Topic 2

• How many bonds can carbon make


  carbon can make four covalent bonds
• Four most common compounds


  - carbon -hydrogen-nitrogen-oxygen
• what is life based on


  carbon compounds
• metabolism


  metabolism- chemical processes in the body, synthesis & breakdown of substances in living organisms. anabolism- the synthesis of complex molecules (simple to complex) (condensation reaction) catabolism- the breakdown of complex molecules into simpler macromolecules (hydrolysis)
• Importance of the artificial creation of urea


  vitalism - states that organic compounds can come from living things, so the creation on urea in a lab disproved this
• international problems with water


  Water is not readily available to all countries. And even within countries there are distribution problems
• What does polar and non polar mean?


  polar means that there is a positive and negative charge and its an equal sharing of electrons, while non-polar means that there is an unequal sharing
• what kind bonds do water molecules make with each other


  hydrogen bonds
• Hydrogen Bonds

  Hydrogen bonds are the weakest because they are positive
• Covalent Bonds


  covalent bonds are strongest because they share a pair of electrons.
• Properties of Water

  Water molecules are polar (forms hydrogen bonds), because of the pull of electrons towards oxygen.Cohesion - when water sticks to itself. Allows surface tension to occur. Adhesion- when water sticks to to other substances. The ability for water to stick to the xylem of plants allows it to be transported throughout the plant. Thermal properties- water has the highest heat capacity of all liquids and so it takes a lot of energy before it will change temperature. It also has a high boiling point because it takes a lot of energy to break hydrogen bonds. This is helpful in sweating b/c the energy provided by the body causes one to sweat - hence the cooling affect.
• Hydrophobic


  - not attracted to water- insoluble in water
• Hydrophilic


  - attracted to water- dissolves well in water- form molecular bonds with water molecules
• What are the four main macromolecules?

  -lipids-carbohydrates -nucleic acids-proteins
• Carbohydrates


  - Sugars- Made of of C, H, and O- main functions are quick energy, storage, raw/structural material- Monosaccharides, disaccharides, polyssacharides
• Monosaccharides


  - sugars that consist of a single sub-unit (monomer)- only contains carbon, hydrogen & oxygen with a ration of 1:2:1eg. glucose (C6H12O6) and fructose

  
• Disaccharides


  - a pairs of monosaccharides linked together by condensationeg. maltose ( glucose + glucose - used for food when plants break down their starch stores), lactose ( glucose + galactose - nursing and milk), sucrose ( fructose + glucose - table sugar)

  
• Polysaccharides


  - complex carbohydrates - chain of many monosaccharides- extremely soluble so a good source of quick energyeg. starch, glycogen, chitin, and cellulose
• How are sugars classified?


  the number of carbons
• Lipids


  - carbon compounds- non polar hydrophobic organic molecules Types of lipids: - triglycerides (eg. fats & oils)- phosopholipids- steroids (eg. testosterone & estrogen)
• Function of lipids

  - twice as much energy as carbohydrates but a slower release - insulation - framework for cell membrane
• Health risks for trans/saturated fat


  - Trans fats increase the "bad" cholesterol which raises the risks of coronary heat disease. - Diets that are high in trans-fat unnecessarily increase the chance that you will consume more than your body needs, because they are energy dense.
• BMI Equation

  bmi = weight of body / (height in meters ^2)
• Fatty Acids

  Types:- Saturated: All atoms in the chain are connected by single bonds- Unsaturated: chain contains one or more double bonds- Monounsaturated: only one double bond- Polyunsaturated: two or more double bonds- Cis-unsaturated: H bonded to C on the same side of the double bond- Trans-unsaturated: H bonded to C on different sides of the double bond.

  
• Polypeptides


  - chain of amino acids- the amino acid sequence of a polypeptide is coded for by a gene. The DNA sequence determines the sequence of amino acids in the polypeptide.- a protein consists of either a single or multiple polypeptides linked together.
• Denaturation


  proteins have a delicate structure that can be damaged by substances or conditions: this is called denaturation- heat causes denaturation- change in pH causes denaturation
• Function of proteins


  wide range of functionsEg:- Rubisco is an enzyme that catalyses the photosynthesis reaction- Insulin is a hormone that lowers the body's blood glucose concentration
• Enzymes

  - biological catalysts - they speed up chemical reactions and metabolism- a reactant is an enzyme catalysed reaction called a substrate-substrates bind to the active site of the enzyme and the products are released.
• Factors affecting enzymes

  1) Temperature- temperature increases enzyme activity- when temperatures are high, enzymes are denatured and stop working. 2) pH- enzyme activity decreases pH decreases from optimum.- above a certain pH, the a;lalinity denatures the enzyme 3) Substrate concentration- at low substrate concentrations enzyme activity increases steeply- at high substrate concentrations, most of the active sites are occupied.

  
• Production of lactose free milk (for lactose intolerant people)


  - lactose is the sugar in milk- it can be hydrolysed into glucose and galactose by the enzyme lactase

  
• DNA

  - nucleic acid- consist of nucleotides- nucleotide: sugar, phosphate, and nitrogenous base(bases: adenine, thymine, guanine, cytosine)

  
• Structure of DNA

  
• RNA

  - single stranded (DNA is double stranded)- thymine is replaced by uracil

  
• Proteome

  the combination of all proteins in an organism, everyone's is unique
• Amino acids


  have a central carbon atom with 4 different atoms linked to it: - R group (R) - amine group (N - Hx2)- carboxyl group (C=o, C-OH) - hydrogen atom (H)

  
• Peptide bonds


  bonds that link amino acids to form polypeptides. you take way the OH and one of te H's from the H2 of the amine group
• primary, secondary, tertiary, and quaternary


  1. order of amino acids2. reactions with amino acids near each other3. reacts with farther apart amino acids, the reaction of the R groups which them determines the quaternary structure4. arrangement of multiple proteins
• The importance of the R group


  This group determines the function of the protein and thus instructs how the it will interact with other amino acids ( which instructs how the amino acid chains are folded)
• Activation energy


  the energy it takes to begin a reaction
• Active site


  the place where the substrate binds to the enzyme; where the reaction occurs