Topic 5: proteins Flashcards
what is an enzyme
a biological catalyst
what is an essential amino acid
an essential amino acid is an amino acid which cant be synthesized by the body, so much be taken in through food
what is a non essential amino acid
a non essential amino acid is an amino acid which can be synthesized in the body, so are not needed to be taken in through food
what does a peptide bond look like
-CONH- with a double bond connecting the C-O
what is another name for a peptide bond
amide link
describe how amino acids join to form proteins
-amino acids join together in a condensation reaction (loss of a water molecule) between the amino acid and the carboxyl group of the next
-this forms a ‘peptide bond’ or an ‘amide link’
how is the primary structure of a protein determined
-the sequence of bases in a gene determines the sequence of amino acids in a protein
-the sequence of amino acids determines how a protein folds
-folding determines the final shape of the protein
why is the primary structure of a protein so important
the final shape of the protein determines its function
explain why the function of an enzyme depends on its shape
-enzyme have an active site which aligns the substrate (reactant) molecules into the correct orientation, and stresses its bond, reducing the activation energy, allowing a reaction to proceed
-shape of active site fits shape of substrate
which bonds are NOT broken when proteins are heated
peptide bonds between amino acids
which forces ARE broken when proteins are heated
intermolecular forces between R groups
what happens to a protein that’s lost its shape
it can no longer function, and is described as ‘denatured’
during digestion, enzyme hydrolysis of protein produces what
amino acids
the ________ of proteins in foods causes the texture to change when its cooked
denaturing
