Digestion of an Avocado
- Sathvika Gandavarapu
- Sep 23, 2020
- 3 min read
The Beginning
The process of digestion starts as soon as you put the first bite into your mouth. When you put the food in your mouth, the first step of digestion is to chew. After that your salivary glands (parotid, sublingual and submandibular glands) release saliva which releases enzymes that start breaking down the food. Teeth break down the avocado while the tongue mixes the avocado with saliva. Muscles in the mouth and throat help to swallow the avocado down the upper esophagus. A process called peristalsis moves the food to the lower end of your esophagus, where signals tell the lower esophageal sphincter to relax and release the food to the stomach.
The stomach has powerful muscles that mix the food into smaller and smaller pieces. Afterwards, digestive glands in the stomach lining produce enzymes and stomach acids that mix the food well enough to form a semifluid called chyme. Once the chyme is mixed up well, muscle contractions propel to a valve called pylorus and into the first section of the small intestine (duodenum). In the duodenum, the chyme mixes with a variety of juices from the pancreas, liver and gallbladder. Pancreas produces digestive enzymes that help break down fats. Liver produces bile that helps digest fats. The gallbladder stores bile and squeezes bile into the small intestine.
Chyme
After the chyme is mixed well, the food is pushed into the jejunum where food is further broken down into smaller molecules of nutrients that are absorbed. After the chyme is mixed well, the food is pushed into the jejunum. The jejunum is where the food is broken down into even smaller nutrients. These nutrients are absorbed by the jejunum. Finally the food is pushed into the third portion of the small intestine which is the ileum. All of the remaining nutrients are absorbed with the lining of the ileum wall. The inside of the small intestine contain villi. Villi have muscle contractions that make absorbing nutrients from the avocado even easier. It also contains microvilli. These are locations where absorption occurs. In each villi are a network of capillaries.
Capillaries take in the nutrients and deliver it to arteries and veins. Arteries and veins are part of the circulatory system and will bring the nutrients to the heart. Fat nutrients are then stored in the adipose tissue. When needed as an energy source, they are moved out of the tissue and broken down even further into glycerol and fatty acids. This all happens in the process of lipolysis.
Stages of Cellular Respiration
There are three stages of cellular respiration. The first step is Glycolysis. Glycolysis is the breakdown of glucose by enzymes. Glycerol is turned into triglyceride from glycolysis. Glycolysis produces 2 ATP. Some of this ATP fuels the other two processes of Cellular Respiration. In Glycolysis, glucose is broken down into triglyceride. Triglyceride is used as an energy source. 2 ATP (energy) is made in the process of Glycolysis. This energy “fuels” the other two processes of Cellular Respiration. Beta-oxidation is a process where fatty acids are changed into acetyl CoA molecules. The acetyl COA is a molecule that takes acetyl to be oxidized. The acetyl CoA molecules then enter the Krebs Cycle.
The second part of cellular respiration is the Krebs Cycle. The Krebs cycle releases stored energy through the oxidation of acetyl-CoA. These come from fats. The second part of Cellular Respiration is when fatty acids are turned into acetyl CoA. Acetyl- CoA brings acetyl to the Krebs cycle. The Krebs cycle releases stored energy through the oxidation of acetyl- CoA. The last step is the Electron Transport System. The Electron Transport System has a series of enzymes in the Mitochondria. NADH and from FADH2 “donate” electrons and they are passed along the series of enzymes. As the enzymes are moving, they release energy.
Chemiosmosis
This energy “fuels” a process called chemiosmosis. In chemiosmosis, H+ ions are moved to the Outer Mitochondrial membrane. The H+ ions travel back into special openings in the membrane. This process “drives” the process of ATP Synthesis. ATP is then created. ATP is sent to the endoplasmic reticulum and given to the other parts of the cell. The Endoplasmic Reticulum are the “pathways” in a cell that “delivers” necessary nutrients to the cell.
Citations:
ook%3A_General_Biology_(Boundless)/7%3A_Cellular_Respiration/7.4%3A_Oxidative_Phosphorylation/7.4B%3A_Chemiosmosis_and_Oxidative_Phosphorylation
- http://faculty.ccbcmd.edu/~gkaiser/biotutorials/energy/atpsynthase_il.html
Comments