Cell structure and transport

• The cell membrane is selectively permeable, allowing some substances to pass through while preventing others from doing so.
• Passive transport does not require energy input and occurs by diffusion or osmosis.
• Active transport requires energy input and involves the use of ATP.
• Cell Membrane


  Controls the entry and exit of substances
• Cytoplasm


  Site of metabolic processes
• Nucleus


  Contains DNA and controls cell activities
• Mitochondria


  Produces energy (ATP) through respiration
• Ribosomes


  Synthesizes proteins
• Cell Wall


  Provides structural support
• Chloroplasts


  Site of photosynthesis
• Large Central Vacuole


  Maintains cell pressure and stores substances
• Specialized Cells


  • Red Blood Cells
  • Nerve Cells
  • Root Hair Cells
• Red Blood Cells


  • No nucleus, biconcave shape, carries oxygen
• Nerve Cells


  • Long and insulated for transmitting electrical signals
• Root Hair Cells


  • Large surface area for absorbing water and nutrients
• Light Microscope


  Uses light to view cells, good for living specimens
• Electron Microscope


  Uses electrons for higher magnification and resolution, good for detailed cell structures
• Diffusion


  Movement of particles from high to low concentration
• Diffusion


  • Gas exchange in lungs
• Osmosis


  Movement of water from high to low water concentration through a semi-permeable membrane
• Osmosis


  • Water absorption by plant roots
• Active Transport


  Movement of particles from low to high concentration using energy (ATP)
• Active Transport


  • Nutrient uptake in intestines
• Factors Affecting Transport


  • Concentration Gradient
  • Temperature
  • Surface Area
  • Distance
• Phospholipid Bilayer


  Semi-permeable barrier
• Proteins


  Aid in transport and cell recognition
• Carbohydrates


  Involved in cell recognition
• Simple Diffusion


  Movement of small molecules
• Facilitated Diffusion


  Movement via protein channels
• Active Transport


  • Sodium-potassium pump
• Endocytosis


  Cell engulfing material into vesicles
• Exocytosis


  Cell expelling material using vesicles
• Cells are the basic units of life, each with specialized structures
• Animal and plant cells have unique and shared components
• Transport mechanisms like diffusion, osmosis, and active transport are crucial for cellular function
• Microscopes help us understand cell structures at different magnifications
• What is an Organ

  Structurally and functionally distinct part of a plant or animal, e.g. heart, leaf
• What is a Tissue


  Group of similar cells that work together to perform a specific function in plants and animals, e.g. muscle tissue
• Function of the Mouth


  Starts the digestive process by breaking down food mechanically and releasing enzymes to begin chemical digestion
• What is an Organ System

  Group of organs that work together to perform a specific function in plants and animals, e.g. circulatory, digestive