module 10

Catabolism

• the breakdown of compounds.

  • Releases energy.

  • Provide building blocks.

Anabolism

• building of compounds

  • Requires energy

  • Use up building blocks

Metabolism

• sum of all chemical reactions within a living organism

Coenzyme

• organic molecule (non-protein) might be required

•  vitamins

Cofactor

• inorganic molecule (non-protein) might be required

  • minerals

Apoenzyme

protein (main part)- may act on its own (depending on the enzyme)

Allosteric site

noncompetitive substrate inhibition; causes active site to change shape

Active Site

• Competitive substrate inhibition-where the substrate binds, and the shape of the cell is essential

Dehydrogenation

movement of a hydrogen atom and an electron

Oxidation

reduction reactions, lose an electron

Reduction

gain an electron

What is an enzyme (define it; two things)?

An enzyme is the metabolism of the cell. It is a catalyst, and most are protein.

What is the function of an enzyme?

·        Lowers activation energy (Catalyst)

·        Bind to reactant molecules

·        Ease chemical bond breaking/forming

How is an enzyme named?

·        Always ends in ase

·        Named for purpose

List and describe three ways of expression or production of enzymes?

·        Constitutive (Produced constantly/same activity)

·        Inducible (Environment causes increased production)

·        Repressible (Environment causes decreased production)

What is the mechanism of action in an enzyme?

1.      Active site (substrate bind)

2.      Form Enzyme (substrate complex)

3.      Substrate transferred to products

4.      Products released

5.      Enzyme is recycled

 

 

What factors influence enzyme activity and why?

 

1. Temperature

   1. Low temp- molecules move more slowly, the enzyme becomes rigid

   2. High temp- protein denatures or unfolds because noncovalent (and hydrogen) bonds are broken

2. pH- high (H+) or (OH-)

   1. extreme pH can cause enzymes to denature

3. substrate concentration

   1. saturation-all active sites are filled with substrate

4. inhibitors

   1. Competitive

   2. non competitive

Compare and contrast the two types of inhibitors (be specific)?

1. Competitive

   1. Binds the active site

   2. Does not undergo any reaction or change (the enzyme)

   3. Irreversible- inhibitor binds and never leaves, reversible- inhibitor binds and leaves and binds and leaves

   4. Antimicrobial agent sulfanilamide

2. Noncompetitive

   1. Binds the allosteric site- some other place on the enzyme

   2. Causes active site to change shape

   3. Can be reversible or irreversible

   4. Feedback inhibition- an end product in a series of reactions inhibits the first enzyme in the series.

Keeps the cell from wasting resources

 

What is feedback inhibition?

An end product in a series of reactions inhibits the first enzyme in the series.

Understand concepts and parts concerning a hypothetical metabolic pathway.

What is a coupled reaction?

It is two reactions happening at once.

protein levels

1. primary

2. secondary

3. tertiary

4. quaternary

denature

loss of conformation or shape

• no longer active

• caused by high temp or extreme pH

ATP