CELL BIOLOGY BOTANY A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z           HOME ABOUT CATEGORIES SITE MAP COPYRIGHT ADVERTISE CONTACT entire Web this site plant cell A typical plant cell Comparison of animal and plant cells Both animal (A) and plant (B) cells have a cell membrane (1), nucleus (2), and cytoplasm (3). But in plants there is also a cell wall (4) and certain organelles, notably chloroplasts, which are unique to plant cells Like all eukaryotic cells, including animal cells, plant cells contain membrane-bounded organelles. Some of these organelles, and other structures, are common to all eukaryotes, while others are found in plant cells but not in animal cells. Among the distinguishing features of plant cells are: Plant cell organelles plastids: a group of organelles characterized by a double membrane envelope and a complex of internal membranes. Plastids contain DNA and replicate autonomously proplastids: specialized for dividing to form new plastid, usually found in meristematic cells chloroplast: contains chlorophyll, internal membranes organized as grana, specialized for photosynthesis chromoplast: contains red, orange, or yellow carotenoid pigments, and imparts color to fruits, etc. leucoplast: specialized for storing starch (amyloplast), oil (elaioplast), or protein (aleuroplast) central vacuole: membrane bound organelle that typically occupies a large volume of the cell cytoplasm. Vacuoles may contain: anthocyanins: red, blue or purple pigments that are water soluble tannins: phenolic compounds that bind with protein; they function in plant defense crystals: usually composed of calcium oxalate Cell wall primary cell wall: a cell wall layer deposited while a cell is growing; typically extensible secondary cell wall: innermost layer of a cell wall deposited after cell enlargement has ceased, often lignified casparian strip: a band of suberin within the anticlinal walls of endodermal and exodermal cells cuticle: a water-repellent layer that coats the outer cell walls of the epidermis on aerial parts of plants, composed of cutin with a surface coating of wax mucigel: a slime sheath secreted by roots polysaccharide: a polymer composed of sugars cellulose: the structural (microfibrillar) portion of the plant cell wall hemicellulose: the alkali-soluble portion of the cell wall matrix pectin: the hot-water-soluble portion of the cell wall matrix lignin: an aromatic polymer that rigidifies may secondary cell walls. Ligin is stained red by phloroglucinol solutions Intercellular connections plasmodesmata: cytoplasmic channels lined with plasma membrane that connect the protoplasts of adjacent cells across the cell wall pit: a region where the secondary cell wall is absent, but the primary cell wall is present simple pit: a pit that is not bordered, may be round or slit-shaped circular-bordered pit: a round pit with a thickened margin Related categories    • CELL BIOLOGY    • BOTANY Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History Transport Concepts & Designs (partner site) BACK TO TOP