Biomolecules: Carbohydrates PDF

8/27/24, 8:22 PM Platform | Study Fetch Biomolecules: Carbohydrates Role of Carbohydrates (00:25 - 01:00) There are four classes of biomolecules: carbohydrates, proteins, lipids, and nucleic acids Carbohydrates function in...

8/27/24, 8:22 PM Platform | Study Fetch Biomolecules: Carbohydrates Role of Carbohydrates (00:25 - 01:00) There are four classes of biomolecules: carbohydrates, proteins, lipids, and nucleic acids Carbohydrates function in energy storage and as structural components, primarily in plants but also in humans Carbohydrates are the energy source for our daily activities Energy and sugar molecules are derived from the sun through photosynthesis in plants Examples of Carbohydrates (01:00 - 01:44) Sucrose is a disaccharide made up of glucose and fructose Lactose is a disaccharide made up of glucose and galactose Maltose is a disaccharide made up of two glucose molecules Enzymes like sucrase, lactase, and maltase break down these disaccharides Glycosidic Bonding (01:44 - 02:14) Disaccharides are formed by the joining of two monosaccharides through glycosidic bonds The enzymes that break down these disaccharides are designated based on the type of glycosidic bond: Sucrase breaks down sucrose Lactase breaks down lactose Maltase breaks down maltose Carbohydrates and Sugars (00:02:14 - 00:02:30) If the monomer sugar is not a glucose molecule, it will be converted into glucose Glucose can be metabolized to form ATP or stored as glycogen Deficiencies in enzymes that convert other forms of sugar into glucose can cause different diseases (00:02:30 - 00:02:43) Carbohydrate sugars are also found in nucleic acids The backbone of our DNA is made up of sugars, ribose or deoxyribose (00:02:43 - 00:03:05) Carbohydrates are made of carbon, hydrogen, and oxygen Examples of carbohydrates: Glucose: C6H12O6 Ribose: C5H10O5 Fructose: C6H12O6 https://www.studyfetch.com/platform/studyset/66cd116dd279f5220d947c66/material/66ce6bcae81bb65113fe36ad/document?go=note 1/5 8/27/24, 8:22 PM Platform | Study Fetch (00:03:05 - 00:03:17) The term "carbohydrate" can be broken down into "carbo" (carbon) and "hydrate" (water) Carbohydrates are essentially hydrated carbons (00:03:17 - 00:03:28) Carbohydrates are made up of carbon, hydrogen, and oxygen in a ratio of 1:2:1 (00:03:28 - 00:03:47) Carbohydrates can be classified as: Monosaccharides: Individual sugar units Complex sugars: Multiple monosaccharides linked together by glycosidic bonds (00:03:47 - 00:04:01) Examples of monosaccharides: Glucose Ribose Fructose Ribose has 5 carbon atoms and is found in RNA (00:04:01 - 00:04:15) The difference between the monosaccharides: Glucose: 6 carbon atoms Ribose: 5 carbon atoms, found in RNA Fructose: 6 carbon atoms Carbohydrates: Monosaccharides and Disaccharides Monosaccharides (00:04:15 - 00:04:27) Ribose and deoxyribose are monosaccharides Ribose and deoxyribose are the building blocks of RNA and DNA, respectively (00:04:27 - 00:04:37) Fructose is a monosaccharide found in honey, fruits, and vegetables Fructose and glucose both have 6 carbon atoms Glucose is the most important energy source for living organisms Fructose is eventually converted to glucose in the body (00:04:37 - 00:04:55) Glucose and fructose are isomers, meaning they have the same chemical formula but different structures https://www.studyfetch.com/platform/studyset/66cd116dd279f5220d947c66/material/66ce6bcae81bb65113fe36ad/document?go=note 2/5 8/27/24, 8:22 PM Platform | Study Fetch Metabolism of glucose, including glycolysis, the citric acid cycle, and the electron transport chain, will be covered in future modules Disaccharides (00:04:55 - 00:05:06) Disaccharides are made up of two monosaccharides Examples of disaccharides include sucrose, lactose, and maltose Enzymes are responsible for breaking down disaccharides into monosaccharides (00:05:17 - 00:05:31) The bond between the two monosaccharides in a disaccharide is called a glycosidic bond Sucrose is made up of glucose and fructose, and is found in fruits, vegetables, sugar cane, and sugar beets (00:05:31 - 00:05:44) Lactose is made up of galactose and glucose, and is the primary sugar found in milk Some people lack the lactase enzyme, making them lactose intolerant (00:05:44 - 00:06:01) Lactose intolerance can cause an overgrowth of bacteria in the gut, leading to diarrhea and upset stomach Undigested lactose in the gut can also pull more fluid into the gut, exacerbating the symptoms of lactose intolerance Carbohydrates and Glycosidic Bonding Disaccharides (00:06:01 - 00:06:11) Maltose is made up of two molecules of glucose Maltose is found in molasses Glucose molecules are linked together to form maltose Lactose and Sucrose (00:06:11 - 00:06:21) Mnemonic for disaccharide: Lactose = Glucose + Galactose The word "lactose" contains "galactose" Oligosaccharides and Polysaccharides (00:06:21 - 00:06:37) Oligosaccharides refer to 3 to 9 sugars linked together Sucrose is glucose and fructose Polysaccharides refer to 10 or more sugar molecules linked together, making them quite large molecules https://www.studyfetch.com/platform/studyset/66cd116dd279f5220d947c66/material/66ce6bcae81bb65113fe36ad/document?go=note 3/5 8/27/24, 8:22 PM Platform | Study Fetch Glycosidic Bonding (00:06:37 - 00:07:01) Glycosidic bonding is a dehydration reaction During this reaction, the OH groups bond together, and H2O is lost There are 20 OH groups that can participate in this bonding Numbering Carbon Atoms (00:07:01 - 00:07:20) Number the carbon atoms in a ring from 1 to 6, going in the direction of the end carbon group The difference between alpha and beta glucose is determined by the position of the hydroxyl group on carbon one Alpha vs. Beta Glucose (00:07:20 - 00:07:50) Alpha glucose: The OH group points down, below the ring Beta glucose: The OH group points up, above the ring Mnemonic: Alpha glucose, the OH points down because alphas look down on people. Beta glucose, the OH points up because life gets better or better. Glycosidic Bonding (00:07:50 - ) Glycosidic bonding is the formation of a covalent bond between a carbohydrate and another molecule, such as another carbohydrate, a lipid, or a protein. Glycolytic and Glycosidic Bonding (00:07:50 - 00:08:06) In alpha 1-2 glycolytic bonding, the carbon 1 of glucose and carbon 2 of fructose are bonded. In alpha 1-4 glycolytic bonding, the carbon 1 of glucose and carbon 4 of the other glucose are bonded. In beta glycolytic bonding, the carbon 1 of galactose and carbon 4 of glucose are bonded. (00:08:06 - 00:08:18) Examples of polysaccharides: Cellulose - found in plants Starches (amylose and amylopectin) - also found in plants Glycogen - the primary short-term energy storage in animals (00:08:28 - 00:08:49) Typically, our blood sugar is maintained at a set level and is taken up by our tissues. https://www.studyfetch.com/platform/studyset/66cd116dd279f5220d947c66/material/66ce6bcae81bb65113fe36ad/document?go=note 4/5 8/27/24, 8:22 PM Platform | Study Fetch When blood sugar falls between meals, glycogen stored in the liver and muscle cells is broken down and released as glucose into the blood. (00:08:49 - 00:09:01) Glucose is the primary fuel source for the brain, although there are some other fuels that can be used. (00:09:01 - 00:09:11) Eventually, if you haven't eaten for quite some time, you'll start using ketone bodies derived from fat as an energy source, after using up all your glycogen stores. (00:09:11 - 00:09:21) Mastering carbohydrates is important for doing well on tests, as you'll be able to answer questions correctly. https://www.studyfetch.com/platform/studyset/66cd116dd279f5220d947c66/material/66ce6bcae81bb65113fe36ad/document?go=note 5/5