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Oxbridge Medicine Academic Questions




  • Consider things that we class as drugs e.g. paracetamol and what we don't class as drugs e.g. water

  • Drugs don't have to necessarily have to be external to the body e.g. insulin injections are classed drugs but insulin is hormone made naturally by the body

  • All 'drugs' seem to have something in common - they interact with major biological molecules in the body

  • Examples to illustrate would be good: - Proteins: enzyme inhibitors such as aspirin - DNA: chemotherapy drugs e.g. cisplatin

  • Typically have a therapeutic effect by affecting a physiological state


  • Immediate changes - reduction in blood volume

  • How would the body respond to this?

  • Reasonable to suggest that it has to make sure that important organs are still perfused properly and it would prioritise conserving water

  • Downstream effects - increase in heart rate, vasoconstriction to maintain blood pressure

  • Could suggest hormones responsible for this such as adrenaline

  • To conserve water the blood flow to the kidney would be reduced

  • Increase in feeling of thirst


  • SARS-CoV-2 is an RNA virus which translates its RNA into proteins upon infecting cells while also replicating its RNA

  • mRNA in the vaccine contains code for the spike protein - the virus uses this to enter cells

  • First the vaccine has to get into cells - it has to cross the cell membrane barrier

  • In some vaccines the mRNA has a lipid coat to enable it enter without needed a protein

  • Once translated the spike protein has to be recognised by the immune system - the cell achieves this by presenting it on its surface

  • This stimulates the production of antibodies which are specific to the spike protein

  • They prevent the spike protein from binding to its receptor


  • There's no right answer here, consider the function of different organs and what would happen to the body without them

  • Brain - processing of sensory information, generating motor commands, source of emotions, consciousness etc. Legal death is brain death therefore a favourite?

  • Heart - pumping of blood to rest of body, without it other organs would die from hypoxia due to lack of oxygen

  • Lungs - gas exchange surface, needed to get rid of carbon dioxide and take in oxygen for cells to respire

  • Kidneys - osmoregulation, filtering of the blood. It's possible to live with just one so this suggests it's not as important as the others

  • Liver - metabolism of harmful substances in the blood, filtering of substances, production of bile etc.


  • Not all DNA forms part of of the coding sequence for proteins hence the term 'junk'

  • While it's referred to as junk DNA, it is still important to suggest their purpose for being in the genome

  • Within genes there are introns which are spliced out during post-transcriptional modification of RNA

  • Exons can be arranged in different ways which increases the diversity of proteins which can be generated from the same gene

  • Sequences upstream of the gene are needed to recruit RNA polymerase and transcription factors e.g. the promoter sequence

  • Part of the DNA is required to recruit ribosomes when transcribed into mRNA (ribosome binding site)

  • Some parts of the DNA have unknown function e.g. repetitive elements

  • Some DNA sequences are remnants of past retroviral infections which have remained integrated into the genome




  • Think about the main functions of a placenta and suggest features accordingly

  • Each feature performs a function that the fetus' organs will perform post-natally (in brackets)

  • Gas exchange surface - high surface area with rich blood supply to maximise transfer of oxygen from mother to fetus (lungs)

  • Excretory functions, water balance, pH regulation - need someway to remove waste products from fetus (kidney)

  • Synthetic and secretory functions - useful to coordinate pregnancy changes in mother and fetus since it acts as the interface between the two (most endocrine glands)

  • Immunological interactions and protection - the fetus is a foreign body so placenta needs to ensure that the mother doesn't reject the fetus during pregnancy


  • Glucose is the substrate for respiration - cancer cells require more since they are constantly growing unregulated by the cell cycle

  • Glucose eventually used to generate ATP

  • ATP drives biosynthetic pathways such as nucleotide synthesis which cancer cells will be doing lots of

  • Gives the cancer cell an evolutionary advantage over other cells if it's able to divide more


  • It's a good idea to first outline how to describe the position of a sound in space

  • (1) Vertical plane - elevation

  • (2) Horizontal plane - azimuth

  • The external ear itself (pinna) can affect elements of the sound depending on its elevation

  • This is interpreted by the brain - how might this 'interpretation' work?

  • Since we have 2 ears it would be reasonable to suggest that there is a time delay in the detection of sound between one ear and the other depending on the position of the sound in the horizontal plane

  • This time delay can be used as a signal by the brain to locate sounds

  • In addition, the head provides an acoustic shadow which reduces the intensity of sounds depending on which side of the head it originated from

  • This difference in intensity between the 2 ears can also be used as a signal to pinpoint the location of a sound


  • At altitude there is a reduction in barometric pressure

  • This causes a reduction in the inspired partial pressure of oxygen (pO2) leading to hypoxia

  • To compensate for this people tend to hyperventilate to increase their pO2

  • However, this reduces their pCO2 since they are exhaling more CO2; this causes an increase in the pH of their cerebrospinal fluid (CSF)

  • Changes in the composition of CSF brings pH back to normal

  • Oxygen diffusion can be rate-limiting at altitude because there is a suppressed partial pressure gradient of oxygen

  • Therefore, it takes longer for oxygen to diffuse into the blood

  • Finally there is an increase in the concentration of 2,3-DPG which causes a right shift in the oxygen dissociation curve

  • This facilitates unloading of oxygen since it has a lower affinity to haemoglobin

  • For permanent residents at high altitude there is a physiological adaptation that occurs to increase oxygen content - a significant increase in the concentration of haemoglobin (polycythemia)




  • Antibiotic - drugs used to kill microorganisms e.g. bacteria

  • Anticancer - drugs used to treat cancer

  • Main difference is in target: pathogens vs cancerous cells

  • Different mechanisms of action, suggest some examples: - Antibiotics can target cell walls (bacteria), lipid within membranes (fungi), enzymes needed for replication (viruses), DNA etc - Anticancer drugs can be broadly split into cytotoxic and molecular targeted drugs - Cytotoxic drugs can target: DNA and its synthesis, enzymes needed for DNA replication, the mitotic spindle etc - Molecular targeted drugs can target: receptors, tyrosine kinases, hormone synthesis and many more

  • Improvements in these drugs mostly come from making them more selective, particularly with anti-cancer drugs because they can be very toxic

  • New drugs are also designed to counteract antibiotic resistance, making better antibiotics may include changing their structure so they bind with higher affinity to their targets

  • Anti-cancer drugs can be made better by targeting molecules/markers specific to the cancer cell

  • Some drugs upregulate the immune response (T cells in particular) to cancer by binding to certain inhibitory molecules on cancer cells, these have shown to be effective in some cancers



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