Day 16 Light Dependent Reaction

Photosynthesis continued

Start off with group presentations!

Chloroplasts- Photosynthesis takes place in this organelle

The Basics of Photosynthesis

Photosynthesis

The reactants (what goes in) of photosynthesis are:

6 H2O (6 water molecules) and 6 CO2 (6 Carbon dioxide molecules) and light energy


The products (what comes out) of photosynthesis are:

6 O2 (6 oxygen molecules, these are a byproduct which means they are not needed. Waste) and C6H12O6 (Glucose)


There are two different reactions in Photosynthesis

  1. The light reaction

-The light reaction converts solar energy into chemical energy

  1. The Calvin Cycle

-The Calvin cycle preforms carbon fixation

The Light Reaction


The light reaction takes place in the membrane of the thylakoids

How does the light reaction convert solar energy into chemical energy?

The light dependent reaction happens within the thylakoid membranes

Here are the steps:

-Within the thylakoid H2O(water) is separated into O2(Oxygen) and H+(Hydrogen Ions)

-The Oxygen is released through the stomata because it is not needed

-The thylakoid fills with H+

-The e- (electrons) from the hydrogen are sent to the photosystem 2

-The e- waits in the reaction center

-Sunlight bounces off of the light pigments sending absorbed energy to the reaction center

-The energy is passed on to the e- which becomes excited and jumps to the primary electron receptor

-The excited e- travels through the electron transport chain 2 releasing its energy in the form of ATP

-The e- then reaches the reaction center of photosystem 1

-Sunlight filters through the pigments of photosystem 1 exciting the e- waiting in the reaction center

-The e- then jumps to the electron receptor of photosystem 1

-The e- travels through the ETC 1 where it then waits for an electron carrier

-NADP+ which is an electron carrier comes and picks up the e- along with an H+ becoming NADPH

-The NADPH then floats off into the cytoplasm where the Calvin cycle takes place

Watch this video on photosynthesis. Take detailed notes and be prepared to discuss photosynthesis. Watch this video in pieces. Watch the first 4.5 minutes of the video. Make sure you fully understand the first 4.5 minutes before you move on to the rest.

This is a second video summing up photosynthesis. You need to watch this video as well. Watching two different videos on the same topic will help you understand the topic.