Photosynthesis - Energy for Life

Flashcards for reviewing photosynthesis lecture notes.

Photosynthesis

Transforms solar energy into chemical energy of carbohydrates; occurs in plants, algae, and cyanobacteria.

Chloroplasts

Organelles containing chlorophyll that trap solar energy to reduce carbon dioxide to carbohydrate.

Photosynthesis

The process by which chlorophyll-containing organelles trap solar energy to reduce carbon dioxide to carbohydrate, converting light energy into chemical energy stored in sugars or other organic compounds.

Stomata

Pores through which carbon dioxide enters leaves.

Mesophyll cells

Cells within leaves where CO2 and H2O diffuse into chloroplasts.

Chloroplast membrane

Double membrane surrounding the stroma in the chloroplast.

Grana

Stacks of thylakoids within the chloroplast.

Thylakoid membrane

Location of chlorophyll and other pigments within the thylakoid membrane where solar energy is absorbed.

Stroma

The reduction of carbon dioxide into carbohydrates occurs here

Pigments

Molecules that absorb solar energy

Wavelengths best absorbed by chlorophyll a and b

Violet, blue, and red wavelengths.

Carotenoids

Yellow or orange pigments that reflect those colors and absorb light in the violet-blue-green range.

Photosynthetic Process

The process where hydrogen atoms removed from water are added to carbon dioxide, requiring solar energy and producing oxygen as a by-product.

Light reactions

Occur in the thylakoid membrane where chlorophyll absorbs solar energy, water is oxidized, ATP is produced, and NADP+ is reduced to NADPH.

Calvin cycle reactions

Occur in the stroma where CO2 is taken up and reduced to a carbohydrate using ATP and NADPH.

Photosystems

Consists of pigment complex and an electron acceptor, serving as an antenna for gathering solar energy.

Photosystem II

Absorption of solar energy energizes electrons; replacement electrons are obtained by splitting water, releasing oxygen as waste.

Electron transport chain

Series of carriers that pass electrons along, releasing energy stored in the form of H+ gradient; the energy will be used to make ATP.

Photosystem I

Absorption of solar energy energizes electrons; electrons are accepted and passed to NADP+ to become NADPH.

Thylakoid membrane

The location promotes efficient transfer of electrons, and ATP synthase complex is also located here.

Thylakoid space

Each time water is split 2 H+ remain here. Energy from electrons transferred between carriers used to pump still more H+ from the stroma into this space; this energy establishes H+ gradient with a large amount of potential energy.

ATP synthase complex

H+ flow down concentration gradient, pass through this complex; energy release allows for production of ATP.

NADP+

A coenzyme that accepts electrons and a H+ to become NADPH.