KEY CONCEPT Respiration is the metabolic process which uses energy stored in food to make ATP molecules which provide usable energy to the cells

1. Aerobic Respiration-Requires Oxygen gas Two forms of Respiration 1. Aerobic Respiration-Requires Oxygen gas 2. Anaerobic Respiration– No Oxygen gas

Two Forms of Respiration Anaerobic Aerobic Do Not Require Oxygen Begins with Glycolysis Consists of Reactions: - Glycolysis - Fermentation Produces 2 ATP Rxns occur in Cytoplasm Require Oxygen Begins with Glycolysis Consists of Reactions: - Glycolysis - Kreb’s Cycle - Electron Transport Chain Produces 38 ATP Rxns occur in Cytoplasm and Mitochondria

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)

Aerobic Respiration (a.k.a. Cellular Respiration) Chemical Equation of Aerobic Respiration C6H12O6 + 6O2 6CO2 + 6H2O + Energy Reactants Products ___________________ _____________  

Cellular respiration occurs in the _Mitochondria .  

energy from glycolysis Kreb’s Cycle Pyruvic acids molecules made in glycolysis move into the Mitochondrial matrix and become reactants in the Kreb’s Cycle E stored in pyruvic acid is released to form 2 High Energy molecules: ATP and NADH 6H O 2 6CO 6O mitochondrion matrix (area enclosed by inner membrane) inner membrane ATP energy energy from glycolysis 1 4 3 and Carbon atoms from the breakdown of pyruvic acid form CO2 - a waste product

energy from glycolysis Electron Transport Chain 1.) A series of protein molecules embedded in the mitochondrial inner membrane along which “excited” electrons released in glycolysis and Krebs Cycle move along releasing energy used make a large number of ATP molecules 6H O 2 6CO 6O mitochondrion matrix (area enclosed by inner membrane) inner membrane ATP energy energy from glycolysis 1 4 3 and Oxygen which is highly electronegative and attracts the electrons serves as the “final electron acceptor” H2O released as byproduct 36 more ATP made Electron Transport

Anaerobic Respiration Occurs in the cytoplasm Breakdown of food molecules without oxygen Begins with glycolysis (just like in aerobic respiration) Glycolysis makes 2 ATP The only way glycolysis can keep working is to replace the molecule NAD+ that is the electron acceptor/transporter

Fermentation Occurs when Oxygen is not available – anaerobic process Occurs in mitochondria Resupplies the NAD+ so glycolysis can keep happening and ATP can be made NO ATP Made

Two Types of Fermentation There are two chemical pathways of fermentation They are named for the final product made Alcoholic fermentation Lactic Acid fermentation Yeast – Bread, Wine Muscles - “The Burn” Bacteria - Yogurt

Fermentation is used in food production. Yogurt Cheese Bread Wine

Different organisms produce different fermentation products

The equation for the overall process is: C6H12O6 + 6O2  6CO2 + 6H2O The reactants in photosynthesis are the same as the products of cellular respiration.

Compare and Contrast the 2 Energy Transformation Processes Photosynthesis 6CO2 + 6H2O--------->C6H12O6 + 6O2 Cellular Respiration C6H12O6 + 6O2 ---------> 6CO2 + 6H2O