ENZYMES/PHOTOSYNTHESIS

ATP

A form of energy that the cell can use, has 3 phosphates and releases energy when the third phosphate is broken off.

ADP

Adenosine diphosphate; ATP after the third phosphate is removed and energy has been released.

ATP hydrolysis

The process required to break the phosphate off ATP.

ATP synthesis

The process of putting the phosphate back on ADP, which requires energy.

Activation energy

The amount of energy needed for a reaction or cell process to occur.

Enzymes

Substrate specific, reusable proteins that lower the activation energy required for reactions.

Substrates

The substances being broken down into products by the enzyme.

Active site

The portion of the enzyme that interacts with the substrate.

Cofactors/coenzymes

Substances that help enzymes function.

Competitive inhibitor

A substance that inhibits enzyme activity by binding to the active site.

Noncompetitive inhibitor

A substance that inhibits enzyme activity by binding allosterically, away from the active site.

Thylakoid

The discs in the chloroplasts where photosynthesis occurs.

Stroma

The liquid surrounding the thylakoid in chloroplasts.

Light dependent stage

The part of photosynthesis that produces ATP and NADPH.

Photosystem 2

The photosystem where light is absorbed, and energy is transferred to a high-energy electron.

Thylakoid lumen

The space in the thylakoid where water is split into oxygen, electrons, and hydrogen ions during photosynthesis.

Cytochrome complex

A protein complex powered by electrons that moves hydrogen ions into the thylakoid.

ATP synthase

An enzyme that creates ATP from ADP and a phosphate as hydrogen ions flow through it.

Photosystem 1

The photosystem that absorbs light and transfers energy to create NADP+ with an electron.

Light independent stage

The part of photosynthesis in which glucose is produced in the chloroplasts.

Light independent equation

CO2 + ATP + NADPH → C6H12O6.

Photosynthesis equation

6CO2 + 6H2O — light energy → 1C6H12O6 + 6O2.

Chlorophyll A

A pigment that releases high-energy electrons and absorbs all colors besides green, reflecting back green.

Accessory pigments

Pigments such as chlorophyll and carotenoids that assist in photosynthesis.

Leaf

A flattened outgrowth from a vascular plant

Epidermis

The outer layer of “skin” on a plant.

Waxy Cuticle

A protective layer of lipids around the epidermis.

Stomata

Openings that let gas in and out of the leaf, regulated by guard cells.

Guard Cells

Cells in the epidermis that regulate gaseous exchange

Vascular Bundle

A tube like tissue that transports material around the plant

Xylem

Transports water/minerals up from the roots. Always the inside layer of the vascular bundle.

Phloem

Transports sugar through the vascular bundle. Always the outer ring.

Palisade Mesophyll

A layer of cells responsible for the majority of photosynthesis.

Spongy Mesophyll

Cells that are more spread out to facilitate airflow.

Contents of a stem/root

Epidermis, vascular bundle, cortex

Cortex

a structure present in the roots and stem that assists in storing nutrients and is responsible for lateral growth.

Plan Diagram

Simple drawings of structures that do not show individual cells.