CELLULAR RESPIRATION: 3/28/2017 Harvesting Chemical Energy

What is cellular respiration? 3/28/2017 the process by which the energy contained in organic molecules is released and transferred into ATP

What is cellular respiration? 3/28/2017 oxygen is consumed as a reactant along with the organic fuel

What is cellular respiration? 3/28/2017 Aerobic respiration can release energy from a molecule of glucose to produce 38 ATP, shown in this equation. C6H12O6+6O2 --Enzymes---> 6CO2+6H2O+38ATP (Glucose) + (oxygen) (carbon-dioxide) (water)

Energy Flow and chemical recycling 3/28/2017

Overview of Cellular Respiration 3/28/2017

ATP Yield during Cellular Respiration 3/28/2017

Function of the Mitochondria The purpose of Mitochondria is to create energy for cellular activity by the process of aerobic respiration

Function of the Mitochondria During aerobic respiration, glucose is broken down in the cells cytoplasm to from PYRUVIC acid which is transported into the Mitochondria. This is called the citric and acid cycle or Krebs cycle, in which the Pyruvic acid reacts with water to produce carbon dioxide and ten hydrogen atoms.

Function of the Mitochondria Coenzymes transport the hydrogen atoms to the cristae where they are given to the electron transport chain use in the formation of ATP.

Glycolysis has NO oxygen requirement occurs in nearly all organisms and probably evolved from ancient prokaryotes before oxygen was available

Glycolysis: the facts glucose splitting 6C glucose  two 3C pyruvate catabolic process occurs in the cytosol nets 2 ATPs by substrate phosphorylation and 2 molecules of NADH

Krebs Cycle occurs in the mitochondrial matrix degrades the pyruvate derivative to carbon dioxide produces little ATP by substrate phosphorylation but much NADH

Electron Transport Chain accepts electrons from glycolysis and the Krebs Cycle passing them “downhill” from one molecule to the next in the chain at the end of the chain, electrons are combined with hydrogen ions and molecular oxygen to form water

Oxidative Phosphorylation occurs in the inner mitochondrial membrane energy released from glycolysis & Krebs is used to make ATP accounts for almost 90% of ATP generated by respiration

Oxidative Phosphorylation electrons lose little potential energy when they are transferred from food to NAD+ each molecule of NADH formed during respiration represents stored energy to make ATP when the electrons “fall” from NADH to oxygen

Oxidative Phosphorylation since oxygen is the final hydrogen acceptor, this process is known as “oxidative” phosphorylation since oxygen is required the process is aerobic respiration

A closer look at glycolysis

A closer look at glycolysis

Junction between Glycolysis & Krebs

A Closer Look at the Krebs Cycle

Summary of the Krebs Cycle

Chemiosmosis – Closer Look at ETS

Review of Cellular Respiration

Oxygen or no oxygen……….. oxidation of glucose is exergonic & some of the liberated energy is used to make ATP by substrate phosphorylation the oxidizing agent of glucose is NAD+ not oxygen glycolysis generates 2ATP (net) whether or not oxygen is present

Anaerobic Respiration Anaerobic refers to respiration where oxygen is not involved Fermentation = ATP production without the help of oxygen

Alcoholic Fermentation (Anaerobic Respiration) ………………………………………… Glucose 2 Pyruvates  2 Acetaldehydes + 2 CO2 2 Ethanols

Lactic Acid Fermentation (Anaerobic Respiration) ………………………………………… Glucose  2 Pyruvates  2 Lactates cheese, yogurt, acetone, methyl alcohol

Lactic Acid Fermentation (Anaerobic Respiration) ……………………………………… occurs when sugar catabolism outpaces the muscle’s supply of oxygen from the blood (oxygen debt) lactate results in muscle fatigue and pain

Lactic Acid Fermentation (Anaerobic Respiration) ……………………………………… lactate is eventually transported by blood to the liver and converted back to pyruvate

…………………………………… Carbohydrates, fats, and proteins can all be used as fuel for cellular respiration. …………………………………….