Lecture4_08 - Chapter 21 Cellular processes continually...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
4/8/2010 1 Chapter 21 Cellular processes continually produces large amounts of an enzyme and plentiful amounts of products if the processes are not regulated. Three general mechanisms exist by which enzymes within a cell can be “turned on” and “turned off.” (1) Feedback control associated with allosteric effects (2) Proteolytic enzymes and zymogens (3) Covalent modification
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
4/8/2010 2 All allosteric enzymes have quarternary structure: Composed of two or more protein chains Have at least two of binding sites: Substrate and regulator binding site Active and regulatory binding sites are distinct from each other: Located independent of each other Shapes of the sites (electronic geometry) are different Binding of molecules at the regulatory site causes changes in the overall three dimensional structure of the enzyme: Change in three dimensional structure of the enzyme leads to change in enzyme activity Some regulators increase enzyme activity activators Some regulators decrease enzyme activity - inhibitors Feedback Control: A process in which activation or inhibition of the first reaction in a reaction sequence is controlled by a product of the reaction
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

Page1 / 8

Lecture4_08 - Chapter 21 Cellular processes continually...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online