Unit 2 Cell Structure and Function Vocabulary

Tissue

The mass of like cells in an animal or plant body, esp. as they form a specific organ.

Organ

In a plant or animal, a specialized structure that performs a particular function, such as the heart.

Organelle

A specialized subunit within a cell that has a specific function, and is usually separately enclosed within its own membrane.

Cell membrane (plasma membrane)

The thin layer of protein and fat that surrounds the cell. Its semipermeable, allowing some substances to pass into the cell and blocking others.

Cytoplasm

The jellylike material outside the cell nucleus in which the organelles are located.

Mitochondrion

Spherical to rod-shaped organelles with a double membrane. The inner membrane is in-folded many times, forming a series of projections (called cristae). It converts the energy stored in glucose into ATP (adenosine triphosphate) for the cell.

Golgi body (Golgi apparatus or Golgi complex)

A flattened, layered, sac-like organelle that looks like a stack of pancakes and is located near the nucleus. It produces the membranes that surround the lysosomes. Its body packages proteins and carbohydrates into membrane-bound vesicles for "export" from the cell.

Lysosome (cell vesicles)

Spherical organelles surrounded by a membrane; they contain digestive enzymes. This is where the digestion of cell nutrients takes place.

Nuclear membrane

The membrane that surrounds the nucleus.

Nucleus

Spherical body containing many organelles, including the nucleolus. It controls many of the functions of the cell (by controlling protein synthesis) and contains DNA (in chromosomes). its surrounded by the nuclear membrane.

Chromosome

One of the tiny, threadlike, DNA-containing bodies found in the cell nuclei of all plants and animals, responsible for transmitting hereditary characteristics.

Ribosome

Small organelles composed of RNA-rich cytoplasmic granules that are sites of protein synthesis.

Rough endoplasmic reticulum (rough ER)

A vast system of interconnected, membranous, in-folded and convoluted sacks that are located in the cell's cytoplasm (its continuous with the outer nuclear membrane). covered with ribosomes that give it its appearance. It transports materials through the cell and produces proteins in sacks called cisternae (which are sent to the Golgi body, or inserted into the cell membrane).

Smooth endoplasmic reticulum 

A vast system of interconnected, membranous, in-folded and convoluted tubes that are located in the cell's cytoplasm (its continuous with the outer nuclear membrane). The space within it is called the lumen. It transports materials through the cell. It contains enzymes and produces and digests lipids (fats) and membrane proteins; buds off from another, moving the newly-made proteins and lipids to the Golgi body, lysosomes, and membranes

Centrosome (microtubule organizing center)

A small body located near the nucleus - it has a dense center and radiating tubules. its where microtubules are made. During cell division (mitosis), it divides and the two parts move to opposite sides of the dividing cell. The centriole is the dense center of it (plant cells do not have centrioles).

Vacuole (animal)

Fluid-filled, membrane-surrounded cavities inside a cell. It fills with food being digested and waste material that is on its way out of the cell.

Vacuole (plant)

A large, membrane-bound space within a plant cell that is filled with fluid. Most plant cells have a single one that takes up much of the cell. It helps maintain the shape of the cell.

Cell wall(plant)

A thick, rigid membrane that surrounds a plant cell. This layer of cellulose fiber gives the cell most of its support and structure. it also bonds with others to form the structure of the plant.

Chlorophyll (plant)

The green pigment in the leaves and stems of plants that is necessary for the production of plant food by photosynthesis.

Chloroplast(plant)

An elongated or disc-shaped organelle containing chlorophyll. Photosynthesis (in which energy from sunlight is converted into chemical energy - food) takes place