TheIB Biology | Year 1 (Junior) · Proteins · part 4/7
Tertiary & Quaternary Protein Structure
IB Biology B1.2, proteins: tertiary structure and quaternary structure (part 4 of 7, higher level). The four interactions between R-groups that hold tertiary structure, polar and non-polar amino acids in a folded protein, quaternary structure, and how the form of a protein fits its function (insulin, collagen, haemoglobin).
In this lesson
- 0:00 Intro
- 0:22 Exam question
- 0:41 Warm-up
- 1:16 Tertiary structure
- 2:06 Polar and non-polar
- 3:01 Quaternary structure
- 4:00 Form and function
- 4:57 Explain: I do it
- 5:22 Explain: we do it
- 5:43 Explain: you do it
- 6:13 What earns the mark
- 6:48 Exam question solved
- 7:34 Recap of the whole topic
Answers to the practice questions at the end of the video
- Hydrogen bonds and ionic bonds [1]; disulfide bonds and hydrophobic interactions [1].
- Similarity: both have more than one polypeptide chain and are non-conjugated [1]. Differences: insulin has two chains and is compact and globular, collagen has three chains wound into a long molecule [1]; insulin is soluble and collagen is insoluble [1].
- Ionic bonds depend on the charges of the R-groups, and pH changes those charges [1]; disulfide bonds are covalent and do not depend on charges [1].
Questions are original, in the style of the exam; marks are estimates.
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