5 Your cells constantly produce carbon dioxide as a normal part of their activity. CO2 + H2O H2CO3H2CO3 CO2 + H2O
6 Your cells constantly produce carbon dioxide as a normal part of their activity. As it enters the blood, CO2 reacts with water to form the highly solublecompound – carbonic acid.CO2 + H2O H2CO3H2CO3 CO2 + H2O
7 Your cells constantly produce carbon dioxide as a normal part of their activity. As it enters the blood, CO2 reacts with water to form the highly solublecompound – carbonic acid.CO2 + H2O H2CO3In your lungs, this reverse reaction produces CO2 gas – released when you exhale.H2CO3 CO2 + H2O
8 Energy is released or absorbed whenever chemical bondsform or are broken.
9 Because chemical reactions involve breaking & formingbonds, they involvechanges in energy.
10 Reactions that release energy often occurspontaneously.
11 Reactions that absorbenergy will not occurwithout an energysource.
17 Humans get that energy by eating plants and/or animals, then metabolizing (breaking down) that food viachemical reactions during digestion.
18 Activation Energy: the energy needed to start a chemical reaction.
19 Activation energy is a factor in whether the reactionreleases or absorbs energy.
20 Energy absorbedWhich is which???Energy released
21 Some chemical reactions necessary for life are too slow, or have veryhigh activation energies thatmake them impractical forliving tissue.Catalysts speed up reactionsby lowering the activation energy.
22 Enzymes are proteinsthat act as biological catalysts.Enzymes speed up the reactionsthat take place in cells.
23 CO2 + H2O H2CO3 …remember this reaction? Without the enzyme carbonic anhydrase to speed it up, CO2 would build up in your bloodstream and cause severe health issues!
25 Enzymes are affected by: • pH• temperature (your enzymeswork best at 98.6⁰)Enzymes play essential roles in:• regulation of chemical pathways• making material needed by cells• releasing energy• transferring information