the function of the nucleus within the cell20 January 2012

Question:

•A healthy cell in the duodenum responsible for producing amylase is found to have an abnormally low concentration of the enzyme. What could be the cause of this anomaly?

•What do we need to know to answer this question?

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ribosome

smooth ER nucleus cell membrane

mitochondrion

lysosome

rough ERGolgi body

transcription and translation

•http://www.youtube.com/watch?v=41_Ne5mS2ls

protein synthesis

1. The nucleus receives a chemical signal to make a specific protein.2. The DNA message for the protein is copied into RNA.3. RNA leaves the nucleus through a nuclear pore.4. The RNA message is delivered to a ribosome5. The ribosome makes the protein.6. The manufactured protein enters the endoplasmic reticulum (ER).7. A vesicle forms at the end of the ER, and carries the protein to the

Golgi.8. The Golgi body repackages the protein for transport out of the cell.9. A vesicle forms off the end of the Golgi body to carry the protein to

the cell membrane.

Back to the original question…

• A healthy cell in the duodenum responsible for producing amylase is found to have an abnormally low concentration of the enzyme. What could be the cause of this anomaly?

• error in nucleotide sequence• error in transcription from DNA mRNA• error in translation from mRNA protein• other possibilities?

interesting/useful links

• DNA structure: http://www.youtube.com/watch?v=qy8dk5iS1f0

• foldit: http://fold.it/portal/

• Protein synthesis: http://www.wisc-online.com/Objects/ViewObject.aspx?ID=AP1302