click below
click below
Normal Size Small Size show me how
Micro Exam 2
| Question | Answer |
|---|---|
| What is found on the 5' end of the DNA strand? | a phosphate group |
| semiconservative DNA replication | each daughter DNA molecule is composed of one original strand and one new strand |
| what are the characteristics of Okazaki fragments? | they are made by DNA polymerase III, they make up the lagging strands of replicated DNA, they begin with RNA primer, they are joined together by DNA lligase |
| what processes are involved in protein synthesis? | translation only |
| during transcription, RNA polymerase makes mRNA by "reading" what strand of DNA | template |
| using the genetic code, what amino acid is coded by the mRNA codon AAA? | lysine |
| what the anticodon attach to? | the mRNA codon |
| genes | segments of DNA that codes for a functional product |
| chromosomes | genes essential for survival |
| plasmid | extra chromosomal DNA that replicate independently not essential for normal bacterial metabolism, growth or reproduction, can confer survival advantages |
| gene expression | gene activity leads to a protein product in a cell (protein synthesis) |
| complementary base pairing | 5 prime end is down and 3 prime end is up |
| what are the 5' and 3' ends | the way the DNA replicate, the newly made "leading strand" is synthesized continuous and the newly made "lagging strand is synthezised discontinuously |
| antiparallel | complementary DNA strands are antiparallel newly made strands have to run 5 prime to 3 prime |
| which strand of DNA is continuous | the leading strand |
| what is the origin of replication | direction of leading parental strand |
| DNA helicase | unwinds DNA and creates replication fork pull apart double strand of DNA |
| Stabilizing proteins | bind to prevent reannealing, it keeps the DNA strands apart |
| replication forks | it moves as replication takes place |
| the lagging strand is | discontinuous |
| DNA polymerase (III) AND (I) | used to help put in RNA primers, binds and adds nucleotides to hydroxyl group at 3 end of nucleic acid. It replaces RNA primer with DNA |
| RNA primer | complementary to "moms" DNA to nucleotides |
| RNA polymerase | synthesizes short RNA sequencing called primers= starting points for DNA synthesis |
| DNA ligase | seals gap between okazaki fragments |
| okazaki fragment | short, newly synthesized DNA fragments |
| RNA | single strand and is composed of the sugar ribose, substitutes uracil for thymine |
| mRNA | carries genetic information to ribosomes |
| rRNA | found in ribosomes |
| tRNA | transfers amino acids to the ribosomes where the protein product is synthesized (transfer) |
| transcription | DNA transcribed to RNA |
| translation | RNA translated to form polypeptides |
| coding strand | strand of DNA that codes for a protein, it is the same as the mRNA except for substitution bases- uracil thymine |
| template strand | complementary to coding strand, this is the strand that is transcribed to make mRNA |
| codon | reading the genetic code three bases at a time |
| operon | group of genes that work together and helps regulate gene expression |
| what are the components of the operon | promoter, operator, structural genes |
| operator | DNA segment, repressor protein binds to prevent the attachment of promoter gene |
| promoter | DNA segment where the RNA polymerase attaches to being transcription |
| structural genes | code for specific proteins |
| inducible operons | gene usually not transcribed, must be turned off by a substance |
| repressible | gene always transcribed (on) must be turned off |
| mutation | change in sequence of bases within a gene |
| mutagens | agents that cause mutations |
| point mutations | single base at one point in the DNA sequence is inserted, deleted, or substituted by another base |
| frameshift mutations | one or several base pairs are deleted or inserted in to the DNA sequence, shifts from the "transitional reading frame" |