Respiration Chapter 9

Breathing Lungs Muscle cells Cellular respiration Figure 6.4

Cellular Respiration The exact opposite of photosynthesis. The process by which living organisms get energy by breaking down carbohydrates. This important job is the responsibility of the mitochondria.

Ruby Lu’s cells are doing respiration ALL the time, even when she is sleeping! The bears are not living, so no respiration!

Ruby & Bella playing means more energy is needed, so more cellular respiration!

Figure 9–2 Cellular Respiration: An Overview Mitochondrion Electrons carried in NADH Electrons carried in NADH and FADH2 Pyruvic acid Glucose Electron Transport Chain Krebs Cycle Glycolysis Mitochondrion Cytoplasm

The Overall Equation for Cellular Respiration A common fuel molecule for cellular respiration is glucose This is the overall equation for what happens to glucose during cellular respiration Carbon dioxide Water Energy Glucose Oxygen Unnumbered Figure 6.1

Cellular Respiration Three Stages Glycolysis Citric acid cycle (Kreb’s Cycle) Electron transport chain

Glycolysis Glycolysis is an anaerobic reaction Glucose is broken in half producing 2 pyruvic acid These molecules release 4 ATP’s. Unfortunately, glycolysis requires 2 ATP’s to get started so it is not very efficient.

To the electron transport chain Figure 9–3 Glycolysis Section 9-1 Glucose 2 Pyruvic acid To the electron transport chain

To the electron transport chain Figure 9–3 Glycolysis Section 9-1 Glucose 2 Pyruvic acid To the electron transport chain

To the electron transport chain Figure 9–3 Glycolysis 9-1 Glucose 2 Pyruvic acid To the electron transport chain

NAD High energy electrons created in glycolysis is passed to NAD Occurs very quickly in a reaction. Glycolysis would stop if no NAD was present to carry the electrons.

Oxygen Respiration can occur with or without oxygen. When there is no oxygen, you have two entirely different sets of reactions dependent on what type of organism you are.

Alcoholic Fermentation Occurs in yeast cells and some other organisms. Occurs when there is no oxygen. This is what causes bread to rise when being baked. This is also how we get wine and beer.

Lactic Acid Fermentation Occurs in animal cells Occurs when there is little or no oxygen What causes the burning sensation in muscles. Used in dairy industry to make cheese & yogurt

Figure 9–4 Lactic Acid Fermentation Section 9-1 Figure 9–4 Lactic Acid Fermentation Lactic acid Glucose Pyruvic acid

Figure 9–4 Lactic Acid Fermentation Section 9-1 Figure 9–4 Lactic Acid Fermentation Lactic acid Glucose Pyruvic acid

Figure 9–4 Lactic Acid Fermentation Section 9-1 Figure 9–4 Lactic Acid Fermentation Lactic acid Glucose Pyruvic acid

Citric Acid Cycle Also called the Krebs cycle- a series of aerobic chemical reactions in which electron carriers (NADH & FADH) are produced. These carriers provide the electrons(energy) for the next step of respiration.

Figure 9–6 The Krebs Cycle Section 9-2 Figure 9–6 The Krebs Cycle Citric Acid Production Mitochondrion

Figure 9–6 The Krebs Cycle Section 9-2 Citric Acid Production Mitochondrion

Electron transport chain The 3rd and final stage. The electrons from the krebs cycle pass through the mitochondrion wall and bond to oxygen. This chain releases 32 ATP’s and H2O as long as Oxygen is present. Very efficient.

Energy Production Comparisons

Eukaryotes (Have Membranes) Total ATP Yield 02 ATP - glycolysis (substrate-level phosphorylation) 04 ATP - converted from 2 NADH - glycolysis 06 ATP - converted from 2 NADH - grooming phase 02 ATP - Krebs cycle (substrate-level phosphorylation) 18 ATP - converted from 6 NADH - Krebs cycle 04 ATP - converted from 2 FADH2 - Krebs cycle 36 ATP - TOTAL

Photosynthesis vs Cellular Respiration

Bill Nye and Respiration