Cellular Respiration breaking down food (chemical energy) to get ATP

  • Published on
    24-Feb-2016

  • View
    38

  • Download
    0

DESCRIPTION

CH 9 Cellular Respiration . Cellular Respiration breaking down food (chemical energy) to get ATP. mitochondria. Powerhouse of the cell! The organelle responsible for cellular respiration The Krebs Cycle and ETC take place here ATP is produced here! It is a double membrane - PowerPoint PPT Presentation

Transcript

CHAPTER 9 CELLULAR respiration

Cellular Respiration breaking down food (chemical energy) to get ATP

CH 9 Cellular Respiration mitochondria

Intermembrane Space

Powerhouse of the cell! The organelle responsible for cellular respiration

The Krebs Cycle and ETC take place here ATP is produced here!

It is a double membrane with the inner membrane highly folded (to increase the surface area and make the mitochondria more efficient). Cellular Respiration Background info Equation C6H12O6 + 6O2 6CO2 + 6 H2O + 36 or 38 ATP

When food is broken down, energy is released gradually and stored in ATP.

Respiration is done by BOTH plants and animalsGeneral overview Cellular Respiration

Glycolysis: In the cytosol Anaerobic Turns glucose to 2 pyruvate net gain of 2 ATP and 2 NADHKrebs: In the mitochondrial matrix Makes little ATP, NADH, and FADH2 (electron taxis) Passes e- to ETCETC uses chemiosmosis to make LOTS of ATPGlycolysis

Main Goal of Glycolysis is to turn glucose into two pyruvate: - Series of 10 steps - Produces a net gain of 2 ATP and 2 NADH (e- carriers) - From here it can go to the Krebs cycle (aerobic respiration) or to Fermentation (anaerobic) - Glycolysis is anaerobic - Occurs in the cytosol

Overall: Glucose 2 Pyruvate; net gain 2 ATP and 2 NADHIntermediate step

Pyruvate (made in the cytosol via glycolysis) diffuses into the mitochondria. As it diffuses is, it loses a carbon (goes from 3C to 2C) when it produces one molecule of CO2. This new 2C molecule is acetyl CoA. Acetyl CoA is what goes into the Krebs cycle. Krebs/ citric acid cycle

Main Function of the Krebs to make electron carriers (NADH and FADH2) to send to the ETC Series of 8 steps; Occurs in the mitochondrial matrixSo1 glucose produces: 2 ATP6 NADH2 FADH2(remember: 1 glucose = 2 pyruvates)Acetyl CoA (2C) enters the Krebs and combines with another molecule (4C) to form citric acid (hence citric acid cycle)Electron Carriers

Krebs Makes 1 ATP, 3 NADH, and 1 FADH2 per turnYou do NOT need to memorize this!Electron transport chain (ETC)

Occurs on the inner membrane of the mitochondria; Energy from NADH and FADH2 power ATP synthesisThe ETC is a series of proteins throughout the membrane; the electrons lose energy every time they get passed down the chainOXYGEN IS THE FINAL ELECTRON ACCEPTOR!!! oxygen combines with the electrons and H+ to make WATERMain Goal of the ETC its a stepwise free energy drop from food to oxygen; it creates a proton gradient that powers chemiosmosis to create ATP via ATP Synthase

The ETC uses energy from the electrons and pumps the protons OUT of the matrix into the intermembrane space; it then diffuses back in via ATP synthase. NADH and FADH2 drop off e- to the ETC-As the e- get passed down the chain, they lose energy; that energy is used to pump H+ OUT of the matrix into the intermembrane space-This creates a concentration gradient-The protons then diffuse back INTO the matrix via the ATP synthase (chemiosmosis); this creates ATP -Makes a TON of ATP!!!Final e- acceptor after they go down the ETC is OXYGEN (from the atmosphere) it combines with e- and H+ to make WATERCellular Respiration overview

ATP Summary Glycolysis 2Krebs 2ETC 32/34Cellular respiration vs. fermentationOxygen Present Aerobic Respiration (efficient!)

Oxygen NOT Present Fermentation (not efficient)

Respiration = 66% efficientFermentation = 3.5% efficientFermentation If there is no oxygen present (anaerobic) the pyruvate (from glycolysis) goes to fermentationThe main goal of fermentation is to make NAD+ to put back into glycolysis; it makes NO ATP on its own (it just keeps glycolysis going so that it can make 2 ATP at a time)Occurs in cytosol2 types of fermentation: alcohol and lactic acid

Pyruvate is turned into ethanol CO2 is released (bubbles!) Done by yeast for brewing

3C Pyruvate 2C EthanolRemember: Goal is to produce NAD+ to send back to glycolysis so it can keep going and produce more ATPAlcoholic FermentationLactic acid fermentation

- Pyruvate is turned into Lactate (or lactic acid)Lactate is eventually carried away by the blood to the liver where it gets converted back into pyruvateExample: Muscle Cells!! The lactic acid is what makes your muscles sore after lifting or intensive exercise No CO2 is released3C Pyruvate 3C LactateRemember: Goal is to produce NAD+ to send back to glycolysis so it can keep going and produce more ATPLactic acid vs. alcohol fermentation

Both start with pyruvate from glycolysis

Alcohol makes ethanol and gives off CO2

Lactic acid makes Lactic acid and does NOT give off CO2

Both create NAD+ to be sent back to glycolysis

Neither make any ATP on their ownFermentation - Overview

Obligate Aerobes needs oxygen; can do respiration only

Obligate Anaerobes cant have oxygen; fermentation only

Facultative Anaerobes can live with or without oxygen; prefer oxygen b/c more efficientRespiration is 19 times more efficient than fermentation (38 ATP vs. 2 ATP)

Recommended

View more >