Photosynthesis

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.

Where does Photosynthesis happen? (read) It takes place inside the CHLOROPLAST, with dozens of them found in the cells of each leaf

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

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

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

As the chlorophyll in leaves decays in the Fall, the green color fades and is replaced by the oranges and reds of carotenoids

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

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

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.

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

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

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= ATP and NADPH Calvin Cycle Reactants= ATP, NADPH, CO2, (and RuBP) Calvin Cycle Products= NADP+, ADP, Glucose (orgaqnic compunds)

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

Factors Affecting Photosynthesis 1) Light Intensity in light = ____ in the rate of photosynthesis 2)Temperature – best between 0 C and 35 C 3) Carbon Dioxide Levels in CO2 = ____ in the rate of photosynthesis

Review ?’s(p.118, p.126,127) Where in the chloroplast do the light reaction and calvin cycle take place? Light Dependent Reaction=Thylakoid membranes/Calin=Stroma