Mikrobiologi - Eukaryoters opbygning | Biotech Academy

Classification of Organisms: Eukaryotes vs. Prokaryotes

Overview of Cellular Classification

• All organisms can be categorized as either eukaryotes or prokaryotes, based on the structure of individual cells.

• The main difference is that eukaryotes have a nucleus, while prokaryotes do not possess a nucleus.

Characteristics of Eukaryotic Cells

• Eukaryotic organisms include both animal and plant cells, which are generally more complex in structure and function.

• These cells contain multiple compartments separated by membranes.

Organelles: Functional Units within Eukaryotic Cells

Introduction to Organelles

• The compartments within eukaryotic cells are called organelles, each serving specific roles.

• Membranes ensure that molecules inside an organelle do not mix with those in the rest of the cell, preventing unwanted reactions.

Key Organelles and Their Functions

Nucleus

• The nucleus contains and protects DNA, which is the genetic material of the cell; it is where DNA replication and initial protein synthesis occur.

Mitochondria

• Known as the powerhouse of the cell, mitochondria convert energy from sugars and fats into ATP (adenosine triphosphate), the energy currency of the cell.

Endoplasmic Reticulum (ER)

• The endoplasmic reticulum consists of a tubular system with rough (ribosome-covered) and smooth sections; rough ER participates in protein synthesis while smooth ER synthesizes lipids.

Golgi Apparatus

• This organelle functions as a packaging system for proteins destined to be exported from the cell; it modifies new proteins by adding sugar groups.

Lysosomes

• Lysosomes act as waste disposal units containing enzymes that break down worn-out cellular materials and foreign substances like bacteria.

Comparison Between Animal and Plant Cells

Unique Features in Plant Cells

• Plant cells differ from animal cells by having additional structures such as a cell wall that provides extra support.

• They also contain chloroplasts, which convert light energy into ATP through photosynthesis.

Vacuoles in Plant Cells

• Additionally, plant cells feature large vacuoles for storing various substances and maintaining proper fluid levels within the cell.