Prokaryotic vs Eukaryotic Cell Structure

Study Notes

Prokaryotic Cell Structure

Prokaryotic cells are simpler in structure than eukaryotic cells.
They lack a nucleus and membrane-bound organelles.
Their genetic material, DNA, is located in a region called the nucleoid.
Cell walls are present in most prokaryotes, providing structural support and protection.
Cell walls of bacteria are composed of peptidoglycan.
Some prokaryotes have flagella for movement.
Cell membranes are present, regulating the passage of substances into and out of the cell.
Ribosomes are present for protein synthesis.
Some prokaryotes have plasmids, small, circular DNA molecules that can replicate independently.

Eukaryotic Cell Structure

Eukaryotic cells are more complex and larger than prokaryotic cells.
They possess a membrane-bound nucleus, containing the genetic material (DNA).
Various membrane-bound organelles, such as mitochondria, endoplasmic reticulum, Golgi apparatus, and vacuoles, are present.
Each organelle has a specific function within the cell.
Mitochondria are responsible for energy production (cellular respiration).
The endoplasmic reticulum (ER) is involved in protein and lipid synthesis.
The Golgi apparatus processes and packages proteins.
Vacuoles store water, nutrients, and waste products.
Lysosomes are organelles that contain enzymes for digestion of waste materials.
Cytoskeleton provides structural support and facilitates movement of materials within the cell.
Cytoplasm is the gel-like substance filling the cell, providing a medium for cellular activities.

Microorganisms

Microorganisms are microscopic organisms; examples include bacteria, archaea, fungi, protists, and viruses.
Bacteria and archaea are prokaryotic, while fungi, protists, and some other organisms are eukaryotic.
Viruses are not considered living organisms as they lack cellular structure and cannot reproduce independently.
Bacteria display a wide range of shapes (cocci, bacilli, spirilla) and exhibit various metabolic characteristics.
Some bacteria are pathogenic, causing diseases.
Others are beneficial, playing essential roles in various ecological processes like decomposition.
Fungi are eukaryotes that obtain nutrients by absorption.
Many fungi are decomposers, playing vital roles in the environment.
Protists are diverse eukaryotic organisms, including algae and protozoa.
Some protists are photosynthetic, producing oxygen.
Others are heterotrophic, consuming other organisms.

Comparing Prokaryotic and Eukaryotic Cell Structures

The primary difference between prokaryotic and eukaryotic cells lies in the presence or absence of a nucleus and membrane-bound organelles.
Prokaryotic cells are generally smaller and simpler in structure.
Eukaryotic cells are more complex and larger, with specialized organelles carrying out specific functions.
Both types of cells have cell membranes, ribosomes, and genetic material (DNA).

Microorganism Importance

Microorganisms are essential to the environment, contributing to:
- Decomposition of dead plants and animals.
- Nitrogen fixation (converting nitrogen gas into usable forms for plants).
- Photosynthesis, producing atmospheric oxygen in various environments.
- Food production (e.g., yogurt, cheese).
- Industrial processes (e.g., fermentation).
- Human health (both beneficial and pathogenic impacts).

Description

Test your knowledge on the differences between prokaryotic and eukaryotic cell structures. This quiz covers the basic features, such as the presence of organelles, cell walls, and genetic material organization. Understand the key distinctions that define these two types of cells.