- the breaking down of macromolecules (glucose, fa8y acids, amino acids, etc.) in the presence of oxygen to produce ATP (occurs in mitochondria) (glucose)
Burning Calories and Cellular RespiraDon Burning calories refers to the process of using biomolecules to make ATP in cellular respiradon Metabolic rate is the rate at which your body turns food molecules into usable energy (ATP) Metabolic rate is increased by exercise and adding muscle mass
What is ATP? Stands for adenosine tri- phosphate Produced in mitochondria during cellular respiradon Macromolecules from food (glucose, fa8y acids, amino acids) are needed to make ATP Nature.com
ATP Hydrolysis
To burn, or not to burn Glucose is preferendally used by most cells (if it is available) Cells will use fa8y acids or amino acids as an energy source if the glucose concentradon is not high enough Cardiovascular exercise sdmulates the use of fa8y acids for energy Both glucose and fa8y acids are used to make ATP h8p://genesdev.cshlp.org/content/20/24/3347/f7.expansion
Energy from food is measured in Calories Energy is stored in the bonds (electrons) of the food molecules Electrons from food molecules are used in the cell to produce ATP
Electron Carriers A molecule capable of accepdng one or more electrons from another molecule Carriers donate these electrons to another molecule during the process of electron transport. The energy from the electrons is used to help make ATP NAD + and FADH are e- carriers NAD+ picks up 2 e- from glucose and transports them to the e- transport chain chemistry.ewu.edu
3 Steps of Cellular Respira1on (each produces some ATP) 1) Glycolysis - spli[ng of glucose (2 ATP) (anaerobic - no O 2 needed) 2) Citric Acid (Kreb s) cycle (2 ATP) (aerobic - O 2 needed) 3) Electron transport chain (32-34 ATP) (aerobic) *steps 2 and 3 happen inside mitochondria *step 1 happens in the cytoplasm outside the mitochondria
Mitochondria Structure video h8p://www.cartage.org.lb/en/themes/sciences/zoology/animalphysiology/anatomy/animalcellstructure/mitochondria/mitochondria.htm
Cellular Respiration Overview G L U C O S E 2 3 1 2 2 32-34
Glycolysis Summary Glucose is split in half in the cytoplasm (into 2 molecules of pyruvic acid) Pyruvic acid enters the mitochondria A net gain of 2 ATP Electron carrier NADH is produced
Glycolysis (glucose to pyruvate in 10 easy steps!) tutorvista.com
What happens without oxygen? Kreb s cycle and electron transport chain (ETC) cannot occur Glycolysis is followed by fermenta2on There are two types of fermentadon: alcoholic and lac2c acid See diagram
Glucose O 2 Citric acid cycle and Electron transport chain Is split apart in Glycolysis No O 2
LacDc Acid FermentaDon Happens in muscle Dssue of humans and other animals in the absence of oxygen (anaerobic) LacDc acid and CO 2 are produced Does not produce ATP, but it does allow glycolysis to occur again and again Produces burning feeling during exercise
Alcoholic FermentaDon Happens in microorganisms (yeast and bacteria) in the absence of oxygen (anaerobic) Alcohol and CO 2 are produced Does not produce ATP, but it does allow glycolysis to occur repeatedly Used in the beer and wine industry
Kreb s Cycle (Citric Acid, TCA cycle) Follows glycolysis in aerobic condidons Happens in the mitochondrial matrix Pyruvic acid from glycoylsis is broken down more 2 more ATP are made CO 2 is produced electron carriers pick up more electrons Tutorvista.com
Electron Transport Chain Electron carriers from glycolysis and Kreb s cycle donate electrons to help make a large amount of ATP
Aerobic vs. Anaerobic Anaerobic Respira1on (glycolysis & fermenta1on) Energy produced quickly No oxygen needed Few ATP produced Used in sprindng, jumping, weight lihing Aerobic Respira1on (glycolysis, Kreb s cycle, ETC) Energy produced more slowly Oxygen needed More ATP are produced per molecule of glucose Used in endurance acdvides
Summary QuesDons 1) What occurs during glycolysis? Can this process take place without oxygen? 2) Where do the citric acid cycle and the electron transport chain take place? Can these processes take place without oxygen? 3) When would the citric acid cycle and the electron transport chain not occur? What process would happen in their place? 4) What are two benefits of anaerobic respiradon (glycolysis and fermentadon)? What is a major drawback of anaerobic respiradon?