biomolecules

• what are proteins?


  Proteins: 3D folding of a polypeptide + made from more than 50 amino acids

  
  

  C, H, O, N, sometimes S

  • Synthesised from monomers (amino acids)
  • Important functions:
  • Enzymes: catalyse specific biochem reactions
  • Hormones: control biological processes
  • Structural components: muscles, cell membrane
  • Transport: haemoglobin transports oxygen to cells
  • Antibodies: critical component of immune system
• what is the reaction that proteins are made from?

  Condensation: 2 small molecules combine to produce larger molecule + small molecule that is usually water is eliminated

  • Condensation polymerisation → monomers need 2 kinds of reactive FG with one at each end of molecule
  • Homopolymer: 2 identical FG 
  • Heteropolymer: 2 diff groups → most biopolymers
  • H2O is by-product
  • made up of amino acids (20)

  general formula: H2NCH(R)-COOH

  • Known as 2-amino acids: amino FG bonded to C2 as C1 is carboxyl FG
• what is the bond that is formed b/w amino acids?

  peptide bond

  • Condensation reactions occur b/w carboxyl group + amino group → amide FG forms (-C=ONH-)
• dipeptide vs polypeptide

  Dipeptide: formed when 2 amino acids react tgth

  Polypeptide: many amino acids forming a polymer
• Properties of R groups

  • Side chain: makes major diff b/w amino acids
  • Can be:
  • Non-polar: only has C and H (-CH3)
  • Polar: -OH exposed group (-CH2OH)
  • Acidic or proton donors: -CH2COOH → also polar
  • Basic or proton acceptors: -CH2CH2CH2CH2NH2 → also polar
• how do you name polypeptides

  Free amino group on left + free carboxyl group on right (name this way)
• what are carbohydrates?


  C,H,O

  general formula: Cx(H2O)y (x & y = whole no. )

  • E.g. cellulose (trees, plants), starch (bread, cake), glucose (C6H12O6)
• photosynthesis

  endothermic: sunlight → chem potential energy in glucose

  
• what are monosaccharides

  Highly soluble in water bc of hydroxyl groups (-OH)

  
  

  Most common: fructose, glucose, galactose

  same molecular formula= isomers → Slight variation in structure lead to sig differences in function in living organisms

  Glucose: found in all living things bc key energy source

  Fructose: fruit juices + honey → energy source used in similar manner to glucose

  Galactose: found in lactose (dissacharide → in dairy)

  
• what are disaccharides

  formed from condensation b/w 2 monosaccharides → Condensation reaction b/w hydroxyl FG on neighbouring molecules

  Water produced as by-product of reaction

  2 monosaccharides joined by oxygen atom

  
• what is the connection b/w 2 monosaccharides called

  ether link
• what is the connection b/w 2 carbohydrates called

  glycosidic link
• what are polysaccharides

  Polysaccharides: reaction of disaccharides w other monosaccharides continue to produce polymer (can contain thousands of glucose units)

  • Generally insoluble in water + no taste
  • E.g. glycogen, cellulose, starch
• what is starch and the 2 types?

  Starch: condensation reaction b/w glucose molecules (glycosidic links) → water are by-products

  Water molecules= No. glucose- 1

  plants produce + polymerise glucose → form starch

  Plants use starch for storage of energy→ when needed break down into glucose to maintain functions

  E.g. potato = high starch

  
  

  amylose + amylopectin
• what is amylose

  Linear polymer of starch = AMYLOSE

  Long molecules coil into helices + pack tgth

  • Many -OH groups are inside helices + away from contact w water (cant for H-bonds)
• what is amylopectin


  Branched structure of starch = AMYLOPECTIN → form if some of a-glucose molecules undergo condensation reactions b/w -OH groups at diff positions

  Branches typically occur after 20-24 glucose units

  Branching of molecules restricts coiling of polymer → leaves more -OH groups exposed= SOLUBLE/dissolves in water
• what is glycogen

  Polymer of a-glucose that's highly branches in very similar manner to amylopectin (branched starch)

  branching occurs every 7-11 monomer

  
  

  animals use glycogen for energy storage: made from excess glucose + stored in water or muscle tissue

  If energy needed → glycogen breaks down to glucose → can then be used in cellular respiration
• what is cellular respiration

  exothermic → energy of products is lower than energy of reactants

  
• what are lipids (fats + oils)


  C,H,O

  
  

  Found in meat, fish, dairy products, eggs, friend foods, vege oil, canola (unsaturated-margarine)

  
  

  Major energy source: used to store chem energy
• what are triglycerides

  Triglycerides : fats/ oils made up of large, non-polar molecules: triglycerides

  Fats + oils hv similar chem structures - only separated based on physical state at room temp → fats = solids, oils = liquid

  non-polar molecule

  
  

  Triglycerides cant dissolve in water (no H- bonds) → fats = insoluble, oils = immiscible (both liquids but cant mix)

  
  

  Made by condensation reactions b/w glycerol + 3 fatty acids
• what reaction occurs to make triglycerides

  Condensation reaction occurs b/w carboxyl group (-COOH) of each fatty acid + hydroxyl groups (-OH) of the glycerol molecule

  ester FG (-COO) is formed → links the 2 molecules tgth (3 formed) - Each time fatty acid links to glycerol, water molecule eliminated (total=3)

  
  

  Fatty acids hv a carboxyl FG

  Tail makes up bulk of the molecule + can be saturated

  or unsaturated

  Most fatty acids hv even no. of Cs: 8-20

  
• unsaturated vs saturated fatty acids

  ester FG (-COO) is formed → links the 2 molecules tgth (3 formed)

  
  

  Each time fatty acid links to glycerol, water molecule eliminated (total=3)
• equation for fermentation

  renewably produce ethanol

  renewable: produced same rate or faster than consumed

  sustainable: meet energy demands now + future

  
  

  made from feedstock → sugar cane, wheat, forest waste → lots of carbohydrates