Prokaryotes vs. Eukaryotes

Megan WilkersonUniversity of West Alabama

Helpful Definitions Cell- the smallest structural unit of an organism Nucleus- a central part around which other parts are collected Cytoplasm- protoplasm outside a cell nucleus Protoplasm- a complex substance constituting the living matter

of cells and performing basic life functions Ribosome- a spherical particle active in the synthesis of protein Synthesis- the fusion of separate elements to form a whole Organelle- a specialized part of a cell that resembles and

functions as an organ Mitochondrion- a microscopic body occurring in the cells of

living organisms and containing enzymes responsible for the conversion of food to energy

Meiosis- cell division in sexually reproducing organisms Mitosis- cell division in non- sexually reproducing organisms

Cells Living organisms are constructed of cells and

may consist of one or many cells. Cells are the basic unit of structure and

function in organisms. There are two basic types of cells: prokaryotes

and eukaryotes. Cells vary in size based on the volume of the

organism. As the volume increases, the cell size diminishes.

All cells are derived from other cells.

History of Prokaryotes “Karyose” comes from the Greek

word which means “kernel” “Pro” means “before” “Prokaryotic” means “before a

nucleus”

ProkaryotesProkaryotes:• Were the first living organisms to evolve• Lack a nucleus• Are the material that create bacteria• Are almost always single- celled• Can have whip- like flagella for movement or

hair- like pili for adhesion• Come in various shapes- cocci (round), baccilli

(rods), spirilla (elongated spiral), or spirochetes (helical cells)

More Information about Prokaryotes Prokaryotic cells have 0.001 times as much

DNA as eukaryotic cells. At fairly high frequencies, spontaneous

mutations can cause prokaryotes to turn into a female.

Prokaryotes have a wonderful "motor" for swimming, but can only run in two directions and at one speed. In forward, prokaryotes are propelled in one direction at 30 mph. In reverse, the prokaryote can turn flips or tumble. It can only do one or the other. It cannot stop.

History of Eukaryotes “Eu” means “true” or “good” “Eukaryotic” means “possessing a

true nucleus”

EukaryotesEukaryotes:• Evolved from a prokaryote predecessor• Are more complex than prokaryotes• Can be single or multi- celled• Comprise most living things, including plants,

animals, and humans• Have a nucleus• Can reproduce in several ways, including

mitosis and meiosis

More Information about Eukaryotes The basic eukaryotic cell contains

the following: plasma membrane glycocalyx cytoplasm cytoskeleton membrane enclosed subcellular

organelles

Plasma Membrane A lipid/protein/carbohydrate

complex, providing a barrier and containing transport and signaling systems.

Nucleus Double membrane surrounding the

chromosomes and the nucleolus. Pores allow specific communication with the cytoplasm. The nucleolus is a site for synthesis of RNA making up the ribosome

Mitochondria Surrounded by a double

membrane with a series of folds called cristae. Functions in energy production through metabolism. Contains its own DNA, and is believed to have originated as a captured bacterium.

Vacuoles Membrane surrounded "bags" that

contain water and storage materials in plants

How are Prokaryotes and Eukaryotes Alike? Both perform many of the same

functions. Both have DNA Both can have cell walls Both can have cytoplasm Both have ribosomes

How are Prokaryotes and Eukaryotes Different? Eukaryotes are larger than prokaryotes Eukaryotes are more complex than

prokaryotes Eukaryotes have a nucleus; prokaryotes

do not Prokaryotes are almost always single

celled Eukaryotes have organelles

Cell Structure of Prokaryotes

Cell Structure of Eukaryotes (Plant cell)

Cell Structure of Eukaryotes (Animal cell)

Prokaryotes vs. EukaryotesComparison TableComparison Table Prokaryote

s Eukaryotes

Nucleus No Nucleus Has a Nucleus Size of cell Smaller in size Larger in size

Structure Simple Structure Complex Structure Membrane-enclosed organelles No Organelles Has Organelles Cell division Binary fission Mitosis

Sexual reproduction Transfer of DNA Meiosis Chromosome (DNA) arrangement Single chromosome Multiple

chromosomes

TEST YOUR CELL KNOWLEDGE!!!!!!!!! Which of the following is not alive, but requires life to be able to reproduce? Viruses- Correct.

Yes, a virus requires a living cell for reproduction, and cannot reproduce by itself. Which statement best describes the function of the rough endoplasmic

reticulum? Synthesis and assembly of membrane and secreted proteins- Correct!

Rough ER is covered with ribosomes (causing the "rough" appearance) which are involved in the process of synthesizing proteins for secretion or localization in membranes.

Which statement best describes the function of the Golgi apparatus? Processing of membrane and secreted proteins, including

glycosylation- Correct!The Golgi apparatus processes proteins after they leave the endoplasmic reticulum.