Cellular respiration review
|Cellular respiration||The process by which organisms break down glucose into a form that the cell can use as energy|
|ATP||Adenosine triphosphate, the primary energy carrier in living things|
|Mitochondria||The eukaryotic cell structure where cellular respiration occurs|
|Cytoplasm||Jelly-like substance that fills the space between organelles|
|Aerobic||Process that requires oxygen|
|Anaerobic||Process that does not require oxygen|
|Fermentation||An anaerobic pathway for breaking down glucose|
- Muscle cells can continue to produce ATP when oxygen runs low using lactic acid fermentation. However, this often results in muscle fatigue and pain.
- Many yeast use alcoholic fermentation to produce ethanol. For this reason, humans have domesticated yeast to use for many commercial purposes including baking as well as beer and wine production.
Aerobic vs anaerobic respiration
|Reactants||Glucose and oxygen||Glucose|
|Products||ATP, water, CO||ATP and lactic acid (animals); or ATP, ethanol, and CO (yeast)|
|Location||Cytoplasm (glycolysis) and mitochondria||Cytoplasm|
|Stages||Glycolysis (anaerobic), Krebs cycle, oxidative phosphorylation||Glycolysis, fermentation|
|ATP produced||Large amount (36 ATP)||Small amount (2 ATP)|
Common mistakes and misconceptions
- Anaerobic respiration is a normal part of cellular respiration. Glycolysis, which is the first step in all types of cellular respiration is anaerobic and does not require oxygen. If oxygen is present, the pathway will continue on to the Krebs cycle and oxidative phosphorylation. However, if oxygen is not present, some organisms can undergo fermentation to continually produce ATP.
- Plants undergo cellular respiration. Many people believe that plants undergo photosynthesis and animals undergo respiration. Really, plants do both! Plants simply undergo photosynthesis first as a way to make glucose. Animals don't need to photosynthesize since they get their glucose from the food they eat.
- Cellular respiration is not simply the same as "breathing." This can be confusing! People often use the word "respiration" to refer to the process of inhaling and exhaling. However, this is physiological respiration, not cellular respiration. The two are related processes, but they are not the same.