MICRB 265 (09/27/13) BIOENERGETICS: Part 1 - Energetics and Enzymes (con't) | Part 2 - Fermentation and Respiration

4 Pages
79 Views
Unlock Document

Department
Microbiology (Biological Sciences)
Course
MICRB265
Professor
Brian Lanoil
Semester
Fall

Description
MICRB 265 (September 27, 2013) BIOENERGETICS: Part 1 – Energetics and Enzymes | Part 2 – Fermentation and Respiration  Enzymes often bind substrates of similar structures Allosteric regulation – binding to enzyme of an effector molecule that causes an increase/decrease in protein activity  Binding of effector molecule to allosteric site  enzyme shape change  substrate’s ability to attach to enzyme is affected  Positive effector – CAUSES binding of substrate to catalyst  Negative effector – PREVENTS binding of substrate to catalyst (by changing the shape of the enzyme  “lock change”) Feedback inhibition of a Sequential Reaction  Concentration of end product acts as modulator. o If concentration is high, it binds to the first enzyme in the pathway (acts as a negative effector) to shut down its own production o Why the first enzyme in a sequential reaction?  Because the intermediates preceding the production of the end product may be toxic Feedback Inhibition: Branched Pathway  Glutamic acid has two production pathways… one for the production of ARGININE and one for the production of PROLINE o They are created on completely disjoint pathways so the feedback inhibition of one does not affect the production of another o Just like in single path sequential reactions, it is the first enzyme in the sequence that gets inhibited when end product concentrations get too high Covalent Modification  Reversible addition of phosphoryl, methyl, or adenyl groups will either inhibit or activate enzyme activity Start of Part II: Fermentation and Respiration Overview of Cell Metabolism “Auto-“ – organism can fix own carbon “Litho-” – organism implements inorganic carbon Mixotrophy – combined chemolithotrophy and chemoorganotrophy  H 2xidizing bacteria will either grow with C2 fixing bacteria or on their own as organotrophs  Some chemolithotrophs lack enzymes for CO fi2ation Respiration and Fermentation  Both are ways of getting ATP o Fermentation via substrate-level phosphorylation o Respiration via oxidative phosphorylation  More energy per molecule created than fermentation  Energized membrane used for phosphorylation  Respiration implements substrate-level phosphorylation too but is it not the cell’s main source of
More Less

Related notes for MICRB265

Log In


OR

Join OneClass

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

Sign up

Join to view


OR

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.


Submit