Test Date: Nov 28 th (B-DAY) Nov 29 th (A-DAY) Lab: Closed-toe shoes Thursday (BDAY) Friday (ADAY)

Essential Questions What is cellular Respiration? What is the equation for cellular respiration? What are the similarities/differences with photosynthesis? Stages: AerobicAnaerobic – glycolysisglycolysis – Krebs cyclefermentation – Electron Transport

Food A living organism such as an animal consumes food, then converts some of that food into useable ATP. The rest gets stored and converted later Proteins, carbohydrates, lipids can all be used to convert to ATP but at different rates Lipids give long term large amounts of energy carbs give short term quick energy Proteins give the least amount of useable energy, so body usually stores it instead of converting it

The role of ATP Adenosine Triphosphate is the energy currency in living organisms It cannot be stored-instead glucose is stored and converted as the body needs it. This conversion is called cellular respiration When ATP is made, it then can be released and used by the cells in functions such as making proteins, active transport, and maintaining homeostasis Glucose must be converted slowly in order to get the maximum amount of ATP from it. It does this in stages

Cellular Respiration Overview Goal: to convert chemical energy (food) into useable energy (ATP) Two types – aerobic  in the presence of oxygen – anaerobic  without oxygen Glycolysis is the first step regardless if there is oxygen or not – takes place in the cytoplasm of the cell

Equation

Glycolysis-pre step Goal: One molecule of glucose is broken in half, producing two molecules of pyruvic acid Steps: – Two ATP molecules are used to break down a glucose molecule – It is split into two three carbon molecules (3Carbon; 3C). Enzymes rearrange the molecules – Energized electrons from the molecules are transferred to molecules of NAD+ to make NADH – A series of reactions converts the 2 3C molecules to pyruvate, which will enter the mitochondria for cellular respiration – 4ATP are made Equation: – Glucose+2ATP  2Pyruvate+NADH+4ATP

Krebs Cycle (citric acid cycle)-aerobic Named after Sir Hans Adolf Krebs Each pyruvate will enter the Kreb’s cycle and be transformed into several products: – 4NADH – 3CO 2 – FADH 2 – 1ATP Equation: 2pyruvate  8NADH+6CO 2 +2FADH 2 +2ATP

Steps to Krebs Cycle 1. Pyruvate broken down into two 2C molecules- NADH is formed, CO2 is released 2. Coenzyme A bonds to 2C molecule-this molecule goes into Krebs cycle 3. The 2C part binds to a 4C molecule creating citric acid (6C). Coenzyme A goes back to step 2 4. Citric acid is broken down into a 5C molecule. CO2 is released. NADH is formed 5. 5C is broken down into a 4C molecule. CO2 is released. NADH is released. ATP is released 6. 4C molecule is rearranged forming NADH and FADH2 which get released out of the Krebs Cycle

Electron Transport Chain The electron transport chain is a series of chemical reactions ending with hydrogen combining with oxygen to form water. Carbon dioxide is released as a waste product as it is formed in several stages of the Krebs cycle. Each reaction produces a small amount of energy, which by the end of the cycle produces many (up to 36) ATP molecules. The ATP synthesized can be used by the cell for cellular metabolism

ATP created All of the NADH and FADH2 from the Krebs Cycle are converted into ATP which is usable energy. Most scientists will agree that between ATP are formed from the Krebs cycle and Electron Transport. BUT… you spent 2 ATP in glycolysis so truly you only NET ATP.

Anaerobic respiration Glycolysis-same glycolysis as aerobic respiration – One glucose is split into two pyruvate producing two ATP total Fermentation-Two types, both named after products in which they produce. Aerobic respiration produces water – Lactic acid  – Alcoholic 

Equation

Lactic Acid Fermentation Lactic acid fermentation occurs when oxygen is not available, for example, in muscle tissues during rapid and vigorous exercise when muscle cells may be depleted of oxygen. The pyruvic acid formed during glycolysis is broken down to lactic acid, and in the process energy is released (which is used to form ATP). Glucose  Pyruvic acid  Lactic acid + energy The process of lactic acid fermentation replaces the process of aerobic respiration so that the cell can continue to have a continual source of energy even in the absence of oxygen, however this shift is only temporary and cells need oxygen for sustained activity. Lactic acid that builds up in the tissue causes a burning, painful sensation.

Alcoholic Fermentation Alcohol fermentation occurs in yeasts and some bacteria. In this process, pyruvic acid formed during glycolysis is broken down to produce alcohol and carbon dioxide, and in the process energy is released (which is used to form ATP). Glucose  Pyruvic acid  alcohol + carbon dioxide + energy

Why learn about fermentation? Cheese Bread Alcohol Wine

Venn Diagram