A.1

• Water is a solvent that:

  1. Makes up the cytoplasm in a cell (for all reactions to take place)
  2. Makes up the fluid inside the organelles
  3. Found in between cells of multicellular organisms
  4. Permits transport in and out of cells
  5. Essential for blood and many other bodily fluids
  6. Provides medium in which all organisms live
• Polar covalent bonds - unequal sharing of electrons give this polar property. The positively charged H atom attracts the negatively charged O atom, hence hydrogen bonding is present to only the elements with a high electronegative value.
• Cohesion occurs when H2O molecules of the same type are attracted to eachother (H20 - H20)
• Surface tension of water molecules is the force that prevents the water droplets from seperating. Hence why, water molecules show a relatively strong cohesive force. Animals like water striders and basilisk lizards take advantage of water's surface tension.
• Adhesion is the force of attraction between two unlike molecules due ti hydrogen bonding called adhesion.
• Water in the xylem is an active example of cohesion and adhesion. When water moves up the coloumn, cohesion is used. When water is not being moved up, adhesion keeps the entire coloumn from dropping down.
• Any solution with water -> Aqueous Solution

  Any substance that dissolves readily in water is called hydrophillic, and any substance that does not dissolve in water is called hydrophobic.
• Hydrophillic -> glucose, ions, amino acids, and proteins

  Hydrophobic -> Oestradiol, Testosterone and the hydrophobic sections of peripheral and integral proteins.
• The Black throated loon (Gavia Arctica) is a large loon that breeds in the colder environments. It relies on the buoyancy property of water to stay afloat, and has a webbed feet and streamed body shape to aid against the viscosity of water when swimming. It uses its oil glands to apply the oil produced on the feathers the loss of body heat due to thermal conductivity.
• The ringed seal (Pusa Hispada) is a buoyant organism, with less buoyancy rate than the Gavia arctica, where the force of buoynacy is exerted upwards. It has a streamed line shape and paddle like feet to help fight against the viscosity (the resistence of water to move through it). The Pusa Hispada has blubber (a form of fat), which is used to make sue that they do not lose heat to water (insulator).
• The earth's surface is mostly composed of 70% of water, in liquid state. The water on the earth's surface has a gravitational pull to retain the water near the surface.
• The two types of water, water (no neutrons) and deuterium (+1 neutron) is known as heavy water. All the bodies of water contain deuterium and the non-neutron water. This same ratio is found in many asteroids.
• For a planet to be viable for living forms of life, the planet must be in an area of the solar system that enables water to exist in liquid form - Goldilocks Zone.
• DNA and RNA are polymers of nucleotides
• Individual nuclotides consist of three major parts

  1. One phosphate group
  2. One five-carbon sugar (pentose sugar)
  3. Nitrogenous base
• Condensation reaction is when the -OH group of the pentose sugar joins with the -OH group on the phosphate group. This reaction produces water and joins the phosphate group and the pentose sugar group at an O bond. This bond is quite stable and relatively strong, and requires alot of enegry to break.
• RNA nitrogenous bases: Adenine, Uracil, Cytosine, and Guanine.
• DNA has Adenine, Thymine, Guanine and Cytosine.
• RNA - Ribonucleic acid. Joined together by condenstaion reactions by releasing a water molecule. If a molecule contains 322 nucleotides, 321 molecules of water would have been formed, meaning that 321 condensation reactions would have been formed.
• DNA - deoxyribonucleic acid

  Adenine = Thymine (double)

  Cytosine --- Guanine (triple)

  Antiparallel from C5 to C3

  C3 to C5
• DNA

  • Double stranded molecule
  • Nucleotides contain deoxyribose sugar
  • Thymine, Adenine, Guanine and Cytosine
  • Double Helix
  • Permanent genetic code
  • Has - H and OH on bottom base of C3 and C2 carbon