Cellular Respiration 2024 PDF

Cell Energy Cellular Respiration  Aerobic Cellular Respiration – What is it? Definition~ Converting chemical energy (glucose) into usable chemical (cellular) energy (ATP) Where it occurs~ Mitochondria Type of pathway~ Catabolic * Breaks things down –Produces ATP The overall Equati...

Cell Energy Cellular Respiration  Aerobic Cellular Respiration – What is it? Definition~ Converting chemical energy (glucose) into usable chemical (cellular) energy (ATP) Where it occurs~ Mitochondria Type of pathway~ Catabolic * Breaks things down –Produces ATP The overall Equation for Cell Respiration Reactants Products  PHOTOSYNTHESIS 6 CO ___________ 6H O 2 + _________ 2 + ___________ →_______________ C6H12O6 + __________ 6O2 CELLULAR RESPIRATION C6H12O6 + _________ _____________ 6O2 →________ 6 CO2 + __________ 6 H2O + __________ The two equations are exact opposites! ______________________________________________________________  Mitochondria Mitochondria Video Respiration at the Cellular Level Cells that require more energy have more mitochondria so they can do more cellular respiration☺ List the types of organisms that do… Cell Respiration Photosynthesis Both Cell Respiration & Photosynthesis  HARVESTING CHEMICAL ENERGY All organisms do cellular respiration!!! Photosynthesis & Cellular respiration ~ opposite reactions (rxns) cricket Animation  Why do plants need both chloroplasts & mitochondria? Chloroplasts ~ use solar energy to produce glucose Mitochondria~ convert the glucose to cell energy - ATP  What is ATP? Adenosine Triphosphate Energy currency of the cell Ex. Cash – ATP / Checking account Glucose When a phosphate group is removed ~ ATP becomes ADP ( + P) – When this occurs, energy is released (Exothermic) ATP is used for: Growth and reproduction Cell Transport Mechanical work Ex. Muscle contractions  How is ATP used? As ATP is broken down into ADP, it gives off usable energy for chemical work and non-usable energy as heat. Why do cells use ATP energy and not energy from glucose? Breaking down glucose yields too much unusable energy at once; most of the energy would be wasted as heat. 1 Glucose---- 36-38 ATP (w/ oxygen) How efficient are cells at converting glucose into ATP? 38% of the energy from glucose yields ATP 62% wasted as heat  Cellular Respiration Step 1 : Glycolysis (ALWAYS occurs first) (occurs first in ALL conditions) The next stage depends on whether or not oxygen is present !!! If no oxygen, Step 2: Anaerobic Respiration AKA: Fermentation If oxygen is present, Step 2: Aerobic Respiration AKA: Cellular Respiration  Stage 1: Glycolysis - details ‘GLYCO LYSIS’ = ‘The Splitting of Glucose’ Occurs: In the CYTOPLASM (Cytosol) From Glycolysis, cells either go into – Anaerobic respiration (fermentation in the cytoplasm) or – Aerobic cellular respiration (in mitochondria)  Stage 1: Glycolysis Does not rely on Oxygen Splits glucose into 2 Pyruvates (3-carbon), also called Pyruvic Acid YIELDS a small amount of ATP –2 ATP needed to start reaction –4 ATP are produced –Net gain (total overall) is 2 ATP –NADH is made (energy carrier) Glycolysis Overview  If there is NO Oxygen Step 2~ Anaerobic Resp - Fermentation Occurs in the Cytoplasm 2 Types of Fermentation: – Alcohol Fermentation – yeast (fungi) – Lactic Acid Fermentation – bacteria & animal cells Video on Fermentation (8min)  Anaerobic Respiration This occurs when NO OXYGEN is available to the cell – TWO KINDS: Alcoholic and Lactic Acid AKA: Fermentation This results in WAY LESS ATP than in aerobic respiration  Lactic Acid Fermentation in Human Muscle Cells Lactic acid is produced in the muscles during rapid exercise when the body cannot supply enough oxygen to the tissues — causes burning sensation in muscles pyruvate + NADH lactic acid + NAD+ (still only yields 2 ATP from glycolysis, process occurs to recycle NAD+) Alcohol Fermentation Occurs in bacteria