Lactase (a protein): Difference between revisions
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Lactase is a protein. Like many proteins that function as enzymes (e.g. polymerase, amylase, kinase, peroxidase), its name ends in -ase. | Lactase is a protein. Like many proteins that function as enzymes (e.g. polymerase, amylase, kinase, peroxidase), its name ends in -ase. | ||
Proteins are macromolecules assembled from amino acid building blocks. The amino acids are linked through condensation reactions, forming a <scene name='10/1056674/Secondary/4'>linear chain</scene> (the primary structure) connected by peptide bonds | Proteins are macromolecules assembled from amino acid building blocks. The amino acids are linked through condensation reactions, forming a <scene name='10/1056674/Secondary/4'>linear chain</scene> (the <scene name='10/1056674/Primary/1'>primary structure</scene>). | ||
<jmol> | |||
<jmolButton> | |||
<script>zoomto 4</script> | |||
<text>zoom in</text> | |||
</jmolButton> | |||
</jmol> | |||
The amino acids are connected by peptide bonds. For this reason, proteins may also be called polypeptides. This protein has 1225 amino acids. Can you find the peptide bonds in <scene name='10/1056674/Peptide_bond/1'>this segment of three amino acids</scene> (showing the amino acids 833 through 835)? | |||
[[Image:Peptide bond.jpg|300px]] | [[Image:Peptide bond.jpg|300px]] | ||
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[[Image:Secondary structure OpenStax.jpg|360px]] | [[Image:Secondary structure OpenStax.jpg|360px]] | ||
Tertiary structure refers to the overall shape resulting from the assembly of secondary structure elements through <jmol> | <scene name='10/1056674/Tertiary/5'>Tertiary structure</scene> refers to the overall shape resulting from the assembly of secondary structure elements through interactions between their sidechains. The details are easier to see if you <jmol> | ||
<jmolLink> | <jmolLink> | ||
<script> moveto 1.0 { 761 578 295 157.18} 1237.57 0.0 0.0 {-25.64624999999998 35.13546296296296 -40.1739398148148} 150.0601990776041 {0 0 0} 0 0 0 3.0 0.0 0.0; | <script> moveto 1.0 { 761 578 295 157.18} 1237.57 0.0 0.0 {-25.64624999999998 35.13546296296296 -40.1739398148148} 150.0601990776041 {0 0 0} 0 0 0 3.0 0.0 0.0;</script> | ||
<text> | <text>zoom in</text> | ||
</jmolLink> | </jmolLink> | ||
</jmol>. | </jmol> and just show <scene name='10/1056674/Tertiary/3'>part of the structure</scene>. | ||
[[Image:Tertiary_interactions2.png|300px|frame|Tertiary interactions include (a) ionic interactions, (b) hydrogen bonds, (c) disulfide bonds and (d) hydrophobic interactions.]] | [[Image:Tertiary_interactions2.png|300px|frame|Tertiary interactions include (a) ionic interactions, (b) hydrogen bonds, (c) disulfide bonds and (d) hydrophobic interactions.]] | ||