Cellular biology is an important subject throughout healthcare and nursing. There is so much information to cover when it comes to biology of cellular functions and can seem tedious when taking your pre-healthcare requisites in college. However, it’s important to understand how cell function so we can understand how different medications and diseases effect body systems. So here is the breakdown on cells, cell functions, and cellular structures.
ARE WE PROKARYOTES OR EUKARYOTES?
Living cells are generally divided into two major classes prokaryotes and eukaryotes.
- Prokaryotes contain no organelles (membrane-bound intracellular compartments like a well-defined nucleus) and their nuclear material is not encased by a nuclear membrane.
- Cyanobacteria, bacteria, and rickettsiae
- Eukaryotes are larger, have more extensive intracellular anatomy, and organization.
- Higher animals, plants, single-celled organisms’ fungi, protozoa, and most algae
WHAT ABOUT THOSE CELLULAR FUNCTIONS?!
Cell are specialized through the process of differentiation, or maturation, so that some cells eventually perform one kind of function and other cells perform other functions.
There are eight chief cellular functions:
- Movement. Muscle cells can generate forces that produce motion. For example, the contraction of smooth muscle cells surrounding blood vessels changes the diameter of the vessels. Contraction of muscles in the walls of the urinary bladder expels urine.
- Conductivity. Conduction as a response to a stimulus is manifested by a wave of excitation, an electrical potential that passes along the surface of the cell to reach its other parts. This is the chief function of nerve cells.
- Metabolic absorption. All cells take in and use nutrients and other substances from their surroundings. For example, kidney tubules reabsorb fluids and synthesize proteins. Intestinal epithelial cells reabsorb fluids and synthesize protein enzymes.
- Secretion. Certain cells can synthesize new substances from substances they absorb and then secrete. For example, cells of the adrenal gland, testis, and ovaries can secrete hormonal steroids.
- Excretion. All cells can rid themselves of waste products resulting from the metabolic breakdown of nutrients. For example, lysosomes within cells contain enzymes that break down, or digest, large molecules, turning them into waste products that are released from the cell.
- Respiration. Cells absorb oxygen, which is used to transform nutrients into energy in the form of adenosine triphosphate (ATP). Cellular respiration, or oxidation, occurs in an organelle called mitochondria.
- Reproduction. Tissue growth occurs as cells enlarge and reproduce themselves. If cells lack the ability to grow, tissue maintenance requires the new cells to be produced to replace cells that are lost normally through cellular death. As stated previously, not all cells are capable of continuous division.
- Communication. Communication is a vital function for cells to survive. For example: pancreatic cells secrete and release insulin necessary to signal muscle cells to absorb sugar from the blood for energy.