Energy level s of electrons of an Atom:
- Chemical bond: sharing of electrons
- Electrons exist in district surrounds of orbitals.
- Higher energy state- further away from the nucleus.
- Electro negativity: more electronegative tends to hold the electron closer to the atomic
nucleus. – contains less energy.
Food as Fuel
- 2 god fuels: Gasoline and glucose
- Glucose: Lots of potential energy
• Electrons in C-H bonds are equidistant from both nuclei
- ^ good for respiration , C-H bonds- contains high energy- can be easily removed
- O highly electronegative- less energy- hard to remove
- Lipids have more energy than glucose.
- Fatty acids- more potential energy than glucose – but hydrophobic
- Fatty acids used as energy for organisms.
- Reduction-Oxidation Reactions (always coupled)
- OIL RIG
- Oxidation reaction – for respiration
- Oxidation of one thing is always reduction of something else.
- Transfer electrons from donor to acceptor atoms
- Electrons lose energy as they pass from donor to acceptor molecule.
- Electrons are accompanied by one or more electrons.- usually protons accompany the
electrons - Donor become oxidized as it releases electrons
- Oxygen is very often an electron acceptor
Oxygen is being reduced.
Redox reactions can involve a change in the degree of electron “sharing”
- Metabolic process that organisms use to obtain energy by oxidizing molecules.
- Energy is released during oxidations – captured in ATP
- C6H12O6+6O2+32ADP+32Pi 6H20+6CO2+32ATP
Cellular respiration is controlled combustion:
- Energy to be extract from glucose molecule at a time.
- At body temperature most of the steps are spontaneous.
- Each one of the steps requires enzymes to catalyse the process.
- Delta G is the same- just the way to get there is different. (graph)
Electron carrier NAD+ (most common carrier)
- Nicotinamide adenine diphosphate
- NAD+ become reduced NADH (H is the hydrogen)