Beginner Topic 987 of 1102 Biochemistry, Environment & Industry

Enzymes

Protein catalysts that speed up biochemical reactions.

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In-depth explanation of Enzymes

Enzymes are biological catalysts, most of them proteins and some functional RNA molecules, that lower the activation energy of a reaction without being consumed. They work under mild conditions of temperature and pH and show very high specificity for their substrates. By stabilising the transition state, enzymes often accelerate reactions by factors of a million or more. Their activity depends on temperature, pH, substrate concentration and cofactors, and it can be inhibited or regulated by other molecules. Most enzyme names end in the suffix -ase, which indicates their function.

Going deeper: Enzymes

Key ideas: Biological catalysts, mostly proteins, that lower activation energy without changing equilibrium or delta G. Typical rate boosts are 10 to the 6 to 10 to the 12 times. Michaelis-Menten kinetics: v equals Vmax times S over (Km plus S); Km is the substrate concentration at half Vmax, and low Km means high affinity. Optimum around 37 C and pH 7 for most human enzymes, pepsin near pH 2.

Common mistakes and connections: Students say enzymes are used up, or that they shift equilibrium; neither is true. Rate rises with temperature only until denaturation sets in. Enzyme names usually end in -ase. Links to catalysis in kinetics, inhibitors and cofactors.

Visualization of Enzymes

An enzyme-catalysed pathway has a lower overall barrier through the enzyme-substrate complex and a stabilised transition state, speeding the reaction without changing its overall energy change. The interactive lesson shows this as a live animation or chart.

Worked example and use case

Salivary amylase begins breaking down starch in the mouth as food is chewed.

Frequently asked questions about Enzymes

What is Enzymes?

Protein catalysts that speed up biochemical reactions.

Is Enzymes a beginner, intermediate or advanced topic?

Enzymes is a beginner topic in Biochemistry, Environment & Industry. It needs no earlier chemistry lessons and is a good starting point.

What should I learn before Enzymes?

Study these earlier topics in Biochemistry, Environment & Industry first: Alpha Helix and Beta Sheet, Denaturation, Essential Amino Acids.

What comes after Enzymes?

The next topics in Biochemistry, Environment & Industry are Active Site and Lock and Key vs Induced Fit.

Can I practise Enzymes with quizzes?

Yes. The interactive lesson includes a self-check question on Enzymes, and the Biochemistry, Environment & Industry quiz draws on every topic in this area.

Where Enzymes fits in Biochemistry, Environment & Industry

Enzymes is topic 12 of 127 in Biochemistry, Environment & Industry.