BGM1002/L01 Proteins Overview Flashcards
Why are proteins studied?
To understand how cells work.
Give 2 examples of proteins in Medicine.
Herceptin - anticancer antibody
Insulin - protein hormone used to treat T1 Diabetes
What is the active/targeted component in most vaccines?
Proteins
In a 75kg human, what is the approximate protein weight?
Wet - 12kg
Dry - 25%
Approximately what percentage of cell material is protein?
50%
What percentage of protein in the body is muscle?
50-75%
What structures can proteins form? (Give 5)
Cytoskeleton
Enzymes
Cell receptors
Toxins
Antibodies
Hair
Fingernails
Histones
Transporters
Ribosomal proteins
DNA/RNA polymerase
How many different varieties of protein are in the human body?
Approximately 20,000.
How many biogenic amino acids are there?
20/21
How many levels of protein structure are there? Name them.
4 - Primary, secondary, tertiary, quaternary.
What is the relationship between all proteinogenic amino acids?
They are L-isomers
Name the 6 common aliphatic amino acids.
Alanine, Glycine, Isoeucine, Leucine, Proline, Valine.
Name the 3 common aromatic amino acids.
Phenylalanine, Tryptophan, Tyrosine.
Name the 2 common acidic amino acids.
Aspartic acid, Glutamic acid.
Name the 3 common basic amino acids.
Arginine, Histidine, Lysine
Name the 2 common hydroxylic amino aids.
Serine, Threonine.
Name the 2 common Sulfur-containing amino acids.
Cysteine, Methionine.
Name the 2 common amidic amino acids.
Asparagine, Glutamine.
What type of reaction occurs during formation of a peptide bond?
Condensation.
Which parts of the amino acids react during formation of a peptide bond?
Carboxylic acid and amino groups.
What type of isomerisation can a peptide bond undergo?
Cis/trans
What unit of measurement is used for a C-N peptide bond and what is it equal to?
Å (angstrom = 0.1 nm)
In which way is the polypeptide backbone directional?
N-term to C-term.
Which organelle synthesises proteins?
Ribosomes.
What type of amino acids do ribosomal proteins have exclusively?
L-amino acids.
What type of amino acids are found in some non-ribosomal proteins? Give one example.
D-amino acids - bacterial cell walls.
What is a covalent bond?
The strongest molecular bond of two atoms sharing pairs of valence electrons.
What are ribosomes composed of?
Large and small sub-units.
How do ribosomes catalyse formation of peptide bonds?
By binding mRNA and charged tRNA molecules.
What are amino acids delivered to the ribosomes by?
tRNA
What occurs as a result of stopping peptide bond formation? Why is this useful?
It stops protein synthesis and kills the cell.
It is useful as a drug target.
What is a proteome?
The sum of all the proteins in a cell.
How are proteins modified after translation?
Post-translational modification.
What is a primary protein?
A single linear string of amino acids
What is a secondary protein?
A folded ‘backbone’ of amino acids, in a regular arrangement
What is a tertiary protein?
Overall 3-dimensional arrangement of bonded amino acids
What is a quaternary protein?
A globular or fibrous structure with multiple strings of protein; a functional arrangement with other proteins or cofactors
What is the CORN law?
A rule used to distinguish enantiomers from each other (whether an amino acid is an L-isomer or D-isomer).
Which way is a protein read?
From the amino group to the carboxyl group
What type of bond is a peptide bond?
Planar bond
Which type of bond is the strongest of all molecular bonds?
Covalent bond (shared pairs of valence electrons)
What effect does a mutation in the genome have on the resultant protein/amino acid?
It creates a variant protein/different amino acid
What type of bodily response can occur due to spike proteins?
Autoimmune response
