Cell Membrane and Mitosis

Cell Membrane

• Also known as the plasma membrane
• Thin, semi-permeable layer of lipid and protein molecules surrounding the cell
• Functions:
  • Separates cell from external environment
  • Regulates movement of substances in and out of the cell
  • Maintains cell shape
  • Provides mechanical support
• Composed of:
  • Phospholipid bilayer (hydrophilic heads and hydrophobic tails)
  • Proteins ( integral, peripheral, and lipid-anchored)

Mitosis

• Type of cell division that results in two daughter cells with identical genetic material
• Occurs in somatic cells (non-reproductive cells)
• Stages:
  1. Interphase: cell grows, replicates DNA, and prepares for cell division
  2. Prophase: chromatin condenses, nuclear envelope breaks down, and spindle fibers form
  3. Metaphase: chromosomes align at the center of the cell
  4. Anaphase: sister chromatids separate and move to opposite poles
  5. Telophase: nuclear envelope reforms, and chromosomes uncoil
  6. Cytokinesis: cytoplasm divides, and cell splits into two daughter cells

Cell Division

• Process by which a cell becomes two daughter cells
• Types:
  • Mitosis: somatic cell division (results in two identical daughter cells)
  • Meiosis: reproductive cell division (results in four haploid daughter cells with unique genetic material)
  • Binary fission: cell division in prokaryotes (simple, single-celled organisms)
• Importance:
  • Essential for growth, development, and repair
  • Allows for adaptation to changing environments
  • Enables reproduction and transmission of genetic information

Cell Organelles

• Specialized structures within a cell that perform specific functions
• Examples:
  • Nucleus: contains genetic material (DNA)
  • Mitochondria: generates energy for the cell through cellular respiration
  • Endoplasmic reticulum (ER): involved in protein synthesis, transport, and storage
  • Ribosomes: site of protein synthesis
  • Lysosomes: contain digestive enzymes for breaking down and recycling cellular waste
  • Golgi apparatus: involved in protein modification, sorting, and secretion
  • Cytoskeleton: provides structural support, shape, and movement

Cell Membrane

• Acts as a barrier between the cell and its external environment
• Regulates the movement of molecules in and out of the cell
• Maintains cell shape and provides mechanical support
• Composed of a phospholipid bilayer with hydrophilic heads and hydrophobic tails
• Embedded with proteins such as integral, peripheral, and lipid-anchored proteins

Mitosis

• A type of cell division that results in two identical daughter cells
• Occurs in somatic cells (non-reproductive cells)
• Consists of interphase, prophase, metaphase, anaphase, telophase, and cytokinesis stages
• Chromatin condenses, and nuclear envelope breaks down during prophase
• Chromosomes align at the center of the cell during metaphase
• Sister chromatids separate and move to opposite poles during anaphase

Cell Division

• The process by which a cell becomes two daughter cells
• Types of cell division: mitosis, meiosis, and binary fission
• Mitosis occurs in somatic cells, resulting in two identical daughter cells
• Meiosis occurs in reproductive cells, resulting in four haploid daughter cells
• Binary fission occurs in prokaryotes (simple, single-celled organisms)
• Essential for growth, development, repair, and adaptation to changing environments

Cell Organelles

• Specialized structures within a cell that perform specific functions
• Nucleus contains genetic material (DNA)
• Mitochondria generates energy for the cell through cellular respiration
• Endoplasmic reticulum (ER) is involved in protein synthesis, transport, and storage
• Ribosomes are the site of protein synthesis
• Lysosomes contain digestive enzymes for breaking down and recycling cellular waste
• Golgi apparatus is involved in protein modification, sorting, and secretion
• Cytoskeleton provides structural support, shape, and movement