4.4 Overview of Cellular Respiration KEY CONCEPT Respiration is a series of chemical reactions that releases energy stored in food to make ATP molecules. ATP is the energy source for cells to do work

4.4 Overview of Cellular Respiration Two forms of Respiration 1. Aerobic Respiration-Requires Oxygen gas 2. Anaerobic Respiration–Oxygen not needed

4.4 Overview of Cellular Respiration Two Forms of Respiration Anaerobic Does Not Require Oxygen Consists of 2 Stages: - Glycolysis - Fermentation Produces 2 ATP molecules Rxns occur in Cytoplasm Aerobic Requires Oxygen Consists of 3 Stages: - Glycolysis - Kreb’s Cycle - Electron Transport Chain Produces 38 ATP Rxns occur in Mitochondria

4.4 Overview of Cellular Respiration Glycolysis is the first step in both types of respiration Does Not Require Oxygen Occurs in cytoplasm Means “sugar splitting” Glucose is “split” into two pyruvic acid molecules (Hi E) Requires the energy from 2 ATP molecules Net product 2 ATP molecules (makes 4 but requires 2)

4.4 Overview of Cellular Respiration Aerobic Anaerobic GLYCOLYSIS

4.4 Overview of Cellular Respiration Respiration With Oxygen

4.4 Overview of Cellular Respiration Aerobic Cellular Respiration C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O + Energy Reactants Products ___________________ _____________

4.4 Overview of Cellular Respiration Aerobic Cellular Respiration C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O + Energy Reactants Products C 6 H 12 O 6 - Glucose 6CO 2 – Carbon Dioxide gas 6O 2 – Oxygen gas 6H 2 O - Water

4.4 Overview of Cellular Respiration Aerobic respiration occurs in the Mitochondria

4.4 Overview of Cellular Respiration Stage 1: Kreb’s Cycle Pyruvic acid molecules made in glycolysis move into the mitochondria – they become the reactants in Kreb’s cycle Energy stored in pyruvic acid is transferred to other molecules that “carry energy” to next stage Carbon atoms released from the breakdown of pyruvic acid form CO 2, a waste product that we exhale 6H O 2 6CO 2 6O 2 mitochondrion matrix (area enclosed by inner membrane) inner membrane ATP energy energy from glycolysis and

4.4 Overview of Cellular Respiration Stage 2: Electron Transport Chain (ETC) The ETC is a chain of protein molecules attached to the mitochondria’s inner membrane.

4.4 Overview of Cellular Respiration 6H O 2 6CO 2 6O 2 mitochondrion matrix (area enclosed by inner membrane) inner membrane ATP energy energy from glycolysis and The high energy carrier molecules made in in glycolysis and Krebs Cycle release their “excited” electrons which are passed from one protein molecule to another releasing energy with each transfer. That energy is used to make ATP Oxygen is needed because its highly electronegative which attracts the electrons causing them to be “pulled” through the electron transport chain. H 2 O released as waste product 34 more ATP made

4.4 Overview of Cellular Respiration Cytoplasm Mitochondria 2234

4.4 Overview of Cellular Respiration Respiration Without Oxygen Anaerobic Respiration

4.4 Overview of Cellular Respiration Anaerobic Respiration - Fermentation Begins with glycolysis which makes 2 ATP Occurs in the cytoplasm

4.4 Overview of Cellular Respiration Anaerobic Respiration - Fermentation Occurs when Oxygen is not available – anaerobic process NO additional ATP is made

4.4 Overview of Cellular Respiration If no ATP is made, why is fermentation necessary? Replaces molecules needed to keep glycolysis working so 2 ATP can be made

4.4 Overview of Cellular Respiration Two Types of Fermentation There are two reaction pathways of fermentation They are named for the final product made:

4.4 Overview of Cellular Respiration Two Types of Fermentation Lactic Acid fermentation Animals produce in muscle cells During strenuous exercise – Creates “muscle burn” sensation

4.4 Overview of Cellular Respiration Two Types of Fermentation Alcoholic fermentation Yeast – Bread, Wine, Beer Bacteria – Yogurt, Sauerkraut

Different organism produce different fermentation products

4.4 Overview of Cellular Respiration Anaerobic vs. Aerobic

4.4 Overview of Cellular Respiration All organism carry out respiration in their cells All living things must carry out respiration in order to transform the energy stored in food to the energy stored in ATP. Plants also have mitochondria and carry out respiration in order to release the energy stored in the food they made through photosynthesis.

4.4 Overview of Cellular Respiration The equation for the overall process is: C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O The reactants in photosynthesis are the same as the products of cellular respiration.

4.4 Overview of Cellular Respiration Compare and Contrast the 2 Energy Transformation Processes Photosynthesis 6CO 2 + 6H 2 O >C 6 H 12 O 6 + 6O 2 Cellular Respiration C 6 H 12 O 6 + 6O > 6CO 2 + 6H 2 O

4.4 Overview of Cellular Respiration