Where does almost all

energy come from for Earth?

Do you have energy within your body?

Potential Energy – stored energy (ATP molecules, Carbohydrate, Proteins and Lipids)

Kinetic Energy – energy in motion (breaking down ATP to ADP, or any other molecule)

JQ: Why do you think plants are green for most of the year,

instead of red, orange or yellow?

A prism, like the one shown below, is an object designed to alter light as it passes through it.

*BE EXTREMELY CAREFUL WITH ALL THE EQUIPMENT*

1.Obtain a prism and a spectroscope,2.Try to get the prism and spectroscope to

separate white light into colors (might have to go near window)

3.Make a list of all the colors your prism produces, and take a picture if you can.

What’s in Sunlight?

Use your textbook to read about photosynthesis, the process that

supplies all ecosystems with energy. Complete the note sheet

as you go.Link to

Note

Sheet

CO2 + H2O + Sunlight O2 + C6H12O6

What is photosynthesis?

The process of converting

carbon dioxide, water, into oxygen and

glucose. Sunlight

supplies the energy for this

process. The most important biological process on the

planet : )

Who does photosynthesis?

Plants, some bacteria, some

protists, and even some (one known) animal can perform

photosynthesis.

Journal QuestionWhat would happen if all of the

plants on earth suddenly died today? Explain.

Where does it occur? For plants, protists (and that one animal) it occurs inside the cells,

there are special structures called chloroplasts. They are

what make photosynthetic organisms green.

Bacteria don’t have organelles, they perform it on their plasma membrane

One chloroplast

Where does it occur (con’t)? Each chloroplast is covered in 2

bilayers, and contain the following:

1.Granum (stacks of thylakoids)2.Thylakoids (contain chlorophyll, light

reactions occur on the membrane of these)3.Stroma: liquid outside of the granum

One chloroplast

Silly way to remember how the chloroplast is organized:

If the Chloroplast is the Company,Then the Grana (plural of granum) are the garages,And the Thylakoids are the Trucks

How does it occur (overview)? The green pigment

inside chloroplasts, called chlorophyll,

absorb light energy from the sun, and

the cell can use the energy to covert CO2 and H2O into sugar (glucose). Plants also have other pigments that can help.

Link to song

Link to

time

lapse

How does CO2, O2, and Water get in and out of a

plant? 1. Plants have pores on the bottom of

their leaves called stomataThey open and close

to let Oxygen (O2) and Carbon

dioxide (CO2) in and out. Water

can leave through them as well.

Water is taken into plants through

roots.

How does it occur (detailed)? Stage 1: Light reactions

1. What happens here: H2O + Light energy ATP + NADPH + O2

Stroma

Thylakoid Membrane

Inside thylakoid

2. Light energizes, or excites, electrons in chlorophyll molecules in photosystem II (protein with pigments

attached), and electrons leave chlorophyll and travel down the electron transport chain (ETC), which is a

series of proteins that transfer electrons3. Electrons lose energy as they travel through ETC, and that energy used to move protons (H+) from stroma into

thylakoid space (against concetration gradient) H

HH

H

H

HH

H H

Link to animation

How does it occur (con’t)? Stage 1: Light reactions

1. In photosystem I (after photosysten II), light excites electrons, which travel down another ETC.

Stroma

Thylakoid Membrane

Inside thylakoid

2. As electrons lose energy through photosystem I, proteins in the ETC help a chemical reaction that combines

NADP+ , protons (H+), and the electrons to produce NADPH, a high-energy “carrier molecule” that is used in

Stage 2 of Photosynthesis

HH H

NADPHNADPH

H

HH

H

How does it occur (con’t)? Stage 1: Light reactions

1. The reason that plants need water is so that water can be split: electrons from water molecules are used to replenish those lost by Photosystem II (Water is split into 2H+, O, and

electrons)

Stroma

Thylakoid Membrane

Inside thylakoid

2. There is a high concentration of protons (H+) accumulating inside the thylakoid. The H+ build up inside as they are

pumped in during ETC, and as water is split.

H

ATP

HH

H H HH

3. H+ moves down its concentration gradient through ATP synthase, a protein in the thylakoid membrane that makes

ATP from ADP. This is called Chemiosmosis

CO2 + H2O + Sunlight O2 + C6H12O6

Photosynthesis Recap for Phase 1

We don’t know yet(Phase II)

1. H’s go intoThylakoid to establishSteep gradient

2. O combines with another O and diffuses outOf plant (this is why plants make oxygen)

3. Electrons from H’s replenish those lost in photosystem II

1. Is used to Excite Electrons inphotosystem II AndPhotosystem I so They move downelectron transportchain, powering H+gradient to Make ATP and help make NADPH

1. Comes fromSplitting of water

We don’t know yet(Phase II)

How does it occur (con’t)? Stage 2: Dark Reactions (Calvin Cycle)1. What happens here: CO2 + ATP + NADPH C6H12O6

(Glucose)2. CO2 moves through stomata (pores in bottom of leaves) from atmosphere, diffuses through cell membrane and through thylakoid membrane into the Stroma. (what

type of diffusion occurs here?)3. CO2 undergoes a series of chemical reactions with other

molecules to form C6H12O6 (Glucose) . Energy from the ATP and NADPH are used to power the chemical reactions. NADP+ and ADP are sent back to light

reactions4. When CO2 is used in chemical reactions

in order to form molecules inside our body, like glucose, it

is called Carbon Fixation.

Summary of Photosynthesis (con’t)? Both the light reactions and “dark” reactions are occurring

at the same time within the chloroplast, but there are differences.Complete the chart to quiz yourself on some of the basics of

photosynthesisLight Reactions “Dark Reactions” /

Calvin Cycle

1. Where does it occur?

2. What are the reactants (chemicals that go into the process)

What are the products (chemicals that are made from the process

Key players involved?

Does this stage produce usable energy or deplete usable energy?

Active Class Discussion

Your Homework is to come up with 10 questions containing

the word “Attraction”,

…and to finish the chart on the previous slide

Can we capitalize on photosynthesis?

For a very long time, nature

has influenced mankind’s

technology.

Link to leaf-

inspired solar

panel

So then, why are plants green?

A. Which colors do chlorophyll absorb

best?

Absorption Spectrum for Photosynthetic pigments

Plants are green because it helps

them absorb blue and red light,

which are the most energy-efficient colors to absorb

from our sun.

Alien Plants? Based on the colors of the plants on

Pandora, how similar is the sunlight they receive, and their absorption spectrum is

to the plants on earth?

Wrap-Up Photosynthesis1. What is it?

2. Who Does it?3. Where does it happen?

4. Why is photosynthesis so important to life on earth?

How do plants manage all this?

After all, they are barely

living, right?

Click on:

1.Woodland timelapse

2. Meat-eating plant

3.Parasitic plant