Photosynthesis

The Sun powers life. ___________________________________

_____________ capture about 5% of the Sun’s energy and,

through the process of ___________________, provide energy

to __________________________.

Photosynthesis is carried out by :

1.

2.

3.

4.

These organisms all contain the pigment ________________.

There are several types of ______________ found in

photosynthetic organisms; _______________________are 2.

_____________________ is the _____________________

_______________________ in all organisms.

_______________ is composed of a _____________ ring

attached to a __________________________.

Delocalized electrons in the __________________________in the

ring ____________________and begin the photosynthetic process

Cyanobacteria

Cyanobacteria live in many different environments including ________

______________________________________________________.

On rocks, cyanobacteria associate with _______________________.

Probably the first organisms to use ___________________________

___________________________ from water and carbon dioxide.

First cells to produce ___________________, they paved the way for ___________

_________on Earth.

Cyanobacteria are closely related to the ___________________. The __________

_______________ proposes that an ancestor of cyanobacteria was ______________

__________________________________________, an association that was

mutually beneficial.

(Evidence - like mitochondria, have a ____________________, contain their own

_______________________, and the are able to _______________________.)

Eukaryotic Autotrophs

Algae, some protists, and plant cells contain chlorophyll within

the ______________________________________________________________

Chloroplasts _________________________. The membranes enclose a

semiliquid material called _________________.

In the __________, membrane bound sacs called_____________stack to form

____________. (__________________________________.)

____________ are joined by unstacked thylakoids called ________________.

Photosynthesis occurs partly within _________________and partly within the

________________________________.

This overall structure ____________________________________ membrane

and, therefore__________________________.

The reactions of photosynthesis can be broken down into 3 parts

Stage 1: ___________________________________________

Stage 2: ___________________________________________

__________________________________________________

Stage 3: ____________________________________________

___________________________________________________.

Light Energy

Stage 1 and 2 are directly energized __________,

and are called _________________________.

The light energy is eventually transferred to _______

in stage 3, known as __________________ which

takes place in the _______ via the ______________

Used to be called the “______________” - no more

Electromagnetic spectrum

Photosynthetic pigments, called

___________________(embedded in

__________________________) absorb

photons of particular wavelengths and,

through the ______________, transfer their

energy to ____________________________

__________________________________.

Engelmann’s experiment

The __________________ of photosynthesis (wavelength vs rate)

matches nicely a spectrophotometers results of an _________________

____________.

Chlorophyll and Accessory Pigments

________________________absorb photons with energies in the

________________________________.

_________________ is the ________ pigment that can transfer the

___________________________________________reactions.

_______________ acts as an _________________, absorbing

photons that ____________________________________.

Other accessory pigmnets:

______________ (ex. β-carotene) absorb light energy in the range from 400 nm to 500 nm

______________________________________________

____________________ - type of carotenoid that absorb light, which would otherwise

_________________________________. (appear yellow)

Both are found in the ____________________.

_______________________(red, violet, and blue) are primarily located in _____________

and protect against light damage.

When the absorption spectra of all are combined the range

covers ____________________________(400 nm to 700 nm)

This light is called ___________________________________

The Light Reactions

Photosynthesis begins when photons strike a photosynthetic

membrane.

Three parts:

1.

2.

3.

Photoexcitation

Electrons in chlorophyll are in their ____________(lowest

energy)

When a photon of light strikes them, the electron _______

________________________________ level (excitation).

The excited electron is ___________________________.

Energy must be ___________ (heat and light - called

____________________).

In a plant however, the __________________is captured

by a special molecule called the ____________________in

a redox reaction.

Photosystems

In a ________, light is absorbed by a ____________.

Consists of an _____________and a _____________.

The antenna complex is composed of __________

__________________________ set in a ________

________ and embedded in the _________________.

Antenna pigments __________________energy until it

reaches _______________ at the reaction centre.

An electron of this chlorophyll gets excited, and is

transferred to a ______________________________.

