Back to the full dot-point answer
SABiologyQuick questions
Topic 1: DNA and Proteins
Quick questions on Protein structure and function (SACE Stage 2 Biology)
4short Q&A pairs drawn directly from our worked dot-point answer. For full context and worked exam questions, read the parent dot-point page.
What is primary structure?Show answer
The primary structure is the specific sequence of amino acids in the polypeptide, determined directly by the gene. This sequence determines everything that follows.
What is secondary structure?Show answer
The secondary structure is local folding of the backbone, stabilised by hydrogen bonds, into regular patterns - the alpha helix and the beta-pleated sheet.
What is tertiary structure?Show answer
The tertiary structure is the overall 3D folding of the whole polypeptide. It is stabilised by interactions between R-groups, including hydrogen bonds, ionic bonds, hydrophobic interactions and disulfide bridges. This is the level that gives most single-chain proteins their functional shape.
What is quaternary structure?Show answer
The quaternary structure exists only in proteins made of more than one polypeptide subunit. It describes how those subunits fit together. Haemoglobin, with four polypeptide chains, is the classic example.
Have a question we have not covered?
This dot-point answer is short enough that we have not extracted many short questions yet. Read the full dot-point answer or ask Mo, our study assistant, in the chat for follow ups.