2.4. Proteins Flashcards
Proteins contains:
Oxygen, Carbon, Hydrogen and Nitrogen and Sulphur
Amino acid function:
Are the molecules in which peptides and proteins are built.
Main components of the structural formula of Proteins
- An Amino group(-NH2)
- An organic acid group(carboxyl group -COOH)
- Side chain includes a_ R group
Protein types
There are 20 standard Amino acid groups
Peptide Bond/Linkages
Tow amino acids combine to form -> Dipeptide
The (amino group) of one amino acid reacts with the (Carboxyl group) of another amino acid.
remainder /yield = H2O
Condensation reaction:
a reaction in which two molecules combine to form a larger molecule,
Bi product= H2O
Primary Structure
Sequence of amino acids.
Sequence:Determines the shape and
the structure of the protein.
Secondary structure:
Develops when part of polypeptide chain by coiling up take a particular shape eg.
a-helix
b-sheets
these are permanent shapes held in place by hydrogen bonds.
Tertiary structure
- Made up of complex shape.(folded and held in Place)
- Made permanent by four different bonds:
- Established between adjacent parts of the atom(Hydrogen bond _Disulfade _Van der Waals_Ionic bond)
- Tend to take much coils eg.Fibrous and globular
Quaternary Structure
-This arises when two or more proteins are held together.(Forming a complex, biologically active molecule)
Examples of Protein:
Insulin Rubisco Immunoglobulins Rhodopsin Collagen Spider silk
Proteome
- The actual proteins made by a cell.
- Controlled by expression of genes.
- Leads to cell’s phenotype.
Genes
- 20 different amino acids
- Codons
- DNA
- mRNA strands
Protein structure
Amino acid Condensation reaction Dipeptide Polypeptide More than one polypeptide 3D shape
