Ch. 3- Biological Molecules

• Carbon = 2.5
• Hydrogen = 2.1
• Nitrogen = 3
• Oxygen = 3.4
• Phosphorus = 2.1
• Sulfur = 2.5
• Organic molecules: based on carbon

  • covalent bonds
  • max number of bonds is 4
• Macromolecules (carbs, lipids, proteins, nucleic acids) contain functional group and carbon
• Isomers: two or more molecules with the same chemical formula but diff. molecular structure

  • stereoisomers: molecules are mirror images of each other
  • structural isomers: two molecules with the same chemical formula but atoms are connected in diff. ways
• Dehydration synthesis:

  • two molecules combine covalently to make larger molecule
  • removal of water from molecules
• Hydrolysis:

  • breakdown reaction
  • introduction of a water molecule
• Polymer: molecule consisting of many identical or similar subunit molecules chain linked by covalent bonds

  • each subunit is a monomer
  • polymerization: process of assembly of a polymer from monomers
  • carbs, proteins, nucleic acids
• • carboxyl group-acids: donate hydrogen ion in water
  • amino group-bases: accept hydrogen ion in water
  • phosphate groups-acids: donate hydrogen ion in water
• Monosaccharides: structural unit of carbohydrates

  • single sugar
  • carbon chain 3-6 carbon long
  • end in -ose
• Disaccharide:

  • two monosaccharides joined together
  • glycosidic bonds
• Oligosaccharides:

  • short chain of sugar 3-9 units
  • associated with protein or lipids
  • cell communication
• Oligosaccharides:

  • short chain of sugar 3-9 units
  • associated with protein or lipids
  • cell communication

  
• Lipids: hydrophobic nonpolar molecules composed of mainly hydrocarbons

  • forms membrane (structure)
  • used in cell as energy source
  • communication (messengers and recognition)
• Saturated fats: solid at room temp, have max number of hydrogen bonds possible and no double bonds
• Unsaturated fats: one or more double bonds, double bonds create kink reducing number of hydrophobic reactions, liquid at room temp

  
• Hydrogenation: adding hydrogen to something, unsaturated to saturated
• Transfats: neither liquid or solid (semi solid) margarine can't be processed by our bodies
• Proteins:

  • receptor: bind molecules at cell surface or within
  • hormonal: carry regulatory signals between cells
• Cells of all organisms use 20 different amino acids

  • 19 are structurally the same, consisting of a central carbon atom attached to an amino group, carboxyl group, and hydrogen atom
• A always = T, G always = C

  A=10%

  T=10%

  >20%

  C=40%

  G=40%

  >80%

  all equals 100%
• Two types of nucleic acids: DNA & RNA
• A nucleotide consists of 3 parts linked together by covalent bonds:

  1. nitrogenous base
  2. pyrimidines U,T,C
  3. purines A,G
  4. five-carbon, ring shaped sugar
  5. one to three phosphate groups
• tertiary structure determines function
• protein domains have function, even if they are detached, they remain their structure and function
• Every protein has to bind specifically to other molecules to perform its function
• 1859 DARWIN- 1st person to appreciate "descent with modification"
• 1866 MENDEL- established genes
• 1869 MIESCHER- 1st person to isolate nucleic acid
• 1901 KOSSEL- determined chemical composition of nitrogenous bases in nucleic acids. Described A, C, G, T, and U
• Levene describes nucleotide structure- what attached to each carbon is important in 5-carbon sugar
• Phosphodiester bonds create DNA backbone
• DNA sequences are written 5' to 3'
• DNA in prokaryotes:

  • found in nucleoid
  • chromosomal to make a bacteria
• Messenger RNA (mRNA):

  • created during transcription
  • single stranded
  • hairpin loops
  • info to make proteins
• Transfer RNA (tRNA):

  • decodes mRNA sequence into a protein
  • amino acid binding site
  • three-leaf clover structure