Class Notes (807,845)
Canada (492,872)
Biology (6,677)
Biology 1002B (1,340)
All (8)
Lecture 4

LECTURE 4-Fundamentals of Biochemistry.docx

12 Pages
Unlock Document

Western University
Biology 1002B

Biological Function from a cellular point of view so how do organisms work There are two major paths in understanding biology and how it works One is to take a living creature and take it apart to understand subcellular components from that you can learn how the living system works The fundamental component of most cells that is important to cell structure and function are proteins Biochemistry is the area of biology where you figure out biological function by isolating certain proteins It looks at the function of the cell Other pathway looks at organism as a whole and tries to get insight into biological function by looking at genes and taking a genetic approach It looks at mutants Molecular biology brought both parts together Proteins are the structural and functional molecule of a cell Peptides produce proteins Protein abundance is the key If protein is more abundant the function of that protein goes up If less protein is made the function of that protein should go down How do you control protein abundance1Transcriptional control converting gene DNA into mRNA Make more mRNA make more protein2Translational control make lots of transcript but may not lead to an increase in protein abundance because it is regulated at translation The recruitment of tRNAs and the function of the ribosome 3Posttranscriptional control After transcription before translation Control abundance of mRNA about the transcript mRNA can break down it can degrade It is a regulate process mRNA turnoverdecay is a regulated process Break down more mRNA or keep them around longer4Posttranslational control can influence activity of a proteinProtein abundance vs activity Gene expressionConstitutive expressiongene is always on always making the same level of protein Doesnt really change Levels of certain proteins dont change Housekeeping genes Fundamental aspects of cell need a constant supply of this Induced expressionswitched on Usually on but a certain condition or in a certain tissue gene is switched off The protein is switched off Repressed expression Were interested transcript abundance Transcriptional control is a major mechanism that dictates how much protein is made How is transcript abundance measured Using Northern RNA blot analysis 15 samples of different tissues or cell samples Isolate RNA and collect them into different tubes 2Run RNA on a gel Use gel electrophoresis to load samples and isolate RNA and separate them based on size by using electric currents3What a normal RNA gel looks like The large bands are seen The dominant type of RNA in a cell is ribosomal RNA 97 of RNA in a cell is ribosomal Those bands are ribosomal RNA Dont really see mRNA bands
More Less

Related notes for Biology 1002B

Log In


Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.