Chapter 10 Flashcards
What is the Triplet Code?
DNA strand goes through TRANSCRIPTION, to create mRNA. The mRNA goes through translation to create proteins.
What are read in order to identify which amino acids should be picked up?
Codon
Where is the DNA located in the cell?
Nucleus
Proteins are made inside what?
Ribosomes
Define Ribosomes
2 protein units embedded w/ RNA’s (ribosomal RNA) (Single helix that coils up); the site of protein synthesis
Define Transcription
the process of forming a nucleic acid by using another molecule as a template; particularly the process of synthesizing RNA by using one strand of a DNA molecule as a template
Transcription– Initiation?
Binding of RNA Polymerase
Transcription– Elongation?
Lengthening of mRNA strand
Transcription– Termination?
End of Transcription
Define RNA
a natural polymer that is present in all living cells and that plays a role in protein synthesis
Define Translation
the portion of protein synthesis that takes place at ribosomes and that uses the codons in mRNA molecules to specify the sequence of amino acids in polypeptide chains
Define Protein Synthesis
the formation of proteins by using information contained in DNA and carried by mRNA
Define Ribose
a five-carbon sugar present in RNA
Define mRNA (messenger RNA)
a single-stranded RNA molecule that encodes the information to make a protein
Define rRNA (ribosomal RNA)
an organelle that contains most of the RNA in the cell and that is responsible for ribosome function
Define tRNA (transfer RNA)
an RNA molecule that transfers amino acids to the growing end of a polypeptide chain during translation
Define RNA polymerase
an enzyme that starts (catalyzes) the formation of RNA by using a strand of a DNA molecule as a template
Define promoter
a nucleotide sequence on a DNA molecule to which an RNA polymerase molecule binds, which initiates the transcription of a specific gene
Define termination signal
a specific sequence of nucleotides that marks the end of a gene
Define Genetic Code
the rule that describes how a sequence of nucleotides, read in groups of three consecutive nucleotides (triplets) that correspond to specific amino acids, specifies the amino acid sequence of a protein
Define Codon
in DNA, a three-nucleotide sequence that encodes an amino acid or signifies a start signal or a stop signal
Define Anticodon
a region of tRNA that consists of three bases complimentary to the codon of mRNA
Define Genome
the complete genetic material contained in an individual
Define Virulent
describes a mircroorganism that causes disease and that is highly infectious; strictly refers only to viruses that reproduce by the lytic cycle
Define Transformation
the transfer of genetic material in the form of DNA fragments from one cell to another or from one organism to another
Define Bacteriophage
a virus that infects bacteria
Define Nucleotide
in a nucleic-acid chain, a sub-unit that consists of a sugar, a phosphate, and a nitrogenous base
Define Deoxyribose
a five-carbon sugar that is a component of DNA nucleotides
Define Nitrogenous Base
an organic base that contains nitrogen, such as purine or pyrimidine; a subunit of a nucleotide in DNA and RNA
Define Purine
a nitrogenous base that has a double-ring structure; one of the two general categories of nitrogenous bases found in DNA and RNA; either adenine or guanine
Define Pyrimidine
a nitrogenous base that has a single-ring structure; one of the two general categories of nitrogenous bases found in DNA and RNA; thymine, cytosine, or uracil
Define 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
Define Complementary Base Pair
the nucleotide bases in one strand of DNA or RNA that are paired with those of another strand; adenine pairs with thymine or uracil, and guanine pairs with cytosine
Define Base Sequence
The order of nitrogenous bases on a chain of DNA
Define DNA replication
the process of making a copy of DNA
Define Helicase
an enzyme that separates DNA strands
Define 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
Define DNA polymerase
an enzyme that catalyzes the formation of the DNA molecule
Define Semi-conservative replication
in each new DNA double helix, one strand is from the original molecule, and one strand is new
Define Mutation
a change in the nuclotide-base sequence of a gene or DNA molecule
Mutations- Chromosomal level
a lot of DNA can be lost (deletion, duplication, inversion, reciprocal translocation)
Mutations- Gene level
one gene is different
Mutations- Single nucleotide change “point mutations”
substitution (silent mutation), deletion (frame shift), inversion (frame shift)
Define Nonsense mutation
causes a gene to read STOP
James Watson and Francis Crick?
discovered what DNA was, 1950’s won Nobel Peace Prize (helped by Rosalind Franklin)
Frederick Griffith?
conducted in 1928, one of the first experiments suggesting DNA are capable of transforming genetic information, otherwise known as the “transforming principle,” which was later discovered to be DNA.
Organisms and bacteria on DNA
All organisms except bacteria have duplicate chromosomes (bacteria has single). Organism- linear DNA. Bacteria- circular, double helix; single
Define Conjugation
copy of plasmids (get DNA from another bacterium)
Hersey-Chase Experiment
identified DNA to be the genetic material of phages, and ultimately, of all organisms. Proved nucleic acids (DNA&RNA) to be genetic materials)
