AQA A Level Biology Unit 1 Graded A+

AQA A Level Biology Unit 1 Graded A+ How do biological molecules provide evidence for evolution? use the same amino acids and DNA. What are monomers of carbohydrates called? They all have similar molecules and Monosaccharides. Beta Glucose Alpha glucose Glucose formula C₆H₁₂O₆ Name of the bond between monosaccharides? What is sucrose made from? Glycosidic bond. Glucose and fructose. What is lactose made from? What is maltose made from? Testing for reducing sugars? Glucose and galactose. Two alpha glucose. Add Benedict's reagent (blue) and heat in a water bath at a boil. If present: Green → yellow → orange → brick red Test for non-reducing sugars? Add dilute hydrochloric acid and heat, neutralise with Sodium Hydrogencarbonate and add Benedicts reagent. What is the scientific name for carbohydrates? What is starch made of? Polysaccharides. Starch is a mixture of two polysaccharides of alpha glucose: Amylose and amylopectin. What is amylose? A long, unbranched alpha glucose chain. The angles in it make it have a coiled shape which makes it compact and effective for storage. What is amylopectin? A long, braqnched alpha glucose chain. The side branches mean that enzymes can get to and hydrolise glycosidic bonds faster so glucose can be released quickly. What is glycogen? A polysaccharide of alpha glucose with a similar structure to starch except it is more branched, allowing even faster energy release. It is also very compact. What is celluose? it is made of long. straight chains of beta glucose. The chains are linked my hydrogen bonds to form microfibrils, a strong fibre. The strong fibres allow it to provide structural support in cells as cell walls. How to test for starch. Add iodine which is dissolved in potassium iodie ti the sample. Positive result: Turns blue-black. Negative result: stays browny-orange. Which of proteins, polysaccharides and lipids are not a polymer. What are triglycerides made of? Glycerol and fatty acids. What causes lipids to be insoluble in water? Lipids. The hydrophobic fatty acid tails. What is the structure of a fatty acid? What do double bonds cause in fatty acids? Triglyceride formation? What are phospholipids? A kink in the chain. Similar to triglycerides, but one of the fatty acid tails is replaced by a phosphate group head. Which part of a phospholipid is hydrophillic and which part is hydrophobic?