A. Content Objective: Proteins are composed of 20 different amino acids occurring in different combinations based on the genes associated with the protein. This order also determines the structure of the protein which then determines the function.
B. Language Objective: Explain how the levels of protein structure result in a specific shape and function of a protein using named examples.
C. Syllabus Details:
Key Idea 1: Amino acids are linked together by condensation reactions to form polypeptides. There are 20 different amino acids and the sequence of amino acids allows for a huge range of proteins. The structure and function of amino acids is determined by the genes.
Key Idea 1 Syllabus statements:
i. Amino Acids are linked together by condensation to form polypeptides
ii. There are 20 different amino acids in polypeptides synthesized on ribosomes
iii. Amino Acids can be linked together in any sequence giving a huge range of possible polypeptides
iv. The amino acid sequence of polypeptides is coded for by genes
viii. Rubisco, insulin, immunoglobulins, rhodopsin, collagen and spider silk as examples of the range of protein functions
Key Idea 2: The order of amino acids determines the three-dimensional shape of the protein. The shape of the protein determines the structure. Protein structure has four levels. The primary structure is the order of amino acids, the secondary structure is the formation of helixes and sheets of amino acids that are held together by hydrogen bonding. The tertiary structure is the 3D shape held together by interactions between the R-groups. The tertiary structure is the combination of two or more polypeptide chains.
Key Idea 2 Syllabus statements:
v. A protein may consist of a single polypeptide or more than one polypeptide linked together
vi. The amino acid sequence determines the three-dimensional conformation of a protein
vii. Living organisms synthesize many different proteins with a wide range of functions
ix. The sequence and number of amino acids in the polypeptide is the primary structure.
x. The secondary structure is the formation of alpha helices and beta pleated sheets stabilized by hydrogen bonding.
xi. The tertiary structure is the further folding of the polypeptide stabilized by interactions between R groups.
xii. The quaternary structure exists in proteins with more than one polypeptide chain.
D. Pre-lesson work: A set of notes on proteins.
Video
Protein Overview - i-viii
Protein Structure - i-iii, v-vii, x-xii
Reading
Protein Structure - Start at 7.3.U7 - Skip translation and transcription
Proteins Links - A one-sentence summary is enough
Book Reference: 74-79
Activity 1 - Pre-lesson work: A set of notes on proteins.
Video
Protein Overview - i-viii
Protein Structure - i-iii, v-vii, x-xii
Reading
IB Biology Help - My new favorite website - i-viii
IB Biology Help - HL - Check 7.9 and above
Protein Structure - Start at 7.3.U7 - Skip translation and transcription
Proteins Links - A one-sentence summary is enough
Book Reference: 74-79
Activity 2 - Protein Notes - Video Explanation of notes
Activity 3 - Protein Structure Models
Key words: primary structure, secondary structure, tertiary structure, quaternary structure, polypeptide chain, alpha-helices, beta-sheets, order of amino acids, hydrophobic, hydrophilic, hydrogen bonding
Online Version - Foldit Game
Activity 4 - Spider Silk -
Activity 5 - Protein Functions
A. Strengthen Your Skills
Protein Structure - Start at 7.3.U7
Protein Notes
B. Expand Your Knowledge
Foldit - A protein game