Midterm 1 Flashcards
Translation
Process of producing proteins at nucleoprotein structures called ribosomes
Transcription
Process of expressing genetic information, where one strand of DNA is used to direct synthesis of a single RNA
DNA nucleotide
Made up of 5 carbon deoxyribose sugar, phosphate group, and either A G T C
Helicase
Unwinds and unzips DNA, breaks the hydrogen bonds
SSBs
Stabilize single stranded DNA, by not letting the strands rejoin together
Gyrase (topoisomerase)
Relieves torsional stress, by breaking phosphodiester bonds along the length of the DNA
RNA primers
Primes DNA synthesis, allows polymerase to begin
DNA polymerase 1
Replaces RNA nucleotides with DNA nucleotides after the primer is removed
DNA polymerase 3
Elongates the the new strand after the primer is set
DNA ligase
Adds nucleotides to connect lagging (Okazaki) strands
mRNA splicing
Occurs at sites determined by consensus sequences, takes place in nucleus
Alternative splicing
Can give rise to different proteins in different tissues with different functions, splices out introns and keep exons, does not occur in prokaryotes; allows the number of proteins produced to exceed the number of genes that are expressed
tRNA
Transport amino acids to ribosomes to make proteins, binds to codon on mRNA
Ribosomes
Bind mRNA and identify codon for translations, bring pairing btw mRNA codons and tRNA anticodons, catalyze peptide bond formation btw amino acids
Silent mutation
Doesn’t make any change in amino acid sequence
Missense mutation
Change in an amino acid
Nonsense Mutation
A unnecessary stop codon is put out, stoping transcription
Frameshift mutation
Shifts how nucleotides are grouped together
Centromere
Area where sister chromatin are attached and chromatin is most tightly condensed. Where kinetochore is located and spindle fibers attach to pull apart.
Telomeres
When the lagging strand loses the primer, telomeres are the end of the chromosome arm, consisting of a complex of proteins and RNA templates that add repeated DNA sequences to insure that there is no shortening of the strand. When the telomeres are gone, this leads to cell death
Epigenome
Heritable changes that regulate gene expression without altering DNA sequence. Epigenetic trait can be inherited up to 2 generations.
Law of independent assortment
During gamete formation the segregation alleles at one locus is independent of the segregation of alleles at another locus
Law of segregation
Allele pairs separate or segregate during gamete formation, and randomly unite at fertilization
Back cross
Mating of a hybrid organism (offspring of genetically unlike parents) with one it it’s parent or an organism genetically similar to it’s parent.