Class Notes (887,096)
CA (530,907)
Ryerson (29,872)
BLG (541)
BLG 151 (48)
Lecture 10

BLG 151 Lecture 10: Chapter 11 notes

13 Pages

Course Code
BLG 151
Martina Hausner

This preview shows pages 1-3. Sign up to view the full 13 pages of the document.

Loved by over 2.2 million students

Over 90% improved by at least one letter grade.

Leah — University of Toronto

OneClass has been such a huge help in my studies at UofT especially since I am a transfer student. OneClass is the study buddy I never had before and definitely gives me the extra push to get from a B to an A!

Leah — University of Toronto
Saarim — University of Michigan

Balancing social life With academics can be difficult, that is why I'm so glad that OneClass is out there where I can find the top notes for all of my classes. Now I can be the all-star student I want to be.

Saarim — University of Michigan
Jenna — University of Wisconsin

As a college student living on a college budget, I love how easy it is to earn gift cards just by submitting my notes.

Jenna — University of Wisconsin
Anne — University of California

OneClass has allowed me to catch up with my most difficult course! #lifesaver

Anne — University of California
Microbiology Chapter 11: Catabolism Energy Release and Conservation (please review detailed information in textbook) 11.1 Metabolic Diversity and Nutritional Types Requirements for Carbon, Hydrogen, and Oxygen  Often satisfied together  Carbon source often provides H, O, and electrons  Heterotrophs:  use organic molecules as carbon sources which often also serve as energy source.  Can use a variety of carbon sources  Autotrophs:  Use carbon dioxide as their sole or principal carbon source  Must obtain energy from other sources Nutritional Types of Organisms  Based on energy source  Phototrophs: use light  Chemotrophs: obtain energy from oxidation of chemical compounds  Based on electron source  Lithotrophs: use reduced inorganic substances  Organotrophs: obtain electrons from organic compounds Classes of Major Nutritional Types  Majority of microorganisms known  Photolithoautotrophs (photoautotrophs)  Chemoorganoheterotrophs (chemoheterotrophs) - Majority of pathogens  Ecological importance  Photoorganoheterotrophs  Chemolithoautotrophs Fueling Reactions  Despite diversity of energy, electron, and carbon sources used by organisms, they all have the same basic needs  ATP as an energy currency  Reducing power to supply to supply electrons for chemical reactions  Precursor metabolites for biosynthesis Microorganisms May Change Nutritional Type  Some have great metabolic flexibility based on environmental requirements  Provides distinct advantage if environmental conditions change frequently Practice Question  When electrons flow from NAD+/NADH conjugate redox pair, does the reaction begin with NAD+ or with NADH? What is produced – O or H O? 2 2  Answer: i) NADH ii) H O2 o  In general terms, how is G related to E’o? o  Recall: G – standard free energy change at pH7: maximum amount of energy available for useful work under standard conditions  E’ - standard electron potential at pH7: measure of the tendency of the donor of a o half reaction to lose electrons; measure of potential energy  When electrons move from the donor to the acceptor, free energy is released and G of the reaction is directly related to the magnitude of the difference between the reduction potential of the two couples (o’ ): E’ois the E’oof the acceptor - E’oof the donor  The larger the E’othe greater the amount of free energy available 3+ 2+  What is the E’owhen electrons flow from NAD+/NADH redox pair to the Fe /Fe redox pair?  How does this compare to the E’ ohen electrons flow from Fe to Fe conjugate redox pair to the 1/22 / H2O pair?  