Glossary of Terms Related to Plant Anatomy

ATP

Stands for adenosine triphosphate and acts as the main energy storage and transfer molecule in the cell. ATP is produced in chloroplasts and the cristae of the mitochondria and is then metabolized by enzymes and different cellular processes.

Amyloplast

Organelle found in some plant cells that helps store and synthesize starch. When a plant is in need of energy, amyloplasts can also convert its starch back into sugar for food. Many amyloplasts can be found in starchy plants like potato tubers.

Cell membrane

A slim layer of fat and protein that surrounds a cell though still located inside the cell wall. It is semi-permeable, which means it allows for some substances to pass through it while keeping others out.

Cell wall

A tough, rigid layer that surrounds a plant cell. The cell wall is located outside of the cell membrane and acts to support, filter incoming substances, and protect the cell from over-expansion due to water intake. Cell walls can also attach to other cell walls to help form the structure of a plant.

Centrosome

A small organelle located close to the nucleus that acts as the main microtubule organizing center (MTOC) of the cell (it is where microtubules are produced).

Chlorophyll

A green molecule vital for photosynthesis. Chlorophyll captures light energy from the sun in order to convert carbon dioxide and water into oxygen and sugar for plant consumption.

Chloroplast

Disc-shaped organelle containing chlorophyll and the location where photosynthesis occurs.

Collenchyma

Tissue composed of cells with unevenly thickened walls.

Cotyledon

One of the first leaves of the embryo of a seed plant; seed leaf.

Cristae

The folded membranes inside the mitochondria. The walls of the cristae contain proteins and are the site where cell energy production occurs (ATP is produced).

Cytoplasm

A gooey substance that contains all the cell's organelles outside of the nucleus. Most cellular activity occurs within the cytoplasm.

Dicotyledon

Flowering plants that have two seed leaves that emerge after germination.

Endoplasmic reticulum (ER)

A system of membranes forming tubular compartments that permeate the cytoplasm. ER can be smooth or rough, and coated with ribosomes.

Eukaryote

Cells that contain a nucleus and other membrane-bound organelles.

Golgi bodies

Organelles found near the nucleus in most eukaryotic cells that help to process and package proteins and carbohydrates into vesicles that are processed out of the cell.

Mitochondria

Rod to spherical-shaped organelles which contain a double membrane. The mitochondria's function is to convert glucose into ATP in order to power the cell.

Monocotyledon

Flowering plants that have one seed leaf that emerges after germination.

Nucleolus

An organelle contained within the nucleus where ribosomal RNA is formed.

Nucleus

The brain of the cell. It controls many of its functions (through protein synthesis) and contains the DNA (in the form of chromosomes).

Nuclear envelope

Double membrane enclosing the nucleus of a cell.

Organelle

A membrane-bound body in the cytoplasm of a cell.

Parenchyma

Thin-walled cells, varying in shape, size, and function.

Photosynthesis

A process where plants convert water, carbon dioxide, and sunlight into energy, water, and oxygen. Chlorophyll is crucial for photosynthesis to occur.

Plasmodesmata

The site where communication and transport of materials between plant cells occurs.

Plastid

An organelle with a double membrane in the cytoplasm of many eukaryotes. It may be concerned with photosynthesis (chloroplast), contain yellow or orange pigment (chromoplast), or contain starch (amyloplast).

Phloem

The food-conducting tissue of a vascular plant.

Prokaryote

Cells that lack organelles and a nucleus.

Radicle

The young root as it emerges from the seed, normally the first organ to appear on germination.

Ribosomes

Tiny organelles that are made up of RNA-rich cytoplasmic granules in which protein synthesis occurs.

Sclereid

A type of schlerenchyma, made up of gritty cells, often called "stone cells." Sclereids are what make a pear slightly gritty.

Schlerenchyma

Tissue composed of thick-walled cells containing lignin for strength and support.

Sieve element

Cell in the phloem tissue concerned with longitudinal conduction of food materials. In flowering plants, it is called a sieve-tube element.

Sieve tube

A series of sieve-tube elements arranged end to end and interconnected through sieve plates.

Stroma

Dense fluid found between grana (stacks of thylakoid disks) of a plant cell's chloroplast. Stroma is where carbohydrate forming reactions occur during photosynthesis.

Thylakoid

Disk-shaped [membrane-bound] compartment within chloroplasts that contain the chlorophyll. Thylakoids are the site for photosynthesis.

Vacuole

Membrane-lined area within a plant cell that is filled with water. This organelle takes up much of the space inside a cell and help maintains its shape and size.

Vector

An organism (as an insect) that transmits a pathogen or an agent (as a virus) that contains or carries modified genetic material which can be replicated inside a host organism

Vessel

A tube-like series of vessel elements with open ends. The walls that join the members have perforations or holes in them to allow water to pass through freely.

Vessel element

Individual cells that make up vessels.

Xylem

The water-conducting tissue of a vascular plant. Minerals are also transported through the xylem.