ConceptConceptDocsDocuments

IB Biology SL B1.2 Proteins Question Bank

Practise IB Biology SL B1.2 proteins through amino acid structure, peptide bonds, condensation reactions, dietary requirements and structure–function links.

Syllabus
First assessment 2025
Course
Biology SL
Level
SL

Exam points

  • identify amino acid groups and peptide bonds, and distinguish condensation products from hydrolysis reactants
  • explain why some amino acids are essential in the diet and connect dietary supply to protein synthesis
  • link amino acid sequence and R-group chemistry to protein solubility, folding and biological function

Covered syllabus points

B1.2.1—Generalized amino acid structureB1.2.2—Condensation reactionsB1.2.3—Dietary amino acidsB1.2.4—Infinite variety of peptide chainsB1.2.5—Effect of pH and temperature

B1.2 Proteins question 1

[Maximum number: 1]

The diagram shows the molecular structure of the amino acid leucine.

Figure for Question B1.2 Proteins question 1 — IB Biology SL

Draw a circle on the diagram to enclose the carboxyl group.

B1.2 Proteins question 2

[Maximum number: 2]

A short base sequence of mRNA and a table of the genetic code are shown below.
Sequence of mRNA
AUGAGCCGAAGGUAGCUG
Table of the genetic code

Table for Question B1.2 Proteins question 2 — IB Biology SL

Question (a)

(a)

The diagram shows a section of a polypeptide.

Figure for Question (a) — IB Biology SL
[ 2 ]

Question (i)

(i)

Annotate the diagram to show a peptide bond between two amino acids.

[ 1 ]

Question (ii)

(ii)

State the type of reaction that removes water while linking amino acids together to form polypeptides.

[ 1 ]

B1.2 Proteins question 3

[Maximum number: 2]

Some of the twenty amino acids that are linked together to make polypeptides in human cells are essential in the diet and others are not. Distinguish between essential and non-essential amino acids.

All question bank results loaded