Chapter Seven: Using LIght to Make Food

Questions:

1. How do the reactant molecules of photosynthesis reach the chloroplasts in leaves?

  A: CO2 enters leaves through stromata, and H2O enters the roots and is carried to leaves through veins.

2. What do chloroplasts need to produce sugar from carbon dioxide in the dark?

  A: ATP and NADPH.

3. What is the advantage of the light reactions producing NADPH and ATP on the stroma side of the thylakoid membrane?

  A: The Calvin Cycle, which consumes the NADPH and ATP, occurs in the stromata.


Five Main Facts From The Reading:

1. Photosynthesis occurs in chloroplasts in plant cells.
2. Photosynthesis is a redox process, as is cellular respiration.
3. The two stages of photosynthesis are linked by ATP and NADPH.
4. Visible radiation drives the light reactions.
5. Photosynthesis moderates global warming.

A rudimentary overview of photosynthesis in a sunflower (I hate sunflowers.)

Photosynthesis Light Reactions: http://www.youtube.com/watch?v=hj_WKgnL6MI

Ten Key Terms:

Autotroph - make their own foods and thus sutain themselves without consuming organic molecules derived from any other organisms.

Producers - produce food supply to the biosphere. 

Mesophyll - the green tissue in the interior of the leaf.

Stomata - tiny pores in the leaf through which carbon dioxide enters and oxygen exits.

Stroma - thick fluid in the inner compartment of the chloroplast. 

Thylakoids - a system of interconnected membranous sacs.

Electromagnetic Spectrum - the full range of electromagnetic wavelengths from the very short gamma rays to the very long radio waves.

Wavelength - the distance between the crests of two adjacent waves. 

Photon - a fixed quantity of light energy.

Photosystem - a number of light harvesting complexes surrounding a reaction center complex.

This chapter went over Cellular Respiration's "sister," photosynthesis. Photosynthesis in the plant cells ability to take in water, light, NADP+, ADP,  and phosphorous and convent it into sugar molecules to be stored as a source of food. It took us through Light Reactions II and I and into the Calvin cycle, showing us the reactants and products of all three. 

It also discussed the benefits of photosynthetic organisms to the biosphere, and how it is even being studied as a way to slowly repair the Ozone.