Chapter 5 Section 3 Cellular Respiration Objectives Summarize

Chapter 5 Section 3 Cellular Respiration Objectives • Summarize how glucose is broken down in the first stage of cellular respiration. • Describe how ATP is made in the second stage of cellular respiration. • Identify the role of fermentation in the second stage of cellular respiration (next class) • Evaluate the importance of oxygen in aerobic respiration. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved.

New Vocabulary • • Aerobic Anaerobic Glycolysis Krebs Cycle NADH FADH 2 Fermentation Chapter

• What type of organic compounds are made during photosynthesis? Sugars (carbohydrates) • Before organisms use the energy in organic compounds, they must convert this energy to ATP cellular _____ during the process of ________ respiration _________ all • Remember, ____ organisms respire…even plants expire • If they don’t respire, they ______ Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved.

Chapter 5 Section 3 Cellular Respiration Oxygen • _________ in the air you breathe makes the production of ATP more efficient, although some without ATP is made _______ oxygen. • Metabolic processes that require oxygen are called aerobic __________. • Metabolic processes that do not require oxygen are anaerobic called ________, which means “without air. Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved.

Chapter 5 Section 3 Cellular Respiration • In the process of cellular respiration, glucose _________ is broken down to produce energy ______ within a mitochondrion _________ Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved.

Structure of the mitochondrion 2 membranes • _____ • Inner membrane is folded _____ • Space between the two membranes is called intermembrane the _______ space • Space inside the inner membrane is called the mitochondrial matrix ______ Intermembrane space Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved.

• The equation for cellular respiration is… C 6 H 12 O 6 + 6 O 2 6 CO 2 + 6 H 2 O + ATP Which reactant is needed for cellular respiration to be efficient? oxygen In addition to energy, what other products are made? Carbon dioxide, water Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved.

Chapter 5 Section 3 Cellular Respiration The Stages of Cellular Respiration • Cellular respiration occurs in three main stages: cytoplasm Stage 1 Glycolysis: occurs in the _______ mitochondrial Stage 2 Krebs Cycle: occurs in the _______ matrix _____ Stage 3 Electron Transport Chain: occurs along the folded _____ membrane inner Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved.

Chapter 5 Section 3 Cellular Respiration Glycolysis • Process in which ______ glucose is broken down into ______ pyruvates pyruvic or _______ acid cytoplasm • Occurs in the _______ not need oxygen! • Does _____ • 4 steps Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved.

Chapter 5 Section 3 Cellular Respiration Glycolysis: Step 1 2 ATP jumpstart • _____ glycolysis 2 phosphates from ATP • ____ glucose to form an join _____ unstable 6 -carbon compound Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved.

Chapter 5 Section 3 Cellular Respiration Glycolysis: Step 2 • This unstable 6 -carbon compound immediately 2 breaks into ____ 3 -carbon compounds PGAL called ______ Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved.

Chapter 5 Section 3 Cellular Respiration Glycolysis: Step 3 • As glucose is broken down some of its hydrogen atoms join ______ to form NAD+ NADH _____, which is an energy storing molecule • The hydrogen atoms are replaced by two more phosphate groups _____ Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved.

Chapter 5 Section 3 Cellular Respiration Glycolysis: Step 4 • The ____ 4 phosphates bond with 4 molecules of ADP to make 4 _______ ATP molecules • The remaining products are two 3 -carbon pyruvates, which are ions of pyruvic acid ______ • Remember that 2 ATP are needed to start the process, 2 so glycolysis produces a net gain of ______ ATP Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved.

Chapter 5 Section 3 Cellular Respiration Entering the Mitochondria • The 3 -carbon pyruvates are small enough to ______ through the mitochondrial membranes, diffuse where they are each broken down into…. CO 2 – One ____ acetyl – One 2 -carbon compound called an ______ group ______ Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved.

Chapter 5 Section 3 Cellular Respiration • This process releases another hydrogen atom which joins NAD+ to make one more molecule of _____ NADH • The acetyl group is attached to a molecule called Coenzyme A (______) Co. A forming the compound _______, Acetyl-Co. A _________ Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved.

Krebs cycle to start • Each acetyl Co. A enters the _____ stage 2 of cellular respiration twice – It turns _____, once for each acetyl Co. A Hans Krebs – This cycle is name after __________, the scientist who discovered it 4 main steps – Occurs in ____ Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved.

