Exam 1 Topics: Protein Structure and Enzymes

Flashcards covering protein structure, amino acid categories, enzyme kinetics, inhibition, environmental effects, and energy graphs based on Exam 1 topics.

Hydrophilic Amino Acids

Categories of amino acids, including polar and charged types, that tend to be located on the outer surface of a folded protein to interact with water.

Hydrophobic Amino Acids

Nonpolar amino acids that are positioned within the interior core of a folded protein to stay away from water.

Levels of Protein Structure

The hierarchical arrangements (primary, secondary, tertiary, and quaternary) maintained by specific chemical interactions; disruption of these interactions leads to loss of structure and function.

Activation Energy ($E_a$)

The minimum amount of energy required to initiate a chemical reaction, which is lowered by the action of an enzyme.

Competitive Inhibition

A type of enzyme inhibition in which an inhibitor competes directly with the substrate for binding to the active site of the enzyme.

Noncompetitive Inhibition

A type of enzyme inhibition where an inhibitor binds to a site other than the active site, altering the shape of the enzyme and reducing its activity.

Feedback Inhibition

A regulatory mechanism in which the final product of a metabolic pathway inhibits an enzyme that acts earlier in the pathway.

Cofactors

Non-protein molecules or ions required by enzymes to carry out their catalytic function.

Denaturation

The process by which a protein or enzyme loses its three-dimensional structure and catalytic activity due to environmental stress, such as extreme pH or temperature.

Enzyme Activity vs. Temperature

A graph showing enzyme activity increasing with temperature up to an optimal level, followed by a steep drop in activity at high temperatures due to denaturation.

Enzyme Activity vs. pH

A graph illustrating that enzyme activity peaks at a specific optimal pH and decreases when the pH moves above or below this optimal value due to structural changes.

Enzyme Activity vs. Substrate Concentration

A graph depicting reaction rate increasing as substrate concentration rises until active site saturation occurs, after which the rate plateaus.

Enzyme Activity vs. Enzyme Concentration

A graph showing a linear increase in reaction rate with increasing enzyme concentration, provided that substrate is in excess.

Catalyzed vs. Non-Catalyzed Reaction Energy Graphs

Energy diagrams showing that an enzyme-catalyzed reaction has a lower activation energy ($E_a$) barrier compared to an uncatalyzed reaction, while the net energy change between reactants and products remains identical.