Ch 20 Flashcards
(20 cards)
Pyrimidines
Single ring structures
Enzymes in DNA replication?
- DNA Helicase
- DNA Polymerase III
- DNA Polymerase I
- DNA Ligase
Types of RNA?
- mRNA (product of transcribed gene, translated by ribosomes into protein)
- tRNA (deliver amino acids to ribosome during translation)
- rRNA (makes up ribosomes)
Enzyme in Transcription?
RNA Polymerase
Codons
Sequence of 3 nucleotides in DNA
Anticodons
Sequence of 3 nucleotides in mRNA
Gene therapies?
- Gene insertion-gene is injected into chromosome of diseased cell
- Gene modification- gene is chemically modified
- Gene surgery- defective gene is removed & replaced with normal gene
Where are enzymes used?
To isolate/ modify DNA segments in gene surgery and DNA sequencing
- Restriction enzymes (endonuclease)
- DNA Ligase
Genome
Cell’s complete set of DNA
Transformation
Any process in which foreign DNA is incorporated into the genome of cell
Uses vectors as vehicles
Organism with foreign DNA- transgenic
Point mutations
Changes in a SINGLE base pair, may or may not change amino acid sequence
Gene mutations
Changes in more than 1 base pair, will change amino acid sequence
Deletion
Removing 1 or more nucleotides in DNA sequence
Duplication
Adding an extra base pair onto DNA sequence
Inversions
Base pairs that are cut out and glued back in reverse order
Insertion
Extra base pair is inserted INTO DNA, changes readings of codes
Translocation
Transfer of a fragment of DNA from 1 part of genome to another. (Stays in genome)
DO NOT MIX UP WITH RECOMBINANT DNA
(Moving fragments of DNA from 1 source to another)
Expansion
Extra copies of codon repeats itsself
Nonsense mutation
Converts codon for an amino acid into a stop codon (usually lethal for cell)
Purines
Double ring structures
