C1.3 Photosynthesis

Relationship between Photosynthesis and Cellular Respiration

They are reversible to each other essentially

Pigments

• globular protein

• located in thylakoid membrane

  • membrane of the chloroplast

• proteins embedded in the thylakoid bilayer

• found in clusters (photosystems)

Draw and Label a Chloroplast

Thylakoids

Double bilayer membrane

Stroma

Chlorophyll

Two Types:

1. Chlorophyll A

2. Chlorophyll B

The difference between them is that they each absorb and reflect different lengths of light and have different chemical structures

Four Types of Pigments

1. Chlorophyll

2. Betalains

3. Anthocymanins

4. Carotenoids

They are all measured by wavelength (nanometer)

400-700 nm is visible light

Why does a tree change color?

Due to change in temperature of the proteins, which get denatured/degraded

The highest absorbed color means

it is the lowest reflected, or not that color

The lowest absorbed color means

it is the highest reflected, or that color

Organisms that can perform photosynthesis

1. Green plants (excludes plants underwater)

2. Phytoplankton (Protist)

3. Cyanobacteria

Why can organisms perform photosynthesis?

They have special type of cells aka photosynthetic cells that contain chloroplasts

Step One in Thylakoid Membrane

Chlorophyll in photosystem 2 absorbs sunlight

The electrons get excited

They leave into the electron transport chain

Which carries them to photosystem 1

Step Two in Thylakoid Membrane

These electrons should be replaced by breaking down H2O into

• O

• H2

• e-

The process is called photolysis

Step Three in Thylakoid Membrane

The protons (H ion) will move from high concentration (inside the thylakoid) to low concentration (in the stoma) by a protein channel called ATP Synthase

Step Four in Thylakoid Membrane

ATP Synthase makes ATP by adding 3H+ to an ADP

Step Five in Thylakoid Membrane

NADP+ will bind 2e- and 1H+ to form NADPH

ATP is a

energy carrier and used in light independent reactions too

NADPH is an

electron carrier and used in light independent reactions too

Phase One of the Calvin Cycle: Carbon Fixation

5-Carbon (RubP) + 1CO2 → 6 Carbon

6 Carbon made into 2 3-carbon molecules

Phase Two of the Calvin Cycle: Reduction

2 3-Carbon Molecules → Reduced 2 3-Carbon Molecules (1)

then into 6 3-Carbon Molecule and one leaves for glucose

ATP → ADP (2)

NADPH → NADPH+ (3)

3 Products

Phase Three of the Calvin Cycle: Regeneration of RubP

5 of 3-carbon → 5 RubP

How many times does the Calvin Cycle has to happen to create glucose?

Twice because glucose is the product right before phase 3