differences between prokaryotic and eukaryotic cells

Prokaryotic cells can be distinguished from eukaryotic cells as they lack a nucleus (and also lack any other membrane-bound organelles). Therefore prokaryotic DNA is free in the cytoplasm, whereas the DNA of eukaryotic cells is enclosed in a nucleus.

Prokaryotic cells also have different types of DNA to eukaryotic cells: while both prokaryotic and eukaryotic cells contain DNA arranged in chromosomes, prokaryotic cells may additionally contain plasmid DNA (a circular loop of DNA which is separate from chromosomal DNA).

It is important to note that forming single-celled organisms is NOT specific to prokaryotic cells - eukaryotic cells can also form single celled organisms (e.g. amoeba). This is something I didn't initially realise at GCSE!

Prokaryotic: unicellular, contain a cell wall, have no mitochondria or chloroplasts, no nucleus so DNA is free in the cytoplasm (plasmids in bacteria) cell division is binary fission

examples : fungi and bacteria

eukaryotic: multicellular, no cell wall only cell membrane, contain mitochondria and chloroplasts in plant cells, DNA enclosed in a nucleus, cell division is mitosis

examples: plant cells, animal cells

Hi Elizabeth!

The main difference between prokaryotes and eukaryotes is how they store their DNA. Whilst eukaryotes contain this within a nucleus, prokaryotes contain a free-floating loop of DNA with plasmids. Prokaryotes are also usually single-celled (bacteria etc.), whilst eukaryotes make up multicellular organisms.

Nucleus:

Prokaryotic: Lacks a true nucleus; genetic material is in the nucleoid region.

Eukaryotic: Contains a well-defined nucleus where genetic material is enclosed in a membrane.

Membrane-Bound Organelles:

Prokaryotic: Lacks membrane-bound organelles.

Eukaryotic: Contains various membrane-bound organelles like the endoplasmic reticulum, Golgi apparatus, mitochondria, and more.

Cell Size:

Prokaryotic: Generally smaller in size (1-5 micrometers).

Eukaryotic: Typically larger and more complex (10-100 micrometers).

Cell Division:

Prokaryotic: Reproduces through binary fission.

Eukaryotic: Undergoes mitosis or meiosis for cell division.

Genetic Material:

Prokaryotic: Usually a single, circular DNA molecule.

Eukaryotic: Multiple linear DNA molecules associated with histone proteins.

Ribosomes:

Prokaryotic: Smaller ribosomes (70S).

Eukaryotic: Larger ribosomes (80S).

Cell Wall:

Prokaryotic: May have a rigid cell wall made of peptidoglycan.

Eukaryotic: Plant cells have a cellulose cell wall; animal cells lack a cell wall.

Flagella:

Prokaryotic: Simpler flagella.

Eukaryotic: More complex flagella composed of microtubules.

Reproduction:

Prokaryotic: Asexual reproduction is common.

Eukaryotic: Reproduction can be both asexual and sexual.

Eukaryotic cells contain their DNA in a nucleus and have membrane bound organelles such as the smooth and rough endoplasmic reticulum, golgi apparatus, and lysosome. However, prokaryotic cells contain their DNA in the form of circular DNA free in the cytoplasm and also have DNA in plasmids, which are circular.

Nucleus:

• Prokaryotic cells: Lack a true nucleus. Instead, their genetic material is typically found in a region called the nucleoid, which is not enclosed by a membrane.
• Eukaryotic cells: Have a well-defined nucleus enclosed within a double membrane, which contains the cell's genetic material in the form of chromosomes.

Membrane-bound Organelles:

• Prokaryotic cells: Generally lack membrane-bound organelles. They may have some internal structures like ribosomes, but these are not enclosed by membranes.
• Eukaryotic cells: Contain membrane-bound organelles such as mitochondria, endoplasmic reticulum, Golgi apparatus, lysosomes, and chloroplasts (in plant cells). These organelles perform specialized functions within the cell.

Size:

• Prokaryotic cells: Typically smaller and simpler in structure compared to eukaryotic cells.
• Eukaryotic cells: Generally larger and more complex in structure due to the presence of membrane-bound organelles and a well-defined nucleus.

Cell Wall:

• Prokaryotic cells: Most prokaryotic cells have a cell wall, which provides structural support and protection. The composition of the cell wall varies among different types of prokaryotes (e.g., bacteria have a peptidoglycan cell wall).
• Eukaryotic cells: Some eukaryotic cells, such as plant cells and fungal cells, have a cell wall composed of materials like cellulose or chitin. Animal cells do not have a cell wall.

Reproduction:

• Prokaryotic cells: Reproduce primarily through binary fission, a process in which the cell divides into two identical daughter cells.
• Eukaryotic cells: Reproduce through mitosis (for somatic cells) or meiosis (for reproductive cells), processes that involve the division and distribution of chromosomes to daughter cells.

Genetic Material:

• Prokaryotic cells: Typically have a single circular chromosome composed of DNA. They may also contain small, circular pieces of DNA called plasmids.
• Eukaryotic cells: Have multiple linear chromosomes composed of DNA, which are located within the nucleus. Eukaryotic cells may also contain extranuclear DNA in organelles such as mitochondria and chloroplasts.

