Below is a table that compares the differences in cell structure between eukaryotic and prokaryotic cells.
|Criteria||Type of Cell|
|Internal membranes?||No (no organelles)||Yes (membrane bound organelles)|
|DNA||Single chromosome; ring||Many; linear|
|Reproduction method||Asexual (binary fission)||Asexual and sexual|
|Size||Small||10 times as large as prokaryotes|
Heterotrophic vs. Autotrophic
Heterotrophic organisms eat/consume other living organisms to obtain energy molecules and nutrients they require to sustain their own life processes.
Autotrophic organisms create their own energy molecules on their own.
Photoautotroph– sunlight, carbon dioxide and water are converted into energy molecules and nutrients
Chemoautotroph– use energy from their environment and carbon dioxide to make energy molecules and nutrients
Why do eukaryotic cells have membrane-bound organelles?
To increase the efficiency of the cell.
Eukaryotic cells are large > they have low internal S.A. : Volume ratios for metabolic processes
> nutrients are not able to rapidly move to all interior parts of the cell for metabolic processes
Membrane-bound organelles compartmentalize (make little rooms in) the eukaryotic cell.
These little rooms all have specific functions.
Small, numerous, and specialized compartments increase efficiency by:
- isolating needed enzymes to its function
- creating internal conditions needed in its function (ex. pH, ion concentrations)
- increasing the S.A.:Volume ratio for their function
- allowing many different and contrasting functions can be done at the same time
Why aren’t prokaryotes divided into compartments?
Organelles are unnecessary for the prokaryotic cell, because they are much smaller in size.
- nutrients can easily and rapidly reach any part of the cells interior
- all needed materials within the cell are relatively close together
- being small allows for higher S.A. : Volume ratios for metabolic processes
There are two general types of cells, but they are both cells. Even though the cells have differences between them, there are similarities.
The major similarities between the two types of cells include:
- They both have DNA as their genetic material.
- They are both membrane bound (both have a cell membrane).
- They both have ribosomes .
- They have similar basic metabolism .
- They are both amazingly diverse in forms.
- They both perform the same basic life functions.