Qualitative Reaction of Proteins (Lab) Flashcards
are macromolecules that are made from one or more chains of polypeptides
proteins
are linear polymers making up proteins
polypeptides
Polypeptides are linear polymers made up from smaller molecules called
amino acids
Polypeptides
are formed when amino acids are joined together via typical ___bonds that forms between
amino group of one amino acid and carboxyl group
peptide
Proteins are the structural building blocks of almost all major cellular components and
structures, such as
enzymes
ribosomes
cytoskeleton
centrosomes
proteasomes
There are more than _
different amino acids found in biological organisms
20
Amino acids have characteristic chemical and
structural features
amino group (-NH2)
carboxyl group (-COOH)
They have an amino group (-NH2) plus a carboxyl group (-COOH) as functional
groups which are covalently attached to the
first (a) carbon atom
Proteins can be visualized and be tested with the help of series of unique dyes, such as
biuret reagent
coomasie blue (lowry reagent)
Amino acids can be visualized and be tested for with the help of a
chemical reagent called
ninhydrin
However, a simple and relatively quick qualitative test for the
presence of amino acids in solution is the
Whatman filter paper spotting test
is performed to analyze proteins in solid samples
ninhydrin test
samples for protein qualitative analysis
egg albumin
diluted honey
potato starch
milk
egg yolk
glucose
amino acid
meat (pork,fish)
egg white
cooked rich
biuret reagent
sodium hydroxide
copper (II) sulfate
potassium sodium tartate
very poisonous
ninhydrin
inhaling the fumes of ___ is not advisable
ninhydrin
amino acid common structure (3)
amino group
carboxyl group
variable side chain (R group)
gives the amino acid its unique chemical properties.
R group
The specific sequence of amino acids in a protein is the
primary structure
This structure may be recited by naming each amino acid beginning on the _-terminus.
N terminus
Proteins twist, turn, and fold into complex three dimensional shapes.
what structure
tertiary structure
These twists and turns are possible because there is ____ of the bonds around the α-carbon of each amino acid.
free rotation
sequence of amino acids in a polypaptide chain, similar to the sequence of letters that spell out a specific word
what structure
primary structure
the corkscrew like twists or pleated folds formed by hydrogen bonds between amino acids in the polypeptide chain
what structure
secondary structure
the complex three dimensional shape formed by multiple twists and bends in the polypeptide chain, based on the side chains interactions with each other and the aqueous solvent
tertiary structure
two or more polypeptide chians bonded together
what structure
quaternary structure
positive test for biuret indicates
protein is present
biuret positive test
purple
In the presence of alpha (α)-amino acids what is observed in ninhydrin test
blue to blue violet color
ninhydrin reagent
ninhydrin in 10ml of either ethanol or acetone.
deep purple positive for ninhydrin means
For ammonia, primary/secondary amines, and amino acids
yellow positive for ninhydrin means
hydroxyproline and proline
brown positive for ninhydrin means
asparagine
organic macromolecules containing C,H,O,N
proteins
examples of proteins
enzymes
body tissues
many immune system cells
monomers of proteins
amino acid
amino acids joint to form small protein polymers called
peptides
long protein polymers are called
polypeptides