Cell Organelles and Functions

Organelles

• Specialized structures within a cell that perform specific functions
• Examples: nucleus, mitochondria, ribosomes, lysosomes, Golgi apparatus
• Each organelle has a unique structure and function that contributes to the overall functioning of the cell

Nucleus

• Control center of the cell
• Contains most of the cell's genetic material (DNA)
• Surrounded by a double membrane called the nuclear envelope
• Has pores that allow for the exchange of materials with the cytoplasm
• Responsible for regulating cell growth, division, and reproduction

Cell Membrane

• Thin layer of lipid and protein molecules that surrounds the cell
• Semi-permeable, allowing certain substances to pass through while keeping others out
• Functions:
  • Regulates what enters and leaves the cell
  • Provides structural support and maintains cell shape
  • Acts as a barrier against external substances

Cytoskeleton

• Network of protein filaments that crisscross the cell
• Provides structural support and shape to the cell
• Involved in cell movement, division, and signaling
• Composed of three main types of filaments:
  1. Microtubules
  2. Microfilaments
  3. Intermediate filaments

Mitochondria

• Often referred to as the "powerhouses" of the cell
• Responsible for generating energy for the cell through cellular respiration
• Have two main parts: outer membrane and inner membrane
• Inner membrane is highly folded, increasing surface area for energy production

Ribosomes

• Small organelles found throughout the cytoplasm
• Responsible for protein synthesis
• Read messenger RNA (mRNA) sequences and assemble amino acids into polypeptide chains
• Can be found free in the cytoplasm or attached to the endoplasmic reticulum

Cell Transport

• Movement of molecules across the cell membrane
• Types of cell transport:
  • Passive transport:
    • Diffusion
    • Osmosis
    • Facilitated diffusion
  • Active transport:
    • Requires energy input
    • Examples: pumping ions or molecules against their concentration gradient
• Cell transport is essential for maintaining proper cellular function and responding to changes in the environment

Organelles and Cellular Components

• Organelles are specialized structures within a cell that perform specific functions, such as nucleus, mitochondria, ribosomes, lysosomes, and Golgi apparatus.

Nucleus

• The nucleus is the control center of the cell, containing most of the cell's genetic material (DNA).
• It is surrounded by a double membrane called the nuclear envelope, with pores that allow for the exchange of materials with the cytoplasm.
• The nucleus regulates cell growth, division, and reproduction.

Cell Membrane

• The cell membrane is a thin layer of lipid and protein molecules that surrounds the cell.
• It is semi-permeable, regulating what enters and leaves the cell, and provides structural support and maintains cell shape.
• It acts as a barrier against external substances.

Cytoskeleton

• The cytoskeleton is a network of protein filaments that crisscross the cell, providing structural support and shape.
• It is involved in cell movement, division, and signaling.
• The cytoskeleton is composed of three main types of filaments: microtubules, microfilaments, and intermediate filaments.

Mitochondria

• Mitochondria are often referred to as the "powerhouses" of the cell, generating energy through cellular respiration.
• They have two main parts: an outer membrane and a highly folded inner membrane, increasing surface area for energy production.

Ribosomes

• Ribosomes are small organelles found throughout the cytoplasm, responsible for protein synthesis.
• They read messenger RNA (mRNA) sequences and assemble amino acids into polypeptide chains.
• Ribosomes can be found free in the cytoplasm or attached to the endoplasmic reticulum.

Cell Transport

• Cell transport is the movement of molecules across the cell membrane, essential for maintaining proper cellular function and responding to changes in the environment.
• There are two types of cell transport:
  • Passive transport: diffusion, osmosis, and facilitated diffusion
  • Active transport: requires energy input, pumping ions or molecules against their concentration gradient.