Cell and organelle

Based on the structural differences of their cells, organisms have been traditionally divided into two blood groups, the prokaryotes (bacteria) and the eukaryotes (plant, animal, fungi, algae and protozoa). The most fundamental distinction between the two groups is that eukaryotic cells have true membrane-bounded nucleus, whereas prokaryotic cells do not.

The distinction between prokaryotes and eukaryotes is considered to be the most important distinction among groups of organisms. Eukaryotic cells contain membrane-bound organelles, such as a nucleus, while prokaryotic cells do not. Difference in cellular structure of prokaryotes and eukaryotes include the presence of mitochondria and chloroplast, the cell wall, and the structure of chromosomal DNA

Prokaryotic and eukaryotic stores DNA differently

In eukaryotes, DNA stored in a membrane bound nucleus with internal structure.

mRNA translated after exiting the nucleus DNA handled differently during cell division. Binary fission vs. mitosis/

meiosis

Changes in classification of organisms

Why cells are small?

Cells are small because they need to be able to diffuse through materials easily. Also, materials inside and outside of the cell need to easily pass through the cell membrane, which makes it harder and slower for the materials to pass through the cell membrane. Cells are small because the ratio of surface area to volume is the most efficient at their size. This is because when you have a lot of small objects vs a few big objects the surface area is much larger in relation to volume. Another reason is when the cells are small and plentiful, they are easier to replicate and replace when damaged.

Summary

Prokaryotes have “simple” internal structures.

Eukaryotes have more complicated internal membrane structures.

These structures are called organelles compartmentalizing and performing specific function

Some organelles evolved from bacterial ancestors.