Fundamentals of Biochemistry - Module Introduction and Enzyme Concepts

Vocabulary and key concepts from the BI1FB2 Fundamentals of Biochemistry module, covering enzyme structure, metabolism, biochemical techniques, and molecular calculations.

Enzyme

A protein that acts as a catalyst, allowing biological reactions to happen and facilitating the conversion of substrate to product.

Metabolism

Derived from the Greek word "metaballein" meaning "to change"; it refers to all chemical reactions in cells required to sustain life, centered around energy (ATP).

Catabolism

The metabolic process involving the breaking down of molecules to store energy.

Anabolism

The metabolic process involving the building of molecules and driving biological processes using energy.

Protein-encoding Genes

As of 2021, the human genome is estimated to have $21,306$ genes of this type, with approximately $2,742$ (\text{~}13\text{%}) encoding enzymes.

Intramolecular Bonds

Forces that maintain protein structure, including Van der Waal's forces, hydrophobic interactions, electrostatic bonds (ionic), and hydrogen bonds.

Apoenzyme

The protein portion of an enzyme that requires a cofactor but is not yet bound to one.

Holoenzyme

The complete, catalytically active enzyme formed by the combination of an apoenzyme and a cofactor ($\text{Apoenzyme} + \text{Cofactor} = \text{Holoenzyme}$).

Coenzymes

A type of organic cofactor often derived from vitamins, such as Nicotinamide adenine dinucleotide (NAD) and Nicotinamide adenine dinucleotide phosphate (NADP).

Spectrophotometry

A technique used to measure how much light a solution absorbs; the absorption is proportional to the concentration of the molecules.

Beer-Lambert Law

A principle defined by the equation $A = \text{ε}cL$, where $A$ is absorbance, $\text{ε}$ is the molar absorption coefficient, $c$ is molar concentration, and $L$ is the light path (usually $1\text{ }cm$).

Mole

A universal quantity representing the weight of a substance in grams divided by its molecular weight; every mole of a substance contains the same number of molecules.

Molarity (M)

A measure of concentration expressed as the number of moles of a substance per litre of solution ($mol/L$).

ELISA

Stands for Enzyme-Linked ImmunoSorbant Assay; a technique used to detect specific proteins in a sample using an antibody conjugated to an enzyme.

Active Site

A cleft or crevice in a protein structure where substrates bind and undergo chemical transformation; it is characterized by a specific 3D shape and multiple weak interactions.

Lock and Key Model

An early model of enzyme-substrate interaction (1890s) proposing that specific binding depends on a precise, rigid arrangement of atoms.

Induced Fit Model

A dynamic model of enzyme-substrate interaction (1958) suggesting that binding causes changes in the enzyme's structure to facilitate the reaction.

Aspirin

A drug that targets cyclooxygenases (COX-1 and COX-2) to inhibit prostaglandin synthesis; it is also used as antiplatelet therapy.

SDS-PAGE

A biochemical technique used for protein analysis and separation, often followed by western blotting.

Carbonic Anhydrase

An enzyme that speeds up the reaction $CO_2 + H_2O \rightleftharpoons H_2CO_3$ by $10^7$ times, processing $10^5$ molecules per second; it requires a $Zn^{2+}$ cofactor.