One of the most important distinguishing features of plant cells is the presence of a cell wall, a which serves a variety of functions. The cell wall protects the cellular contents, gives rigidity to the plant structure, provides a porous medium for the circulation and distribution of water, minerals, and other small nutrient molecules. It contains specialized molecules that regulate growth and protect the plant from disease. A structure of great tensile strength, the cell wall is formed f

The most important characteristic of plants is their ability to photosynthesize, i.e. make their own food by converting light energy into chemical energy. This process is carried out in specialized organelles called chloroplasts. Chloroplasts are one of three types of plastids, plant cell organelles that are involved in energy storage. The colorless leucoplasts are involved in the synthesis of starch, oils, and proteins. Yellow-to-red colored chromoplasts manufacture carotenoids. The chloroplast is enclosed in a double membrane. Inside, are the stroma, a semi fluid material that contains dissolved enzymes and makes up most of the chloroplast's volume, and the lamellae, internal membranes with stacks of closed hollow disks called the thylakoids. Light travels as packets of energy called photons and is absorbed in this form by light-absorbing chlorophyll molecules embedded in the thylakoid disks. When the chlorophyll molecules inside the thylakoids absorb the photons, they emit electrons. The free electrons are then taken up by molecules in the stroma to produce ATP. ATP is the chemical energy "currency" of the cell that powers the cell's metabolic activities. In the stroma, the light-independent reactions of photosynthesis occur; low-energy carbon dioxide is transformed into a high-energy compound like glucose.

The nucleus is a highly specialized organelle that serves as the information and administrative center of the cell. This organelle has two major functions. It stores the cell's hereditary material, or DNA, and it coordinates the cell's activities, which include intermediary metabolism, growth, protein synthesis, and reproduction. Only the cells of advanced organisms, known as eukaryotes, have a nucleus. Generally there is only one nucleus per cell, but there are exceptions such as slime molds and the Siphonales group of algae. Simpler prokaryotes, like the bacteria and cyanobacteria, don't have a nucleus. In these organisms, all the cell's information and administrative functions are dispersed throughout the cytoplasm. The spherical nucleus occupies about 10 percent of a cell's volume, making it the cell's most prominent feature. Most of the nuclear material consists of chromatin, the unstructured form of the cell's DNA that will organize to form chromosomes during mitosis or cell division. Also inside the nucleus is the nucleolus, an organelle that synthesizes protein-producing macromolecular assemblies called ribosomes. A double-layered membrane, the nuclear envelope, separates contents of the nucleus from the cellular cytoplasm. The envelope is riddled with holes called nuclear pores that allow specific types and sizes of molecules to pass back and forth between the nucleus and the cytoplasm. It is also attached to a network of tubules, called the endoplasmic reticulum, where protein synthesis occurs. These tubules extend throughout the cell and manufacture the biochemical products that a particular cell type is genetically coded to produce. There are two types of chromatin in the nucleus. Euchromatin is the genetically active portion and is involved in transcribing RNA to produce proteins used in cell function and growth. Heterochromatin contains inactive DNA and is the portion of chromatin that is most condensed, since it not being used. Throughout the life of a cell, chromatin fibers take on different forms inside the nucleus.

Plasmodesmata are small tubes that connect plant cells to each other, establishing living bridges between cells. Similar to the gap junction found in animal cells, the plasmodesmata penetrate both the primary and secondary cell walls, allowing certain molecules to pass directly from one cell to another.

An example of a photosynthetic prokaryote is Cyanobacteria. Cyanobacteria or Blue-Green Algae, are members of a group of photosynthetic single-celled organisms tha

Some common words found in the essay are:
Smooth ER, , Transfer RNA, RNA Ribosomes, ATP ATP, Rough ER, Blue-Green Algae, cell wall, Messenger RNA, cell walls, endoplasmic reticulum, plant cells, amino acids, throughout cytoplasm, outside cell, plant cell, secondary cell, cell division, inside outside cell, proteins lipids built, penetrate primary secondary, secondary cell walls, organelles found cytoplasm,
Approximate Word count = 2589
Approximate Pages = 10 (250 words per page double spaced)