and yeast Process used in the baking and brewing industry—yeast produces CO2 gas during fermentation to make dough rise and give bread its holes Pyruvate + NADH ethyl alcohol + carbon dioxide + NAD+ (still yields only 2 ATP from glycolysis)  Total ATP Production from Respiration with No Oxygen Fermentation~ NO (more) ATP – The 2 ATP come from glycolysis, fermentation recycles the electron carriers☺ (NADH → NAD+) Stages of AEROBIC Cellular Respiration Stage 1: Glycolysis –(cytoplasm) Stage 2: Krebs Cycle –(matrix of the mitochondria) Stage 3: ETC –(inner membrane of the mitochondria) (ETC - Electron Transport Chain)  The Krebs Cycle (Stage 2) Overview Net ATP Production is 2 ATP Occurs in mitochondrial matrix Forms a molecule called Citric Acid –Krebs is AKA: The Citric Acid Cycle The Krebs Cycle (Stage 2) Details First thing that happens…… Pyruvate is turned into Acetyl-CoA when a CO2 is removed - the electrons are picked up by NAD+ (NADH)  Krebs Cycle 1 turn of the Krebs Cycle for each pyruvate molecule So…2 pyruvate molecules enter the cycle (from glycolysis) and therefore, 2 turns of the cycle occur What is generated after 2 turns: – 2 ATP – 6 NADH – 2 FADH2 – 4 CO2 HOW MANY GLUCOSE MOLECULES GENERATED THE TOTALS ABOVE? Kreb’s Cycle Video Stage 3: Electron Transport Chain [ETC] Uses the high-energy electrons from the Krebs Cycle to make 32-34 ATP from ADP and P. – High energy electrons are delivered to the ETC by NADH and FADH2 – Energy is used from electrons to pump H+ into IM space – As the gradient builds, hydrogen ions will pass thru ATP Synthase causing ADP to bind with P making 32 ATP – The hydrogen ions will then bind with oxygen to form water molecules (exhaled as water vapor) Electron Transport Chain Video  ATP Totals Aerobic Respiration Glycolysis~ 2 ATP Krebs Cycle ~ 2 ATP Electron Transport Chain~ 32-34 ATP Total = 36-38 ATP generated  Electrons carried in NADH and FADH 2 Mitochondria Electrons carried in In Cytoplasm NADH and Krebs FADH2 Electron Glucose Glycolysis Cycle Transport Chain 2 2 32 Summary of Aerobic Respiration: 3 stages:1st glycolysis 2nd Krebs cycle VIDEO 3rd Electron Transport Chain (ETC) Review of Cell Energy  Check Point 1. How many net ATP are produced during glycolysis? 2. How many ATP are produced during the Krebs cycle? 3. How many ATP produced during the ETC? 4. How many total ATP produced during Aerobic cellular respiration?  How are reactants and products for cellular respiration getting into/out of cell? Which Cell Transport Process moves the following ? – Water – Oxygen (gas) – CO2 (gas) – Glucose  Check Point 1. How many ATP are produced during alcohol fermentation? 2. What organisms do alcohol fermentation? 3. How many ATP are produced during lactic acid fermentation? 4. What organisms do lactic acid fermentation?  Human Energy and Exercise For Quick Intense Energy – Lactic Acid fermentation (ANAEROBIC) is used and produces lactic acid as a by-product, thus the muscle burn. Long-Term Energy – Uses AEROBIC cellular respiration to produce energy (most efficient – but needs OXYGEN)  Totals Anaerobic ~ 2 ATP –2 ATP come from glycolysis Aerobic~ 36-38 ATP –2 ATP from glycolysis, 2 ATP from Krebs cycle, 32-34 ATP from ETC Which is more efficient?? Anaerobic Respiration vs. Aerobic Respiration First step in BOTH is glycolysis Anaerobic Fermentation Location ~ Cytoplasm Alcohol fermentation C6H12O6 glycolysis Bacteria, Yeast No Oxygen glucose (2 ATP) Lactic acid fermentation Muscle cells Krebs ETC Aerobic Respiration Cycle (inner membrane) (matrix) 36-38 ATP Mitochondria  RECAP: Comparing Photosynthesis & Cellular Respiration Photosynthesis Cellular Respiration Function Energy Storage Energy Release Endothermic Exothermic Location Chloroplasts Mitochondria Reactants CO2 and H2O + LIGHT C6H12O6 and O2 Products C6H12O6 and O2 CO2 and H2O + ATP Equation 6CO2 + 6H2O → C6H12O6 + C6H12O6 + 6O2→ 6O2 6CO2 + 6H2O