What are the major components of the eukaryotic cell?

Question

What are the major components of the eukaryotic cell?

Accepted Answer

The virus that causes chicken pox can cause the human body to produce memory cells: After having the chicken pox once, a re-exposure to the virus is fought off by the memory cells, preventing a person from contracting the disease more than once. But in this case, you may not get the “chicken pox,” but another problem: After a chicken pox infection, the virus remains dormant in the body’s nerve tissues. While the immune system keeps the virus at bay, later in life—usually as an adult—the virus (it is called herpes zoster, from the varicella zoster virus) can reactivate (although the reason is unknown, it is often traced to stress or a suppressed autoimmune system). This causes a different form of the viral infection called shingles—which leaves a person with an often painful skin rash.

Many major components in eukaryotic cells exist, all of various sizes and functions. The following table lists the major structures in the cell nucleus, the cytoplasmic organelles, and the cytoskeleton (for both animals and plants):

Structure		Description
Cell Nucleus
	Nucleus	Large structure surrounded by double membrane
	Nucleolus	Special body within nucleus; consists of RNA and protein
	Chromosomes	Composed of a complex of DNA and protein known as chromatin; resemble rodlike structures after cell division
Cytoplasmic Organelles
	Plasma membrane	Membrane boundary of living cell
	Endoplasmic	Network of internal membranes extending through reticulum (E.R.) cytoplasm
	Smooth endoplasmic	Lacks ribosomes on the outer surface reticulum
	Rough endoplasmic	Ribosomes stud outer surface reticulum
	Ribosomes	Granules composed of RNA and protein; some attached to E.R. and some are free in cytosol
	Golgi apparatus	Stacks of flattened membrane sacs
	Lysosomes	Membranous sacs (in animals)
	Vacuoles	Membranous sacs (mostly in plants, fungi, and algae)
	Microbodies (e.g., peroxisomes)	Membranous sacs containing a variety of enzymes
	Mitochondria	Sacs consisting of two membranes; inner membrane is folded to form cristae and encloses matrix
	Plastids (e.g., chloroplasts)	Double membrane structure enclosing internal thylakoid membranes; chloroplasts contain chlorophyll in thylakoid membranes
The Cytoskeleton
	Microtubules	Hollow tubes made of subunits of tubulin protein
	Microfilaments	Solid, rodlike structures consisting of actin protein
	Centrioles	Pair of hollow cylinders located near center of cell; each centriole consists of nine microtubule triplets
	Cilia	Relatively short projections extending from surface of cell; covered by plasma membrane; made of two central and nine peripheral microtubules
	Flagella	Long projections made of two central and nine peripheral microtubules; extend from surface of cell; covered by plasma membrane

Cellular Basics

Structures Inside Cells

What are the major components of the eukaryotic cell?