Genetics

Genetics, a discipline of biology, is the science of heredity and variation in living organisms. Knowledge of the inheritance of characteristics has been implicitly used since prehistoric times for improving crop plants and animals through selective breeding. However, the modern science of genetics, which seeks to understand the mechanisms of inheritance, only began with the work of Gregor Mendel in the mid-nineteenth century.Although he did not know the physical basis for heredity, Mendel observed that inheritance is fundamentally a discrete process where specific traits are inherited in an independent manner—these basic units of inheritance are now called genes.

DNA, the molecular basis for inheritance. Each strand of DNA is a chain of nucleotides, matching each other in the center to form what look like rungs on a twisted ladder.
Genes correspond to regions within DNA, a molecule composed of a chain of four different types of nucleotides—the sequence of these nucleotides is the genetic information organisms inherit. DNA naturally occurs in a double stranded form, with nucleotides on each strand complementary to each other. Each strand can act as a template for synthesis of a new partner strand—this is the physical mechanism for the copying and inheritance of genetic information.
The sequence of nucleotides in DNA is used by cells to produce specific sequences of amino acids, creating proteins—a correspondence known as the genetic code. This sequence of amino acids in a protein determines how it folds into a three-dimensional structure; this structure is, in turn, responsible for the protein's function. Proteins carry out almost all the functions needed for cells to live and reproduce. A change to DNA sequence can change a protein's structure and behavior, and this can have dramatic consequences in the cell and on the organism as a whole.

Epidemiology

Epidemiology is the study of factors affecting the health and illness of populations, and serves as the foundation and logic of interventions made in the interest of public health and preventive medicine. It is considered a cornerstone methodology of public health research, and is highly regarded in evidence-based medicine for identifying risk factors for disease and determining optimal treatment approaches to clinical practice.
The work of communicable and non-communicable disease epidemiologists ranges from outbreak investigation, to study design, data collection and analysis including the development of statistical models to test hypotheses and the 'writing-up' of results for submission to peer reviewed journals. Epidemiologists may draw on a number of other scientific disciplines such as biology in understanding disease processes and social science disciplines including sociology and philosophy in order to better understand proximate and distal risk factors.

Biochemistry

Biochemistry (from Greek: βίος, bios, "life" and Egyptian kēme, "earth" is the study of the chemical processes in living organisms. It deals with the structure and function of cellular components, such as proteins, carbohydrates, lipids, nucleic acids, and other biomolecules. Chemical biology aims to answer many questions arising from biochemistry by using tools developed within chemical synthesis.
Although there are a vast number of different biomolecules, many are complex and large molecules (called polymers) that are composed of similar repeating subunits (called monomers). Each class of polymeric biomolecule has a different set of subunit types. For example, a protein is a polymer made up of 20 or more amino acids. Biochemistry studies the chemical properties of important biological molecules, like proteins, in particular the chemistry of enzyme-catalyzed reactions.
The biochemistry of cell metabolism and the endocrine system has been extensively described. Other areas of biochemistry include the genetic code (DNA, RNA), protein synthesis, cell membrane transport, and signal transduction.

Medical Sociology

Medical sociology is the study of individual and group behaviors with respect to health and illness. Thus "medical" is a little simplistic, as the focus is not only on medical professionals or their behaviours, but also focuses on human behavioural responses to health and illness.
Medical sociology is concerned with individual and group responses aimed at assessing well-being, maintaining health, acting upon real or perceived illness, interacting with health care systems, and maximising health in the face of physiologic or functional derangement. It also analyses the impact of the psychological conditions resulting from our environment on our health.
Talcott Parsons is often considered the father of medical sociology because of his description of the 'Sick Role'. This describes the difference between the role of a sick person as opposed to the 'Social Role' of a healthy person. He defines the sick role as defining the motivation of the patient. Curiously enough, Parsons makes no mention of the role of the doctor or other medical institutions. The sick role comprises four aspects: exemption from normal social role responsibilities, the privilege of not being held responsible for being sick, the desire to get better and the obligation to find proper help and follow that advice.
The field of medical sociology is usually taught as part of a wider sociology, clinical psychology or health studies degree course, or on dedicated Master's degree courses where it is sometimes combined with the study of medical ethics/bioethics.
In the UK, institutions which run Masters degree courses in Medical Sociology include the University of Nottingham and the University of London at Royal Holloway and Goldsmiths College