DO NOWDO NOWPlease hand in homework

into the bin.

Then Answer◦ How do we see colors?

◦ Which color has the longest wavelength? The shortest?

◦ What pigments are in leaves? What colors do they reflect?

◦ What pigment do you think is in the graph?

Photosynthesis Intro VideoPhotosynthesis Intro Videohttps://www.youtube.com/watch?

v=eo5XndJaz-Y

Overview Of PhotosynthesisOverview Of Photosynthesis

ObjectivesObjectivesTo be able to list the inputs and

outputs of photosynthesis.

To be able to identify the structures in a chloroplast.

To be able to summarize light-dependent reactions.

PhotosynthesisPhotosynthesisLight energy ------> chemical energy

Used by autotrophs to produce food

All of our energy starts as light energy!◦Plants use sunlight to make food

animals eat plants other animals eat those animals

Photosynthetic OrganismsPhotosynthetic OrganismsGo through Photosynthesis to produce

GLUCOSE…

Autotrophs -“Producers” in the food web

Consist of plants, protists, cyanobacteria

PhotosynthesisPhotosynthesisOccurs in CHLOROPLASTS!!

Requires the pigment chlorophyll to capture energy from light.

Rearrange molecules of water and CO2 into new products

The ChloroplastThe Chloroplast

Structures within a Structures within a chloroplastchloroplast

Thylakoids: flattened sac-like membranes arranged

in stacks (stacks are called grana). Light-dependent reactions take place

here. Electron transport occurs in the

thylakoid membrane

Stroma: Fluid filled space outside the grana. Light-independent reactions take place

here.

Starting MaterialsStarting Materials1. Carbon Dioxide

2. Water

3. Sunlight

Products!Products!1. Oxygen

2. Glucose! (C6H12O6)

**Plants don’t immediately use all the glucose they make:◦ Stored as STARCH!!

Overall Chemical EquationOverall Chemical Equation

Glucose

Phase OverviewPhase Overview1) Light dependent Reactions

◦Light energy is absorbed and converted into chemical energy in the form of ATP and NADPH. (also produces Oxygen!)

2) Light Independent Reactions:(Calvin Cycle)◦CO2 ATP and NADPH are used to make

glucose. *Glucose is the basic building block for more complex sugars such as starch.*

Do NowDo NowHand in your lab into the bin. Please make

sure your name and your partners name is on it!

Also grab four pieces of construction paper from my desk. Any color(s) of your choosing!

Then answer:◦ What are the reactants and products of

photosynthesis?

◦ What is the equation for photosynthesis?

Light Dependent Light Dependent Reactions IntroReactions Introhttps://www.youtube.com/watch?

v=BK_cjd6Evcw

Light Dependent ReactionsLight Dependent ReactionsStep 1: Light energy reaches

photosystem II causing the water molecule to split

OHH

H2O

H+O2+

*H+ is released to the electron transport system.* O2 is given off as a byproduct.

Step 2: Light energy reaches photosystem I and electrons flow from photosystem II to photosystem I. (to replace the electrons lost)

Step 3: HYDROGEN IONS (protons) are pumped across the membrane into the thylakoid space as the electrons move through the electron transport chain.

Step 4: Electrons from photosystem I move to a protein called FERRODOXIN

**Ferrodoxin = “helper” protein**

Step 5: Ferrodoxin transfers electrons to NADP+ forming NADPH. (Electron Carrier)◦ We need this for the next part of

photosynthesis!

Step 6: Hydrogen ions move through the ATP SYNTHASE because of the concentration gradient, creating ATP. (Chemiosynthesis)

To Calvin Cycle

ChemosynthesisMechanism in which ATP is

produced as a result from the flow of electrons down a concentration gradient.◦Ex: Light reactions (H+ ions and ATP

synthase)

Light Dependent Light Dependent ReactionsReactions

Inputs Outputs

Light

H₂O O₂

ADP ATP*NADP+ NADPH*

**Goal Products!

O₂ is only a byproduct!!

Location: Thylakoid Membrane in Chloroplasts!

Light Dependent Light Dependent ReactionsReactions

Lets see it altogether now!

https://www.youtube.com/watch?v=joZ1EsA5_NY

Do NowDo NowPlease garb the worksheet off my

desk, and begin working on it individually.

Do NowDo NowWhat are the steps of light

dependent reactions? (yay light!)

What is the equation for photosynthesis?

ObjectivesObjectivesList the inputs and outputs of the Calvin

Cycle

Define chemiosmosis and it’s role in photosynthesis.

Summarize light – independent reactions

Perform chromatography to identify the pigments of green leaves.

Intro Video for Calvin Intro Video for Calvin CycleCyclehttps://www.youtube.com/watch?

v=E_XQR800AgM

Light Independent ReactionsLight Independent Reactions(Calvin Cycle)(Calvin Cycle)

Takes place in the stroma

Functions like a sugar factory within a chloroplast◦ **Regenerates the starting material with each turn

Uses NADPH and ATP from Phase I (light dependent reactions)

Needs CO2!!!

Produces GLUCOSE

Light Independent Reaction Light Independent Reaction

Calvin Cycle Calvin Cycle Step 1:

Carbon dioxide molecules breakdown by combining with RuBP. (Carbon Fixation)

Calvin Cycle Calvin Cycle Step 2:

ATP and NADPH transfers energy and electrons to this molecule to create another three carbon molecule called G3P.

Calvin Cycle Calvin Cycle Step 3:

2 G3P molecules will leave the cycle to create glucose.

Calvin Cycle Calvin Cycle Step 4:

An enzyme (Rubisco) converts the remaining G3P molecules into RuBP.

◦ RuBP will combine with new carbon dioxide molecules to continue the cycle.

Calvin CycleCalvin CycleInputs

- 6 CO2 - 18 ATP- 12 NADPH

Outputs

- 2G3P (1 glucose- GOAL!)

- 18 ADP- 12 NADP+

Location: Stroma of the Chloroplast

QUICK!QUICK!Which contains more energy, one

molecule of NADP+ or one molecule of NADPH?

What is the name of the three carbon molecule that is a product of the Calvin Cycle?

AnimationAnimation https://www.youtube.com/watch?v=joZ1EsA5_NY

Let’s try some examplesLet’s try some examplesHow many glucose molecules are

made from 108 ATP in the calvin cycle?

How many carbon dioxide molecules are needed to make 8 glucose molecules?

Factors that can affect the Factors that can affect the rate of photosynthesis!rate of photosynthesis!

Light Intensity (Amount)

Rainfall Amount

Temperature

CO₂ Concentration

Stomata can also affect the rate Stomata can also affect the rate of photosynthesis!of photosynthesis!

Stomata- openings (pores) on the underneath leaves that allow the exchange of carbon dioxide, oxygen, and water.

More water available will open up stomata, less water will cause them to close to reduce water loss.