Chapter 7&8

• Gene: Portions of DNA that code for specific proteins
• Genome: The entire genetic complement of an organism
• Nucleotides: A nucleotide is a molecule consisting of a phosphate group, a pentose sugar, and a nitrogen-containing base
• Base Pairs: Adenine, Thymine, Cytosine, Guanine and Uracil(RNA)
• Complementary: Pairs like A-T, G-C, or A-U in DNA
• Anti-parallel: ’5 strand lines up with 3‘ strand
• Nucleoid: Where the genome resides in Prokaryotic cells
• Chromosome: A threadlike structure of DNA that carries genetic information.
• Genotype: Set of genes within the genome
• Phenotype: Physical features and functional traits
• Amino Acids: the building blocks of proteins.
• Peptide/Protein: A chain of amino acids joined by peptide bonds
• Semi-conservative: DNA replication is semi-conservative, meaning that each new strand is a combination of the original strand and the newly synthesized strand
• Polymerization: The process of joining together many monomers to form a polymer.
• DNA Polymerase: An enzyme responsible for adding nucleotides during DNA replication.
• Replication fork: A region of the DNA molecule where the DNA strands are separated and new DNA is synthesized
• DNA helicase: an enzyme that unwinds the DNA helix and separates the two strands
• Primase: Enzyme that adds RNA primers to the template strands
• Primer: Small pieces of RNA that give DNA polymerase a place to start
• Okazaki fragment: Small segments that make up the lagging strand
• DNA Ligase: Enzyme that “bonds” together individual Okazaki fragments
• Origin(ORI): DNA replication starts here
• Leading Strand: Continuously synthesized from one end of the chromosome towards the other, with no gaps or breaks.
• Lagging Strand: Discontinuous synthesis occurs on this strand because it is made in short sections called Okazaki fragments.
• Central Dogma of Genetics: DNA (genotype) —> mRNA (transcript) —> protein (phenotype)
• Transcription: The process by which RNA polymerase reads the genetic code stored in DNA to produce an mRNA molecule.
• Translation: The process where ribosomes read the sequence of nucleotides in mRNA to assemble amino acids into proteins.
• Genetic Code: A set of rules that determines how information encoded in DNA is used to make proteins.
• Steps of transcription: Initiation, Elongation, & Termination
• Initiation: RNA polymerase binds to 3’ promoter site and unzips DNA
• Elongation: Complementary bases added A-T and G-C
• Termination: Self-terminate or rho-dependent
• DNA replication in prokaryotes is bidirectional and occurs in the cytoplasm. Includes Gyrases and Topoisomersales remove supercoils.
• DNA replication in Eukaryotes is similar to bacterial replication. Differences are it has thousands of replication origins, shorter Okazaki fragments, and uses four DNA polymerases.
• mRNA: messenger RNA, carries the genetic code from the nucleus to the ribosomes
• RNA polymerase: A protein that catalyzes the formation of RNA from DNA.
• Promoters: Are sequences of DNA that are transcribed into mRNA.
• Terminators: A sequence of nucleotides that terminates transcription.
• 5’ cap: A short phosphate group attached to the 5’ end of a DNA molecule
• polyadenylation: the addition of a poly(A) tail to the 3' end of a mRNA transcript