Cellular Respiration Objectives 1. Define Cellular Respiration 2. Identify the two major steps of cellular respiration 3. Compare lactic acid fermentation with alcoholic fermentation 4. Summarize the steps of aerobic respiration

Cellular Respiration First and foremost: IT IS NOT THE SAME AS BREATHING!!! ALL living things must undergo cellular respiration in order to use their food (even plants) This is a complicated process that breaks the chemical bonds of carbohydrates to release the energy

It can be broken down into 2 basic steps: 1. Glycolysis 2. Respiration (2 types) Aerobic respiration (with Oxygen) or Anaerobic (without Oxygen) respiration

1. Glycolysis Glycolysis is the breakdown of carbohydrates made in photosynthesis This happens in the cytoplasm of our cells The 6 Carbon sugar made in photosynthesis is broken into two 3 carbon molecules called Pyruvic acid

In the process, 2 ATP molecules are produced -The pyruvic acid moves onto the next step -But first, the cell must determine whether or not Oxygen is present

Chemiosmosis 4 ATP ADP Pyruvic Glycolysis Acid formed 2 carbohydrates from photosynthesis Pyruvic Acid formed Glycolysis

A choice must be made… If Oxygen IS present then the cell performs Aerobic Respiration If Oxygen IS NOT present, then the cell performs Anaerobic Respiration

Anaerobic Respiration When there is NO Oxygen available, a cell still needs energy so it must take a different route to make it Anaerobic respiration is called fermentation It has two directions to choose from: 1. Lactic Acid Fermentation 2. Alcohol Fermentation

Lactic Acid Fermentation In Lactic acid fermentation, Pyruvic acid is converted into lactic acid This occurs naturally in some foods like milk When it is controlled we can use it to produce sour cream, yogurt, cheese & buttermilk Lactic acid is also produced in our bodies during time of strenuous exercise

You experience soreness, fatigue & sometimes muscle cramping The liver converts it back to pyruvic acid, which is then taken back to the cells

Sour cream, yogurt & buttermilk Liver converts Back to Pyruvic acid Pyruvic acid formed Sour cream, yogurt & buttermilk Liver converts Back to Pyruvic acid Anaerobic Pathway Pyruvic acid is Converted to Lactic acid Lactic Acid fermentation

Alcoholic Fermentation In this form of respiration, pyruvic acid is converted to ethyl alcohol Single celled fungal organisms called yeast perform alcoholic fermentation Beer, & the baking industry & Alcohol fuels are produced this way

Liver converts back to pyruvic acid Ethyl Alcohol Fermentation Pyruvic acid Is converted to Ethyl alcohol CO2 waste Beer, wine Fuels, baking