2 types of photosystems called ____________________

__________________________

_________________ is called P700 because its

absorption spectrum peaks at ____________________

_________________________

________________ is called P680 because it is best at

absorbing photons _____________________________

Noncyclic Electron Flow and Chemiosmosis

Plants use ___________________________to produce

__________________.

Known as _________________________

1. A photon strikes _____________________and excites

an electron of chlorophyll _________.

2. Electron is captured by a ____________________

called ____________.

3. Electron is transferred to ______________ (PQ)

4. Electron transferred to an ________________

_________________. This process occurs twice.

5. A _____________, splits water.

The e- replace the electrons _________________.

O2 leaves as waste, and the H+ remain adding to

the H+ gradient

"Q cycle"

6. As e- pass through the _______,

______ pass from the ________

into the _____________for each

pair of electrons

7. The e- move through

___________, Pc , and replace the

____________that were lost

by ______________ .

8. The e- from ______________ pass

through _______________________

containing _____________ (Fd).

9. Then e- move to the enzyme ____

________________. The ________

________ from the _________ then

reduce ________________.

10. H+ collect in the __________

____________ forming an _____

______________________

11. H+ move through the ______

____________ into the _______,

and _______________________

(photophosphorylation).

Requires ___________ per ATP.

Cyclic Electron Flow

Sometimes e- take pathway that uses ________________________ only.

1. A photon ejects an electron from ____________________of photosystem I.

2. The e- is passed to ______________, and then goes through the _______,

the ____________________, and back to ____________________.

A proton gradient forms _________________________________________.

However no ______________ is made.

Without _____________, the reactions of ______________cannot occur

Rates of _________________

are regulated by the NADPH :

NADP+ ratio

When the ratio is ______,

(high light) _______________

________ because very little

_________will be available.

Part 2 - The Calvin Cycle

Takes place in the _____________.

Similar to the _______________in that some of the starting material is

regenerated.

The Calvin cycle can be divided into three phases:

1.

2.

3.

Phase 1: Carbon Fixation

_____ is added to an already existing 5-

carbon molecule, _____________________,

RuBP, to form two 3-carbon molecules called

_________________________________.

This happens _____ times

3 CO2 react with 3 RuBP to produce six

____ molecules of PGA

Since the first compound contains _______

____________, the Calvin cycle is also

known as ____________________. Most

plants are C3 plants

ribulose bisphosphate carboxylase/oxygenase

Phase 2: Reduction Reactions

The six molecules of PGA ______________ by

an ATP to form six molecules of

___________________________________

A pair of electrons from each of _____________

_______________ reduces six molecules of 1,3-

BPG to six molecules ____________________

_____________________________.

(Think reverse of _________________).

One molecule of ______________________ as

a final product.

Phase 3: RuBP Regeneration

Remaining 5 G3P are rearranged to

form ___________. _____are used in

the process.

RuBP may now fix more ______.

G3P molecules will synthesize larger

sugars

_______ of the Calvin cycle will fix

enough _______ to produce the

equivalent of ___________________

Overall:

You complete the case study on

the Discovering Metabolic

Pathways on pg. 163-164

Complete the Alternative Mechanisms

of Carbon Fixation Worksheet

You know pigments work together in a photosystem to provide

the energy necessary for the light reactions.

Chromatography is a technique used in biology to isolate

molecules in their pure form. Two common types of

chromatography are column chromatography and paper

chromatography. Column chromatography separates

molecules based on their size and/or their electrical charge.

In this investigation, you will use paper chromatography to separate

the photosynthetic pigments in a leaf extract. Paper chromatography

separates molecules based on their different solubilities in a solvent.

Molecules that are very soluble will stay dissolved in the solvent and

travel a greater distance along the chromatography paper.

Molecules that are insoluble will stay near the beginning.

Once the molecules are separated on the paper, the paper can be

cut and each pigment can be redissolved in a solvent. The isolated

photosynthetic pigments can then be studied further to determine

their unique characteristics.