Cellular Respiration

What is Cellular Respiration? When organisms capture the _______ stored in the chemical bonds of food molecules such as glucose and other sugars made in photosynthesis. Cellular respiration builds a molecule called ATP, which powers all work within cells. energy ATP Glucose Fructose Monosaccharides Sucrose: A disaccharide

Why ATP? Why do we transfer the energy in the chemical bonds of glucose into ATP? ATP is small ATP is stable – but not too stable The bond between the 2nd and 3rd phosphates in ATP holds a lot of energy.

Aerobic Respiration Requires Oxygen Many ATP molecules are made by the mitochondria from the glucose.

Label the parts of the mitochondrion Intermembrane space

3 Steps to Cellular Respiration Breaking the bonds of Glucose for ATP Glycolysis: Occurs in the cytoplasm No O2 required 2 made Krebs or Citric Acid Cycle: Occurs in the matrix CO2 gas is released here 2 made Electron Transport Chain Occurs in the folds of the inner membrane (crista) Uses O2 and about 32 and water is made. ATP ATP ATP

Breaking the First Bond of Glucose: Glycolysis “Glyco” “lysis” literally means “sugar” “splitting”

= +2 NADH NAD+ NAD+ NADH NADH Anytime bonds break, energy is released. Energy carriers can capture some of that energy. The remainder is released as heat. NADH NAD+ P NAD+ NADH P NADH = +2

When bonds break, ATP can be made from that energy Just observe what happens next…. ATP ADP P These smaller sugar molecules made from glycolysis are called Pyruvate ATP ADP P ATP = +2

The Krebs Cycle takes place in the Matrix of the Mitochondrion, where more bonds are broken. NAD+ NADH Food for thought… what gas am I? The CO2 that gets exhaled NADH NAD+

The Krebs Cycle takes place in the Matrix of the Mitochondrion, where more bonds are broken. Citric Acid

The Krebs Cycle takes place in the Matrix of the Mitochondrion, where more bonds are broken. NADH NAD+

The Krebs Cycle takes place in the Matrix of the Mitochondrion, where more bonds are broken. NADH NAD+

The Krebs Cycle takes place in the Matrix of the Mitochondrion, where more bonds are broken. ATP ADP NAD+ NADH P

The Krebs Cycle takes place in the Matrix of the Mitochondrion, where more bonds are broken. FADH2 FADH

What is gained per glucose molecule during the Krebs Cycle? Energy Carriers NADH = +4 FADH2 = +1 +8 But there were two molecules of pyruvate that entered the Krebs Cycle… How many would actually be produced in this case? What kind of waste was made in the Krebs cycle? +2 ATP = +1 +2 6 CO2 gas!

What are the energy carriers NADH and FADH2 for? They power the Electron Transport Chain that make a lot of ATP! Inside the mitochondrion. Folds of the inner membrane known as cristae. Many ATP molecules will be produced in these Electron Transport Chains Where is the Electron Transport Chain?

During this process, oxygen gas is used, LOTS of ATP is made, and water is created. NADH ATP ATP 6 O2 FADH2 ATP FADH2 FADH2

Electron Transport Chain NADH NADH and FADH2 Electron Transport Chain 34 ATP 2 ATP 2 ATP

Cellular Respiration Equation: C6H12O6 + 6O2  6CO2 + 6H2O + 36 ATP (Glucose) Light Reactions

Photosynthesis and Respiration With a neighbor, fill in the steps in this cycle of Photosynthesis and Respiration. We will check your answers when you are done!

Fermentation: Anaerobic Respiration Glycolysis Occurs when there is not enough oxygen to sustain an activity, so ATP cannot be made in the mitochondria. Two basic types: Lactic Acid Fermentation (in animals) Alcohol Fermentation (in micro-organisms such as yeast) Fermentation keeps glycolysis going, so at least 2 ATPs can still be made, until oxygen levels are restored.