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AP Bio Unit 6 Vocab
| Question | Answer |
|---|---|
| Purines | nucleotides composed of double ring structures (A. G) |
| Pyrimidines | nucleotides composed of single ring structures (C, U, T) |
| Antiparallel | opposite orientations of the two strands of a DNA helix, 5' end aligns with 3' end |
| Plasmids | small circular DNA molecules that are separate from chromosomes |
| RNA | one of the two types of nucleic acid made by cells, composed of ribonucleic acid, and is single stranded |
| DNA | another one of the two types of nucleic acid made by cells, contains genetic information, composed of deoxyribonucleic acid, and is double stranded |
| Origins of replication | a sequence of DNA at which replication is initiated on a chromosomes, plasmid, or virus |
| Replication fork | the point at which the two strands of DNA are separated to allow replication of each strand |
| Helicase | the enzyme that unwinds DNA strands at each replication fork |
| Topoisomerase | the enzyme that prevents strain ahead of the replication fork by relaxing super coiling |
| Primase | the enzyme that initiates replication by adding short segments of RNA to the parental DNA strand |
| Primers | short segments of RNA which are added to the parental DNA strand |
| DNAP III | attaches to each primer on the parental strand and moves in the 3' to 5' direction |
| DNAP I | replaces RNA nucleotides with DNA nucleoties |
| Leading strand | a single DNA strand, that during DNA replication, is replicated in a 3' to 5' direction (same direction as the replication fork) |
| Lagging strand | the strand of parental DNA that runs in the opposite direction which the replication fork opens |
| Okazaki fragments | small sections of DNA that are formed during discontinuous synthesis of the lagging strand during DNA replication |
| DNA ligase | joins the Okazaki fragments forming on a continuous DNA strand |
| Telomeres | repeating unites of short nucleotide sequences that do not code for genes |
| Telomerase | the enzyme that adds telomeres to DNA |
| Nuclease | if segments of DNA are damaged, nuclease can remove segments of nucleotides |
| Mismatch repair | fixes mis-paired bases right after DNA replication |
| Transcription | the synthesis of RNA using information from DNA |
| Gene expression | the process by which DNA directs the synthesis of proteins |
| Template strand | the strand used by DNA polymerase or RNA polymerase to attach complementary bases during DNA replication or RNA transcription |
| Codon | a sequence of three consecutive nucleotides in a DNA or RNA molecule that codes for a specific amino acid |
| rRNA | helps form ribosomes |
| tRNA | transfer molecules that are important in the process of translation, carry specific amino acid, and can attach to mRNA |
| 5' Cap | the 5' end of the pre-mRNA receives a modified guanine nucleotide cap |
| Poly-A-Tail | the 3' end of the pre-mRNA receives 50-250 adenine nucleotides |
| mRNA | messenger DNA, the copy of DNA information that is moved out of the nucleus to give instructions in the process of protein formation |
| Redundancy | more than one codon can code for each amino acid |
| Reading frame | the codons on the mRNA must be read in the correct groupings during translation to synthesize the correct proteins |
| Alternative splicing | a cellular process in which exons from the same gene are joined in different combinations, leading to different, but related, mRNA |
| RNA splicing | sections of the pre-mRNA, called introns, are removed and then exons are joined together |
| Translation | the synthesis of a polypeptide using information from RNA |
| Anticodon | a trinucleotide sequence located at the end of a tRNA molecule which is complementary to a corresponding codon in a mRNA sequence |
| tRNA | transfer molecules that are important in the process of translation, carry specific amino acid, and can attach to mRNA |
| Stop codon | sequence of three nucleotides in a DNA or messenger RNA that signals a halt to protein synthesis in the cell |
| Operons | a group of genes that can be turned on and off |
| Promoter | where RNA polymerase can attach |
| Operator | the on/off switch |
| Inducible | transcription is usually off by can be induced |
| Cytoplasmic determinants | various molecules in the cytoplasm that contain genetic information or chemicals to spark various reactions |
| Allosteric inhibitor | substrate binds to allosteric site and stabilizes the enzyme shape so that active sites are closed |
| Regulatory gene | produces a repressor protein that binds to the operator to block RNA polymerase from transcribing the gene |
| Allosteric activator | substate binds to allosteric site and stabilizes the shape of the enzyme so the active sites remain open |
| Control elements | A segment of noncoding DNA that helps regulate transcription of a gene by binding a transcription factor |
| Histone acetylation | adds acetyl groups to histones which loosens DNA |
| DNA methylation | adds methyl groups to DNA (causes chromatin to condense) |
| Epigenetic inheritance | chromatin modifications do not alter the nucleotide sequence of DNA but they can be heritable to future generations |
| Gene | a piece of genetic information that codes for a certain trait |
| Differentiation | cells become specialized in their structure and function |
| Morphogenesis | the physical process that gives an organism its shape |
| Repressible | they are on but can be turned off by a small molecule. |
| Induction | cell to cell signals that can cause a change in gene expression |
| Homeotic genes | map out body structures |
| Apoptosis | programmed cell death |
| Pattern formation | a "body plan" for the organism |
| Mutations | changes in genetic material of a cell which can alter phenotypes |
| Genotype | the organism's underlying genetic makeup (combination of alleles) |
| Phenotype | an individual's observable traits |
| Nondisjunction | when chromosomes do not separate properly in meiosis |
| Translocation | a segment of one chromosome moves to another |
| Inversion | segment is reversed |
| Deletion | segment is lost |
| Horizontal gene transfer | the introduction of genetic material from one species to another species by mechanisms other than the vertical transmission from parent(s) to offspring |
| Transformation | uptaking DNA from a nearby cell |
| Conjugation | cell to cell transfer of DNA |
| Transposition | movement of DNA segments within and between DNA molecules |
| Point mutation | change a single nucleotide pair of a gene |
| Duplication | segment is replaced |
| Transduction | viral transmissions of genetic material |
| Substitution | the replacement of one nucleotide and its partner with another pair of nucleotides |
| Gel electrophoresis | a technique used to separate DNA fragments by size |
| PCR | a method used in molecular biology to make several copies of a specific DNA segment |
| DNA sequencing | the process of determining the order of nucleotides in DNA |