Re: What does a liver cell look like (circular, etc.), and what are its structure

Hepatocytes (hepato = liver; cyte = cell) are a good choice for your model, since the majority of their functions involve metabolism, rather than motility, communication, or absorption which can be difficult to show in a model. In vivo (in the living organism) hepatocytes are somewhat cuboidal, often polyhedral, but not spherical. On the other hand, hepatocytes grown in vitro (on tissue-culture plates) flatten out like fried eggs, but still look relatively rectangular when bunched together. Regarding their structure, hepatocytes are rife with cytoplasmic organelles, which perform the various metabolic functions of the hepatocytes. Hepatocytes have several functions which are mirrored by their abundance of specific organelles:

• Detoxifying the blood is carried out by lysosomes and peroxisomes which break down amino acids, fats, toxins (like alcohol), and other garbage into waste products like urea and urobilins (which are returned to the blood for removal by the kidneys), and cholic acid and bilirubins (see below).

• Production of bile is one of the results of blood detoxification. Bile is excreted by the cells into the canaliculi ("little canals") to the bile ducts and into the gall bladder. Bile contains bile salts, sodium salts of cholic acid and taurine (among other things), detergents which are added to food entering the small intestine and aid in digestion.

• Storage of sugar is accomplished in the form of glycogen (a complex starch) which occurs as granules in the cytoplasm.

• Production of blood proteins is carried out by the rough endoplasmic reticulum, golgi stacks, and exocytotic vesicles. These proteins are essential for clotting, osmotic pressure, and immunity, so hepatocytes make a lot.

Further links to pages about organelles can be found here , also this electron micrograph of a section of liver shows the abundance of most of these organelles within normal hepatocytes. I hope this information is helpful, I made a model of a simple eukaryotic cell for my 7th grade science class (about 20 years ago), and learned a great deal about cell structure in doing it. To answer your alternate question, Acantharia are eukaryotic protozoa, so they would count for your project, although descriptive references are not as easy to find as for hepatocytes on the web.