Proteins Flashcards
what are proteins made of
amino acids are the monomers that make up polypeptides. These combine to make proteins.
how many amino acids have been identified
over 100, but only 20 are made naturally.
what is the general structure of all amino acids?
every amino acid has a central carbon atom to which are attached four different chemical groups.
what are the four chemical groups in amino acids?
- -NH2 (amino group)
- -COOH (carboxyl group)
- -H (hydrogen atom)
- R (side chain, varies according to the amino acids)
what is made when amino acid monomers combine?
dipeptide
what is the reaction between two amino acid monomers called?
condensation reaction
how is the water made when amino acid monomers combine?
the -OH from one amino acid combines with the -H from the other amino acid to make H2O
what bond is created after the amino acid reaction
a peptide bond between the C of one acid and the N of the other.
how can the peptide bond be broken
hydrolosis
What is a polypeptide?
lots of amino acids joined together via polymerisation to make a chain of hundreds of amino acids.
What is the primary structure of a protein?
the sequence and number of amino acids
what is the secondary structure of a protein?
When the H from the -NH has a positive charge and the O from the -C=O group is negatively charged. these two attract each other and turn the straight chain of amino acids into a 3D alpha helix.
what bonds occur during the secondary structure?
hydrogen bonds between the +H and -O
what is the Tertiary structure of a protein?
when the alpha helices are twisted and folded into a more complex, but specific structure.
what three bonds are involved in the tertiary structure?
- disulfide bridges (fairly strong, not broken easily)
- ionic bonds ( formed between carboxylic and amino groups and can be broken by pH changes)
- Hydrogen bonds (lot of then and are easily broken)
