Module 3 - Providing the energy for exercise

• • 94 natural occurring elements on earth
  • 60 in our bodies, ~29 affect life & health
• Most abundant elements in body (96%): oxygen (O), carbon (C), hydrogen (H), nitrogen (N)
• 8 other makeup 3.8% of body: calcium (Ca), phosphorus (P), potassium (K), sulphur (S), sodium (Na), chloride (Cl), magnesium (Mg), iron (Fe)
• • Elements are chemically homogenous, (atoms all same)
  • Nuclei all have same # of protons
• Atomic number = protons make atoms of a specific element different from another
• Atomic mass = protons (+ charge) & neutrons (0 charge) in nucleus

  • Isotopes = different amounts of neutrons; changes mass
• Glucose = 6 carbon "organic" molecule
• Glycogen stored in muscle & liver (little bit in brain)
• Neutral = no charge - # of protons (+) & electrons (-) equal
• Electrical charge determined by protons & electrons
• Atoms can gain or lose electrons & become charged:

  • Cation (+ charged) = more protons than electrons
  • Anion (- charged) = more electrons than proteins
• Electron (e-) configuration affects ability to combine/react with other molecules

  • esp # electrons in outer shell (valence e-)
• Valence = number of electrons (e-) in outer shell
• • Unfilled outer shell = instability - will readily combine w/ other elements (eg Na)
  • Filled outer shell = more stable
• Sharing, giving &/or taking electrons binds atoms together
• NaCl = example of an ionic bond

  • Na loses 1 e-
  • Cl gains 1 e-
  • Makes a stable compound
  • Both charged, together NaCl has net charge 0
• H2O = example of covalent bonds (e- shared)

  • Shared bond instead of donating them
  • H2 as mostly bind to self as more stable, wouldn't really exist by its self
  • 8 electrons in outer shell
• Ionic bone = donate/gain electron
• Covalent bond = share 2 e- electrons
• Double bond = 4 electrons shared (instead of 2)

  • Stronger than single bond
  • More liable to be oxidised (rancidity); reaction w/ another compound
• Neutrons, Protons, Electrons form atoms
• Atoms gain/lose:

  • Neutrons to become isotopes
  • Electrons to become ions
  • Protons to become different elements; such as: C, H, O, N - main elements in biomolecules (CHO, Fats, Proteins)
• Isomers = same molecules but ordered & put together differently

  • Constitutional (structural) isomers
  • Stereoisomers (spatial) isomers = same in composition differ in orientation of those parts in space
• Stereoisomers (spacial) isomers:

  • Enantiomers = reflection/mirror images of each other
  • Diasteromers = non-mirror images, same molecular formula & sequence of bonded elements, which are nonsuperimposable
• Diastereomers:

  • Cis isomer = functional groups on same side of the carbon chain
  • Trans isomer = functional group on opposite sides
  • Very different as 1 may be good other toxic
• Small differences in structure can make subtle or big effects
• Fructose vs Glucose

  • 6 carbon molecules, slightly diff. at top
  • Metabolise both (diff. enzymes)
  • Different in functionality
• Lower pH = more acidic (H+)
• Acidity measured by H+ conc:

  • pH = -log[H+]
  • pH 7 = 1 x 10^-7 Moles H+/L
• • Acids donate protons (H+)
  • Bases accept protons (H+)
• Lactate & Lactic acid vary by 1 H+ ion

  • Can go back & forth (bw/ the 2)
• Buffer = donate or accept H+ to maintain pH
• What affects acid-base balance in body:

  • Food/diet
  • Metabolism
  • Hyperventilation (more CO2 blown off)
• • Oxidation = lose electrons (e-) - (often lost to O2)
  • Reduction = gain electrons (e-)
  • REDOX = coupled together (usually case in biological systems)
• Molecular weight = atomic weight of all atoms added up
• 1 mole (M) = 1,000 mmol
• Metabolism = sum of all chemical reactions in body
• Metabolic pathway = a series of reactions that result an end-product. 2 main functions:

  • Catabolism = breakdown of energy-yielding molecules
  • Anabolism = building energy-yielding molecules
• 1st Law of Thermodynamics = Conservation of Energy. Potential Energy into:

  • Kinetic Energy (work)
  • Thermal Energy (heat)
  • Potential Energy (biosynthesis)
• 2nd Law of Thermodynamics:

  • High to low state of potential energy
  • Free energy (can be used for work) - from reactions; chemical energy drives mechanical work of exercise