1.2 PROTEINS Flashcards
What is the Genome?
An organism’s complete set of DNA
What is the Proteome?
The entire set of proteins expressed by a genome.
Why is the Proteome larger than the Genome?
Due to alternative RNA splicing and post-translational modification
What is the result of Gene Expression?
Not all genes are expressed as proteins in a particular cell
What is the benefit of Gene Expression?
Only essential proteins are produced and therefore the cell is more energy and resource efficient
What does amino acid sequence determine?
Protein structure
What is a protein?
A polymer of amino acid monomers
Which type of bond links amino acids?
Peptide bonds
What is a chain of amino acids called?
Polypeptide
What are the four types of protein structure?
Primary, Secondary, Tertiary and Quaternary
What is the primary structure of a protein?
The sequence in which the amino acids are synthesised into a polypeptide
What is the secondary structure of a protein?
Alpha helices / Beta sheets / Turns
What causes secondary structure?
Hydrogen bonding along the backbone of the protein
What is the tertiary structure of a protein?
3D folding of the polypeptide
What causes tertiary structure?
Bonding - interactions between R groups, hydrophobic/hydrophilic interactions, ionic bonds, van der Walls interactions, disulfide bridges
What is an R group?
Functional group attached to the amino and carboxyl group compound (other component of amino acids). They are the only thing which distinguishes the 20 different amino acids.
What affects R group interactions?
Temperature and PH
Other than folding, what else is included in tertiary structure?
Prosthetic groups
What are prosthetic groups?
Non-protein unit bound to a protein which is essential for protein function
What is the quaternary structure of a protein?
Consisting of several connected polypeptide sub-units
What influences the location of proteins in cells?
Hydrophobic and Hydrophilic Interactions
What determines the location of proteins in a cell?
R groups at the surface of the proteins
What is a soluble protein?
A protein found in the cytoplasm
What do Hydrophilic R groups in soluble proteins do?
The R groups predominate at the suface of the protein
What does predominate mean?
To become the strongest or main element; greater in number
What do Hydrophobic R groups in soluble proteins do?
The R groups may cluster at the centre to form a globular structure
What is the name of membrane model we study?
Fluid mosiac model
What are the two types of membrane protein?
Integral and peripheral
Give an example of an integral membrane protein.
Transmembrane protein (eg. Channel, transporter, receptor)