B1: Cell Biology

• Cytoplasm: A jelly-like substance, were chemical reactions take place
• Mitochondria: where energy is released through respiration
• Ribosomes: site of protein synthesis
• Permanent vacuole: contains cell sap
• Chloroplasts: contains chlorophyll to absorb light energy for photosynthesis, only in plant cells
• Cell wall: made of cellulose, strengthen the cell, only in plant cells
• What is a Eukaryotic cell?


  A cell that has a nucleus
• Light Microscopes


  uses light to form images, living samples can be used, relatively cheap, low magnification and low resolution
• Electronic microscope


  uses a beam of electrons to from image, samples can't be living, expensive, high magnification and high resolution
• Magnification of images calculation: Magnification = Image size / Actual size
• most animal cells differentiate

  at an early stage of development
• Most plant cells differentiate through it's lifetime
• what is the function of a sperm cell?

  Function: Fertilize an ovum (egg)
• what is the function of red blood cells?

  Function: Transport oxygen around the body
• what is the function of muscle cells?

  Functions: Contracts and relaxes to allow movement
• what is the function of nerve cells?

  Functions: Carry electrical impulses around the body
• what is the function of root hair cells?

  Functions: Absorb mineral ions and water from soil
• what is the adaptations of root hair?

  long projections sped up absorption of water and mineral ions by increase surface area, lots of mitochondria to release energy for active transport
• what is the function of palisade cells?

  Photosynthesis on leafs
• what is the adaptations of palisade cells?

  lots of chloroplasts containing chlorophyll to absorb light, located on top of leaf so can absorb the most light
• What is the adaptations of Nerve cells?

  Adaptations: Branched endings (called dendrites) make connections with other neurons or effectors, myelin sheath insulates the axon to increase transmission speed of electrical impulses
• what is the adaptation of muscle cells?

  Adaptations: Contains protein fibers (which can contract to make cells shorter), contains lots of mitochondria to release energy from respiration (allowing muscle to contract)
• what is the adaptations of red blood cells?

  Adaptations: No nucleus so more room to carry oxygen, contains a hemoglobin (a red pigment) that binds to oxygen molecules, flat disc shape to increase surface area
• what is the adaptations of sperm cells?

  Adaptations: A tail to swim to the ovum and fertilize it, lots of mitochondria to release energy from respiration (enabling it to get to the ovum)
• what is Diffusion?


  The spreading out of particles, resulting in a net movement from an area of high concentration to and area of low concentration
• is energy required for diffusion?

  No
• what is Osmosis?


  the diffusion of water from a dilute (lower) solution to a concentrated (higher) solution through partially permeable membrane
• is energy required for osmosis?

  no
• examples of osmosis: water moves by osmosis from a dilute solution in the soil to a concentrated solution in the root hair cell
• what is Active Transport?

  the movement of particles from a more dilute (low) solution to a more concentrated (high) solution using energy from respiration
• is energy required for Active Transport?

  Yes
• examples of active transport: allows sugar molecules to be absorbed from the small intestine when the sugar concentration is higher in the blood
• what affects the rate of diffusion?

  difference in concentration, temperature, surface area of membrane
• Single-celled organisms have a large surface area-to-volume ratio, meaning they can transport across all the cell membranes needed

  Multicellular organisms have a small surface area-to-volume ratio,meaning they need specialized organ system and cells to allow enough molecules in and out of their cells
• Villi adaptions for exchanging substances

  network of capillaries, large surface area, thin wall, good blood supply
• aveoli adaptions for exchanging substances

  network of capillaries, provide a good blood supply, has large surface area, is moist
• Fish Grills adaptions for exchanging substance

  a large surface area, a network of capillaries
• root hair cells adaptions for exchanging substance

  lots of mitochondria, large surface area
• Cell Cycle


  series of stages for cell division
• Three main stages of cell cycle