BIOL 220 Lecture Notes - Lecture 7: Organic Food, Archaea, Citric Acid Cycle
Lecture 7
BIO 220
Energetics, Catabolism and Core Metabolic Functions
How is energy stored in cells
oChemical energy
Energy stored in the arrangements of atoms interconnected by bonds which can
be released by a chemical reaction
Organic compounds have lots of stored energy
We access these bonds by breaking them
Energy Carriers
oMany of the cell’s energy transfer reactions involve energy carriers
Molecules that gain or release small amounts of energy in reversible reactions
oSome energy carriers also transfer electrons
Electron donor
Reducing agent
Electron acceptor
Oxidizing agent
ATP
oCarries energy
oAdenosine triphosphate
oAncient component of cells found in all living organisms
oUnder physiological conditions, ATP always forms a complex with MG2+
o3 different ways of transfer
Hydrolysis: releasing phosphate
Hydrolysis: releasing pyrophosphate
Phosphorylation of an organic molecule
Hydrolysis reaction
oBreaking of polymer chain by insertion of water
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
How is energy stored in cells: chemical energy. Energy stored in the arrangements of atoms interconnected by bonds which can be released by a chemical reaction. Organic compounds have lots of stored energy. We access these bonds by breaking them. Energy carriers: many of the cell"s energy transfer reactions involve energy carriers. Molecules that gain or release small amounts of energy in reversible reactions: some energy carriers also transfer electrons. Atp: carries energy, adenosine triphosphate, ancient component of cells found in all living organisms, under physiological conditions, atp always forms a complex with mg2, 3 different ways of transfer. Hydrolysis reaction: breaking of polymer chain by insertion of water. Dehydration reaction: building polymer chain by removal of water. Energetics of atp: atp is a medium sized energy carrier because the cell contains many phosphorylated molecules that yield greater energy upon hydrolysis. Oilrig: oxidation is loss, reduction is gain. Nadh: caries two or three times as much energy as atp.
