Friday, December 6, 2013

Plant Cells

Plants are eukaryotes and have the typical eukaryotic cell organization, consisting of nucleus and cytoplasm. The cytoplasm is enclosed by a plasma membrane and contains numerous membrane-enclosed organelles, including plastids, mitochondria, microbodies, oleosomes, and a large central vacuole. Chloroplasts and mitochondria are semiautonomous organelles that contain their own DNA.

 The main Characteristics are given below: 
Cell wall – rigid, support & protect plant, Cellulose fiber embedded

Vacuoles – fluid-filled; store enzymes & metabolic wastes

Plastids – contain DNA surrounded by 2 membranes. Store starch/fats

Absorb visible light – pigments

Chloroplast – site where photosynthesis takes place

Thylakoids – membranous sacs contains chlorophyll

Plants have & we don’t:

·         Cell wall

·         Vacuoles

·         Plastids (where photosynthesis takes place)

Cell Walls of Plants

·         The cell wall is an extracellularstructure that distinguishes plant cells from animal cells, made of cellulose fibers embedded in other polysaccharides and protein.

·         Prokaryotes, fungi, and some protists also have cell walls.

·         The cell wall protects the plant cell, maintains its shape, and prevents excessive uptake of water.