Cell structure and transport

• What prefixes are used to make calculations easier in the order of size?


  Gm, Mm, km, m, mm, μm, nm
• Why do we use prefixes in measurements?


  To make calculations easier to write
• How is magnification calculated?


  Magnification = image size / real size
• What are the characteristics of electron microscopes?


  • Use a beam of electrons
  • Higher levels of magnification
  • High resolution
  • Only study non-living specimens
  • Two types: SEM and TEM
  • Difficult to use
  • Images are in black and white
• What are the characteristics of light microscopes?


  • Use visible light to magnify objects
  • More accessible and affordable
  • Limited magnification abilities
  • Lower resolution
  • Can view live specimens
  • More compact
  • Easy to use
  • Cannot study subcellular structures
  • Images are in color
• What is the function of ribosomes?


  They are tiny structures where protein synthesis occurs
• What does the nucleus contain?


  Genetic material, including DNA
• What is the role of mitochondria in a cell?


  They contain enzymes for respiration and release energy
• What is the function of the cell wall in plant cells?


  It strengthens the cell and supports the plant
• What is the function of chloroplasts?


  They contain chlorophyll for photosynthesis
• What is the function of the permanent vacuole?


  It helps keep the cell turgid
• How do bacterial cells differ from eukaryotic cells?


  Bacterial cells do not have a nucleus
• What is the role of the slime capsule in bacterial cells?


  It protects them and prevents them from dying out
• What is cell differentiation?


  Cells change into different types to carry out specific functions
• What is the function of xylem cells?


  Transportation of water in plants
• What is the role of muscle cells?


  They allow movement and contain filaments for contraction
• What is the function of sperm cells?


  To carry genetic material to the female egg cell
• How do nerve cells transmit impulses?


  They have many short extensions for connections and a long fiber for distance
• What is the function of root hair cells?


  To absorb water and minerals from the soil
• What is the role of phloem cells?


  Transportation of sugar through the plant
• What does surface area to volume ratio compare?


  It compares the surface area of an object to its total volume
• What is diffusion?


  It is the net movement of particles from an area of high concentration to low concentration
• How does temperature affect diffusion?


  Diffusion happens faster at higher temperatures
• How do villi in the small intestine aid diffusion?


  They increase the surface area for diffusion
• What adaptations do lungs have for gas exchange?


  They have alveoli and a thin lining for efficient gas exchange
• How do gills adapt for efficient gas exchange?


  They have a large surface area and many blood vessels
• What is osmosis?


  The diffusion of water from high to low concentration through a partially permeable membrane
• What is active transport?


  The movement of particles from low concentration to high concentration using energy
• What energy source is used in active transport?

  Energy from respiration, specifically ATP
• Why do root hair cells have many protein carriers?


  To absorb specific mineral ions from the soil
• Why is glucose taken in by active transport?


  Because there is often more glucose in gut cells than in the gut fluid
• Why do sports drinks contain sodium ions?


  To help ensure glucose uptake in the gut
• What are the differences between diffusion, osmosis, and active transport?


  • Diffusion: Movement from high to low concentration, no energy needed
  • Osmosis: Diffusion of water through a partially permeable membrane, no energy needed
  • Active Transport: Movement from low to high concentration, requires energy
• What are the adaptations of the small intestine for diffusion?


  • Villi increase surface area
  • Folded structure increases surface area
  • Lining is 1 cell thick for short diffusion path
  • Close blood vessels maintain concentration gradient
• What are the adaptations of the lungs for gas exchange?


  • Alveoli increase surface area
  • Folded sac shape increases surface area
  • Lining is 1 cell thick for short diffusion path
  • Close blood vessels enhance gas exchange
• What are the adaptations of gills for gas exchange?


  • Large surface area from folded gill filaments
  • Many blood vessels for efficient oxygen absorption
  • Lining is 1 cell thick for short diffusion path
• What are the adaptations of roots and leaves for diffusion?


  • Short diffusion pathway (few cells thick)
  • Large surface area (thin and flat leaves)
  • Root hair cells extend into soil for water/mineral uptake
  • Stomata allow gas exchange
• What is the importance of a steep concentration gradient in diffusion?


  • It increases the rate of diffusion
  • Ensures efficient gas exchange
  • Maintains nutrient absorption
• What is the significance of the partially permeable membrane in osmosis?


  • It allows water to move while restricting solute movement
  • Facilitates the balance of concentrations on both sides
• What is the role of ATP in active transport?


  • Provides energy for the movement of particles against a concentration gradient
  • Powers the shape change of carrier proteins