Biology

• Bioethical Approaches


  • Consequences-based
  • Duty/rule-based
  • Virtues-based
• Consequences-based approach


  1. Places central importance on the consideration of the consequences of an action (the ends)

  2. Aims to achieve maximisation of positive outcomes and minimisation of negative effects

  3. Key terms: outcomes, benefits, consequences, effects
• Duty/rule-based approach


  1. Consideration with how people act (the means) and places central importance on the idea that people have a duty to act in a particular way

  2. Certain ethical rules must be followed, regardless of the consequences that may be produced

  3. Key terms: obligation, duty, responsibility, commitment
• Virtues-based approach


  1. Is person rather than action-based

  2. Consideration is given to the virtue or moral character of the person carrying out the action

  3. Provides guidance about the characteristics and behaviours a good person would seek to achieve to then be able to act in the right way

  4. Key terms: any reference to virtues, such as good, honest, caring
• Ethical Concepts

  • Integrity
  • Justice
  • Beneficence
  • Non-maleficence
  • Respect
• Integrity


  1. The commitment to knowledge

  2. This concept encourages individuals to act honestly and truthfully, especially when presenting their findings or results

  3. Integrity prioritises an accurate understanding and representation of the facts, whether favourable or unfavourable to an individual's personal position, and encourages scrutiny and criticism
• Justice


  1. The commitment to fairness

  2. This concept encourages consideration of different people's opinions and positions, especially those directly affected or marginalised by a course of action

  3. Justice priorities the fair distribution of resources, as well as equal access to the benefits of an action, policy, investigation or research
• Beneficence


  1. The commitment to maximising benefits

  2. This concept encourages individuals to act in a way that benefits others

  3. Beneficence promotes the personal wellbeing and good of other persons, particularly direct stakeholders such as patients and research subjects
• Non-maleficence


  1. The commitment to minimising harm

  2. This concept encourages individuals to act in a way that removes as much harm as possible

  3. While actions may always involve some degree of possible harm, non-maleficence priorities minimising this harm, sometimes to the detriment of people's freedom of choice and autonomy
• Respect


  1. The commitment to consideration

  2. This concept encourages individuals to consider the value of others, including their personal welfare, beliefs, freedom and autonomy

  3. Respect prioritises the freedom of others to make their own decisions and be protected from persecution or exploitation
• Nucleic acid


  Organic polymers that store genetic information and provide instructions for protein synthesis
• Nucleotide


  Monomer that makes up nucleic acids
• Purines


  • Guanine
  • Adenine
• Pyrimidines


  • Cytosine
  • Thymine
  • Uracil
• DNA vs RNA


  • Function, Organic Molecule, # of Strands, Sugar, Nitrogenous bases, Base pairing, Locations found, Types and Function
• Types of RNA

  • Messenger RNA (mRNA), Ribosomal RNA (rRNA), Transfer RNA (tRNA)
• Both DNA and RNA are formed by condensation polymerisation
• mRNA is complementary with the template strand of DNA and codes for specific amino acids
• tRNA carries specific amino acids, helps with protein synthesis, and can be either unloaded or loaded
• rRNA makes up ribosomes
• DNA Characteristics


  • Universal, Unambiguous, Degenerate
• Step 1: Transcription


  1. Rewriting DNA into pre-mRNA

  2. RNA polymerase binds to the promoter region of DNA

  3. RNA polymerase moves along the template strand of DNA, allowing a complementary strand of mRNA nucleotides to join

  4. RNA polymerase allows the formation of a pre-mRNA strand
• Step 2: RNA Processing


  Introns, Exons, Pre-mRNA to mature mRNA strand, Splicing of introns, Joining of exons, Addition of 5’ methyl cap and poly A tail
• RNA processing


  1. Introns are removed

  2. Exons are joined together

  3. A 5’ methyl cap is added to the end of the strand (prevents the degradation of the strand)

  4. A poly A tail is added to the other end of the strand (prevents the degradation of the strand and helps the RNA bind to the ribosomes)
• Translation


  1. The mature mRNA leaves the nucleus and attaches to a ribosome

  2. The tRNA have anti-codons that code for specific amino acids

  3. If the anti-codons are complementary to the codons in the mRNA, the tRNA unloads the specific amino acid

  4. Adjacent amino acids will form a peptide bond with each other to form a polypeptide chain
• Alternative Splicing


  1. Allows for a single gene to code for multiple proteins

  2. Does not re-order the exons

  3. Needs to re-transcribe

  4. Splices introns as well as some exons
• Proteome: The entire set of proteins expressed by an organism or cell at a given time
• All amino acids have a common structure with a central carbon atom bonded to 4 things: A hydrogen atom (H), A carboxyl group (COOH), An amine group (NH¬2), An R-group
• There are 20 different types of R-groups, which is what makes amino acids different from each other. This means that there are 20 different amino acids that are involved in the synthesis of proteins
• A polypeptide chain is formed when amino acids are linked together via a condensation reaction to form peptide bonds between adjoining amino acids
• This process requires energy endergonic and is anabolic
• A polypeptide chain may be function by itself or may need to be joined to other polypeptide chains to become functional
• Condensation Polymerisation


  1. Amino acids are joined by peptide bons which involves the removal of water (dehydration)

  2. Water is released and a dipeptide is formed holding the two amino acids together

  3. The backbone of the polypeptide chain is formed by the repeats of the carboxyl and amine groups, with the R groups forming the side chains of the polypeptide chain

  4. This forms the primary structure of a protein. With further modification and folding, a fully functioning protein can be formed
• OH is taken from the carboxyl group - H is taken from the amine group
• Correct shape = correct function - Folding/shape = folding
• Each protein folding level has a certain temperature/environment they can function in
• If a protein is exposed to an unsuitable environment, it causes the protein to denature
• These proteins are not able to return to their folded state and therefore unfunctional
• Primary (non-functional) - Peptide bonds - Sequence of amino acids
• Secondary (non-functional) - Hydrogen bonds (weak) - Includes alpha helixes and beta sheets - Both can happen at the same time