Carbohydrates 1 Flashcards
<p>What is a carbohydrate?</p>
<p>Sugar and starch molecules</p>
<p>Why are carbohydrates and major energy source?</p>
<p>They are high oxidisable, containing large amounts of high energy H atoms and associated electrons</p>
<p>What are some functions of carbohydrates?</p>
<p>Store potential energy</p>
<p>Structural and protection functions (EM)</p>
<p>Cell to cell communication</p>
<p>How are carbohydrates used to store potential energy?</p>
<p>As glycogen</p>
<p>What are monosaccharides?</p>
<p>Any class of sugar that cannot be hydrolysed to give simpler sugars</p>
<p>What are the 3 important hexoses (6C sugars)?</p>
<p>Glucose</p>
<p>Fructose</p>
<p>Galactose</p>
<p>What are disaccharides?</p>
<p>Formed from monomers that are linked by glycosidic bonds</p>
<p>How do monosaccarides combine to form disaccharides?</p>
<p>Covalent bonds are formed when hydroxyl groups of one monosaccharid reactions with another anomeric carbon of another</p>
<p>What is the anomeric carbon of glucose?</p>
<p>C1on glucose</p>
<p>What are properties of the anomeric carbon of glucose?</p>
<p>Stabalises the structure and is the only one that can be oxidised</p>
<p>What are different anomers to each other?</p>
<p>Mirror images</p>
<p>What are 3 important disaccarides?</p>
<p>Maltose</p>
<p>Lactose</p>
<p>Succrose</p>
<p>Do we get much maltose in our diet?</p>
<p>No, it is found in starch and beer</p>
<p>Why is maltose termed a reducing sugar?</p>
<p>Anomeric C1is available for oxidation</p>
<p>What forms maltose?</p>
<p>Two molecules of glucose</p>
<p>What is a reducing sugar?</p>
<p>A sugar that can be oxidised</p>
<p>What is lactose the main sugar of?</p>
<p>Milk</p>
<p>How is lactose formed?</p>
<p>Glycosidic bond between galactose and glucose</p>
<p>Galactose + Glucose⇔ Lactose</p>
<p>Why is lactose a reducing sugar?</p>
<p>Anomeric carbon in the glucose available for oxidation</p>
<p>Where is succrose commonly found?</p>
<p>Table sugar</p>
<p>What is succrose only made by?</p>
<p>Plants</p>
<p>Is sucrose a reducing sugar?</p>
<p>No, because no free anomeric carbon atom</p>
<p>How is succrose formed?</p>
<p>By glucose and fructose</p>
<p>Glucose + Fructose⇔ Succrose</p>
<p>What are polyassacharides?</p>
<p>Carbohydrate whole molecule consists of a number of sugar molecules bonded together</p>
<p>How can polyassacharides differ from one another?</p>
<p>Types of monomers</p>
<p>Length of chain</p>
<p>Types of bonds linking monomers</p>
<p>Amount of bonding</p>
<p>What are the 2 types of polyassacharides?</p>
<p>Homopolyassacharides (single monomer spieces)</p>
<p>Heteropolyassacharides (two or more monomer spieces)</p>
<p>What 2 types of glucose monomers does starch contain?</p>
<p>Amylose (D glucose in a1-4 linkage)</p>
<p>Amylopectin (glycosidic a1-4 bonds join glucose in chain but branches are a1-6)</p>
<p>What does aX-Yrefer to in terms of bonding?</p>
<p>The number of carbon in the sequence connected to each other</p>
<p>How many reducing and non reducing ends does starch have?</p>
<p>Many non reducing and very few reducing ends</p>
<p>Do enzymes act of non reducing or reducing ends?</p>
<p>Reducing ends</p>
<p>What allows for glycogen to have lots of non reducing ends?</p>
<p>Branch points (a1-6) every 8 to 12 residues</p>
<p>What do lots of branches in glycogen allow for?</p>
<p>To be quickly broken down or built up</p>
<p>Where is 90% of glycogen found?</p>
<p>Liver</p>
<p>Skeletal muscle</p>
<p>What is the purpose of the glycogen in the liver?</p>
<p>Replenish blood glucose whilst fasting</p>
<p>What is the purpose of glycogen in skeletal muscles?</p>
<p>Catabolism to produce ATP for contraction</p>
<p>Why is glycogen osmotically inactive?</p>
<p>It is not in solution</p>
<p>Why is glycogen being osmotically inactive important?</p>
<p>If it was free glucose (osmotically active) it would constantly leave the cell down its concentration gradient</p>
<p>What are glycoproteins?</p>
<p>Proteins that have carbohydrates covalently attatched</p>
<p>What may carbohydrates attached to proteins do?</p>
<p>Increase protein solubility</p>
<p>Influence protein folding</p>
<p>Protect it from degradadtion</p>
<p>Act as communication between cells</p>
<p>What are glycoaminoglycans (GAGs)?</p>
<p>Unbranched polymers made from repeating units of hexuronic acid and an amino-sugar</p>
<p>What are properties of glycosaminoglycans (GAGs) and where are they found?</p>
<p>Slimy, sticky molecules found in mucous and synovial fluid</p>
<p>What are proteoglycans?</p>
<p>Formed from glycosaminoglycans (GAGs) covalently attatched to proteins, more carbohydrates than protein</p>
<p>Where are proteoglycans found?</p>
<p>In connective tissue</p>
<p>What do proteoglycans do?</p>
<p>Allow the cell to connect to the extracellular matrix (EM)</p>
<p>Do glycoproteins have more protein or carbohydrate?</p>
<p>Protein</p>
<p>Where are glycoproteins often found?</p>
<p>On the outside of the cell membrane and in the extracellular matrix (EM)</p>
<p>What do you generally find anywhere you need to stick things together?</p>
<p>Proteins attatched to carbohydrates</p>
<p>What are mucopolyassacharides?</p>
<p>Group of genetic disorders caused by absence or modification of enzymes that are required for breakdown of glycosaminoglucans (GAGs)</p>
<p>What do mucopolyassacharide disorders cause?</p>
<p>A build up of glycosaminoglycans in cells which is damaging</p>
<p>What is an example of a mucopolyassacharide disorder?</p>
<p>Hurler syndrome</p>
