Enzymes and Their Functions

This set of flashcards focuses on the key concepts, mechanisms, and factors relating to enzymes as discussed in the lecture notes.

What are enzymes?

Biological catalysts that increase the rate of chemical reactions without being consumed.

How do enzymes work?

Enzymes lower the activation energy of a chemical reaction providing an alternative reaction pathway.

What suffix do most enzyme names end with?

-ase.

What is activation energy (Ea)?

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

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

It is the region where the substrate binds, allowing the enzyme to catalyze a reaction.

What is the Lock and Key hypothesis?

The active site has a specific shape that is complementary to the substrate, allowing for binding to occur.

What happens during denaturation of an enzyme?

The enzyme loses its specific shape, particularly in the active site, and can no longer catalyze reactions.

What is the optimum temperature for most enzymes?

About 37-40°C.

What do hydrolases do?

Catalyze hydrolysis reactions, breaking down molecules using water.

What is a competitive inhibitor?

A molecule that competes with the substrate for the active site of an enzyme.

What is a non-competitive inhibitor?

A molecule that binds to an allosteric site, changing the enzyme's shape and preventing substrate binding.

How does temperature affect enzyme activity?

As temperature increases, enzyme activity typically increases until the optimum temperature is reached, after which it decreases due to denaturation.

What is the difference between immobilized enzymes and free enzymes?

Immobilized enzymes are fixed or bound, while free enzymes can move freely and generally show greater activity.

What happens to enzyme activity at low pH?

Lower pH can lead to denaturation, altering the enzyme's active site and reducing its activity.

What is the significance of enzyme concentration in reactions?

Increasing enzyme concentration increases the rate of reaction until all substrate molecules are bound.

What are biosensors used for?

Devices that can rapidly detect biologically significant molecules, such as glucose or urea, often involving immobilized enzymes.

What is the induced-fit hypothesis?

The substrate binding induces a conformational change in the enzyme, optimizing the fit between the enzyme and substrate.

What are the four main factors affecting enzyme activity?

Temperature, pH, substrate concentration, and enzyme concentration.

What is the effect of increasing substrate concentration on enzymatic reaction rates?

It increases the rate until a saturation point is reached where all active sites are occupied.

Name one advantage of using immobilized enzymes in industry.

They can be reused multiple times, reducing costs and contamination.

What are some examples of enzymes and their substrates?

1. Amylase breaks down starch into glucose. 2. Lipase breaks down fats into glycerol and fatty acids.

What is the primary benefit of using lactase in lactose intolerance treatment?

It breaks down lactose into glucose and galactose, making dairy products digestible for lactose-intolerant individuals.

How do competitive inhibitors affect reaction rates?

They slow the reaction rate by competing with the substrate for the active site.

What is a characteristic of non-competitive inhibition?

The inhibitor binds at a different site than the active site, reducing overall enzyme functionality regardless of substrate concentration.

What is the role of a transducer in a biosensor?

It converts biochemical signals from enzyme activity into electrical signals for measurement.

What is an example of immobilized enzyme usage in biosensors?

Immobilized urease detects urea concentrations in medical diagnostics.

What happens to enzyme-substrate complexes at high temperatures?

The enzyme may denature, preventing substrate binding and halting the reaction.

What benefits do immobilized enzymes offer regarding thermal stability?

They can operate at higher temperatures without denaturing.

What is the importance of the specific shape of an enzyme's active site?

It ensures that only specific substrates can bind and be catalyzed, maintaining enzymatic specificity.