Which of the following statements is correct concerning biotin. A. Intestinal biotinyl carboxylase cleaves biotin from biotin-containing proteins B. Biotinidase cleaves biocytin to yield biotin C. The first step in the intestinal digestion of biotin –containing proteins is the oxidation of the valeric side chain D. A and B E. B and C 8. Identify
The first function of the digestive system is the intake of food; the mouth is responsible for this as this is where food enters the body. Enzymes inside the mouth serve two purposes, one is to kill bacteria and two, begin digestion. Salivary Amylase begins to breakdown starch, carbohydrate in our food. Lingual lipase is an enzyme that stays neutral in the mouth but is active when it reaches the stomach. You should note that enzymes are like tiny biochemical machines that disassemble large macromolecules like proteins, lipids carbohydrates into smaller molecules, the breakdown of these foods continue throughout the digestive system until they are ready to enter the blood stream by absorption.
When we eat our food it is broken down into nutrients then absorbed into the bloodstream, our body then discards the indigestible parts of the food, this process is called digestion. The oesophagus is a tube that passes through the chest and connects the mouth to the stomach. The stomach leads to the small intestine, which is a narrow long tube from which most of the food absorption into the bloodstream takes place. The reason why we need to digest our food is because we need various molecules from the food we eat. We need carbohydrates for energy; we need amino acids to build protein.
2. List and describe the location of the accessory organs of the digestive system. a. Salivary glands—located in the oral cavity. b. Liver—lies just below the diaphragm on the right side of the body. c. Gallbladder—lies on posterior side of the liver.
These minuscule projections are approximately 1mm high and play a number of roles in the human body. In the middle of each villus is a dense capillary bed, the villi are connected to blood vessels that carry the nutrients away. When it comes to digestion and absorption of nutrients, the villi increase the small intestine's absorptive area. They slow the movement of food particles in the intestine, and the result is more nutrients can be absorbed. Another role played by these tiny hair-like projections is that they actually aid in the digestion of food.
Hydrolysis of a disaccharide yields two monosaccharide molecules. Fats are broken down into glycerol and fatty acids. 4.3 Control of Metabolic
Unit: Digestion HW 1 Read Concepts Pages 106 (Protozoa) - 112 Answer the following: 1. Define the terms intracellular and extracellular digestion. Intracellular digestion occurs inside a cell while extracellular digestion occurs outside of a cell 2. How does mechanical digestion aid chemical digestion Mechanical digestion physically breaks down food thus increasing the surface area of the food and allowing chemical digestion performed by enzymes to occur faster 3. Why is a one-way digestive tract evolutionarily more efficient than a two way tract?
The stomach secretes acid and powerful enzymes that continue the process of breaking down food. The small intestine is made up of the duodenum, jejunum and ileum. It is a long muscular tube that breaks down food using enzymes that have been released by the pancreas and bile from the liver. The continuous breaking down process is mainly done by the duodenum, while the jejunum and ileum are mainly responsible for the absorption of nutrients into the bloodstream. Peristalsis also moves food through the small intestine, mixing it with digestive secretions from the pancreas and liver.
The small intestine digests most nutrients and the nutrients are absorbed into the body. From there the food and fibers finally then enters the colon where it is absorbed and forms stools. The last part of the colon, the sigmoid colon and rectum stores the stools before being excreted. The colon consists of six sections including the ascending colon, the transverse colon, the descending colon, the sigmoid colon, the rectum, and the anus. The intestinal walls consist is three layers.
The small intestine leads to the large intestine, another tube for which absorption takes place. In the large intestine fluid is reabsorbed back into the bloodstream and faeces is formed; the faeces exits through the anus. Although these are the main organs involved in digestion, they are supported by the accessory organs. These include; the liver, gallbladder, pancreas, and salivary glands. Figure 1 (below) shows the location of these organs (madders.s, 2007).