Semi final/science

• Properties used to describe gas

  • Pressure
  • Temperature
  • Volume
• For containers having the same number of gas molecules

  The container with the smaller volume will experience higher pressure than the container with a larger volume
• Relationship between volume and pressure

  • Lesser Volume, higher pressure
  • Greater Volume, lower pressure
• Describing Gas Pressure Units

  • Atm
  • torr
  • N/m^2 Pa
  • mmHg
  • si
• Number of gas particles

  More gas particles, more pressure exerted
• Gas has mass
• Air can still be pumped inside a balloon even though it is already inflated since gas is compressible
• Boyle's Law


  The volume of a gas is inversely proportional to pressure
• Water pressure increases with depth


  When one swims to greater depths, the lungs get compressed
• Air bubbles approach the surface

  They increase in size due to lower water pressure
• Deep sea fishes are brought to the surface

  They die due to a decreased pressure, resulting in the increased volume of gases in their bodies
• The volume inside of a balloon is brought to a high altitude


  The volume increases since pressure there is lesser
• Relationship between number of gas molecules and pressure

  • Lesser number of gas molecules, less pressure
  • Greater number of gas molecules, greater pressure
• The pressure of a bicycle tire decreases


  The volume of the tire increases and the tire becomes flat or less inflated
• Boyle's Law


  V1*P1 = V2*P2
• Solving for initial conditions

  1. V1 = V2*P2/P1

  2. P1 = V2*P2/V1
• Solving for final conditions

  1. V1*P1/V2 = P2

  2. V1*P1/P2 = V2
• Charles' Law


  The volume occupied by a fixed amount of gas is directly proportional to its absolute temperature, if the pressure remains constant
• Charles' Law examples


  • Balloon expands when subjected to heat
  • Hot air balloon
  • Pressure cooker
  • The volume of the dough increases as its temperature increases
• Charles' Law relationship


  V ∝ T
• Biomolecules


  • Lipids (Glycerol and Fatty acids)
  • Nucleic acid (Nucleotide)
  • Carbohydrates (Monosaccharides)
  • Protein (Amino acid)
• Biomolecules


  Also called biological molecules, any of numerous substances that are produced by cells and living organisms
• Carbohydrates


  Major source of energy of the body, these are simple sugar, starch and cellulose, structure is (CH2O)n
• Most abundant organic molecules in nature are referred to as saccharides
• Carbohydrates are soluble in water
• Classification of carbohydrates


  • Monosaccharides
  • Disaccharides
  • Polysaccharides
• Monosaccharides


  Glucose, fructose, galactose, mono means one, simplest sugar and the basic subunit of a carbohydrate, white solid at room temperature, most common are glucose (dextrose) and fructose (fruit sugar)
• Disaccharides


  Two monosaccharides that are chemically combined, examples are sweetened coffee (sucrose or table sugar) and lactose (milk sugar)
• Polysaccharides


  Containing numerous monosaccharides monomers, three common are starch, glycogen, and cellulose
• Starch


  The chief storage form of carbohydrates in plants and the most important source of carbohydrates in human nutrients
• Glycogen


  A polysaccharide similar to starch because it is also composed of alpha glucose units
• Cellulose


  Arranged in a way that hydrogen bonds link (hydroxyl) groups of adjacent glucose molecules to form insoluble fibrous sheets
• Lipids


  Water insoluble molecules (hydrophobic or water fearing) that are composed of carbon, hydrogen and oxygen, aside from carbohydrates, lipids are another class of biomolecules that have the job of storing energy for later use
• Fats and oils


  Also called triglycerides, come from the combinations of glycerol and three fatty acids
• Lipids are also found in hormones and cell membrane components
• Waxes


  Lipids that come from the combination of a long chain alcohol and a fatty acid, many plants have wax covered leaves to prevent water loss
• Steroids


  A class of lipids whose molecules are composed of fused rings of atoms, the most important steroid is cholesterol
• Steroids


  • Characterized by a four ring structure, found in the cell membrane where they influence the membrane's fluidity, can also act as hormones in the body
• Nucleic acids


  Molecules that code for hereditary traits by controlling the production of protein, there are two kinds: DNA (deoxyribonucleic acid) and RNA (ribonucleic acid)
• DNA


  Found mainly in the cell nucleus, contains the genetic information that codes for the sequence of amino acids in protein