Cellular Organelles and Functions

Cell Membrane

• Regulates the passage of substances entering and leaving the cell.
• Composed of a phospholipid layer structure.
• Characterized by an amphiphilic (amphipathic) nature:
  • Hydrophilic region: Possesses an affinity for water.
  • Hydrophobic region: Repels water.

Cytoplasm

• Houses cellular organelles, holding them either floating or anchored in specific locations.

Cytoskeleton

• Establishes and maintains the shape of the cell.
• Repairs the cell structure whenever deformities occur.

Endoplasmic Reticulum

• Rough Endoplasmic Reticulum (RER):
  • Covered with ribosomes across its surface.
  • Participates directly in the production, regulation, and transport of proteins.
• Smooth Endoplasmic Reticulum (SER):
  • Lacks ribosomes on its surface.
  • Synthesizes lipids and forms specialized substances such as triacylglycerols.

Ribosomes

• Responsible for synthesizing and producing proteins.
• Abundance varies depending on the metabolic activity level of the cell.

Mitochondria

• Converts glucose into usable energy via cellular respiration.

Golgi Apparatus

• Receives proteins and lipids synthesized in the endoplasmic reticulum.
• Packages and transports these lipids and proteins in the form of vesicles.

Lysosomes

• Digests internal cellular substances present within the cell.
• Digests external materials and substances that enter the cell from the outside environment.

Peroxisomes

• Responsible for breaking down toxic substances and fatty acids.

Nucleus and Nucleolus

• Nucleus:
  • Contains cellular DNA.
  • Controls all activities and functions of the cell.
  • Surrounded by a membrane.
  • Houses the nucleolus within its interior.
• Nucleolus:
  • Located inside the nucleus.
  • Responsible for the production of ribosomes.

Vacuole

• Stores excess nutrients and cellular waste products until they are required or removed.