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16 Cards in this Set
- Front
- Back
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What is primary structure |
Sequence of amino acids in a polypeptide chain |
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What bond joins two amino acids together |
Peptide |
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How many amino acids occur commonly in proteinsf |
20 |
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What is an essential amino acid |
Amino acids that animals can only obtain from their diet |
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Definition of secondary structure |
Interactions between amino acids in the polypeptide chain cause the chain to twist and fold into a three-dimensional shape |
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Describe an alpha helix |
Shape like an extended spring and can be up to about 35 amino acids long |
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How do hydrogen bonds form during the secondary structure and why? |
H bonds form between the slightly negative c = o and the slightly positive -NH of different amino acids that lie above and bellow each other, stabilising the shape. |
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Describe B - pleated sheet |
Amino acid chains may fold back on themselves linking together with hydrogen bonds holding the parallel chains in an arrangement known as B - pleated sheet |
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What chemical reaction joins two proteins together |
Condensation |
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What bonds are present in Tertiary and quaternary protein structure |
Hydrophobic and hydrophilic interactions Ionic bonds Disulphide bonds |
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Quaternary structure |
Proteins with more than one polypeptide chain |
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Adv and disadv of ionic/ disulphide bonds |
Much stronger than H bonds Very sensitive to changes in PH |
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What is a conjugated protein |
Have another chemical group associated with their polypeptide chain |
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Why is the structure of a protein important |
Shape of a protein allows it to perform its particular role or function |
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What is a globular protein and properties |
Polypeptide chain is folded into a compact spherical shape Soluble due to hydrophobic side chains that project on the outside. So can be transported in fluids |
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What is a fibrous protein and structure |
Several Long polypeptide chains cross linked for additional strength Important structural proteins found in connective tissue such as tendons |
