Photosynthesis

Which part of the plant cell performs photosynthesis

• The Mitochondria

• The Chloroplast

• The Nucleus

• The Cell Wall

What does light do when it strikes the chlorophyll molecules of photosystems I & II

• Light causes glucose to be synthesized directly inside the chlorophyll of the photosystems

• Light causes the conversion of water into carbon dioxide

• Light directly causes carbon dioxide to attach to RuBP during the carbon fixation stage of the Calvin Cycle

• Light causes electrons to get excited (gain energy) and travel down an electron transport chain embedded in the thylakoid membrane

After light excites electrons and they leave Photosystem II down the first electron transport chain. How are these electrons replaced by Photosystem II?

• Oxygen is reduced and the electrons are given to the chlorophyll molecules of photosystem II

• Water is split, and the electrons are given to the chlorophyll molecules of photosystem II

• Carbon dioxide is split, and the electrons are given to the chlorophyll molecules of photosystem II

• Hydrogen undergoes fusion, and the electrons are given to the chlorophyll molecules of photosystem II.

The splitting of water at the photosystem II is known as ________ and results in the production of _________.

• Photosynthesis; carbon dioxide, G3P, and electrons that are given to the photosystem

• The Calvin Cycle: Carbon dioxide, G3P, and electrons that are given to the photosystem

• Chemiosmosis: oxygen, hydrogen ions (protons), glucose, and electrons that are given to photosystems II.

• Photolysis: oxygen, hydrogen ions (protons), and electrons that are given to photosystems II.

As the electrons travel from photosystem II down the first electron transport chain, their energy is used to....

• form oxygen, water, NADPH, and glucose

• pump hydrogen ions into the stroma, producing a concentration gradient that will later be used by an enzyme to form ADP and phosphate.

• create glucose directly

• pump hydrogen ions into thylakoid space, producing a concentration gradient that will later be used by ATP synthase to form ATP.

Why do hydrogen ions flow from the thylakoid space to the stroma through ATP synthase?

• they are pumped actively through ATP synthase. This uses up ATP and causes the production of ADP and phosphate

• they flow through the Calvin cycle and produce light

• Hydrogen ions do not actually flow from the thylakoid space to the stroma. They flow the opposite way.

• They flow passively from high concentration to low concentration via facilitated diffusion. As they flow through ATP synthase, the enzyme spins and produces ATP

After electrons get excited by light a second time (at photosystem I), where do they go?

• they travel down a second electron transport chain and are donated to ADP which is then converted to ATP

• They travel down a second electron transport chain and are donated to NADP+ which becomes NADPH (an electron carrier)

• They remain excited and then travel to photosystem II where they get even more excited until they spontaneously combust.

• They travel down a second electron transport chain and are donated to oxygen which then bonds to hydrogen ions to form water.

Which products of the light-dependent reactions are used in the Calvin Cycles to help form reduced organic compounds?

• Oxygen, ATP, NADPH, and CO2

• Water and CO2

• ATP and NADPH

• Light, Water, and CO2

What happens during the carbon fixation stage of the Calvin Cycle?

• Energy from ATP and electrons from NADPH are used to reduce 3-phosphoglycerate to form G3P molecules (which can be used to form other organic molecules such as glucose)

• The enzyme Rubisco attaches to CO2 to RuBP, causing the formation of molecules 3-phosphoglycerate

• The remaining G3P molecules that have not exited the cycle are used to re-form RuBP through a series of chemical reactions, so that the Calvin cycle can continue

• Oxygen is produced through this process

What happens during the reduction stage of the Calvin Cycle?

• The remaining G3P molecules that have not exited the cycle are used to re-form RuBP through a series of chemical reactions, so that the Calvin cycle can continue

• Energy from ATP and electrons from NADPH are used to reduce 3-phosphoglycerate to form G3P molecules (which can be used to form other organic molecules such as glucose)

• Oxygen is produced through this process

• The enzyme Rubisco attaches to CO2 to RuBP, causing the formation of molecules 3-phosphoglycerate