BIO 206 QUIZ

Metabolism

All chemical reactions happening within the cell , keep cells working repair tissues, maintains body temp, and fuels movement.

What are the 2 types of Metabolism

Catabolism and Anabolism.

Catabolism

Breaks things down, releases energy (like breaking up Lego’s)

Anabolism

Builds things up, consumes energy (like building a Lego set)

Second law of Thermodynamics

The universe always tends towards increasing disorder or in other words the universe is always becoming more chaotic/messy

Gibbs Free Energy (△G)

measure how far away from equilibrium a reaction or system is.

What do all chemical reactions tend to do?

proceed toward equilibrium

Gibbs Free Energy Equation

△G = △H - T (△S)

Enthalpy

△H, measures heat exchange. Negative △H is exothermic positive △H is endothermic.

Entropy

△ S, measures molecular randomness or disorder. Nature likes mess so positive disorder increases and

Negative disorder decreases.

Temperature (T)

Temperature is always in Kelvin ( J+273.15)

Spontaneity

When a reaction happens naturally without constantly forcing it

Non-spontaneous reaction

△G is positive ad needs constant push of energy to happen.

Spontaneous Reaction

△G is negative and can go whenever

Endergonic Reaction

A reaction that requires a net input of free energy resulting in a positive △G , non-spontaneous

Exergonic Reaction

A reaction that releases free energy into the surrounding, resulting in a negative △G , spontaneous

Why is this a Endergonic reaction?

Product used up a bunch of energy

Why is this a Exergonic reaction?

Products releases energy

Activation Energy (Ea)

The minimum amount of energy required for a chemical reaction to start.

“All reactions have an Activation Energy”

True

What is the relationship between Activation Energy and Reaction Rate?

Inverse relationship ( One variable increases while the other decreases at a corresponding rate)

The higher the activation energy, the ________ the reaction rate. It ____ catalyst and needs ____ energy.

Blank 1 : slower

Blank 2: Does not have

Blank 3: more

The lower the activation energy, the ________ the reaction rate. It ____ catalyst and needs ____ energy.

Blank 1 : Faster

Blank 2: has

Blank 3: less

Active Site

A specialized pocket or groove on an enzyme where reactant molecule bind and undergo a chemical reaction.

Substrate

The specific reactant molecule that binds to the enzyme active site.

What can we think of Active Site and Substrate as to remember?

Active Site is the lock and Substrate is the key.

What is an Active Site formed by?

By specific amino acids folded into a 3D shape.

What does an Active Site do to attract a substrate?

They attract compatible molecules based on their properties (eg. Negative active site + Positive substrate). It creates a 3D environment that physically matches the size and shape of the target substrate kind of like a puzzle.

What things allow substrate with matching properties to bind stably to Active Site.

Opposite charges, hydrogen bonds, and hydrophobic or hydrophilic interactions

Induced Fit

The active site changes shape through induced fit to better bind the substrate and stabilize the transition state.

What happens if a "wrong" (non-complementary) substrate binds to an enzyme?

It cannot trigger induced fit (the enzyme won't change shape to tightly bind it). The molecule will eventually fall off without reacting.

Competitive Inhibition (Binding site)

The inhibitor binds directly to the active site, competing face-to-face with the substrate.

Competitive Inhibition (structure

Mimics the exact size and shape of the real substrate, fighting over the exact same "parking spot."

Competitive Inhibition (How to Overcome)

A high concentration (large number) of the substrate can outcompete the inhibitor.

What happens if the substrate binds to the active site first?

The inhibitor is locked out of the enzyme.

What happens if the inhibitor binds to the active site first?

The substrate is locked out of the enzyme.

How do you overcome the Competitive Inhibitor?

By flooding the system with substrate so that the substrate molecules vastly outnumber the inhibitor.

What is Competitive inhibition to the cells?

Just a temporary block to keep your cells from overproducing resources, its Binds to an enzyme and leaves it temporarily inactive. It also forms a covalent bond with enzymes.

Kinetic impact of Competitive Inhibition

Vmax (Maximum Velocity) stays the same while Km (Michaelis Constant) increases.

Noncompetitive Inhibition (Binding site)

The inhibitor binds to an allosteric site (a separate location from the active site).

Noncompetitive Inhibition (Structure)

It does not need to resemble the substrate.

Noncompetitive Inhibition (How to overcome)

Adding more substrate cannot overcome or reverse the inhibition.

Is Noncompetitive Inhibition reversible or irreversible?

Reversible

Is Competitive Inhibition reversible or irreversible?

irreversible

What type of chemical bond makes noncompetitive inhibition reversible, and how does the enzyme recover when the inhibitor leaves?

When it detaches, the enzyme undergoes a reverse conformational change, snapping back into its native, active state.

What is Noncompetitive inhibition to the cells?

A master breaker switch as it allows the cell to completely shut down a pathway regardless of how much substrate it accumulates.

What is A?

Transition State

What is B?

Reactants

What is C?

Activation Energy

What is D?

Free energy

What is E?

Products