proteins Flashcards
(19 cards)
what is the monomer of a protein
an amino acid
what is the bond called between 2 amino acids
polypeptide
what is the formula of the carboxylic acid group of an amino group
-COOH
what is the formula of the amino group of an amino acid
-NH2
what property does the amino group have
It can act as a base at it can accept a proton
state what is meant by the R group of an amino acid
It is the variable group and it changes for each of the 20 amino acids
the carboxylic acid, amino and R group are all bonded to a central carbon. What other atom is bonded to the central carbon
a hydrogen atom
how many naturally occurring amino acid types are there
20 amino acid types
what is the test for to test for proteins called
the biuret test
What does the biuret test used to detect
used for detecting the presence of peptide bonds between the amino acids
if peptide bonds are present that indicates the solution contains protein what colour change would be observed
the biuret reagent will turn from blue to purple
what is the intensity of the colour directly proportional to
its directly proportional to the protein concentration
why is this tests a qualitative test
as the concentration of protein present in solution is based of the intensity of the colour e.g if the colour observed was dark purple it would indicate a more concentrated protein
what could be used to measure the concentration of proteins present in a sample
by adding the purple biuret to a colorimeter
what would be needed to detect the concentration of a specific protein
a biosensor would be needed
how to proteins differ from carbohydrates in what atoms are present
they have carbon, hydrogen, oxygen and nitrogen atoms
what does the shape of a protein determine
its function
what are chains of amino acids called
polypeptides
define the term peptide bond
the chemical bond formed by a condensation reaction between the amino acid group of 1 amino acid and the carboxyl group of another
