Cell & Molecular

Biology

Enzymeand Generally

ProteinRegulation

Chapters 3 & 4

EnzymeKinetics

Turnover Number

“...how rapidlythe substratecan be processed.”

Figure 3-26a Essential Cell Biology (© Garland Science 2010)

Figure 3-26b Essential Cell Biology (© Garland Science 2010)

Figure 3-24 Essential Cell Biology (© Garland Science 2010)

Enzymes and substratesencounter each otherthrough diffusion.

Figure 3-22 Essential Cell Biology (© Garland Science 2010)

Inhibitors

http://www.pdb.org/pdb/static.do?p=education_discussion/molecule_of_the_month/pdb45_1.html

Estrogen receptor with DNA and estradiol bound

http://www.pdb.org/pdb/static.do?p=education_discussion/molecule_of_the_month/pdb45_1.html

Tamoxifenblocksthe actionof estrogen

CompetitiveInhibition

Figure 3-28a Essential Cell Biology (© Garland Science 2010)

Figure 3-28b Essential Cell Biology (© Garland Science 2010)

h"p://cnx.org/content/m11456/latest/Trypsin

Benzamidine

NoncompetitiveInhibition

FeedbackInhibition

Figure 4-34 Essential Cell Biology (© Garland Science 2010)

NegativeRegulation

Figure 4-35 Essential Cell Biology (© Garland Science 2010)

Figure 4-36 Essential Cell Biology (© Garland Science 2010)

AllostericRegulation

ProteinPhosphorylation

The reversible additionof a phosphate groupto a protein.

Figure 4-38a Essential Cell Biology (© Garland Science 2010)

Figure 4-38b Essential Cell Biology (© Garland Science 2010)

GTP Binding

Figure 4-39 Essential Cell Biology (© Garland Science 2010)

http://www.rcsb.org/pdb/101/motm.do?momID=81

Elongation FactorEF-Tu

tRNA