Definitions Exam #3

Question 1

Biological Membrane

Answer 1

Lipid bilayer containing protein which completely surrounds and isolates biomolecules

Question 2

Ionophores

Answer 2

A biomolecule which facilitates the movements of ions across a biological membrane

Question 3

Lipid

Answer 3

Biomolecules which are insoluble or slightly soluble in water and usually extractable by an organic (nonpolar) solvent.

Question 4

Cascade

Answer 4

A series of biochemical reactions which amplify so that the final number of products is orders of magnitude greater than the number of initiating molecules. Usually found in signal transduction pathways

Question 5

Effector Enzymes

Answer 5

An enzyme component of a signal transduction pathway which is bound to a membrane, activated by a transducer, and produces a second message.

Question 6

Receptor

Answer 6

A transmembrane protein component of a signal transduction pathway to which an external signal molecule will bind to cause a conformational change and subsequently activate a transducer molecule.

Question 7

Second Messenger

Answer 7

A molecule which is part of a signal transduction pathway and which is produced as a consequence of binding of the extracellular signal. Typically this molecule freely diffuses through the cell and is not bound to the cellular membrane.

Question 8

Signal Transduction

Answer 8

The transfer of information from one side of a membrane to another.

Question 9

Transducer

Answer 9

A protein component of a signal transduction pathway which is activated by a receptor and in turn alters the activity of an effector enzyme. It is normally associated with a membrane.