Which will yield the largest amount of free energy to the cell? 11.2 There Are Three Chemo-organotrophic Fueling Processes Chemoorganotrophic Fueling Processes  Chemoorganotrophs are also called chemoheterotrophs  Processes  Aerobic respiration  Anaerobic respiration  Fermentation Chemoorganic Fueling Processes – Respiration  Respiration involves use of an electron transport chain  As electrons pass through the electron transport chain to the final electron acceptor, PMF is generated and used to synthesize most ATP by ox phos and a small amount by SLP Chemoorganic Fueling Processes – Respiration  Aerobic respiration  Final electron acceptor is oxygen  Anaerobic respiration  Final electron acceptor is different exogenous acceptor such as NO ,3SO , 4O , Fe2, or SeO 42-  Organic acceptors may also be used Chemoorganic Fueling Processes – Fermentation  Uses an endogenous electron acceptor: usually an intermediate of the pathway used to oxidize the organic energy source e.g. pyruvate  Does not involve the use of an electron transport chain nor the generation of a proton motive force  ATP synthesized only by the substrate-level phosphorylation (SLP) Energy Sources  Many different energy sources are funneled into common (but Few) degradative pathways  Having only few pathways that degrade many nutrients greatly increase metabolic efficiency  Most pathways generate glucose or intermediates of the pathways used in glucose metabolism and funnel metabolites into the glycolytic pathway or tricarboxylic acid cycle Catabolic Pathways  Enzyme catalyzed reactions whereby the product of one reaction serves as the substrate for the next  Pathways with enzymes that function both catabolically and anabolically also provide materials for biosynthesis – amphibolic pathways Amphibolic Pathways  Function both as catabolic and anabolic pathways  Important ones:  Embden-Meyerhof pathway (figure below)  Pentose phosphate pathway  Tricarboxylic acid (TCA) cycle Question  Is NAD+ reduced to NADH in the catabolic or anabolic direction of this pathway? 11.3 Aerobic Respiration Can Be Divided into Three Steps Aerobic Respiration  Process that can completely catabolize a reduced organic energy sour2e to CO using  Glycolytic pathways (glycolysis)  TCA cycle (Krebs)  Electron transport chain with oxygen as the final electron acceptor  Produces pyruvate, NADH, FADH 2r both  Partially oxidized carbon is fed into the TCA cycle and oxidized complet2ly to CO , some GTP or ATP, NADH and FADH wh2ch are oxidized in an electron transport chain to produce ATP 11.4 Glucose to Pyruvate: The First Step The Breakdown of Glucose to Pyruvate – The Bacterial Way!  Three common routes of catabolizing glucose to pyruvate – all glycolysis!  Embden-Meyerhof pathway  Pentose phosphate pathway  Entner-Duodoroff pathway The Embden-Meyerhof Pathway  Occurs in cytoplasmic matrix of most microorganisms, plants, and animals  The most common amphibolic pathway for glucose degradation to pyruvate  Provides precursor metabolites, NADH and ATP to the cell  Funtions in presence or absence of2O  Two phases:  Six carbon phase (6-C)  Three carbon phase (3-C) Six Carbon Phase:  ATP is used to phosphorylate glucose twice, adding phosphates to each end of the sugar  2 ATP is invested so that more ATP can be made later (‘priming the pump’) Three Carbon Phase:  Energy conserving phase, ATP and NADH are produced  ATP is made by SLP because ADP phosphorylation is coupled to exergonic hydrolysis of a high energy molecule, with a higher phosphate transfer potential than ATP (1,3- biphosphogylcerate) nd  A 2 ATP is made by SLP when phosphate on phosphoenolpyruvate is donated to ADP  Pyruvate is formed  4 ATP and 2 NADH per glucose are generated in this phase Summary of Glycolysis  Embden Meyerhoff  Most common  Important in anabolic pathways since it provides several precursor molecules  Occurs in cytoplasm  Produces 2 ATP (4 ATP from 3C phase minus 2 ATP from 6C phase), 2NADH (3C phase), 2H+ (3C phase), 2 pyruvate (3C phase) The Entner – Duodoroff Pathway  Used by some soil bacteria and a few other Gram – negative bacteria  Replaces the first phas
More Less
Unlock Document
Subscribers Only

Only pages 1-3 are available for preview. Some parts have been intentionally blurred.

Unlock Document
Subscribers Only
You're Reading a Preview

Unlock to view full version

Unlock Document
Subscribers Only

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.