This covers the material in Option B: Biochemistry.

CORE

SPREAD 1: Introduction to biochemistry

The diverse functions of biological molecules depend on their structures and shapes.

Metabolic reactions take place in highly controlled aqueous environments.

Reactions of breakdown are called catabolism, and reactions of synthesis are called anabolism.

Biopolymers form by condensation reactions and are broken down by hydrolysis reactions.

Photosynthesis is the synthesis of energy-rich molecules from carbon dioxide and water using light energy.

Respiration is a complex set of metabolic processes providing energy for cells.

What is biochemistry?

It's the branch of science concerned with the chemical and physico-chemical processes and substances that occur within living organisms, in other words, the chemistry of the body.

This mainly involves organic reactions, but there are inorganic aspects to some reactions. Given that molecules involved in biological function are inevitably organic and organic molecules have functional groups at specific locations on the chain, it is no surprise that a lot of the functions of these biological molecules depend on their structure and their shape. The intermolecular forces, in particular hydrogen bonds, are also of great importance.

The other significant factor to understand is that the solvent in which the reactions are carried out is also crucial. It's water of course, water that is under a very tight set of conditions. Water is a solvent, a reagent, a coolant, a temperature control and a transport medium.

A few significant terms:

Metabolism— these are the name given to the set of chemical reactions that happen in cells that are crucial for sustaining reactions. They are also known as metabolic reactions.

These metabolic reactions can be further broken down into:

Catabolism: reactions where organic matter is broken down to use for in respiration and other energy-based needs.

Anabolism: reactions where new molecules are made from the energy provided by catabolic reactions, such as proteins or nucleic acids.

Biopolymers— these are, as the name suggests, polymers found in organisms: there are three sorts— polysaccharides, poly peptides (proteins) and polynucleotides (DNA, RNA). As with all condensation polymers they can be broken down by hydrolysis reactions (reaction with water) and can be created by the elimination of a small molecule from between the polymers: more later.

Photosynthesis— the synthesis of energy-rich molecules (like sugars) from carbon dioxide and water using light energy.