4 Molecularbiology in medicine

Figure 4.1 The influenza virus has two surface proteins: neuraminidase and haemagglutinin. These proteins change continually, making it virtually impossible for a body to developprotection against future infections.

• Early work in molecular biology involved investigating metabolic __________ and the roles played by proteins and enzymes.• Discovery of the ______________ of

DNA in 1953 became a pivotal point for the current and ongoing developments that exist in _____________ biology today.

Inherited diseases

• __________ a newborn baby with the heel prick test for Hypothyroidism, _________ fibrosis, Galactosaemia and _____.

• What are these disorders and why is so much trouble taken to test every baby born in Australia?

Gene therapy

• Gene __________ is a procedure with the potential to _________ some genetic defects.• Gene therapy involves inserting a

_____________ piece of DNA into the cells of an individual with a genetic _________.• Virus _________ are commonly used

to carry ______ into other cells.

Medical diagnosis

• Different genetic conditions can develop at ___________ ages in individuals.

• ______ exist to distinguish functional from non-functional segments of DNA in an individual.

• In these tests, the DNA of one individual is often ______________ with the DNA of other family members.

• Tests can determine whether or not the tested individual has a particular ____________ or is likely to develop the condition.

Rational drug design

• If we understand the ____________ by which an infective organism or agent causes disease, we may be able to design a drug to ___________ it occurring.

• One of the __________, an enzyme, on the outer layer of the flu virus has a

_____-variable active site that is important for the continuation of their life cycle.

Developing vaccines

• Vaccinations contain _________ from disease-causing organisms that stimulate the immune system to develop _____________ for future protection from the disease.

• It is difficult to make vaccines against some ____________ because of the complexity of the life cycle and knowing which of their _________ are most important in their disease-causing capacity.

• Vaccines must generally be refrigerated for storage and require trained staff to _____ them.

Manufacturing biologicalmolecules

• Some ____________ caused by a deficiency of a particular protein can be treated with a genetically engineered (GE) form of the protein.

• GE proteins are produced by bacteria carrying GE ___________.

• Very tiny particles, called nanoparticles, have been designed to carry and deliver drugs to cancer cells.

• Our opinions are moulded by the knowledge we have and our experiences.

Figure 4.29 (a) DNA carrying the instructions (code) for making insulin (or other protein) is inserted into a plasmid vector. (b) Plasmid vectors replicate inside host bacterial cells and bacterial cells undergo binary fission. Many pieces of the passenger DNA make many molecules of insulin or other protein depending on the code instructions).

Delivery of drugs by nanoparticlesFigure 4.31 Stylised representation of the _____________ used in the delivery of an anti-cancer drug directly to cancer cells. The basic structure is a branched polymer molecule called a _______________ to which the drug, folic acid and a fluorescent stain are attached.

One nanometre is one billionth ofa metre (10–9 m).