2.4 Proteins

IB Syllabus Statements

Understandings:

Amino acids are linked together by condensation to form polypeptides.
There are 20 different amino acids in polypeptides synthesized on ribosomes.
Amino acids can be linked together in any sequence giving a huge range of possible polypeptides.
The amino acid sequence of polypeptides is coded for by genes.
A protein may consist of a single polypeptide or more than one polypeptide linked together.
The amino acid sequence determines the three-dimensional conformation of a protein.
Living organisms synthesize many different proteins with a wide range of functions.
Every individual has a unique proteome.

Applications and skills:

Application: Rubisco, insulin, immunoglobulins, rhodopsin, collagen and spider silk as examples of the range of protein functions.
Application: Denaturation of proteins by heat or by deviation of pH from the optimum.
Skill: Drawing molecular diagrams to show the formation of a peptide bond.

What process links amino acids together to form polypeptides? Show this with a diagram.
How many different amino acids can be synthesized by ribosomes?
Explain why there is almost an infinite number of polypeptides that could be theoretically produced.
Explain the relationship between genes and polypeptides.
Explain the relationship between the terms protein and polypeptide.
How does the amino acid sequence determine the three-dimensional conformation of a protein?
List five different functions of proteins that can be synthesized by living organisms.
Explain the concept of a proteome.
Briefly outline the functions of the following range of proteins: rubisco, insulin, immunoglobulins, rhodopsin, collagen, spider silk
Explain the denaturation of proteins by heat.
Explain the denaturation of proteins as a result of deviation of pH from the optimum.
Draw a molecular diagram to show the formation of a peptide bond.
Explain how egg white (albumen) can be used in denaturation experiments.
Do all organisms use the exact same 20 amino acids? Explain.