8.2 The Light reactions convert light energy to chemical energy

=8.2 The light reactions convert light energy to chemical energy=

*Vocab

-wavelength=>distance between adjacent waves

-electromagnetic spectrum=> range of types of electromagnetic energy from gamma waves to radio waves

-pigment=>chemical compound that determines a substance's color

-paper chromatography=> laboratory technique used to observe the different pigments in a material

-photosystem=>cluster of chlorophyll and other molecules in a thylakoid

*Light Energy and Pigments

-Sunlight: form of electromagnetic energy

gamma rays-X-rays-UV-visible light-infrared-microwaves-radiowaves

>Pigments and Color

pigment choose the color of a substance

-three things happens to different wavelengths when it shines an object->absorbed, tranmitted, or reflected

-If a color is green, it is green because green is reflected from the object and other color is absorbed

>Identifying Chloroplast pigments

-We can observe different pigments in a green leaf by using laoratory tech called paper chromatography

-paper chromatography can separate and analyze the pigments in a leaf

*Harvesting Light energy

-We can watch the process occuring in a chloroplast as sunlight strikes a leaf.

-photosystems contains pigment molecules-the solar collectors

-Pigment's electrons gains energy as pigment molecules absorbs light energy

-chlorophyll a molecule get trapped by primary electron acceptor to be used to make ATP and NADPH

*Chemical Products of the Light Reactions

-light strikes photosystem and transfer excited electrons to the primary electron acceptor.

-electrons split water and releases oxygen

-excited electron goes through electron transport chain and pumps H+ions across the membrane to thylakoid.

-light excited electrons get ransferred to NADP+

*Concept Check

1.Explain why a leaf appears green

-leaf appears green because it reflects green light and absorb the other light colors

2.Describe what happens when a molecule of chlorophyll a absorbs light.

-when a molecule of chlorophyll a absorbs light it gets trapped by primary electron acceptor to produce ATP and NADPH.

3.Besides oxygen, what two molecules are produced by the light reactions?

-ATP & NADPH

4.Where in the chloroplast do the light reactions take place?

-It takes place in the thylakoid membrane

Concept 8.1 Photosynthesis Uses Light Energy to Make Food

=8.1 Photosynthesis uses light energy to make food=

*Vocab
-chloroplast=> The cellular organelle where photosynthesis takes place.
-chlorophylls=> Chemical compound that give chloroplast to have green color
-Stroma=> thick fluid contained in the inner membrane of a chloroplast.
-Thylakoid=>Disk shaped sac in the stroma of a chloroplast; site of the light
-Light reaction=> The reactions that convert the energy in sunlight to chemical energy
- Calvin cycle=> cycle in plants that makes sugar from carbon dioxide, H+ions, and hight-energy electrons carried by NADPH

*The Structure of Chloroplasts
-All the green parts of the plant contain cells with chloroplasts and carry out photosynthesis
-Leaves has the mot chloroplasts in plants
-Stomatas are pores where CO2 enters and O2 exits
-Chloroplast's inner membrane has stroma, the thick fluid, and thylakoids are suspened in the stroma as disk-shaped sacs.
-Chloroplasts' shape is easy to organize the reaction of phosynthesis

*Overview of Photosynthesis
-Photosynthesis 6CO2+6H2O ->-> C6H12O6+6O2
- There are two main stages in photosynthesis: Light reactions & The Calvin Cycle
*light reactions produce ATP to calvin and get ADP+phosphate from Calvin cycle
*Calvin Cycle produces sugar

*Concept Check
1. Draw and label a simple diagram of a chloroplast that includes the following structures: outer an inner membranes, stroma, thylakoids.
-

2.What are the reactants for photosynthesis? What are the products?
-Reactants: Carbon dioxide & Water
-Products: Glucose & Oxygen

3.Name the two main stages of photosynthesis. How are the two stages related?
- The two main stages are the light reactions and the calvin cycle. Both are related in the way they produce ATP and together, collaborate to produce O2 and Sugar.