Biological Molecules

• What is the structure of DNA?

  • DNA is a polymer made of two chains forming a double helix.
  • Monomers are nucleotides with a phosphate group, deoxyribose sugar, and nitrogenous bases (adenine, thymine, cytosine, guanine).
• What is the process of forming a polynucleotide?

  Condensation reactions occur, forming phosphodiester bonds between nucleotides.
• What are the complementary base pairs in DNA?

  Cytosine pairs with guanine, and adenine pairs with thymine.
• What are the key differences between DNA and RNA?

  • RNA has ribose sugar instead of deoxyribose.
  • RNA contains uracil instead of thymine.
  • RNA is usually single-stranded and shorter than DNA.
• What is the function of rRNA?

  rRNA combines with proteins to form ribosomes.
• What is semi-conservative replication of DNA?

  • One original strand combines with one newly synthesized strand.
  • This process ensures each new cell has a copy of the genome.
• What role does DNA helicase play in replication?

  DNA helicase breaks hydrogen bonds, unwinding the double helix.
• What is the function of DNA polymerase during replication?

  DNA polymerase joins adjacent nucleotides together to form phosphodiester bonds.
• Who discovered the structure of DNA?

  Watson and Crick discovered the structure of DNA.
• What is ATP and its function?

  ATP is a nucleotide derivative that serves as an immediate source of energy for biological processes.
• How is ATP synthesized?

  ATP is synthesized from ADP and inorganic phosphate in a condensation reaction using ATP synthase.
• What happens when ATP is hydrolyzed?

  Energy is released when the bonds between the phosphates are broken, forming ADP and inorganic phosphate.
• What is phosphorylation in relation to ATP?

  Phosphorylation is the transfer of an inorganic phosphate to another compound, making it more reactive.
• What are the five key properties of water?

  1. Water is a metabolite.
  2. Water is a good solvent.
  3. Water has a high heat capacity.
  4. Water has a large latent heat of vaporization.
  5. Water exhibits strong cohesion.
• Why is water described as a polar molecule?

  Water is polar because oxygen has a slight negative charge and hydrogen has a slight positive charge.
• How does water act as a metabolite?

  Water is involved in chemical reactions such as condensation and hydrolysis.
• What is the significance of water's high heat capacity?

  It buffers temperature changes, preventing enzyme denaturation.
• What is the role of cohesion in water?

  Cohesion allows water molecules to stick together, aiding in the movement of water in plants.
• What are the functions of key inorganic ions in biological systems?

  • Hydrogen ions: alter pH and affect enzyme activity.
  • Iron ions: component of hemoglobin for oxygen transport.
  • Sodium ions: involved in co-transport of glucose and amino acids.
  • Phosphate ions: found in DNA, RNA, and ATP.
• How do hydrogen ions affect enzyme activity?

  Hydrogen ions can alter the pH of a solution, impacting enzyme function.
• What is the role of iron ions in the body?

  Iron ions are a component of hemoglobin and are involved in oxygen transport.
• What is the function of sodium ions in biological systems?

  Sodium ions are involved in the co-transport of glucose and amino acids.
• What is the significance of phosphate ions in nucleic acids?

  Phosphate ions form phosphodiester bonds in DNA and RNA.