| Accessory pigments |
Light-absorbing pigments, other than chlorophyll, that are found in chloroplasts. |
| Adhesion |
A force where dissimilar molecules stick together; in plants this force of adhesion between water and the walls of the xylem helps hold the water in the xylem against the downward force of gravity. |
| Antenna complex |
Structure of chlorophyll and accessory pigments that are embedded in the thylakoid membranes; captures and routes energy from sunlight to a collector called a reaction center. |
| Apoplast |
Space outside the cell membrane where water and minerals can move freely; interrupted by the casparian strip in roots. |
| ATP |
A principle molecule for storing and transferring energy in cells; created in the LR. |
| Carotenoid pigments |
Accessory pigments that absorb green light and reflect yellow and red light; overtaken by chlorophyll during the growing season, so we do not see the yellow-red reflection. |
| Cellulose |
A long chain of glucose that is a main constituent of the cell wall and key to a plant’s structural integrity; sequesters atmospheric CO2 for long-term storage. |
| Chlorophyll |
Green photosynthetic pigment found in plants, algae, and cyanobacteria that captures light for photosynthesis. |
| Chlorophyll a |
Type of chlorophyll; mainly absorbs violet and red light while reflecting green light. |
| Chlorophyll b |
Type of chlorophyll; mainly absorbs blue and orange light while reflecting green light. |
| Chloroplasts |
Membrane-bound organelles found within cells that house chlorophylls and accessory pigments. |
| Cohesion |
A force where similar molecules stick together; in plants this occurs with water molecules bonding together. |
| Evapotranspiration |
Movement of water in the plant from the root through the stem to the leaf and out the stomata to the atmosphere; also called transpiration. |
| Fructose |
Simple sugar; can be produced via photosynthesis. |
| Gas exchange |
Movement of oxygen and carbon dioxide through stomata in the plant. |
| Glucose |
Simple sugar; can be produced via photosynthesis. |
| Grana |
Stacks of thylakoids. |
| Guttation |
Dew-like drops of water that are forced out of the leaves of some plants due to root pressure. |
| Hydrogen bond |
When water molecules are near each other and the negative region of one molecule is attracted to the positive region of another; a weaker bond than covalent bonds. |
| Light absorption |
Process in which light is absorbed and converted to energy. |
| Light Independent Reaction (LIR) |
Second half-reaction in photosynthesis; occurs without the presence of light and uses the energy produced in the Light Reaction to grab the carbon from carbon dioxide and use the carbon to build simple sugars. |
| Light Reaction (LR) |
First half-reaction in photosynthesis; occurs with the presence of light and uses light energy to split water, which transforms the energy from the sun into hydrogen ions and electrons. |
| Light reflectance |
Light wavelengths that are not absorbed, but are reflected back. |
| Light wavelength |
Length of the wave from one peak to the next; measured in nanometers. |
| NADPH |
Energy created in the LR; used to drive the LIR. |
| Palisade mesophyll |
Densely packed, columnar-shaped, elongated cells full of chloroplasts; analogous to cortex parenchyma cells in the stem, but in the leaf they are specialized for light energy capture. |
| Photoautotrophs |
Name given to living things, namely plants, that use energy from light to produce organic molecules with which they build their cells and store energy; self-nourishing. |
| Photon |
Particle representing a quantum of light; provides the energy that drives photosynthesis. |
| Photosynthesis |
Process of capturing light energy and producing carbon-based organic molecules. |
| Reaction center |
Complex of pigments, proteins, and other factors that execute the primary energy conversion reactions of photosynthesis, primarily where water is split in the LR to form the energy carriers ATP and NADPH. |
| Resonance |
Energy that is passed from one molecule to the next. |
| Rubisco |
One of the most abundant proteins on earth; catalyzes the step in the process where carbon from atmospheric CO2 is incorporated into an organic molecule; full name: Ribulose-1,5-bisphosphate carboxylase/oxygenase. |
| Simple sugars |
Monosaccharides; examples include glucose and fructose. |
| Starch |
Key energy storage compound in plant cells; a long glucose chain that sequesters atmospheric carbon for short-term use. |
| Stroma |
Interior of the chloroplast; site of the LIR. |
| Sucrose |
Sugar that is transported by the phloem throughout the plant to provide energy and building blocks for other organic molecules like starch and cellulose. |
| Symplast |
Interior to the cell membrane, where water and minerals are transported through cells. |
| Tension |
Differential pressure; in plants this occurs as water molecules are pulled through the plant via transpiration. |
| Thylakoid membrane |
Membrane that surrounds the thylakoid. |
| Thylakoids |
Membrane-bound compartments inside chloroplasts and cyanobacteria; the site of the light-dependent reactions of photosynthesis. |
| Transpiration |
Movement of water in the plant from the root to stem to leaf and out through the stomata to the atmosphere; also called evapotranspiration. |
| Triose phosphate |
A 3-carbon sugar (triose) with phosphorus and oxygen atoms (phosphate); G3P is an example. |
| Turgor pressure |
Water pressure inside of cells. |
