Cellular RespirationEnergy for Life

Life Needs Energy

All living things need energy to carry on their life functions.

How do you get energy?

Energy from food molecules cannot be used directly by the cell – it must be converted to the only energy that cells can use – ATP!!

Cellular Respiration

Organisms obtain energy in a few different ways, but the majority of them perform cellular respiration within the mitochondria of their cells.

Energy is found within the bonds of the glucose molecule. When the glucose molecules are broken down in the mitochondria it gets converted adenosine triphosphate - (ATP)

(Krebs Cycle)

(Electron Transport System)

Cellular Respiration

Cellular Respiration is a very complex series of biochemical reactions but the net result can be summarized in the equation:

C6H12O6 + 6O2 6CO2 + 6H2O + ATP

In words this equation means: glucose and oxygen react to produce

carbon dioxide and water and ATP (energy).

Aerobic vs Anaerobic C/R Notice that in order for C/R to occur it needs

oxygen. Living organism that require oxygen for C/R to

occur use a form called: aerobic respiration. Some living organisms (mostly bacteria) can also

perform anaerobic respiration (called fermentation), which does not require oxygen.

Both types of C/R produce ATP (energy) …BUT in very different amounts! Aerobic respiration produces 36 ATP from each

glucose molecule whereas anaerobic produces 2 ATP. Which one is more efficient?

Anaerobic Respiration

Some organisms thrive in environments with little or no oxygen, such as bogs, sewage treatment ponds, guts of animals

This process is done by yeast to make bread rise and to create the alcohol in beer.

It is also done in your muscles when you feel the “burn” during weight training.

GlycolysisThis diagram shows the complex steps it takes to break down glucose molecules to form energy. The process of breaking down glucose is known as “Glycolysis”

Krebs Cycle and Electron Transport System

This diagram shows the Kreb cycle – where byproducts of Glycolysis get further broken down to form energy and other molecules. This occurs inside the matrix of the Mitochondria. The Electron Transport System is a series of electron carries that help pump Hydrogen ions into and out of the Mitochondria.

Summary Diagram:• Cellular Respiration occurs

in the mitochondria.

• The mitochondria takes in oxygen and glucose to create energy. It also releases carbon dioxide and water molecules in the process.

• Carbon Dioxide, and water help photosynthesis occur within chloroplasts.

• Along with sunlight, the chloroplasts are able to complete the photosynthesis reactions and produce glucose – its food. Which is also used in the mitochondria.

• These two processes support one another.

Adaptations for RespirationBacteria, Protists & Fungi

Respiratory gases are exchanged by diffusionhttp://www.biologycorner.com/bio1/protista.html , http://en.wikipedia.org/wiki/Fungus , http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/E/Eubacteria.html

Plants Respiratory gases are exchanged

through leaves, stems, and roots Moves in and out of cells by diffusion but

leaves and stems also have openings to the environment (stomata)

Adaptations for Respiration

Animals - techniques vary: Simple diffusion across cell

membranes Diffusion across moist skin into a

circulatory system Openings to the environment that can

be flapped open and closed with a circulatory system to transport gases

Specialized respiratory structures (e.g. lungs, gills) to speed exchange of respiratory gases