Date: December 10, 2015 Aim #34: How do plants carry out the process of photosynthesis? HW:...

Date: December 10, 2015

Aim #34: How do plants carry out the process of photosynthesis?

HW: 1) Article- Changing Colors of Leaves2) Bring in headphones/ear buds for computer lab

please 3) Missing work?? Please get in ASAP4) Plant Packet (follow calendar of suggested

deadlines!!)

Do Now: Warm-Up NotebookDate Title of Activity Page #12/10 Light! Pigments! Action! 60

Aim #34: How do plants carry out the process of photosynthesis?

1) What is the formula of Aerobic Cell Respiration?

Light + 6H2O + 6CO2 ----------> C6H12O6+ 6O2

2) What is the formula of Photosynthesis?

C6H12O6 + 6O2 6CO2 + 6H2O + 38ATP

Cell Respiration- there is a “fall” of electrons from glucose to O2 (ETC) that releases energy to form ATP.

Photosynthesis- energy from sunlight is used to boostelectrons from water “uphill” to produce glucose.

3) What is the difference between the two?

4) Where in the cell does photosynthesis take place?

StromaInner

Membrane Outer Membrane

Thylakoid

GranaChloroplast

5) Two Main Stages of Photosynthesis:

a) Light Reactions- convert the energy in sunlight to chemical energy. It takes place in the membrane of the thylakoids.

b) Calvin Cycle- makes glucose from the atoms of CO2, plus the H atoms and highenergy electrons of NADPH & ATP producedduring the light reactions. Takes place in thestroma.

Photosynthesis

https://www.youtube.com/watch?v=W-PgR8dYpOo

(3 minutes)

6) Details of the Light Reactions:

Light + 6H2O + 6CO2 ----------> C6H12O6+ 6O2

+ H2O

O2 released into atmosphere

H atoms & electrons

Light splits water into oxygen, H atoms, and electrons

This is called photolysis

Light Reactions:H atoms & electrons + NADP+ NADPH

ETC

ATP

7) What is Chlorophyll?

Are the pigments (chemical compounds that give a substance its color) found inthe chloroplasts.

There are different types of pigments in thechloroplasts.

Ex: Chlorophyll a, Chlorophyll b, Carotenoids

8) What is the role of the chlorophyll pigments in the light reactions?

Within the thylakoid membrane, chlorophyll and othermolecules are arranged in clusters called photosystems

The clusters of pigment molecules act like a lightgathering panel (solar collector)

What is the role of Chlorophyll?

Ground State

Energy

Excited State Ground State

Each time a pigment molecule absorbs light energy, its electrons gain energy and become “excited”.

Almost immediately, the excited electron falls back tothe ground state & transfers the energy to its neighboring molecule

What is the role of Chlorophyll?

This transfer of energy to neighboring pigment molecules sets off a chain reaction.The chain reaction will continue until it reaches the reaction center of the photosystem.

Here the electron is captured by the primary electronacceptor.

What does the primary electron acceptor do with the electrons?

The electrons are sent down an electron transport chain which helps produce some ATP.

Next, the electrons are passed on to a second photosystem.

This photosystem passes the light-excited electronsto NADP+ and combine with the H+ from H2Oforming NADPH.

Let’s take a look at this:

Primary Electron Acceptor

ETC

Photosystem e-

H2O

Electron Acceptor

(protein)

O2H+

Electron Transport Chain

e-

Electron Acceptor

(protein)

Electron Acceptor

Electron Acceptor

9) Details of the Calvin Cycle (Dark Reaction or Carbon Fixation):

2)Calvin Cycle- makes glucose from the atoms of CO2, plus the H atoms and highenergy electrons of NADPH & ATP producedduring the light reactions. Takes place in thestroma.

CO2 + NADPH + ATP G3P Glucose

Comes fromatmosphere

Comes fromLight Reactions

Light Reactions & Calvin Cycle:

Calvin Cycle

Photosynthesis Summary

Energy Sunlight Chemical bonds in glucose

Materials used carbon dioxide, and water

Materials produced

Glucose, water, and oxygen

Time frame Daylight hours

Location chloroplasts

Importance Stores energy from sun… made available to other organisms

Water

Light Energy

Carbon Dioxide

Oxygen

Glucose

A more detailed summary:Light dependent reaction

Light independent reaction

AKA Light reaction Dark reaction, Calvin Cycle or carbon fixation

Location Grana Stroma

What’s going on…

•Water is split (photolysis)•Oxygen is released into atmosphere•NADPH and ATP are made to be used in Light Independent reaction

•Enzyme Rubisco converts inorganic CO2 into organic glucose by combining two PGAL molecules (a 3 C molecule)

Amoeba Sisters

https://www.youtube.com/watch?v=uixA8ZXx0KU

(~8 minutes)

Light-dependent reaction1. In thylakoid spaces of the grana in the

chloroplast.2. Sunlight strikes the chlorophyll contained within

the thylakoid spaces which causes electrons to become excited and infused with energy.

3. Electrons are transferred down an electron transport chain.

4. The energy in the electrons is used to set up a proton gradient across the membrane of the thylakoid spaces.

5. Protons flowing back across the thylakoid membrane according to the concentration gradient are harnessed to produce ATP and NADPH (the reduced form of NADP).

6. As a by-product of this process, molecules of water are split into molecular hydrogen and oxygen (photolysis).

7. The plant needs the hydrogen to produce ATP. 8. The oxygen you’re breathing right now is some of that waste

product.

9. The purpose of the light reaction is to make the usable energy necessary to run the light-independent reaction.

Light-independent reaction

1. AKA the Calvin cycle, or carbon fixation or dark reaction

2. The reaction takes place in the stroma of the chloroplast

3. In the dark reaction, the carbon from carbon dioxide is added to the five-carbon sugar ribulose bisphosphate (RuBP) to produce a six-carbon compound.

4. This unstable six-carbon sugar is immediately split into two three-carbon molecules, which in a chain reaction using the ATP and NADPH from the light reaction are modified to form glyceraldehyde 3-phosphate.

5. The glyceraldehyde 3-phosphate can be synthesized into carbohydrates such as glucose.

6. One of the glyceraldehyde 3-phosphate molecules is made into carbohydrates, while the other molecules remain in the Calvin cycle to serve as raw materials for the next round of production.