Cellular Respiration

What is Cellular Respiration? Step-by-step breakdown of glucose molecules to release energy Produce ATP Takes place day and night in ALL LIVING CELLS

Glucose + Oxygen  Carbon Dioxide + Water + Energy Cellular Respiration C6H12O6 + 6O2  6CO2 + 6H2O + Energy Glucose + Oxygen  Carbon Dioxide + Water + Energy

Where does it occur? In the Cell Mitochondria

Cellular Respiration 3 Stages Stage 1: Glycolysis O2 not required (anaerobic) Stage 2: Krebs Cycle O2 required (aerobic) Stage 3: Electron Transport Chain 2 ATPs 2 ATPs 32 ATPs

GLYCOLYSIS 2 energy tokens GLYCOLYSIS mitochondrion cytosol (ATP) - reactants products glucose GLYCOLYSIS 2 ATP Insert 1 Glucose 2 energy tokens 2 NADH GLYCOLYSIS mitochondrion cytosol (ATP) glucose derivatives - carbon dioxide 2 NADH 2 energy tokens carbon dioxide - KREBS CYCLE KREBS CYCLE - - 6 NADH 2 ATP 2 FADH2 Figure: 07-04a-b Title: Overview of energy harvesting. Caption: a. In metaphorical terms. Just as the video games in some arcades can use only tokens (rather than money) to make them function, so our bodies can use only ATP (rather than food) as a direct source of energy. The energy contained in food is transferred to ATP in three major steps: glycolysis, the Krebs cycle, and the electron transport chain. Though glycolysis and the Krebs cycle contribute only small amounts of ATP directly, they also contribute electrons (on the left of the token machine) that help bring about the large yield of ATP in the electron transport chain. b. In schematic terms. As with the arcade machine, the starting point in this example is a single molecule of glucose, which again yields ATP in three major sets of steps: glycolysis, the Krebs cycle and the electron transport chain (ETC). These steps can yield a maximum of 36 molecules of ATP: 2 in gylcolysis, 2 in the Krebs cycle, and 32 in the ETC. As noted, however, glycolysis and the Krebs cycle also yield electrons that move to the ETC, aiding in its ATP production. These electrons get to the ETC via the electron carriers NADH and FADH2, shown on the left. Oxygen is consumed in energy harvesting, while water and carbon dioxide are produced in it. Glycolysis takes place in the cytosol of the cell, but the Krebs cycle and ETC take place in the cellular organelles called mitochondria. - - 32 energy tokens - ELECTRON TRANSPORT CHAIN ELECTRON TRANSPORT CHAIN - 32 ATP Oxygen Water

Types of Cellular Respiration 1. Aerobic Occurs in the presence of oxygen Breaks down glucose completely Releases large amounts energy 36 ATP

Types of Cellular Respiration 2. Anaerobic Occurs when there is no oxygen available Partially breaks down glucose Releases very small amount of energy 2 ATP

Fermentation Anaerobic process that follows Glycolysis when there is NO OXYGEN Provides a means to continue producing ATP until Oxygen is available Does NOT produce and additional ATP JUST keeps GLYCOLYSIS going over & over

GLUCOSE 2 ATP Glycolysis Fermentation (anaerobic) Aerobic Respiration Krebs Cycle ATP Electron Transport Chain ATP

Fermentation Lactic Acid Fermentation Occurs in animal muscle cells Produces Lactic Acid as waste Only oxygen can get rid of lactic acid

Fermentation Alcoholic Fermentation Plants, Yeast & Bacteria Ethyl alcohol is produced as waste-product Basis of wine & beer industry Bread making (rise)

Respiration vs. Photosynthesis C6H12O6 + 6O2  6CO2 + 6H2O + Energy Photosynthesis: 6CO2 + 6H2O + Energy  C6H12O6 + 6O2

PHOTOSYNTHESIS The process by which light energy is used to make simple sugars (glucose) Producers/Autotrophs  the type of organisms that perform photosynthesis

Photosynthesis Equation Light Energy + 6CO2 + 6H2O  C6H12O6 + 6O2 aka SUN + Carbon Dioxide + Water  Glucose + Oxygen

Starting Materials Carbon  obtained from carbon dioxide taken in from air Light  from SUN Water  absorbed through roots

PRODUCTS Glucose  C6H12O6 used for energy Oxygen released into atmosphere as waste

TWO STAGES Light Dependent Reactions 1. Requires sunlight 2. Traps light energy in chlorophyll 3. Forms ATP

TWO STAGES B. Calvin Cycle “Light-Independent Reactions” 1. Does NOT require sunlight 2. Glucose is made using ATP from 1st stage

Plant Cell Structure Chloroplast – organelle in plant cell, site of photosynthesis

Plant Cell Structure Chlorophyll- pigment in chloroplast that absorbs ALL but green light

Microscopic view of plant cells

Cellular Respiration vs. Photosynthesis Energy from sun stored in glucose Energy in glucose released Carbon dioxide: Oxygen: Produces: Requires Light Does Not require Light Occurs only in: Occurs in:

Cellular Respiration vs. Photosynthesis Food (glucose) Produced Food (glucose) broken down Energy from sun stored in glucose Energy in glucose released Carbon dioxide: Oxygen: Produces: Requires Light Does Not require Light Occurs only in: Occurs in:

Cellular Respiration vs. Photosynthesis Food (glucose) Produced Food (glucose) broken down Energy from sun stored in glucose Energy in glucose released Carbon dioxide: Taken In Carbon dioxide: Given Off (released) Oxygen: Produces: Requires Light Does Not require Light Occurs only in: Occurs in:

Cellular Respiration vs. Photosynthesis Food (glucose) Produced Food (glucose) broken down Energy from sun stored in glucose Energy in glucose released Carbon dioxide: Taken In Carbon dioxide: Given Off (released) Oxygen: Given Off (released) Oxygen: Taken In Produces: Requires Light Does Not require Light Occurs only in: Occurs in:

Cellular Respiration vs. Photosynthesis Food (glucose) Produced Food (glucose) broken down Energy from sun stored in glucose Energy in glucose released Carbon dioxide: Taken In Carbon dioxide: Given Off (released) Oxygen: Given Off (released) Oxygen: Taken In Produces: Sugar (glucose) Produces: Water & Carbon Dioxide Requires Light Does Not require Light Occurs only in: Occurs in:

Cellular Respiration vs. Photosynthesis Food (glucose) Produced Food (glucose) broken down Energy from sun stored in glucose Energy in glucose released Carbon dioxide: Taken In Carbon dioxide: Given Off (released) Oxygen: Given Off (released) Oxygen: Taken In Produces: Sugar (glucose) Produces: Water & Carbon Dioxide Requires Light Does Not require Light Occurs only in: organisms that contain chlorophyll Occurs in: ALL living cells