Cellular Respiration 8.1 Overview
What is respiration? Three definitions Inspiration-expiration Exchange of O 2 for CO 2 in lungs Consumption of O 2 and production of CO 2 in tissues Involves glucose Exergonic Produces ATP Redox reaction
What are NAD + and FAD? Enzymes use these during oxidation respiration FAD sometimes used instead
What are the phases of respiration? Glycolysis Krebs cycle (citric acid cycle) Electron transport chain
Cellular Respiration 8.2 Glycolysis
What is glycolysis? Literally means _________ Happens outside mitochondrion Goal is to generate pyruvate Two stages Energy investment Phosphoryation using 2 ATP Energy harvest See next slide…
What happens during energy harvest? Substrate level phosphorylization To make ATP Pyruvate also formed Overall reaction:
Cellular Respiration 8.3 Krebs Cycle
What is the Krebs Cycle? AKA the citric acid cycle Happens in mitochondrial matrix Goal: generate ATP, FADH2 and NADH from pyruvate Series of redox reactions A type of metabolic pathway
What are the steps? Prepatory step Convert pyruvate to acetyle co-A
What happens next? Citric Acid Cycle Key: it’s a cycle– it repeats!
What are the products of the Krebs cycle?
Cellular Respiration 8.4 Electron transport chain
What is the electron transport chain (ETC)? Series of redox reactions to make ______ Happens in cristae Oxidative phophorylation Consumes oxygen Produces ATP + H 2 O
What are the steps of the ETC? Chemiosmosis involved Passing of Electrons H +
What is energy yield of oxidative respiration? After all three stages
Cellular Respiration 8.5 Fermentation
What happens if no oxygen is present? Anaerobic respiration Inorganic molecule is final electron acceptor Some bacteria use Fermentation Organic molecule is final electron acceptor Different types Alcoholic fermentation Lactic acid fermentation
What happens in fermentation? Glycolysis Then pyruvate reduction NAD regeneration
What are the pros and cons of fermentation? Pros Oxygen not necessary Cons Very low ATP production
What is the metabolic pool? Compounds oxidized for entry into biosynthesis reactions Catabolism Deamination (in liver) Anabolism