light reactions

Question 1

what are the two types of light reactions?

Answer 1

light dependent and light independent

Question 2

light dependent happens in the

Answer 2

thylakoid

Question 3

light dependent reactions

Answer 3

The light-dependent reactions occur in the thylakoid. Chlorophyll in the thylakoids absorbs light energy, exciting electrons that power the process. Water molecules are split inside the thylakoid, releasing oxygen, electrons, and protons. The excited electrons travel through the electron transport chain, located in the thylakoid membrane, creating a proton gradient that helps produce ATP. The electrons also reduce NADP+ to form NADPH, which, along with ATP, powers the Calvin cycle

Question 4

light independent

Answer 4

The light-independent reactions, or Calvin cycle, take place in the stroma of the chloroplast. During these reactions, ATP and NADPH from the light-dependent reactions are used to convert carbon dioxide into glucose. The enzyme Rubisco fixes carbon dioxide, which is combined with a 5-carbon sugar to form a 6-carbon molecule. As the cycle continues, ATP is used to provide energy for the reactions, converting it into ADP, while NADPH is used to reduce the molecules. Ultimately, glucose is produced and can be used by the plant for energy and growth, while ADP and NADP+ are recycled back into the light-dependent reactions.

Question 5

why does light reaction have to happen first?

Answer 5

because the molecules produced in the light dependent reaction are then used to power the light independent reactions

Question 6

thylakoid membrane

Answer 6

Phospholipid Bilayer, chlorophyll, protein complexes, proton gradient, stroma lamellae

Question 7

photosystems

Answer 7

Photosystems are protein and pigment complexes found in the thylakoid membrane that play a crucial role in the light-dependent reactions of photosynthesis.

1. Photosystem II (PSII): Absorbs light energy, excites electrons, and splits water molecules to release oxygen, protons, and electrons.
2. Photosystem I (PSI): Absorbs light energy to re-energize electrons, which are used to reduce NADP+ to form NADPH

Question 8

Electron Transport Chain (ETC)

Answer 8

a series of proteins embedded in the thylakoid membrane that transfer excited electrons from Photosystem II (PSII) to Photosystem I (PSI). As electrons move through the chain, they release energy that is used to pump protons into the thylakoid space, creating a proton gradient

Question 9

atp synthase

Answer 9

an enzyme complex located in the thylakoid membrane that plays a critical role in the light-dependent reactions of photosynthesis. It uses the proton gradient created by the electron transport chain (ETC) to synthesize ATP from ADP and inorganic phosphate (Pi). As protons flow through ATP synthase from the thylakoid space to the stroma, the energy from this movement drives the phosphorylation of ADP to form ATP. This ATP is then used in the Calvin cycle to help produce glucose

Question 10

factors that affect photosynthesis

Answer 10

the more water, light, and/or CO2 the faster the photosynthesis. the more temperature the less photosynthesis, since the temp affects the enzymes, making it decrease .

Question 11

High temp and dry climate

Answer 11

most go through C3, but high temp places use C4. the carbon fixation happens in 2 cells in dry climate (CAM), but it happens at two different times (day and night).