Biological Molecules (OCR A Level Biology)

Which of the following reactions, A to D, describes the conversion of a polymer to a monomer?

Collagen is found in tendons. Tendons attach muscles to bones.

Which of the following lists of properties, A to D, makes collagen suitable for this role?

The following are a series of organic molecules and the chemical processes that occur to convert them into different molecules.

Which of the rows, A to D, is correct?

The following table describes the approximate percentage mass of different chemical elements in organic polymers. 

Which of the rows, A to D, is correct?

Which of the following processes involves the formation of ester bonds?

1   synthesis of polynucleotides
2   synthesis of triglycerides
3   synthesis of polypeptides

Which of the following could not be an amino acid?

Lipids are a diverse group of chemicals that are neither polar nor charged and hence are insoluble in water. The ___(1)___ nature of the heads of phospholipids allows them to form membranes. ___(2)___ also contain fatty acids and form part of the membrane. Lipids can be used for energy storage in the form of ___(3)___. Some hormones are also lipids and they are similar in structure to ___(4)___.

Which row shows the correct sequence of missing words?

Which of the statements, A to D, correctly describes the process of adhesion?

Which of the statements, A to D, about amylopectin is correct?

An unknown solution of a single sugar was tested. The results were recorded in Table 9.1.

Table 9.1

Identify the unknown sugar.

Some of the properties of water make it a vital component of certain organelles such as the matrix in mitochondria. 

Which of the following statements does not describe a useful property of water in the mitochondria?

Fibroin, the protein found in silk, mainly consists of amino acids in anti-parallel beta-sheets.

Which of the following statements explains why haemoglobin has a more complex structure than fibroin?

Chitin is a structural polysaccharide that is found in the cell walls of fungi. The chemical structure of chitin is shown below, it shares some similarities with the structure of cellulose.

Which of the following statements accurately compares the structures of cellulose and chitin?

A patient is experiencing the following symptoms:

• Muscle cramps
• Seizures
• Headaches
• Increased urine production.

Which of the following ions is likely to be deficient in this patient?

Sickle cell anaemia is a genetic disease affecting red blood cells which is caused by base substitution in the haemoglobin protein which results in a polar amino acid being replaced with a non-polar amino acid in the globin subunits.

The diagram below shows the difference between a normal red blood cell and a sickle cell.

Which of the following statements correctly explain the impact of the amino acid substitution?