Protein: Difference between revisions
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A protein is a biological molecule which is made up of [[Amino acid|amino acids]]. The amino acids join together with peptide bonds to form a polypeptide chain. A protein can be made up of a single polypeptide chain or multiple polypeptides linked together. | A protein is a biological molecule which is made up of [[Amino acid|amino acids]]. The [[Amino_acids|amino acids]] join together with peptide bonds to form a polypeptide chain. A protein can be made up of a single polypeptide chain or multiple [[Polypeptides|polypeptides]] linked together. | ||
Examples of proteins include [[Enzyme|enzymes]], [[Receptor|receptors]] and [[Hormone|hormones.]] They are found in evey form of life from viruses to bacteria, yeasts to humans. | Examples of proteins include [[Enzyme|enzymes]], [[Receptor|receptors]] and [[Hormone|hormones.]] They are found in evey form of life from viruses to bacteria, yeasts to humans. | ||
A protein has several 'layers' of structure. The primary structure is the sequence of [[Amino acids|amino acids]]. This is determined by the [[DNA|DNA]] sequence that encodes for that particular protein, called the gene. Secondary structure is the first level of protein folding. A protein can fold in two different ways or not at all. It can either fold as an [[Alpha-helix|alpha-helix or]] a [[Beta-sheet|beta-sheet]] depending on the sequence of amino acids. Tertiary structure relates to the protein function. If the tertiary structure is wrong then the protein is unlikely to function properly. Tertiary structure is held together by either hydrogen bonds or disulphide bridges depending o the amio acids present. Finally, if there are more than one peptide chains linked together to form a protein then you get a quarternary structure. | A protein has several 'layers' of structure. The [[Primary structure|primary structure]] is the sequence of [[Amino acids|amino acids]]. This is determined by the [[DNA|DNA]] sequence that encodes for that particular protein, called the [[Gene|gene]]. [[Secondary structure|Secondary structure]] is the first level of protein folding. A protein can fold in two different ways or not at all. It can either fold as an [[Alpha-helix|alpha-helix or]] a [[Beta-sheet|beta-sheet]] depending on the sequence of [[Amino_acids|amino acids]]. [[Tertiary structure|Tertiary structure]] relates to the protein function. If the [[Tertiary structure|tertiary structure]] is wrong then the protein is unlikely to function properly. [[Tertiary structure|Tertiary structure]] is held together by either [[Hydrogen bonds |hydrogen bonds]] or [[Disulphide bridges|disulphide bridges]] depending o the [[Amino_acids|amio acids]] present. Finally, if there are more than one peptide chains linked together to form a protein then you get a [[Quarternary structure|quarternary structure]]. | ||
Revision as of 11:49, 13 November 2010
A protein is a biological molecule which is made up of amino acids. The amino acids join together with peptide bonds to form a polypeptide chain. A protein can be made up of a single polypeptide chain or multiple polypeptides linked together.
Examples of proteins include enzymes, receptors and hormones. They are found in evey form of life from viruses to bacteria, yeasts to humans.
A protein has several 'layers' of structure. The primary structure is the sequence of amino acids. This is determined by the DNA sequence that encodes for that particular protein, called the gene. Secondary structure is the first level of protein folding. A protein can fold in two different ways or not at all. It can either fold as an alpha-helix or a beta-sheet depending on the sequence of amino acids. Tertiary structure relates to the protein function. If the tertiary structure is wrong then the protein is unlikely to function properly. Tertiary structure is held together by either hydrogen bonds or disulphide bridges depending o the amio acids present. Finally, if there are more than one peptide chains linked together to form a protein then you get a quarternary structure.