Cell Structure and Functions

Cell Structure and Functions

Cell Membrane

• Semi-permeable membrane that surrounds the cell
• Composed of phospholipid bilayer with embedded proteins
• Functions:
  • Regulates movement of substances in and out of the cell
  • Maintains cell shape and structure
  • Provides barrier against external environment

Organelles

• Specialized structures within the cell that perform specific functions
• Examples:
  • Nucleus: stores genetic information
  • Mitochondria: generates energy for the cell
  • Endoplasmic Reticulum (ER): synthesizes and transports proteins
  • Ribosomes: synthesizes proteins
  • Lysosomes: breaks down and recycles cellular waste

Cell Signaling

• Process by which cells communicate with each other
• Involves reception, transduction, and response to signals
• Types of signals:
  • Hormone signaling: uses hormones to transmit signals
  • Neurotransmitter signaling: uses neurotransmitters to transmit signals
  • Direct signaling: involves direct contact between cells

Cytoskeleton

• Network of filaments that provides structural support and shape to the cell
• Composed of:
  • Microtubules: provides structural support and shapes the cell
  • Microfilaments: involved in muscle contraction and cell movement
  • Intermediate filaments: provides mechanical support and stability

Mitosis

• Process of cell division that results in two identical daughter cells
• Stages:
  1. Interphase: cell grows and prepares for division
  2. Prophase: chromatin condenses, and nuclear envelope breaks down
  3. Metaphase: chromosomes align at the center of the cell
  4. Anaphase: sister chromatids separate
  5. Telophase: nuclear envelope reforms, and chromosomes uncoil
  6. Cytokinesis: cytoplasm divides, and cell splits into two daughter cells

Cell Structure and Functions

Cell Membrane

• Acts as a semi-permeable membrane, regulating the movement of substances in and out of the cell
• Composed of a phospholipid bilayer with embedded proteins, which maintains cell shape and structure
• Provides a barrier against the external environment

Organelles

• Nucleus stores genetic information
• Mitochondria generates energy for the cell through cellular respiration
• Endoplasmic Reticulum (ER) synthesizes and transports proteins
• Ribosomes synthesize proteins
• Lysosomes break down and recycle cellular waste

Cell Signaling

• Involves reception, transduction, and response to signals
• Hormone signaling uses hormones to transmit signals
• Neurotransmitter signaling uses neurotransmitters to transmit signals
• Direct signaling involves direct contact between cells

Cytoskeleton

• Provides structural support and shape to the cell
• Composed of microtubules, microfilaments, and intermediate filaments
• Microtubules provide structural support and shape the cell
• Microfilaments are involved in muscle contraction and cell movement
• Intermediate filaments provide mechanical support and stability

Mitosis

• Results in two identical daughter cells
• Interphase: cell grows and prepares for division
• Prophase: chromatin condenses, and nuclear envelope breaks down
• Metaphase: chromosomes align at the center of the cell
• Anaphase: sister chromatids separate
• Telophase: nuclear envelope reforms, and chromosomes uncoil
• Cytokinesis: cytoplasm divides, and cell splits into two daughter cells