Nucleic acids 0.0 / 5 ? BiologyCellular processesASAQA Created by: amm242Created on: 15-05-18 12:12 Descrice nucleotide structrure Pentose sugar, phosphate group, nitrogen-containing organic base 1 of 28 How are nucleotides joined? Condensation reactions form phosphodiester bond between deoyribose sugar and phosphate group 2 of 28 How is RNA different to DNA? Single short polynucleotide chain and uracil replaces thymine 3 of 28 Name DNA's four organic bases Adenine & thymine, cytosine & guanine 4 of 28 Why is DNA a stable molecule? Phosphodiester backbone protects reactive bases, hydrogen bonds form bridges between complementary organic bases 5 of 28 Why is DNA described as antiparallel? Strands run in opposite directions, one 3' to 5' the other 5' to 3' 6 of 28 What is the function of DNA? Hereditary material that passes genetic information from cell to cell and through generations 7 of 28 Why must DNA be replicated before nuclear division? Ensures all daughter cells have correct genetic information 8 of 28 What is semi-conservative replication? DNA strands unwind and seperate so each new copy has one new strand and one old strand 9 of 28 What is the function of DNA helicase? Breaks H bonds inbetween bases to split the two strands 10 of 28 What happens to the free nucleotides? Specific base pairing to complementary bases 11 of 28 What is the function of DNA polymerase? Joins nucleotides with phosphodiester bonds 12 of 28 What is the structure of ATP? Adenine, ribose and three phosphate groups 13 of 28 How does ATP store energy? Bonds between phosphate groups are unstable (low Ea) so are easily broken to release lots of energy 14 of 28 What is the function of ATP hydrolase? Catalyses hydrolysis reaction of ATP to form ADP, Pi & energy 15 of 28 How is ATP reformed? Condensation reaction using ATP synthase to add Pi to ADP 16 of 28 Why is ATP a good immediate energy source? Releases less energy than glucose so quantities more manageable, much quicker to hydrolyse 17 of 28 Name one process ATP is used in Metabolic processes - provides energy to make macromolecules from basic units 18 of 28 Why is water a dipolar molecule? Oxygen has -ve charge, Hydrogen has +ve charge 19 of 28 How does water bond to each other? Opposite poles attract forming H bonds 20 of 28 Why is water difficult to heat up? Specific heat capacity makes sure small temperature changes do not effect external and internal conditions 21 of 28 What is latent heat vaporisation? Lots of energy is needed to evaporate small amount of water - sweating is effective 22 of 28 Why is it important that water is has cohesion and tension? Cohesion - sticks together so can be pulled up xylem vessels, tension - surface supports pond skaters 23 of 28 Why is water important in metabolism? Hydrolysis reactions, photosynthesis and aqueous medium 24 of 28 What is the function of iron ions? Haemoglobin - transport oxygen 25 of 28 What is the function of phosphate ions? DNA structure and energy stores in ATP 26 of 28 What is the function of hydrogen ions? Determine pH of solutions for enzymes 27 of 28 What is the fucntion of sodium ions? Transport glucose 28 of 28
Biological molecules AQA AS Biology PART 5 of 8 TOPICS: Nucleic acids 5.0 / 5 based on 1 rating Teacher recommended
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