What is a Eukaryotic cell? (an overview)

Eukaryotic cell Definition

A eukaryotic cell contains membrane-bound organelles such as a nucleus, mitochondria, and an endoplasmic reticulum. Organisms based on the eukaryotic cell include protozoa, fungi, plants, and animals. These organisms are grouped into the biological domain of Eukaryota. Eukaryotic cells are larger and more complex than prokaryotic cells found in domains Archaea and Bacteria.

What is a Eukaryotic cell? Overview

A eukaryote is any cell or organism that possesses a clearly defined nucleus. The eukaryotic cell has a nuclear membrane that surrounds the nucleus, in which the well-defined chromosomes (bodies containing the hereditary material) are located.

Eukaryotic cells also contain organelles, including mitochondria (cellular energy exchangers), a Golgi apparatus (secretory device), and an endoplasmic reticulum (a canal-like system of membranes within the cell), and lysosomes (digestive apparatus within many cell types).

There are several exceptions to this, however; for example, the absence of mitochondria and a nucleus in red blood cells and the lack of mitochondria in the oxymonad Monocercomonoides species.

let’s understand with the real-life example. What would it be like to live in a one-room cabin? Well, things would probably be pretty simple. You would eat, sleep, work, and relax in a single room—which might be a bit cramped, but would certainly make cleaning the house a snap!

Prokaryotic cells, the simple cells of organisms like bacteria, are sometimes compared to one-room cabins: they don’t have internal membranes, so they’re like a single room with no walls to carve it up.

If we extend this analogy to eukaryotic cells, the more complex cells that makeup plants, fungi, and animals, we’ll find that they’re a definite step upward in the real estate market.

Just as a large family home is split into many rooms with different purposes (bedrooms, bathrooms, kitchen, living room, etc.), eukaryotic cells contain a variety of different compartments with specialized functions, neatly separated from one another by layers of membrane. This organization lets each compartment maintain its own conditions, the ones it needs to carry out its job.

For instance, compartments called lysosomes, which act as recycling centers for the cell, must maintain an acidic pH in order to dispose of cellular waste. Similarly, structures called peroxisomes carry out chemical reactions called oxidation reactions and produce hydrogen peroxide, both of which would damage the cell if they weren’t safely stored away in their own “room.”

The ability to maintain different environments inside a single cell allows eukaryotic cells to carry out complex metabolic reactions that prokaryotes cannot. In fact, it’s a big part of the reason why eukaryotic cells can grow to be many times larger than prokaryotic ones.

Eukaryotic Cell vs Prokaryotic Cell

The difference between a eukaryotic cell and a prokaryotic cell is simple: eukaryotic cells have membrane-bound organelles. Within a prokaryotic cell (such as a bacteria) the DNA simply floats around the cytoplasm. While prokaryotic cells do have one type of organelle (ribosomes), these organelles are not covered in a plasma membrane

By contrast, eukaryotic cells are full of membrane-bound organelles that divide the cell into many different compartments. The nucleus houses the DNA. The endoplasmic reticulum creates many chambers to carry out specific biochemical reactions.

The Golgi apparatus folds and packages various proteins and cellular products. Lysosomes store digestive enzymes to break down incoming food. Plus, eukaryotic cells contain mitochondria to create ATP molecules from glucose and chloroplasts to create glucose from sunlight (only in plants and algae).

Characteristics of Eukaryotic Cells

• The features of eukaryotic cells are as follows:
• Eukaryotic cells have the nucleus enclosed within the nuclear membrane.
• The cell has mitochondria.
• Flagella and cilia are the locomotory organs in a eukaryotic cell.
• A cell wall is the outermost layer of the eukaryotic cells.
• The cells divide by a process called mitosis.
• The eukaryotic cells contain a cytoskeletal structure.
• The nucleus contains a single, linear DNA, which carries all the genetic information.

Examples of Eukaryotic cell

All eukaryotes belong to Domain Eukaryota. Organisms belonging to this domain are animals, plants, fungi, and protists.

Animals

Animals are eukaryotes that distinct from the other groups of eukaryotes by being heterotrophic, motile, and multicellular, a body organized into cells, tissues, organs, and systems, lacking cell walls and chloroplasts, and growing from a blastula during embryonic development.

Plants

Plants are photosynthetic eukaryotes. They have chlorophyll and other pigments that help in photosynthesis. They have a cell wall comprised mainly of cellulose. It provides structural support. They are not as motile as the animals. Movements are limited but their growth is not. They are capable of unlimited growth through meristematic tissues. They lack the sense organs in animals. Nevertheless, they can sense certain stimuli and respond accordingly to tropisms.

Fungi

Similar to plants, fungi have cell walls. However, the cell walls are made up chiefly of chitin (material in the exoskeleton of insects). Fungi lack chlorophyll and therefore are heterotrophic. Many of them are multicellular, forming hyphae and mycelium. Few species are unicellular. Examples of fungi are yeasts, rusts, stinkhorns, puffballs, truffles, molds, mildews, and mushrooms.

Protists

Protists are unicellular eukaryotes. However, some species form filaments or colonies of the same species. They move around as they have locomotory organs, such as pseudopods, cilia, and flagella. Others lack these organs and therefore are non-motile. Protists include the following: (1) protozoa, the animal-like protists, (2) algae, the plant-like protists, and (3) slime molds and water molds, the fungus-like protists.

FAQs