Eukaryotic Cells Overview

Eukaryotic Cells

• Eukaryotic cells are more complex and larger than prokaryotic cells, typically ranging from 10-100 µm.
• Cells are highly compartmentalized into organelles, facilitating specialized functions.
• Major classifications include Protista, Fungi, Plantae, and Animalia, each with unique characteristics but sharing common features.

Cell Structures

• Cell structures fall into five main categories:
  • Structures for protection
  • Genetic control organelles
  • Manufacturing, storing, distributing, and breakdown organelles
  • Energy processing organelles
  • Organelles for structural support, movement, and intercellular communication

Structures for Protection

Cell Membrane

• Acts as a barrier to segregate the cell's internal environment from its external surroundings.

• Regulates the movement of molecules in and out of the cell, enabling selective permeability.

• Comprised of a phospholipid bilayer, made of two sheets of phospholipids.

• Each phospholipid has:

  • A hydrophilic polar head (phosphate group and glycerol)
  • Two hydrophobic non-polar fatty acid tails

• The arrangement results in:

  • Hydrophobic tails clustering away from the environment, forming the inner layer of the membrane.
  • Hydrophilic heads orienting towards the exterior and interior of the cell.

• Selective permeability restricts non-polar molecules like glucose from freely entering or exiting the cell.

Membrane Proteins

• Cell membranes contain randomly distributed proteins and other molecules, contributing to the membrane's fluid characteristics.
• The term "Fluid Mosaic" describes this structure, highlighting the dynamic nature of the phospholipid bilayer and the embedded proteins, as coined by researchers Nicolson and Singer.

This quiz focuses on the characteristics and structures of eukaryotic cells, which are complex and larger than prokaryotic cells. It explores the various organelles and the classification of eukaryotes into groups such as Protista, Fungi, Plantae, and Animalia. Test your knowledge on the unique features that define these advanced cellular structures.