Whenever glucose levels decrease, glycogen is broken down to release glucose. Cellulose is one of the most abundant natural biopolymers. The cell walls of plants are mostly made of cellulose, which provides structural support to the cell.
Wood and paper are mostly cellulosic in nature. Cellulose is made up of glucose monomers that are linked by bonds between particular carbon atoms in the glucose molecule. Every other glucose monomer in cellulose is flipped over and packed tightly as extended long chains.
This gives cellulose its rigidity and high tensile strength—which is so important to plant cells. Cellulose passing through our digestive system is called dietary fiber.
While the glucose-glucose bonds in cellulose cannot be broken down by human digestive enzymes, herbivores such as cows, buffalos, and horses are able to digest grass that is rich in cellulose and use it as a food source. In these animals, certain species of bacteria reside in the rumen part of the digestive system of herbivores and secrete the enzyme cellulase.
The appendix also contains bacteria that break down cellulose, giving it an important role in the digestive systems of ruminants. Cellulases can break down cellulose into glucose monomers that can be used as an energy source by the animal. Carbohydrates serve other functions in different animals. Arthropods, such as insects, spiders, and crabs, have an outer skeleton, called the exoskeleton, which protects their internal body parts. This exoskeleton is made of the biological macromolecule chitin , which is a nitrogenous carbohydrate.
It is made of repeating units of a modified sugar containing nitrogen. Thus, through differences in molecular structure, carbohydrates are able to serve the very different functions of energy storage starch and glycogen and structural support and protection cellulose and chitin. Registered Dietitian: Obesity is a worldwide health concern, and many diseases, such as diabetes and heart disease, are becoming more prevalent because of obesity. This is one of the reasons why registered dietitians are increasingly sought after for advice.
Registered dietitians help plan food and nutrition programs for individuals in various settings. They often work with patients in health-care facilities, designing nutrition plans to prevent and treat diseases.
For example, dietitians may teach a patient with diabetes how to manage blood-sugar levels by eating the correct types and amounts of carbohydrates. Dietitians may also work in nursing homes, schools, and private practices. In addition, registered dietitians must complete a supervised internship program and pass a national exam. Those who pursue careers in dietetics take courses in nutrition, chemistry, biochemistry, biology, microbiology, and human physiology.
Dietitians must become experts in the chemistry and functions of food proteins, carbohydrates, and fats. The underground storage bulb of the camas flower shown below has been an important food source for many of the Indigenous peoples of Vancouver Island and throughout the western area of North America.
Camas bulbs are still eaten as a traditional food source and the preparation of the camas bulbs relates to this text section about carbohydrates.
Most often plants create starch as the stored form of carbohydrate. Some plants, like camas create inulin. Inulin is used as dietary fibre however, it is not readily digested by humans.
If you were to bite into a raw camas bulb it would taste bitter and has a gummy texture. The method used by Indigenous peoples to make camas both digestible and tasty is to bake the bulbs slowly for a long period in an underground firepit covered with specific leaves and soil. The heat acts like our pancreatic amylase enzyme and breaks down the long chains of inulin into digestible mono and di-saccharides. Properly baked, the camas bulbs taste like a combination of baked pear and cooked fig.
It is important to note that while the blue camas is a food source, it should not be confused with the white death camas, which is particularly toxic and deadly. The flowers look different, but the bulbs look very similar. Lipids include a diverse group of compounds that are united by a common feature. This is because they are hydrocarbons that include only nonpolar carbon-carbon or carbon-hydrogen bonds. Lipids perform many different functions in a cell. Cells store energy for long-term use in the form of lipids called fats.
Lipids also provide insulation from the environment for plants and animals. For example, they help keep aquatic birds and mammals dry because of their water-repelling nature. Lipids are also the building blocks of many hormones and are an important constituent of the plasma membrane. Lipids include fats, oils, waxes, phospholipids, and steroids.
A fat molecule, such as a triglyceride, consists of two main components—glycerol and fatty acids. Glycerol is an organic compound with three carbon atoms, five hydrogen atoms, and three hydroxyl —OH groups. In a fat molecule, a fatty acid is attached to each of the three oxygen atoms in the —OH groups of the glycerol molecule with a covalent bond.
During this covalent bond formation, three water molecules are released. The three fatty acids in the fat may be similar or dissimilar. These fats are also called triglycerides because they have three fatty acids. Some fatty acids have common names that specify their origin. For example, palmitic acid, a saturated fatty acid, is derived from the palm tree. Arachidic acid is derived from Arachis hypogaea , the scientific name for peanuts. Fatty acids may be saturated or unsaturated.