Prokaryotic cells:

• don't have a nucleus.
• contain circular DNA.
• contain Plasmids.
• the DNA is associated with no proteins called Histones.
• they lack membrane-bound organelles (like mitochondria, nucleus, golgi bodies, etc)
• very small (0.5-5um in diameter)
• contain 70s ribosomes.

Eukaryotic cells:

• have a nucleus.
• contain linear DNA.
• the DNA is wrapped around proteins called Histones, to form chromosomes.
• contain membrane-bound organelles.
• small, but bigger than prokaryotes (up to 100um in diameter)
• contain 80s ribosomes.

There are many differences between prokaryotic and eukaryotic cells! For example, prokaryotic cells have no membrane bound organelles, whereas eukaryotic cells do. Hope this helps.

Eukaryotic - a nucleus

Prokaryotic - a free-floating strand of DNA

Eukaryotic - large ribosomes

Prokaryotic - smaller ribosomes

Prokaryotic - no mitochondria

Eukaryotic - mitochondria

The main difference between prokaryotic and eukaryotic cells is that eukaryotic cells have membrane-bound organelles, meaning that their sub cellular components such as the mitochondria, and most importantly the nucleus (where the DNA is kept) are surrounded by an extra layer of protection known as a membrane.

In prokaryotic cells, all sub cellular structures are floating around in the cytoplasm, even the DNA; though the DNA is coiled up and mostly floats in an area of the cell known as the nucleoid.

There are some other major differences, such as prokaryotic are really small in comparison to eukaryotes, their chromosomes are circular and short, where as eukaryotes have linear and longer chromosomes and the type of ribosomes that they have are also different.

Prokaryotic and eukaryotic cells are the two primary types of cells, differing fundamentally in their structure and complexity. Here are the key differences between them:

1. Nucleus:

• Prokaryotic cells lack a true nucleus. Their genetic material is not enclosed within a nuclear membrane; instead, it is located in a region called the nucleoid.
• Eukaryotic cells have a well-defined nucleus, where the cell’s DNA is enclosed within a nuclear envelope.

1. Cell Size:

• Prokaryotic cells are generally smaller, typically between 0.1 to 5 micrometers in diameter.
• Eukaryotic cells are larger, usually between 10 to 100 micrometers in diameter.

1. Cell Complexity:

• Prokaryotic cells are simpler in structure, with fewer types of organelles.
• Eukaryotic cells are more complex, containing a variety of organelles such as mitochondria, the endoplasmic reticulum, and the Golgi apparatus.

1. Cell Wall:

• Many prokaryotes have a rigid cell wall composed of peptidoglycan (in bacteria) or other substances.
• Eukaryotic cells may or may not have a cell wall. If present, the cell wall is usually made of cellulose (in plants) or chitin (in fungi).

1. Ribosomes:

• Prokaryotic cells contain 70S ribosomes, which are smaller.
• Eukaryotic cells contain 80S ribosomes, which are larger.

1. DNA Structure:

• Prokaryotic DNA is typically circular and not associated with histone proteins.
• Eukaryotic DNA is linear and closely associated with histones to form chromatin and chromosomes.

1. Reproduction:

• Prokaryotes reproduce asexually through processes such as binary fission.
• Eukaryotes can reproduce both sexually and asexually, with mechanisms including mitosis and meiosis.

1. Organelles:

• Prokaryotic cells lack membrane-bound organelles.
• Eukaryotic cells have multiple membrane-bound organelles, such as mitochondria, chloroplasts (in plants), the endoplasmic reticulum, and the Golgi apparatus.

1. Cytoplasmic Division:

• Prokaryotic cells often divide by binary fission, where the cell simply splits into two.
• Eukaryotic cells divide by mitosis or meiosis, involving complex processes of chromosomal alignment and separation.

1. Genetic Recombination:

• Prokaryotic genetic recombination occurs through processes such as transformation, transduction, and conjugation.
• Eukaryotic genetic recombination primarily occurs during meiosis.

These differences reflect the evolutionary distance between prokaryotic and eukaryotic organisms, with eukaryotic cells representing a more complex and compartmentalized cellular organization.

Key differences between prokaryotic cells and eukaryotic cells are:

The cells are much smaller.

No membrane bound-organelles

Smaller ribosomes

No nucleus

A cell wall made of murein

There are many differences between these two.

Firstly Prokaryotic cells are cells that do not have any encapsulated organelles. This means it has no nucleus or mitochondria. Instead of having a nucleus, all of the genetic material are found as strands of chromosomes or loops of plasmid. An example would be bacteria.

Eukaryotic cells are cells that do have a nucleus and therefore the DNA is stored there. Examples are Animal and Plant cells.

Prokaryotic are always unicellular, while eukaryotic are usually multi-celled organisms.

Eukaryotic Cells have the following (Prokaryotic cells do not)

• A nucleus (The brain of the cell)
• Mitochondria (The power house of the cell)
• Endoplasmic reticulum (A structure that provides protein synthesis and is a transport system)
• Lysosomes (Proteins that act as the digestive system of a cell)