The Basis for Life on Earth Photosynthesis- The Basis for Life on Earth NOTE: ONLY WRITE DOWN THE SLIDES WITH THE BLACK BACKGROUND!!! THEY ARE A SUMMARY OF THE PREVIOUS SLIDES!

Photosynthesis- is the process that converts light energy into chemical energy. Glucose has more energy than carbon dioxide and water. The reaction is endergonic and requires an energy input of ATP and NADPH2

The equation below describes the Calvin cycle of photo-synthesis and the chemical energy needed to make the sugar. In order to keep the reaction going, the cell must regenerate ATP and NADPH

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Photosynthesis-converts light energy to chemical energy. Light reaction-uses light energy to make the chemical energy needed to make glucose in the form of NADPH and ATP Dark reaction (light independent reaction/Calvin cycle)-This where the sugar is actually made

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White light is mixture of different colors of light with different wave lengths and frequencies. When white light lands on a blue object, red and green light is absorbed and blue is reflected. Chlorophyll is green and reflects green light and absorbs red and blue. Some photosynthesis will occur in green light because of yellow accessory pigments-caroteinoids and xanthophylls

The absorption graph shows that the pigments absorb red and blue/violet light best. This next graph is the action graph is a reflection of the absorption but it does show photosynthesis ocurring in green light. This is due to the accessory pigments. Chlorophyll is made from a tetrapyrole ring with Mg in the middle and a hydrocarbon tail.

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The light reaction works best in red and blue light because chlorophyll A & B absorbs red and blue light and reflects green light (chlorophyll is green). Some of the light reaction will occur in green light because there are yellow pigments (carotenes/xanthopyll)

Chloroplasts have 3 membranes Chloroplasts have 3 membranes. The outer 2 are smooth and the inner one makes stacks of thylakoids. The chlorophyll and other pigments are found inside the thylakoid membrane. They have the ability to convert light energy into chemical energy.

A stack of thylakoids is called a granum A stack of thylakoids is called a granum. The matrix that the grana are embedded in is the stroma. It contains enzymes for carbohy-drate synthesis. Below is a diagram of a thylakoid and the location of chlorophyll.

The chloroplasts has 3 membranes-The outer two are smooth and the third one makes up a stacks of thylakoids where the light reaction takes place. A stack of thylakoids are called a granum and is imbeded in matrix called the stroma. The stroma is where the dark reaction occurs. 13

The chlorophyll molecules and accessory pigments form photosystems (I & II). Once photons are absorbed by chlorophyll, the electron becomes excited and the energy is passed on from molecule to molecule until it reaches the reaction center pigment, which passes the electron to the electron transport system. #4

The chlorophyll molecules and accessory pigments form photosystems (I & II). Once photons are absorbed by chlorophyll, the electron becomes excited and the energy is passed on from molecule to molecule until it reaches the reaction center pigment, which passes the electron to the electron transport system. 15

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The electron transport chain is a series of proteins that have the ability to be reduced and oxidized and is in the thylakoid membrane. The electron loses energy as the electron moves through electron transport chain. One protein (PQ) has the ability to pump H+ from the stroma into the thylakoid. The electron is energized again in the second photosystem and with a second shot of light. At the end of the electron transport chain, the electron is received by NADP which adds H+ to become NADPH. 17

The electron transport chain is a series of proteins that have the ability to be reduced and oxidized and is in the thylakoid membrane. The electron loses energy as the electron moves through electron transport chain. One protein (PQ) has the ability to pump H+ from the stroma into the thylakoid. The electron is energized again in the second photosystem and with a second shot of light. At the end of the electron transport chain, the electron is received by NADP which adds H+ to become NADPH. 18

The electron has now left the electron transport chain The electron has now left the electron transport chain. Some enzymes in the thylakoid has the ability to split water, the e- (are replacement e- ), H+ and O2. The oxygen goes to the atmosphere. #7 #8 19

The electron has now left the electron transport chain The electron has now left the electron transport chain. Some enzymes in the thylakoid has the ability to split water, the e- (are replacement e- ), H+ and O2. The oxygen goes to the atmosphere. 20

As the electron transport chain runs, there is an accumulation of H+ on the inside of the thylakoid. This is due to the splitting of water and the proton pump, PQ. As the H+ collect, the pH of the interior is lowered and there is a separation of charge across a membrane. This can now do work. On the thylakoid membrane, there is a CF1 particle, with an enzyme ATP synthetase. This enzyme has the ability to phosphorylate ADP--->ATP as 3 H+ pass through. #9 10 21

As the electron transport chain runs, there is an accumulation of H+ on the inside of the thylakoid. This is due to the splitting of water and the proton pump,PQ. As the H+ collect, the pH of the interior is lowered and there is a separation of charge across a membrane. This can now do work. On the thylakoid membrane, there is a CF1 particle, with an enzyme ATP synthetase. This enzyme has the ability to phosphorylate ADP--->ATP as 3 H+ pass through. 22

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