Substrate-active Site

What is the role of the active site in an enzyme?

The active site binds to the substrate molecule, holds on to it, and lowers the activation energy for the reaction.

What is the induced fit model in enzyme function?

The enzyme changes its shape slightly to adapt to the substrate upon binding.

How does the specificity of an enzyme relate to its active site?

The overall 3D structure and the amino acid sequence of the active site are specific to the substrate, ensuring effective binding.

Enzyme activity is the catalysis of a reaction by an enzyme:

steps

1. What does the substrate(s) bind to?

The active site of the enzyme because of its structural and chemical specificity

2. What occurs when the substrates are bound to the active site?

Bonds in the substrate are weakened, causing a change into different chemical substances (products)

3. What happens to the products of the reaction once formed?

The products are released from the active site, leaving it vacant for new substrates to bind.

Where are most enzymes and their substances found?

In solutions (cytoplasm)

What is the significance of molecular movement in enzyme activity?

Molecular movement allows substrates and active sites to collide, facilitating enzyme activity.

The greater the KE of an enzyme and substrate…

The greater the chance of collisions

What moves when there are both enzymes and substrates within a solution?

Both unless the enzyme is immobilised

What are immobolised enzymes used as?

A cell-free preparations industrially in preparing lactose free milk

What are enzymes attached to?

An insoluble material or membrane with the substrate moving over it avoiding having to add enzymes to a sample

The formation of an enzyme-substrate complex overall depends on three important aspects

1. What motion?

The molecular motion to cause random collisions between molecules

Where do all metabolic reactions occur?

In aqueous solution, enabling the molecule’s continual motion

2. What affects the success of the collision?

The correct alignment and angle between substrate and enzymes

3. What is affected by molecule size?

The speed of movement

What is usually smaller substrates or enzyme?

Substrates - they are faster

What happens if the shape of the active site is changed significantly?

It becomes denatured, the enzyme-substrate specificity is compromised

What effect does temperature have on enzyme functionality?

High temperatures can cause denaturation, breaking intra-molecular bonds and compromising enzyme activity.

What is the impact of pH on enzymes?

Changes in pH can break hydrogen bonds within the enzyme, potentially denaturing it.