Introduction to Cellular Respiration

Your combustion engine

• Energy used by living things comes in the form of chemical energy

• Organisms are ultimately a living chemistry lab, where most of the chemical reactions are designed to produce energy required to power necessary functions for life

• http://www.metacafe.com/watch/434121/energy_of_candy_gummi_bears_vs_m_ms_experiment/

Cellular Respiration

• You’ve heard the term respiration before and it is usually associated with breathing

• So what does CELLULAR respiration mean?

The well known equation

• All through junior sciences, you have been introduced to the cellular respiration equation and have seen it linked to photosynthesis before as well

• You should notice that oxygen plays an important role in this equation

Breathing cells

• Hence, the process by which cells make energy is referred to as CELLULAR respiration

Photosynthesis and Cellular Respiration

• It makes sense when you think about the purposes of the processes – that photosynthesis and cellular respiration are linked

Cellular respiration and Photosynthesis – reverse reactions

Basic energy source

• All living things rely on glucose as their primary energy source

The use of macromolecules

• Our body orders the importance of these molecules as energy sources based on the ease of use

Are carbs bad?

Lipids next

• Fats are usually the next store of energy to be broken down into glucose after carbohydrate reserves are used up

Proteins last

• Proteins and thus amino acids are usually the last macromolecule to be metabolized

We are designed for carbs

• In fact, the metabolism of proteins and fats on a regular basis for energy leads to acidosis and ketosis – excess acidity in the blood that can lead to respiratory failure

Glucose is key

• Therefore it is important to note that our main source of energy must originate with molecules of glucose

ATP• Just as different mechanical devices are designed

for specific fuels, the cells of organisms are designed to use one specific molecule to harness energy

ATP – The body’s gasoline

ATP in action

• http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter10/animation__breakdown_of_atp_and_cross-bridge_movement_during_muscle_contraction.html

The breakdown

• When an organism “eats” and breaks down food, what does it do?

The basic equation

• The equation for cellular respiration reflects this

Chemical Processes in the Mitochondria