Mastering Biology Assignment 8

Wavelengths of light that are absorbed by chlorophyll trigger the light-dependent reactions.

Energy in sunlight is transformed to chemical energy.

6 CO2 + 6 H2O → C6H12O6 + 6 O2

water ... NADPH NADPH is a reactant in the Calvin cycle

Photophosphorylation

false The chemiosmotic hypothesis states that the flow of electrons through an electron transport chain generates a proton gradient that leads to the synthesis of ATP.

Proton gradient A proton gradient across chloroplast and mitochondrial membranes drives ATP synthesis by the enzyme ATP synthase.

protons The channels formed by ATP synthase are specific for protons.

false The region of ATP synthase that catalyzes ATP production protrudes out of, but does not span, the chloroplast membrane; the region that spans the membrane is an ion channel through which protons can pass.

Photosynthesis Oxygen is a by-product of the photosynthetic process.

The light-dependent reactions The light-dependent reactions use H2O and produce O2.

The light-independent reactions turn CO2, a gas, into usable carbon in the form of sugars. CO2 is unusable until plants have "fixed" this carbon into sugar

true The water molecules are split to replenish electrons in photosystem II, leaving behind protons, which are used to generate a proton gradient for the formation of ATP, and oxygen, which is released as a by-product.

NADPH The NADPH produced by photosystem I is used to supply energy for the production of sugars during photosynthesis.

They convert carbon dioxide to sugar. All organisms use the sugars produced by photosynthesis to generate energy.

The light-dependent reactions produce ATP and NADPH, which are then used by the light-independent reactions.

RuBP In the Calvin cycle, carbon dioxide is added to RuBP

NADPH NADPH supplies the electrons that reduce the phosphorylated 3-PGA.

6 Six carbon dioxide molecules are required to produce two G3P molecules, which can be combined to make one glucose molecule.

In both systems, ATP is produced by chemiosmosis.

PS II → pheophytin → plastoquinone → cytochrome complex → plastocyanin → PS I → ferredoxin In the final step of the Z scheme, electrons are transferred from ferredoxin to NADP+ (by the enzyme NADP+ reductase ) to produce NADPH.

It becomes bonded to an organic compound.

Photosynthesis would occur but photorespiration would not. Photosynthesis depends on binding of CO2, whereas photorespiration depends on binding of O2 to rubisco.

Sucrose is water soluble and used in respiration and sugar transport.