Proteins Flashcards
what are the monomers that make up proteins?
amino acids
what do proteins contain?
carbon, hydrogen, oxygen, nitrogen (some contain sulphur and phosphorus)
functions of proteins (8)?
enzymes, transport, movement, cell recognition, channels, structure, hormones, protection
what is the name of the bond between amino acids?
a peptide bond
how are dipeptides formed?
amino acids line up
amine and carboxyl groups align
OH from carboxyl and an H from the amine to produce one molecule of water
peptide bonds form between the carbon and nitrogen
what do ribosomes do for amino acids?
they facilitate for amino acids in order so they can bond and form peptide bonds
what is the primary structure?
the primary structure of a protein is its specific order of amino acids in the polypeptide chain
what is the secondary structure?
the secondary structure is the folding of the polypeptide chains e.g. alpha helix, beta pleated sheet
how does the secondary structure form and stay together?
hydrogen bonds form between the oxygen remaning on the carboxylic end and the hydrogen remaining on the amine end of different amino acids. this holds the alpha helix or beta pleated sheet in its formation
what is the tertiary structure?
the tertiary structure is the folding of the folds - forms a specific 3D structure e.g. enzymes
how do tertiary structures bon?
R groups - these form tertiary structure bonds: hydrogen bonds, polar-polar bonds, non-polar-non-polar bonds, ionic bonds, di-sulphide bonds - bonds that can form between R groups
what is the quaternary structure?
two or more polypeptide chains bonded together and this can also include an inorganic prosthetic group (e.g. copper ions, iron ions) these structures can be globular- round shaped e.g. haemoglobin or fibrous proteins e.g. collagen
structure of haemoglobin:
- 4 polypeptide chains
- 2 alpha chains
- 2 beta chains
-each chain contains a prosthetic group with one Fe3+
-soluble to maintain shape and insoluble so it doesn’t dissolve
what is the test for proteins?
biuret regent light blue - lilac
how to carry out two way chromatography?
- turn chromatogram on its side
- use different solvent to separate pigments with similar solubility in the first solvent
