process by which organic molecules, taken in as food, are broken down in the cells to release energy for the cell's activities
adenosine triphosphate
a molecule that stores energy in cells
how energy is stored in ATP
energy is stored in the bondbetween the end phosphate group and the rest of the molecule. this bond is more easilybroken than the bond between the other phosphate groups, allowing the energytobereleased when needed
adenosine diphosphate
the substance formed when the end phosphate group is removed from a molecule of ATP
glycolysis
the breakdown of a glucose molecule to pyruvic acid; it releases energy to form two molecules of ATP
anaerobic respiration
respiration that does not require oxygen
aerobic respiration
respiration requiring oxygen
oxygen debt
extra oxygen required, in addition to the normal resting requirement, to remove the lactic acid produced during exercise
recovery oxygen
the extra oxygen needed to 'recover' after exercise
cell activities that need energy
movement, uptake of materials from surrounding, production and secretion of new chemical compounds
cellular respiration word equation
Glucose + Oxygen → Carbondioxide + Water + up to 38ATPmolecules
heat energy
60% of available energy is released as heat which cannot be used by cells but is important for maintaining the body temperature constant as the body is constantly losing heat to the environment #physics
how ATP is formed
ATP is formed when an inorganic phosphate group is joined to ADP
lactic acid
formed through fermentation of pyruvate during anaerobic respiration. it is taken by blood to the liver where it recombines with oxygen to form glucose and eventually glycogen, a polysaccharide
steps of aerobic respiration
glycolysis
Pyruvate is converted to acetyl coenzyme A (acetyl CoA)
Acetyl CoA enters the Krebs/citric acid cycle
Electron transport system / oxidative phosphorylation
Pyruvate is converted to acetyl coenzyme A (acetyl CoA)
a carbon dioxide molecule is removed from pyruvate, the remaining two-carbon structure joins to coenzyme A, no ATP is produced
Krebs/citric acid cycle
carbon atoms are released in carbon dioxide, for every acetyl CoA that enters, one molecule of ATP is produced, therefore two ATP molecules are produced per glucose molecule
electron transport system
only stage that uses oxygen, electrons are passed between molecules, resulting in the oxygen molecules forming water. between 26-34 ATP molecules are formed