DOC PREVIEW
UW-Madison BIOLOGY 151 - Chemiosmosis

This preview shows page 1 out of 3 pages.

Save
View full document
View full document
Premium Document
Do you want full access? Go Premium and unlock all 3 pages.
Access to all documents
Download any document
Ad free experience
Premium Document
Do you want full access? Go Premium and unlock all 3 pages.
Access to all documents
Download any document
Ad free experience

Unformatted text preview:

BIO 151 1st Edition Lecture 26 Outline of Last Lecture 1. Beginning of cycle2. Rest of cycle3. Krebs cycle (know this)4. But...5. Intermembrane Space6. Oxidative Phosphorylation7. Electron Transport Chain8. Electrons in chain often carried by metal atoms9. Mitochondrial ATP synthase is a turbine10. 2 steps of oxidative phosphorylation11. How efficient is it?Outline of Current Lecture 1. Chemiosmosis2. Complexities with respiration #13. Fermentation4. What if there is oxygen?5. Complexities #2: What if there's no sugar?6. Complexities #3: Homeostatic control7. Where do animals and fungi get their energy-yielding organic molecules?8. Chloroplast9. Light Reactions vs. Dark Reactions10. Calvin Cycle11. Calvin Cycle x3 - know this12. Photorespiration - When good rubisco goes bad!Current Lecture Chemiosmosis:- flow of ions across a lipid bilayer- usually used to mean flow of H+ through ATPase, as in mitochondria and chloroplasts- if no oxygen (O2), then the electron transport chain won't work- also effects glycolysis and Krebs cycle because of buildup of NADH and lack of NAD+- NAD+ is a reactant for bothComplexities with respiration #1:- aerobic = with oxygen- anaerobic = no oxygen, no respiration- limited pool of NAD+- conversion of NADH back into NAD+ by oxidative phosphorylation requires oxygen- no NAD+ = no glycolysis or Krebs cycle- solution: add steps to glycolysis to regain NAD+ from NADH = fermentationFermentation:- to get NAD+ back if there is no O2These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.- 2 common types- 1) lactic acid fermentation (used by us)- 2) ethanol fermentation (used by yeast)- products of fermentation cannot enter the Krebs cycle- no NADH for oxidative phosphorylation- 2 ATPs per glucoseWhat if there is oxygen?:- some rapidly dividing yeasts prefer fermentation instead of respiration- rapidly dividing cancer tumors use lactic acid fermentation instead of respiration- "Warburg" effect- Why?- leading hypothesis: rapidly dividing cells need products of fermentation to build new molecules more thanthey need ATP- need raw ingredients more than energy for growth?- several other branches leading away from glycolysis - pentose phosphate pathwayComplexities #2: What if there's no sugar?:- alternative inputs: cells get energy from many organic molecules, not just sugarsComplexities #3: Homeostatic control:- can use negative feedback for allosteric control of enzyme activity- ex. ATP or citric acid binds to enzyme, inhibits glycolysis - phosphofructokinaseWhere do animals and fungi get their energy-yielding organic molecules?:- 1) From stored resources- 2) From other animals and fungi- 3) From plants which can do photosynthesis- energy from sunlight = photosynthesis in chloroplastsChloroplast:- surrounded by 2 membranes- space inside inner membrane = stroma- membrane-bound discs in stroma = thylakoids, stacked into granaLight Reactions vs. Dark Reactions:- light - use light and electrons from H2O to make O2, ATP and electron in NADPH, in thylakoid membranes- dark - use CO2, ATP, and electrons in NADPH to make sugar, in stroma- dark reactions in stroma of chloroplast = the Calvin CycleCalvin Cycle:- 1) Carbon "fixation" - rubisco enzyme adds CO2 to 5-carbon ribulose bisphosphate (RuBP)- 2) Reduction produces glyceraldehyde - 3-phosphate (G3P)- 6 3-carbons produces 6 3-carbon G3Ps- 1 G3P removed from cycle, used to make sugars- 3) Regeneration of RuBP- 5 G3Ps and ATP regenerate 3 5-carbon RuBP (starting material)- count the carbons in cycleCalvin Cycle x3 - know this:- 1) Carbon fixation - 3 RuBP + 3 CO2 -> 6 3-carbon chains, including rubisco- 2) Reduction - produces 6 G3Ps, 1 of which is used to make sugars- 3) Regeneration - remaining 5 G3Ps regenerate 3 5-carbon RuBPs- 3x through Calvin Cycle uses 9 ATPs, electrons in 6 NADPHsPhotorespiration: when good rubisco goes bad!:- when O2 concentration gets much higher than CO2, rubisco adds O2 to 5-carbon RuBP, some of product makes CO2- to keep CO2 concentration high, C4 and CAM plants fix and "store" CO2, release before Calvin


View Full Document

UW-Madison BIOLOGY 151 - Chemiosmosis

Documents in this Course
Load more
Download Chemiosmosis
Our administrator received your request to download this document. We will send you the file to your email shortly.
Loading Unlocking...
Login

Join to view Chemiosmosis and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view Chemiosmosis 2 2 and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?