Question

Write a 700-800 word APA format essay showing the difference between eukaryotic and prokaryotic cells. List their features and functions.

Answer 1

There are three domains on earth. Eukarya and two prokaryote (Bacteria and Archea)

Prokaryotic cell: They are the small , simple and most primitive. Three shapes are common among the prokaryotes: Cocci, Bacilli and Spiral forms. Their cells donot have membrane-enclosed internal compartments.

Prokaryotes are very diverse in their metabolic capabilities. Prokaryotic cells are smaller than eukaryotic cells, ranging in dimension from 0.25 1.25 m to 1.5 4 m. Although each prokaryote is a single cell, many are usually seen in pairs, chains, small clusters, or even colonies containing hundreds of individuals.

Cell Structure: All prokaryotic cells have a plasma membrane, a nucleoid, and cytoplasm filled with ribosomes.

Plasma membrane encloses the cell regulating the entry of materials into and out of the cell. The nucleoid is a clear area that contains hereditary material (DNA) of the cell. The material within the membrane is called cytoplasm which is made up of cytosol and insoluble suspended particles. Many prokaryotes have have a cellwall located outside the plasma membrane. The cell walls of most bacteria Gram positive) , but not archea, contain peptidoglycan, a polymer of amino sugars, cross-linked to form a single molecule around the entire cell. In Some bacteria (Gram negative), another layer-the outer membrane made up of a polysaccharide rich phopholipid membrane encloses the cell wall. Enclosing the cell wall and outer membrane in many bacteria is a slime layer composed of polysaccharide is referred as capsule. It protect the bacteria from environment. Some prokaryotes have hair like projections called flagella and Pili contribute movement and adhesion.

In some bacteria - the cyanobacteria carryon photosysnthesis.. In this energy of sunlight is converted to chemical energy that can be used for a variety of energy requiring reactions such as the synthesis of cellular proteins and DNA. Some prokayotes possess some membranous structures called mesosomes, which function in cell division.

Reproduction is Asexual by simple cell division.

Eukaryotic cell: Animals, plants, fungi, and protists have cells that are larger and structurally more complex than that of prokaryotes. The eukaryotic cella are defined by one or two membranes that regulate entry of particles inside and outside the cell. They possess distinctive shapes and functions, are called organells. The membranes of all the organells have similar structure (a phospholipid bilayer), dimensions, and appearence. The differences between nuclei from plant and animal cells. Both cells possess the golgi apparatus, function in the storage, internal transport and processing of proteinn and other substances. Plant cells have some specialized organelle , called the chloproplast, site for capturing light energy and using it for the synthesis of carbohydrates from crbo dioxide and water. Animal cells lack chloroplasts. Animal cells synthesize and secrete digestive enzymes have more ribosomes and associated membranes.

Membranes of eukaryotes have membrane barriers-permit the passage of certain materials. Thus transport is a major function of all membranes. The hydrophobic interior of the membrane serves as a barrier to the passage of charged or polar materials that are readily soluble in water. Membranes participate in many activities besides transport. The mitochondrial membranes carry enzymes responnsible for energy transformations in the cell.

The nucleus is the largest organelle in a cell. IThe possession of membrane enclosed nucleus is a defining property of eukaryotes. Information is stored as sequence of bases in DNA molecules, which resides in the nucleus. Nucleus is surrounde by two membranes which are called nuclear envelope. The membranes of nuclear envelope are separated by are perforated by nuclear pores that connect the interior of the nucleus with cytoplasm. RNA and water-soluble molecules pass through these pores to enter or leave the nucleus. The outer membrane of the nuclear envelope folds outward into the cytoplasm and is continuos with the membrane of another organelle called endoplasmic reticulum. Inside the nucleus, DNA combines with proteins to form a fibrous complex called chromatin.There are water and dissolved substances collectively referred as nucleoplasm, At the periphery of the nucleus, chromatin attaches to a protein meshwork called nuclear lamina. It maintains the shape of the nucleus by its attachment to both chromatin and nuclear envelope. Chromatin condenses and coils tightky to form chromosomes. Each chromosome is contains one long molecule of DNA. The chromosomes carry hereditary information, DNA carries the information required to perform the synthetic function of the cell. A dense, roughly, spherical bodies called nucleoli are visible in the nucleus.

In both prokayotes and eukaryotes, proteins are synthesized on ribosomes.

In eukaryotes, utilization of food molecules such as glucose begins in the cytosol. The fuel molecules thar result from partial degradation of this food enter mitochondria, whose primary function is to convert the potential chemical energy into energy rich molecules called ATP.

Reproduction is by Sexual, asexual or by budding