T2- cell, dna, heredity

• Cells


  Smallest functional and structural units of organisms, basic building blocks of human body
• Human cells


  • Must perform functions that include maintaining shape and integrity, taking in nutrients and converting into energy for specific tasks, disposing of wastes
• Cell components


  • Plasma membrane (cell membrane)
  • Nucleus
  • Cytoplasm, including cytosol and organelles
• Mitochondria


  'Powerhouse' of cell, digest organic molecules such as glucose to produce energy in the form of ATP
• Rough endoplasmic reticulum


  Membrane network containing ribosomes that synthesises, modifies and stores proteins
• Smooth endoplasmic reticulum


  Membrane network without ribosomes that synthesises, transports and stores lipids, metabolises carbohydrates, and detoxifies cell of drugs and poisons
• Golgi apparatus


  Comprised of sack like structures, modifies and stores proteins formed by RER, forms secretory vesicles
• Lysosomes


  Small membranous sacs that use digestive enzymes to break down molecules that enter the cell
• Peroxisome


  Membrane-enclosed sacs, smaller than lysosomes, that break down molecules and form specific types of lipids
• Nucleus


  Contains genetic material
• Plasma membrane


  Substances exit and enter cell by crossing membrane, selectively permeable
• Phospholipids


  Lipid molecules comprised of fatty acid 'tails' (repel water) and phosphate heads (attract water). Forms double layer call phospholipid bilayer allowing lipid soluble substances to easily pass through membrane
• Membrane transport


  1. Cell must obtain nutrients and dispose of wastes

  2. Achieved by transporting water and solutes across plasma membrane

  3. Passive process- not require energy- diffusion and osmosis

  4. Active process- require energy, active transport and vesicular transport
• Tonicity


  • Fluid surrounding cell has same concentration of water and solute compared to inside cell is known as isotonic solution
  • When cell immersed in isotonic solution, water will move freely into and out of cell without impacting cell's volume
  • When fluid surrounding cell has high concentration of water and lower concentration of solute than inside cell called hypotonic solution. When immersed on solution water will move into cell from surrounding solution in order to equalise concentrations. Potential of swelling and eruption
  • When fluid surrounding cell has lower concentration of water and higher concentration of solute than inside the cell known as hypertonic solution. Cell immersed in hypertonic solution, water will move out of cell and into surrounding solution in order to equalise. Cell shrink
• DNA


  Composed of two linear chains of nucleotides bound together
• DNA replication


  1. Mitosis- create a copy of itself

  2. During s-phase of mitosis, interphase, double stranded DNA will unwind and bonds between nucleotides are broken. One of the two strands of DNA will act as a template, creating a complimentary and opposing strand
• DNA transcription and translation

  In nucleus DNA -> mRNA -> in cytosol mRNA -> amino acids via ribosomes -> amino acids fold into 3D protein
• Autosomal inheritance


  How we inherit traits on our 22 pairs of chromosomes
• Punnett square


  Used to determine likelihood of offspring possessing a particular genotype and phenotype
• Sex-linked inheritance


  How we inherit traits on our 1 pair of sex chromosomes
• XY = male and XX = female
• Inheritance patterns for sex linked traits usually occur on X chromosomes