Chemistry Lecture Notes

DNA and RNA

General Notes

• DNA: Deoxyribonucleic Acid
  • Double-stranded helix
  • Contains bases: Adenine (A), Thymine (T), Guanine (G), Cytosine (C)
  • Backbone: Alternating sugar and phosphate molecules
  • Hydrogen bonds hold the two strands together
• RNA: Ribonucleic Acid
  • Single-stranded
  • Contains bases: Adenine (A), Uracil (U), Guanine (G), Cytosine (C)
  • Uracil (U) replaces Thymine (T)
  • Made through transcription from DNA

Key Processes

• Replication
  • Making an exact copy of DNA for cell division (mitosis)
  • Enzyme involved: DNA polymerase
• Transcription
  • Reading DNA to make messenger RNA (mRNA)
  • Enzyme involved: RNA polymerase
• Translation
  • mRNA is read to make a string of amino acids (forms a protein)
  • Takes place in the cytoplasm
  • Types of RNA involved: mRNA, tRNA (transfer RNA), rRNA (ribosomal RNA)

Important Terms

• Codon: A sequence of three nucleotides on mRNA
• Anti-codon: A sequence of three nucleotides on tRNA
• Hydrogen Bonds: Weak bonds that hold the DNA strands together
• mRNA: Messenger RNA; carries the code from DNA
• tRNA: Transfer RNA; brings amino acids to the ribosome
• rRNA: Ribosomal RNA; part of the ribosome structure

Enzymes

• Facilitate biological processes by lowering activation energy
• Examples:
  • DNA Polymerase: For DNA replication
  • RNA Polymerase: For transcription

Glycolysis and the Krebs Cycle

• Catabolism: Breaking down large molecules into smaller ones
  • Example: Glycolysis (breaking down glucose into pyruvate)
  • Produces energy (ATP)
• Anabolism: Synthesizing large molecules from smaller ones
  • Example: Storing excess glucose as glycogen

ATP: Adenosine Triphosphate

• Energy molecule of the body
• Structure: Adenine, ribose sugar, three phosphate groups
• High-energy bond: The bond between the second and third phosphate group
• Coupled Reactions: Paired reactions where one releases energy and the other uses it

Transition Notes

• Students should know their schedules for transitions to different semesters

Miscellaneous

• Enzymes: Lower the activation energy for chemical reactions
• Sodium-Potassium Pump: Uses energy from ATP to move sodium out of cells and potassium into cells

(Note: The above outlines common details; specific details about transitions, dates, and personal questions have been omitted.)