In a fatty acid chain, if there are only single bonds between neighboring carbons in the hydrocarbon chain, the fatty acid is saturated. Saturated fatty acids are saturated with hydrogen; in other words, the number of hydrogen atoms attached to the carbon skeleton is maximized. When the hydrocarbon chain contains a double bond, the fatty acid is an unsaturated fatty acid. Most unsaturated fats are liquid at room temperature and are called oils. If there is one double bond in the molecule, then it is known as a monounsaturated fat e.
Saturated fats tend to get packed tightly and are solid at room temperature. Animal fats with stearic acid and palmitic acid contained in meat, and the fat with butyric acid contained in butter, are examples of saturated fats. Mammals store fats in specialized cells called adipocytes, where globules of fat occupy most of the cell. In plants, fat or oil is stored in seeds and is used as a source of energy during embryonic development.
Unsaturated fats or oils are usually of plant origin and contain unsaturated fatty acids. Olive oil, corn oil, canola oil, and cod liver oil are examples of unsaturated fats. Enzymes adopt a specific three-dimensional structure, and may employ organic biotin and inorganic magnesium ion cofactors to assist in catalysis.
Something about cofactor: Some enzymes do not need any additional components to show full activity. However, others require non-protein molecules called cofactors to be bound for activity. Cofactors can be either inorganic e. Organic cofactors can be either prosthetic groups, which are tightly bound to an enzyme, or coenzymes, which are released from the enzyme's active site during the reaction. What biochemical molecules make up enzymes? Examples of structural proteins are collagen, elastin, and keratin.
Enzymes: These are globular conjugated proteins that are also known as biological catalysts. They catalyze metabolic reactions by reducing the activation energy that increases the rate of the reaction. Some examples of protein enzymes are DNA polymerase, lysozyme, nitrogenase, and lipase.
Hormones: These are long polypeptides composed of long chains of linked amino acids. They play critical roles in regulating the physiological processes of the body, these processes include reproduction, growth and development, electrolyte balance, sleep, etc. Respiratory pigments: These are globular protein pigments that are usually soluble in water. Examples include myoglobin which provides oxygen to the working muscles and hemoglobin which transfers blood to all the tissues and organs through the blood.
Transport proteins: These are structural components of the cell membrane. They form channels in the plasma membrane to transfer selective molecules inside the cells. Some of them also form components of blood and lymph in animals. Examples of transport proteins are serum albumin transport hemin and fatty acids , channel proteins, and carrier proteins. Motor proteins: These proteins are involved in the contraction and relaxation of the muscle muscle movement. It includes actin, myosin, kinesin, and dynein.
Storage proteins: These proteins are the storage reserve of amino acids and metal ions in cells. They are present in eggs, seeds, and pulses. Examples of storage proteins include ferritin, ovalbumin, and casein. Toxins: These proteins are generally produced by bacteria. They include diphtheria toxin, Pseudomonas exotoxin, and ribosome-inactivating proteins.
They help bacteria to attack and kill their host organism by creating cytotoxicity. Nucleic Acids Nucleic acids are macromolecules present in cells and viruses, and they are involved in the storage and transfer of genetic information.
The nucleotides are comprised of three components: Nitrogenous base: These are heterocyclic, planar, and aromatic molecules. It is of two types: purines and pyrimidines. These sugars in nucleic acids have the D-stereoisomeric configuration. A phosphodiester bond links two or more nucleotides leading to the formation of polynucleotides. Do You Know? Lipids Lipids are organic compounds that are insoluble or poorly soluble in water but soluble in organic solvents like dissolves like such as ether, benzene, or chloroform.
Classes of Lipids and Their Functions Different classes of lipids include: Fatty acids: These are the simplest forms of lipids. They are composed of hydrocarbon chains of carbons and one acidic group. They can be linear or branched. Moreover, fatty acids are the building blocks of other types of lipids. Waxes: These are esters of fatty acids and long-chain alcohols. They are composed of hydrocarbon chains of carbons.
They are synthesized by many plants and animals. However, the best-known wax is bee wax which is composed of an ester of palmitic acid with triacontanol alcohol. Phospholipids: These are composed of fatty acids, an attachment platform for fatty acids, a phosphate, and an alcohol attached to phosphate. They are part of the cell membrane of the organisms. Glycolipids: These are lipids containing saccharide groups. They are constituents of the cell membrane and are involved in signal transductions.
Steroids: These are complex derivatives of triterpenes. For example, cholesterol is a constituent of the cell membrane and acts as a precursor for the biosynthesis of steroid hormones and bile acids.
Video from: Noel Pauller. A classroom demonstration using salivary amylase enzyme which breaks down starch into simple sugars. To what group of biomolecules do enzymes belong? Chemistry Organic Chemistry Biochemical Molecules. Apr 29,
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