Cellular Respiration 8.1 Overview. What is respiration? Three definitions Inspiration-expiration Exchange of O 2 for CO 2 in lungs Consumption.

Cellular Respiration

8.1 Overview

What is respiration? Three definitions

Inspiration-expiration Exchange of O2 for CO2 in lungs Consumption of O2 and production of CO2 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 +

H2O

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