What are coenzymes and what do you need to know about them at A-Level?

In this short lesson you learn some key coenzymes and how coenzymes function.

By the end of this a level biology revision lesson you'll be able to: -

1. Understand that a coenzyme is a molecule that in some way helps an enzyme.

2. Give examples of coenzymes and how they are used.

Coenzymes are nonprotein organic molecules that aid, in some way the action of the enzyme.

Coenzymes typically assist the Enzyme-Substrate interaction by means of donating or accepting particular chemical groups. One of the most important coenzymes is the e- acceptor NAD+ (nicotinamide adenine dinucleotide).

Other key coenzymes utilised during cellular respiration are Coenzyme A which plays a key role in the oxidation of pyruvate via the Krebs cycle. Coenzyme A transfers acetate between molecules during aerobic respiration… and FAD (flavin adenine dinucleotide).

NAD and FAD transfer H+ from one molecule to another and play key roles in redox reactions (since both NAD and FAD are able to give H+ (i.e. reduce molecules) and accept H+ (i.e. oxidise molecules).

In photosynthesis the coenzyme utilised is NADP+ (nicotinamide adenine dinucleotide phosphate). NADP+ is able to transfer H+ from one molecule to another NADP+ is able to give H+ (i.e. reduce molecules) and accept H+ (i.e. oxidise molecules).

See Also the Biology dictionary to learn key terms, such as, Aerobic respiration