO2 = ____ in the rate of photosynthesis

Why does the RATE of photosynthesis plateau/peak even though light intensity continues to increase?