This preview shows page 1. Sign up to view the full content.
Unformatted text preview: s, such as temperature and pH – Chemicals that speciﬁcally inﬂuence the enzyme Rate of reaction Eﬀects of Temperature and pH Optimal temperature for typical human enzyme Optimal temperature for enzyme of thermophilic (heat-tolerant) bacteria 40 60 80 Temperature (ºC) (a) Optimal temperature for two enzymes 0 20 100 • • 4 5 pH (b) Optimal pH for two enzymes 0 1 2 3 Rate of reaction Each enzyme has an opEmal temperature in which it can funcEon Each enzyme has an opEmal pH in which it can funcEon Optimal pH for pepsin (stomach enzyme) Optimal pH for trypsin
(intestinal enzyme) 6 7 8 9 10 Exergonic vs. Endergonic reac1ons • Exergonic reacEons release energy to the system. • ΔG < 0 • Exergonic reacEons proceed spontaneously • Endergonic reacEons absorb energy from the system. • ΔG > 0 • Endergonic reacEons are not spontaneous ATP powers cellular work by coupling exergonic reacEons to endergonic reacEons • A cell does three main kinds of work: – Chemical – Transport – Mechanical • To do work, cells manage energy resources by energy coupling, the use of an exergonic process to driv...
View Full Document