MISTAKES biology unit 3 aos1

polymer

a large molecule made up of many smaller, repeating units together

Monomer

are the small units that repeat in a polymer

Describe the chemical reaction that takes place to join amino acids together

Condensation polymerisation reaction, where water is released and ATP is used for peptide bonds to form, between the amino group (from one animo acid) and carboxyl group (to another animo acid)

Macromolecule

A macromolecule is a large molecule formed by linking many smaller molecules (monomers), example: protein would be insulins macromolecule.

Definition and function of DNA

DNA codes for the protein

Definition and function of tRNA

 tRNA carries the amino acids to ribosomes to make an amino acid

Definition and function of mRNA

mRNA carries the instructions from DNA to the ribosomes, which determine the order of amino acids in the polypeptide chain

Definition and function of ribosome

The ribosomes read the instructions from the mRNA and joins the amino acids together in the correct order to form the polypeptide chain

If a protein were immersed in boiling water for a period of time, what changes would you expect to see in the amino acid sequence of the polypeptide?

No change, as peptide bonds are strong

If this protein were immersed in boiling water for a period of time, what changes would you expect to see in the structure of the alpha helix and beta pleated sheets?

They would denature as the hydrogen bonds between amino acids would break, unravelling the structure of the secondary, leaving the linear chain of polypeptide

Explain how there can be over 300 monomers in a section of a RNA molecule but only 10 amino acids translated.

Introns are removed during RNA splicing and untranslated regions do not code for amino acids. Only exons are translated, and since each amino acid is coded by a codon of three nucleotides, 10 amino acids require only 30 nucleotides.

transcription of the structural genes in trp operon will only begin when

RNA polymerase is attached to the promoter

Transcription of structural genes in trp operon will result in the molecule of

mRNA

Function of RNA polymerase

Separating the double helix when connected to the promoter, connecting free RNA nucleotides to make a strand of ‘pre-mRNA’ (complementary the template strand) (RNA polymerase joins RNA nucleotides together using phosphodiester bonds from a condensation reaction)

Regulatory gene vs Structural

Influence the transcription of other genes i.e block RNA polymerase.

Proteins that have a function throughout the body

Describe the function of a hormone

Hormones are cell signalling molecules that can be used to transmit signals from one part of the body to another

Poly A tail is attached on the… Methyl cap is attached on the…

3’ Prime and 5’ Prime

How does Bacteria, humans, cows all produce insulin through the same pathway of protein synthesis

Bacteria, humans, pigs, and cows can all produce insulin through the same pathway due to the universal nature of the genetic code, which involves nearly all organisms using the same set of rules in the production of proteins.

An endergonic reaction is a chemical reaction

that requires an input of energy to occur (anabolic - joining together)

An exergonic reaction is a chemical reaction

that releases energy to the surroundings (catabolic - breaking down)

Enzyme

An organic molecule, usually a protein, that acts as a biological catalyst to speed up chemical reactions without being consumed.

substrate

The reactant molecule that binds to an enzyme’s active site and is converted into a product during the reaction.

active site

The specific region of an enzyme where the substrate binds and the chemical reaction is catalysed.

products

The molecules formed as a result of the enzyme-catalysed reaction after the substrate has been converted.

step 1 in trp operon

In trp operon repression, to regulate the expression of the structural genes, the regulatory gene for the trp operon is constantly expressed, producing a repressor protein.

When high levels of tryptophan are present, two tryptophan molecules bind to the repressor protein, which changes its shape into its active form, to bind to the operator (switches off transcription)

gene expression

conversion of the code in DNA of a gene into a protein, through protein synthesis. Gene expression is transcription and translation.

process their mRNA

prokaryotes dont have introns

A 5΄ methyl cap

is added to help protect it from being degraded by enzymes when it exits the nucleus. It also helps it to be positioned correctly on the ribosome during translation

A poly-A tail

(a long string of adenine bases) is added to the 3΄ end. (This also helps prevent it being broken down by enzymes in the cytoplasm, increases mRNA stability)

Quaternary structure

Two or more polypeptide chains interacting with one another, undergo the same folding (tertiary structures joining together to form Quaternary) - disulphide bonds

integrity

This concept encourages individuals to act honestly and truthfully, especially when presenting their findings or results. Integrity prioritises an accurate understanding and representation of the facts, whether favourable or unfavourable to an individual’s personal position, and encourages criticism.

justice

the commitment to fairness. This concept encourages consideration of different people’s opinions and positions, especially those directly affected or marginalised by a course of action. Justice prioritises the fair distribution of resources, as well as equal access to the benefits of an action, policy, investigation, or research.

Beneficence

The commitment to maximising benefits. This concept encourages individuals to act in a way that benefits others. Beneficence promotes the personal wellbeing and good of other persons, particularly direct stakeholders such as patients and research subjects.

Non–maleficence

The commitment to minimising harm. This concept encourages individuals to act in ways that remove as much harm as possible. Indeed, while actions may always involve some degree of possible harm, non–maleficence prioritises minimising this harm, sometimes to the detriment of people’s freedom of choice and autonomy.

respect

the commitment to consideration. This concept encourages individuals to consider the value of others, including their personal welfare, beliefs, freedom, and autonomy. Respect prioritises the freedom of others to make their own decisions and be protected from persecution or exploitation.