Mutations A gene mutation is a change in the sequence of base pairs in a DNA molecule that may result in an altered polypeptide Mutations occur continuously and spontaneously Errors in the DNA ofte...
DNA Replication Before a (parent) cell divides, it needs to copy the DNA contained within it Doubling the DNA ensures that the two new (daughter) cells produced will both receive full copies of the...
Practical: Investigating the Effect of Enzyme and Substrate Concentrations Enzyme concentration Enzyme concentration affects the rate of reaction The higher the enzyme concentration in a reaction m...
Mode of Enzyme Action Enzymes are globular proteins This means their 3D shape (as well as the shape of the active site of an enzyme) is determined by the complex tertiary structure of the protein t...
Enzymes as Catalysts Enzymes are biological catalysts ‘Biological’ because they function in living systems ‘Catalysts’ because they speed up the rate of chemical reactions without being used up or ...
Fibrous Proteins: Structure & Function Structure Fibrous proteins are long strands of polypeptide chains that have cross-linkages due to hydrogen bonds These proteins have little or no tertiary...
Globular Proteins: Structure & Function Structure Globular proteins are Compact Roughly spherical (circular) in shape Globular proteins form a spherical shape when folding into their tertiary s...
Levels of Protein Structure There are four levels of structure in proteins Three are related to a single polypeptide chain The fourth level relates to a protein that has two or more polypeptide cha...
Amino Acid: Structure Proteins Proteins are polymers (and macromolecules) made of monomers called amino acids The sequence, type and number of the amino acids within a protein determines its shape ...
