There are several classifications of epithelial cells. They are, simple squamous epithelial cells,
which are wider than their height and aide in absorption due to its thinness. It is found where
there is lots of chemical compounds are passing, for example, the segments of kidney tubules
or capillaries lining. The simple cuboidal epithelium cells have similar height and width, whose
main function is secretion and absorption, and is commonly found in the lining of the kidney
tubules or ducts of glands. The simple columnar epithelium cells are much taller than their
width, acting a protectant or barrier, for example, they are found in the lining of the stomach to
protect from any bacteria that may have been ingested. Pseodstratified columnar epithelial cells
are found in the respiratory tract and functions in collecting bacteria and basically protecting the
lungs from irritants. Stratified squamous cells are found in almost all parts of the body. They
function to protect the body from water loss and desiccation. The 5 leukocytes are monocytes,
which functions in the break down of bacteria; lymphocytes, that makes antibodies that fight
bacteria and bad invaders, neutrophils who kill and digest bacteria and fungi; basophils that are
small cells that alarm the body of infectious invaders in the blood, they give off chemicals like
histamine that identifies allergic disease and controls immune responses. Lastly, eosinphils that
attack parasites, cancer cells etc. and aid in allergic responses.
The cytoskeletal is made up of three main parts, the microfilament, microtubules and intermediate
filaments. Microtubules are long filaments whose main function is to aid in support and maintaining the
shape of the cell and play a vital role in mitosis, microfilaments are mostly found in muscle cells and are
active in muscle contractions. They participate in organelle movements. Intermediate filaments are
found in many cells are provide structural support or microfilaments and microtubules. They form
keratin in epithelial cells and neurofilaments in neurons.
Glycolytic pathway mainly shows the oxidation of glucose to pyruvate with the generation ATP and
NADH. It is a multi-step pathway that is common in the cytoplasm of animal, plant and other
microorganisms cells. In step one, for each mol of glucose, 2 mols of ATP are consumed. In this process a
phosphate from the ATP is transferred to the glucose and will result in a Glucose-6- phosphate in the
presence of the enzyme hexokinase and glucokinase. In this reaction, there is a conversion of an aldose
into a ketose. The carbonyl oxygen shifts from C1 to C2. Thus, the isomerization of Glucose-6-phosphate
to fructose 6-phosphate is catalyzed by phosphohexoisomerase/phosphoglucoisomerase. Fructose -1, 6biphosphate is basically cleaved into 2 3-carbon units of glyceraldehyde-3-phosphate. Lasty, is the
harvesting stage. From each initial, 2 mols of pyruvate and 4 mols of ATP are obtained as the end
products, and glyceraldehyde-3-phosphate becomes oxidized to pyruvate.