Chapter 5 Section 3 Cellular Respiration Stage Two: Krebs Cycle (Step 1) • Acetyl-Co. A enters the Krebs cycle by joining a 4 -carbon compound called _______ oxaloacetic _______ acid Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved.

Chapter 5 Section 3 Cellular Respiration Stage Two: Krebs Cycle (Step 1) • The new 6 -carbon compound is called citric _______ acid • Since this is the first product of the Krebs cycle, it also often called the _______ citric acid _____ cycle Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved.

Chapter 5 Section 3 Cellular Respiration Stage Two: Krebs Cycle (Step 2) CO 2 is released • _____ from citric acid, 5 resulting in a ___ carbon compound Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved.

Chapter 5 Section 3 Cellular Respiration Stage Two: Krebs Cycle (Step 3) CO 2 is released • _____ from the 5 -carbon compound, forming a ____ 4 carbon compound • So how many molecules of CO 2 are made during the Krebs cycle? 2, but it turns twice so 4 Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved.

Chapter 5 Section 3 Cellular Respiration Stage Two: Krebs Cycle (Step 4) • The 4 -carbon compound is _______, rearranged making oxaloacetic acid available for the cycle again Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved.

Chapter 5 Section 3 Cellular Respiration • This cycle also makes energy storing compounds… 3 NADH – ____ 1 ATP – ____ 1 FADH 2 • Remember that the cycle turns twice, so it is really… 6 NADH – ____ 2 ATP 2 FADH 2 – ____ Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved.

Chapter 5 Section 3 Cellular Respiration Stage Three: Electron Transport Chain • _____ NADH and ____ FADH 2 carry high energy _____ electrons to the inner membrane of the mitochondria, where they pass through an electron transport chain _______ Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved.

Chapter 5 Section 3 Cellular Respiration • The energy released from the moving electrons is used to pump _______ ions from hydrogen mitochondrial matrix to the ________ intermembrane space Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved.

Chapter 5 Section 3 Cellular Respiration • This creates a build-up of hydrogen ions which will _______ through the ATP _______ diffuse synthetase large pump, producing _____ amounts of ATP Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved.

Chapter 5 Section 3 Cellular Respiration • As the diffusion of water is called osmosis, the diffusion of chemicals, like H+, is called chemiosmosis __________ Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved.

Chapter 5 Section 3 Cellular Respiration • The last molecule in the electron transport chain to O 2 receive an electron is oxygen gas _______. It binds H 2 O with hydrogen ions to make _____ Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved.

Chapter 5 Section 3 Cellular Respiration oxygen • Without ______, the electron transport chain cannot pass along electrons and it easily gets _____ blocked or clogged up Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved.

Chapter 5 Section 3 Cellular Respiration • This is why oxygen is so essential for most organisms…without it the electron transport chain will _____ stop working and _____ ATP will no longer be produced Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved.

• The process of making large amounts of ATP in the electron transport chain is called _______ oxidative ___________ phosphorylation electrons are lost or – Oxidation results when ______ donated to other molecules • Electrons are _____ passed from molecule to molecule in the electron transport chain phosphate – Phosphorylation occurs when a ______ group is added to a molecule ADP • Phosphates are added to _____ Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved.

• Summary of ATP made during cellular respiration 2 ATP – Glycolysis = ____ 2 ATP – Krebs Cycle = ____ 32 ATP to ___ 34 ATP – Electron Transport Chain = ____ – Total… 36 ATP to ___ 38 ATP = ____ Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved.

Question 1 • What substance is broken down during cellular respiration? A. CO 2 (carbon dioxide) B. H 2 O (water) C. O 2 (oxygen) D. C 6 H 12 O 6 (glucose) Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved.

Question 2 • Why must glucose be converted to 2 pyruvates in the cytoplasm, before these molecules cross through the mitochondrial membranes? Glucose is too big to diffuse across the membranes Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved.

Question 3 • What is the first compound made during the Krebs cycle? A. Oxaloacetic acid B. Citric acid C. Acetyl Co. A D. pyruvate Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved.

Question 4 • Which energy storing compound is not made during the Krebs cycle?

Question 5 • Which molecule is necessary to prevent the electron transport chain from becoming clogged or backed up? A. CO 2 (carbon dioxide) B. H 2 O (water) C. O 2 (oxygen) D. C 6 H 12 O 6 (glucose) Chapter menu Resources Copyright © by Holt, Rinehart and Winston. All rights reserved.