Proteins Flashcards
What is the primary sequence of a protein forming?
The order of amino acids in a polypeptide chain are formed and stabilised by peptide bonds
What is the secondary structure of a protein forming?
The polypeptide chain may form into α-helixes or β-pleared sheets and are stabilised by hydrogen bonds
What is the tertiary structure of a protein?
the polypeptides fold into three-dimensional structures which determine their function and are stabilised by hydrogen bonds, disulfide bridges and hydrophobic reactions. Some proteins do not develop further
How do polypeptides behave in an acqeous environment during the tertiary stage
the polar side chain form hydrogen bonds to water while the nonpolar side chains are packed into a hydrophobic ‘core region’
What is the quaternary stage of a protein?
two or more polypeptides may assemble to form larger proteins
What is a protein?
A sequence of amino acids wherein each amino acid has a carboxyl and amino functional group attached to a carbon atom
How are amino acids distinguished from each another?
Their side group (r-group)
What happens if proteins are misfolded?
The function of said protein may change or the protein might lose its function
Why might a proteins structure change?
Due to interactions with other molecules or enzymatic processes
What determines protein activity?
The polypeptides ability to bind to other proteins or molecules
What is the main function of enzymes?
To catalyse biochemical reactions
How do enzymes catalyse reactions?
By lowering the activation energy required for a reaction to proceed
What are three (non-negative regulation) factors which affect how proteins function?
Subcellular localisation, association with other proteins and ligand binding
What is negative regulation of a protein?
Mechanisms which inhibit proteins function
What are three forms of negative regulation?
Allosteric inhibition, inhibitory proteins, feedback inhibition
