Cell Structure and Function

Cell Structure

• A cell is the basic structural and functional unit of life.
• It is a microscopic, self-contained unit that carries out all the functions necessary for life.
• Cells are the building blocks of life and are found in all living organisms.

Cell Membrane

• Also known as the plasma membrane, it is a thin, semi-permeable membrane that surrounds the cell.
• Functions:
  • Controls what enters and leaves the cell
  • Protects the cell from its environment
  • Maintains cell shape
  • Regulates cell growth and division
• Composed of:
  • Phospholipid bilayer (double layer of lipids)
  • Proteins (embedded in the phospholipid bilayer)

Cell Organelles

• Organelles are specialized structures within a cell that perform specific functions.
• Types of organelles:
  1. Nucleus: contains genetic material (DNA)
  2. Mitochondria: generates energy for the cell (ATP production)
  3. Endoplasmic Reticulum (ER): involved in protein synthesis and transport
  4. Ribosomes: site of protein synthesis
  5. Lysosomes: contain digestive enzymes that break down waste and foreign substances
  6. Golgi Apparatus: involved in protein modification and transport

Cell Transport

• Movement of materials in and out of the cell.
• Types of cell transport:
  1. Passive Transport: movement of molecules from high to low concentration without energy expenditure
     • Diffusion: random movement of molecules from high to low concentration
     • Osmosis: movement of water molecules from high to low concentration
  2. Active Transport: movement of molecules from low to high concentration with energy expenditure

Cell Division

• Process by which a cell divides into two daughter cells.
• Types of cell division:
  1. Mitosis: division of somatic cells (non-reproductive cells)
     • Results in two genetically identical daughter cells
  2. Meiosis: division of gametes (reproductive cells)
     • Results in four genetically unique daughter cells
• Phases of cell division:
  1. Interphase: cell grows, replicates DNA, and prepares for cell division
  2. Prophase: chromatin condenses, nuclear envelope breaks down
  3. Metaphase: chromosomes line up at the center of the cell
  4. Anaphase: sister chromatids separate and move to opposite poles
  5. Telophase: nuclear envelope reforms, chromatin uncoils
  6. Cytokinesis: cytoplasm divides, and the cell splits into two daughter cells

Cell Structure

• Cells are the basic structural and functional units of life, carrying out all the functions necessary for life
• They are microscopic, self-contained units found in all living organisms

Cell Membrane

• The cell membrane, also known as the plasma membrane, is a thin, semi-permeable membrane that surrounds the cell
• It controls what enters and leaves the cell, protects the cell from its environment, maintains cell shape, and regulates cell growth and division
• The cell membrane is composed of a phospholipid bilayer and proteins embedded in the phospholipid bilayer

Cell Organelles

• Organelles are specialized structures within a cell that perform specific functions
• The nucleus contains genetic material (DNA)
• Mitochondria generate energy for the cell through ATP production
• The endoplasmic reticulum (ER) is involved in protein synthesis and transport
• Ribosomes are the site of protein synthesis
• Lysosomes contain digestive enzymes that break down waste and foreign substances
• The Golgi apparatus is involved in protein modification and transport

Cell Transport

• Cell transport refers to the movement of materials in and out of the cell
• Passive transport is the movement of molecules from high to low concentration without energy expenditure
• Diffusion is the random movement of molecules from high to low concentration
• Osmosis is the movement of water molecules from high to low concentration
• Active transport is the movement of molecules from low to high concentration with energy expenditure

Cell Division

• Cell division is the process by which a cell divides into two daughter cells
• Mitosis is the division of somatic cells (non-reproductive cells), resulting in two genetically identical daughter cells
• Meiosis is the division of gametes (reproductive cells), resulting in four genetically unique daughter cells
• Interphase is the stage of cell division where the cell grows, replicates DNA, and prepares for cell division
• Prophase is the stage where chromatin condenses, and the nuclear envelope breaks down
• Metaphase is the stage where chromosomes line up at the center of the cell
• Anaphase is the stage where sister chromatids separate and move to opposite poles
• Telophase is the stage where the nuclear envelope reforms, and chromatin uncoils
• Cytokinesis is the stage where the cytoplasm divides, and the cell splits into two daughter cells

This quiz covers the basic structure and functions of cells, including the cell membrane and its roles.