Cellular Respiration (2.9) Flashcards
What is the most widely used energy source in living organisms?
Glucose
What is cellular respiration?
The gradual and controlled release of energy by breaking down organic compounds to produce ATP (Adenosine TriPhosphate).
What is the goal of cellular respiration?
To generate ATP
What are ATP, its function, and its structure?
An important “energy molecule” found in all life forms. Specifically, it is a coenzyme that works with enzymes such as ATP triphosphatase to transfer energy to cells by releasing its phosphate groups
How does ATP give you energy?
Energy is produced when ATP is hydrolyzed.
What does respiration mean?
Do not confuse respiration with breathing. In some languages, such as French, Portuguese, and Spanish, ‘respire’ means breathing. In biology, respiration always refers to the breakdown of organic compounds and the production of ATP in the cell.
Where do glycolysis, Krebs cycle, and oxidative phosphorylation take place in a cell?
Glycolysis takes place in the cytoplasm, while the Krebs cycle and oxidative phosphorylation (and electron transport chain) occur in the mitochondria.
Within the mitochondrion, the Krebs cycle occurs in the matrix, while the electron transport chain is located on the inner membrane of the mitochondrial envelope.
What are the two types of cellular respiration?
Anaerobic and Aerobic
What happens if a cell doesn’t have oxygen (related to cellular respiration)?
Respiration occurs only in the cell cytoplasm as it involves only glycolysis (to be able to complete the other steps, oxygen is required).
What are the two types of anaerobic cellular respiration?
Alcoholic and Lactic fermentation.
Summarize lactic acid fermentation:
Glucose → lactate + 2 ATP molecules
Alcoholic fermentation can be described as:
Glucose → ethanol + carbon dioxide + 2 ATP molecules
Where can we find alcoholic cellular respiration?
In yeast. Yeast respires anaerobically to produce ethanol and CO2 when fermenting raw ingredients to make beer, wine, or bread. The CO2 produced by yeast is used to make bread rise, while the ethanol is evaporated away during baking. Bread made without yeast would be very flat.
Where can we find lactic acid fermentation cellular respiration?
In our muscles. Although we breathe air (and thus oxygen) during strenuous exercise, our muscle cells may use up all the available oxygen. Nonetheless, the muscle cells still need ATP to continue the exercise. So where does the ATP they require come from? Without oxygen, the muscle cells start to respire anaerobically and are able to produce a very small amount of ATP, which allows the power of muscle contractions to be maximized in the absence of oxygen. During anaerobic respiration, animals produce lactate (also known as lactic acid). Sometimes you can feel soreness in your muscles after strenuous exercise. This was once believed to be caused by the build-up of lactic acid, but more recent research has shown that this pain is caused by microscopic damage to the muscle fibers.
What is the net yield of ATP produced by anaerobic respiration in yeast?
2 ATP molecules
0 ATP molecules
The same number as in aerobic respiration
4 ATP molecules
2 ATP molecules
Why does aerobic respiration produce more ATP than anaerobic respiration?
During aerobic respiration, all four steps of cellular respiration are completed (in anaerobic respiration only glycolysis is completed). The reason for this increased yield is that 6-carbon glucose is systematically and gradually broken down to 6 CO2 molecules. Each step yields potential energy, which can be converted into ATP in the electron transport chain.
