Respiration Converting and using energy

Respiration

Photosynthesis Review ► Photosynthesis stored energy in the form of glucose.  Glucose is what animals and plants use as their source of energy. ► But ATP is the usable energy in a cell…not glucose. So…

Respiration: What is it? ► Essentially cellular respiration breaks food particles (glucose) down into ATP. ATP is the form of energy that cells can use.ATP is the form of energy that cells can use. Respiration provides all living things with the energy they need.Respiration provides all living things with the energy they need. This is aerobic respiration, which requires oxygen.This is aerobic respiration, which requires oxygen.

Respiration: What is it?

Respiration: Who does it? ► All living things do cellular respiration …including plants.

Respiration: Where does it happen? ► Mitochondria of a cell  The “powerhouse” of the cell  Found in plants and animals

Respiration: How does is happen? 3 steps of respiration: 1. Glycolysis:  Glucose broken down into smaller parts (2 molecules of Pyruvic Acid)  ATP produced 2. Citric Acid Cycle (Krebs Cycle):  Pyruvic Acid is broken down into CO 2  More ATP is produced.

Respiration: How does is happen? 3 steps of respiration: 3. Electron Transport Chain (ETC): Hydrogen is released and forms with oxygen to create water. Hydrogen is released and forms with oxygen to create water. More ATP is produced More ATP is produced

Respiration: How does is happen? glucose + oxygen  CO 2 + water respirationphotosynthesis Therefore the overall reaction of cellular respiration is the reverse of photosynthesis:

So what’s the moral of the photosynthesis – respiration story?? ITS ALL ONE BIG CYCLE!! NO TREES MEANS NO BREATHE

Check your understanding 1. How is respiration different than photosynthesis, how are they the same? 2. What is the definition of respiration? 3. Through what 3 steps does respiration produce ATP? 4. The cell of an organism that starved to death is tested and found to have a high concentration of pyruvic acid. What failed?

Anaerobic respiration ► Often referred to as fermentation (in yeast) ► Does not require oxygen (O 2 ) Byproduct is alcoholByproduct is alcohol Only happens in oxygen deprived environmentsOnly happens in oxygen deprived environments - We had anaerobic respiration in our yeast lab! - Brewing Does not produce as much ATP as aerobic respiration, therefore plants and animals use aerobic respiration whenever they can.Does not produce as much ATP as aerobic respiration, therefore plants and animals use aerobic respiration whenever they can.

Anaerobic respiration ► In animal cells the product is Lactic Acid ► Occurs during oxygen (O 2 ) stress It leads to muscle fatigue in athletes.It leads to muscle fatigue in athletes. Good cardio-vascular fitness can prevent muscle fatigue.Good cardio-vascular fitness can prevent muscle fatigue. Does not produce as much ATP as aerobic respiration, therefore plants and animals use aerobic respiration whenever they can.