Search over 10,000 free study notes

Enzymes are proteins that are polymers made up of amino acid building blocks. When enzymes are made by cells, they are made as a long chain of amino acids that after some time, can fold up to form a speci...

DNA replication begins with the unzipping of the double stranded DNA by the enzyme DNA helicase, which breaks hydrogen bonds as it separates the strands. Another enzyme known as topoisomerase holds the tw...

A stimulus causes a small influx of sodium ions into the cell, leading the cell to become more depolarised or more positive. If this reaches the threshold potential, of about -55 mV, then it will initiate...

Enzymes are biological catalysts, which means that they increase the rate of a specific reaction by lowing the required activation energy.
The lock and key hypothesis explains how the substrate (key)...

Okay, so let's get back to basics. What is an enzyme? An enzyme is a biological catalyst that speeds up chemical reactions. How does it do this? All enzymes have active sites, which is where certain molec...