Chapter 9 - Cellular

Respiration

What is the relationship between

Photosynthesis and Cellular

Respiration?* atoms get rearranged during these processes

Role of the Sun?

Role of Glucose?

Provide energy (sun light) which plants use to create glucose from water and CO2

Broken down by cells to create (ATP)

Cellular Respiration Overview

C6H12O6 + 6O2 6CO2 + 6H2O + 38 ATP

Cellular Respiration (process in which living things convert the chemical potential energy stored in glucose and other food into chemical potential energy in the form of ATP). This occurs in the presence of oxygen (aerobic process)

How do organisms harvest the

energy stored in foods?

Cellular Respiration: chemical process that uses oxygen to convert the chemical energy stored in organic molecules into another form of chemical energy (ATP)

ATP (adenosine triphosphate) is a usable form of chemical energy

Energy is stored in the bonds. http://www.nutridesk.com.au/simple-sugars.phtml

Stored Chemical Energy in food

Energy in food can be measured in calories or Calories

calorie: amount of energy needed to raise 1g of H20 by 1°C

A Calorie is what they use on food labels and is actually a kilocalorie (1000 calories)

Chemical energy from food is converted into ATP

Exercise – Expended Energy

Bicycling (Slowly) – 170 cal per hour

Bicycling (Racing) – 514

Dancing (Slow) – 202

Dancing (Fast) – 599

Running – 865

Swimming – 535

ATP provides energy for cellular work.

ATP Packs Potential Energy!!!!When a phosphate group is pulled away…energy is released. This Energy is used for Cellular Work

Varying energy in the bonds between phosphates

Mitochondria

Outer Membrane

Inner Membrane Space

Matrix

There are 3 Stages of Cellular Respiration

1. Glycolysis 2. Krebs Cycle 3. Electron Transport Chain

Location in Cell Cytoplasm Mitochondria Mitochondria

What is Produced 2 Pyruvic Acid 4 ATP

4 CO2 2 ATP

H2O34 ATP

Equation for Cellular Respiration

In cellular respiration, the atoms in glucose and oxygen are rearranged, forming carbon dioxide and water. The cell uses the energy released to produce ATP.

Cellular Respiration converts energy in

food to energy in ATPStages Include… Glycolysis The Krebs Cycle ETC

What is produced?

Glycolysis (aka “splitting of

sugar”)

Occurs in the cytoplasm

Glucose (6C) is broken down into 2 Pyruvic Acid (3C molecules)

2 ATP molecules used, 4 ATP molecules produced

Net Gain of 2 ATP

Krebs (Citric Acid) Cycle Occurs in the mitochondrial matrix

Pyruvic acid from glycolysis is used to produce NADH, ATP, and FADH2

The NADH and FADH2 feed into the last step of cellular respiration (the electron transport chain)During Krebs cycle 2 ATP produced and carbon dioxide produced

Electron Transport Chain

Occurs in the mitochondrial inner membrane

Uses the high energy electrons from glycolysis and the Krebs cycle to convert ADP into ATP

High energy electrons are passed from one carrier to the next

Oxygen serves as the final electron acceptor of the electron transport chain (this is why oxygen is a requirement of cellular respiration)

Oxygen and the Electron Transport

Chain

As electrons move down each step in the chain, a small amount of energy is released

The energy is used to generate ATP molecules

The totals

Cellular respiration (glycolysis, the Krebs cycle, and electron transport chain) release about 36 molecules of ATP per molecule of glucose.

Q: How efficient is cellular respiration?

A: converts about 36 percent of the total energy in glucose into ATP

This is very efficient when compared to many human inventions. For example the gasoline engine in a car is only about 25% efficient.

Other food?

The diets of humans (and many other organisms) that utilize cellular respiration contain more than just glucose.

The cell can generate chemical energy in the form of ATP from just about any source

To simplify things we focus on how it generates ATP from glucose