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Chapter 10
Vocabulary
Term | Definition |
---|---|
virulent | describes a microorganism that causes disease and that is highly infectious; strictly, refers only to viruses that reproduce by the lytic cycle. |
transformation | the transfer of genetic material in the form of DNA fragments from one cell to another or from one organism to another |
bacteriophage | a virus that infects bacteria |
nucleotide | in a nucleic-acid chain, a subunit that consists of a sugar, a phosphate, and a nitrogenous base. |
deoxyribose | a five carbon sugar that is a component of DNA nucleotides |
nitrogenous base | an organic base that contains nitrogen, such as a purine or pyrimidine; a subunit of a nucleotide in DNA and RNA. |
purine | a nitrogenous base that has a double-ring structure; one of the two general cat. of nitrogenous bases found in DNA and RNA. |
pyrimidine | a nitrogenous base that has a single-ring structure; one of the two general cat. of nitrogenous bases found in DNA and RNA. |
base-pairing rules | the rules stating that cytosine pairs with guanine and adenine pairs with thymine in DNA, and that adenine pairs with uracil in RNA. |
complementary base pair | the nucleotide bases in one strand of DNA or RNA that are paired with those of another strand. |
base sequence | the order of nitrogenous bases on a chain of DNA |
DNA replication | the process of making a copy of DNA |
helicase | an enzyme that separates DNA strands. |
replication fork | a y-shaped point that results when the two strands of a DNA double helix separate so that the DNA molecule can be replicated. |
DNA polymerase | an enzyme that catalyzes the formation of the DNA molecule |
semi-conservative replication | in each new DNA double helix, one strand is from the original molecule, and one strand is new |
mutation | a change in the nucleotide-base sequence of a gene or DNA molecule. |
ribonucleic acid | a natural polymer that is present in all living cells and that plays a role in protein synthesis. |
transcription | the process of forming a nucleic acid by using another molecules as a template; particularly the process of synthesizing RNA by using one strand of a DNA molecule as a template. |
translation | the portion of protein synthesis that takes place at ribosomes and that uses he codons in mRNA molecules to specify the sequence of amino acids in polypeptide chains. |
protein synthesis | the formation of proteins by using information contained in DNA and carried by mRNA. |
ribose | a five-carbon sugar present in RNA |
messenger RNA | a single-stranded RNA molecule that encodes the information to make a protein. |
ribosomal RNA | an organelle that contains most of the RNA in the cell and that is responsible for ribosome function. |
transfer RNA | an RNA molecule that transfers amino acids to the growing end of a polypeptide chain during translation. |
RNA polymerase | an enzyme that starts the formation of RNA by using a strand of a DNA molecule as a template |
promoter | a nucleotide sequence on a DNA molecule to which an RNA polymerase molecule binds, which initiates the transcription of a specific gene. |
termination signal | a specific sequence of nucleotides that marks the end of a gene. |
genetic code | the rule that describes how a sequence of nucleotides, read in groups of three consecutive nucleotides that correspond to specific amino acids, specific the amino acid sequence of a protein. |
codon | a three-nucleotide sequence that encodes an amino acid or signifies a start signal or a stop signal. |
anticodon | a region of tRNA that consists of three bases complementary to the codon of mRNA. |
genome | the complete genetic material contained in an individual. |