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• DNA is a complex molecule containing the genetic information that makes up the chromosomes.
• RNA is a single-stranded nucleic acid that passes along genetic messages.
• DNA provides living organisms with guidelines—genetic information in chromosomal DNA—that help determine the nature of an organism's biology.
• DNA consists of two long chains of nucleotides twisted into a double helix and joined by hydrogen bonds between the complementary bases adenine and thymine or cytosine and guanine.
• DNA has two main roles: protein synthesis and replication.
• A nucleotide is the monomer of nucleic acids made up of a 5-carbon sugar, a phosphate group, and a nitrogenous base.
• Deoxyribonucleic acid (DNA) is a type of nucleic acid.
• Purines include Adenine and Guanine.
• Pyrimidines include Cytosine and Thymine & uracil.
• Hydrogen bonds hold the two DNA strands together (between the nitrogenous bases).
• The backbone of DNA is made up of a phosphate group and deoxyribose.
• Semi-conservative replication means that in each new DNA double helix, one strand is from the original molecule, and one strand is new.
• DNA replication is the process in which DNA makes a duplicate copy of itself.
• DNA polymerase is the enzyme responsible for replicating DNA — for using a template strand to construct a complimentary sequence of nucleotides, creating a double-stranded DNA molecule.
• DNA polymerase can also proofread the new strand as it is created and is involved in repairing DNA damage and mutations.
• Genes are the biochemical units of heredity that make up the chromosomes; a segment of DNA capable of synthesizing a protein.
• Initiation: DNA helicase unwinds the double helix, creating a replication fork.
• Tumor suppressor genes: A gene whose protein product inhibits cell division, thereby preventing the uncontrolled cell growth that contributes to cancer.
• Point mutation: A different amino acid - the location of the amino acid changed will impact the scale of the changes.
• Negative cell-cycle regulatory proteins: Proteins that halt the cell cycle.
• Frameshift mutations: Caused by insertions or deletions - NOT POINT MUTATIONS.
• Silent mutation: A mutation that changes a single nucleotide, but does not change the amino acid created.
• Elongation: DNA polymerase adds complementary nucleotides to the template strands, synthesizing new DNA strands.
• DNA is read 5' to 3'.
• DNA ligase joins the Okazaki fragments on the lagging strand, completing the replication process.
• Conditional mutations: A mutation that results in a characteristic phenotype only under certain environmental conditions.
• Nonsense mutation: Converts a sense codon (like the 3 bases which pair with an amino acid) to a stop codon (nonsense codon).
• Checkpoints and cancer: S-phase checks that DNA replication was proper.
• Gene mutation: A change in the sequence of the bases in a gene, which changes the structure of the polypeptide that the gene codes for.
• Missense mutation: A nucleotide-pair substitution that results in a codon that codes for a different amino acid (a base gets changed creating a different amino acid).
• Cancer: Any malignant growth or tumor caused by abnormal and uncontrolled cell division.
• Termination: 3rd step of DNA replication.
• Oncogenes: Genes that cause cancer by blocking the normal controls on cell reproduction.
• Positive cell-cycle regulatory proteins: Progress the cell cycle - when these become oncogenes, this would lead to cancerous spreading.
• During translation, the mRNA docks with the ribosome (also known as rRNA) at the AUG or methionine codon.
• A tRNA (called transfer RNA) is a structure who has an anticodon that pairs with a specific codon on the mRNA.
• The first tRNA moves into the A-site of the ribosome.
• The e site of the ribosome holds the tRNA that carries the growing polypeptide chain.
• The A site of the ribosome holds the tRNA that carries the next amino acid to be added to the chain.
• During the process of transcription, a DNA template strand is used to make mRNA using RNA Polymerase.