Molecular Genetics Flashcards
Each strand of DNA separately serves as a template for a new complementary strand
semiconservative
The area that is being separated from the parent DNA as it is unwound
replication fork
The new DNA strand that can be continuously synthesized in the 5’ to 3’ direction
leading strand
the strand that is made in okazaki fragments in the 5’ to 3’ direction
lagging strand
a __ ____, a short segment of nucleotides, is laid down by the enzyme ____. Once this is place __ __ can latch onto it and synthesize a new strand of DNA
RNA primer, primase, DNA polymerase
__ ___ unwinds the the DNA strand, forming a ____ shaped replication fork. __ ___ ___ proteins keep the DNA uncoiled until the replication process is complete. ______ will break and rejoin the double helix ahead of the replication fork in order to prevent __ and coiling
DNA helicase, Y, single stranded binding, topoisomerase, knotting
DNA _____ occurs when DNA ___ __ is used for replication. It moves in a __ to ___ direction
elongation, polyermase III, 5’ 3’
Since DNA must be synthesized in the __ to __ direction, the lagging strand is synthesized in segments as the polymerase must wait for the DNA to further ___. These fragments are called ____ fragments. For each individual okazaki fragment an ____ ___ is needed for each.
5’, 3’, unwind, okazaki, RNA primer
In DNA termination, __ __ removes the RNA primer strips and replaces them with DNA. Then __ ___ seals the ___ ____ between the okazaki fragments. ___ ___ and ____ proofread the strands to remove and replace wrong segments
polymerase I, DNA ligase, phosphodiester bonds, polymerase I, III
process by which DNA results in the synthesis of RNA and protein, leading to expressible changes
gene expression
Transcription takes place in the __ in eukaryotes, and in the ___ in prokaryotes
nucleus, cytoplasm
the enzyme that latches on to DNA and makes the complementary RNA strand
RNA polymerase
The ___ or the _____ strand is what acts as a guide for the synthesis of a new RNA strand, while the ___ or ____ strand does nothing
template, anti-sense, coding, sense
Before RNA polymerase starts synthesizing an RNA strand, it bind to the _____ segment of the DNA, which is ____ of the site of RNA synthesis. The parts of the promoter that the RNA polymerase actually bind to are called the ___ element or the TATA box, and the ___ element.
promoter, upstream, -10, -35
In transcription ___, RNA polymerase binds to specific promoter regions indicated by ____ ____, which determine the genes that should be expressed. Once RNA polymerase binds to the DNA it ___ it
initiation, transcription factors, unwinds
During transcription elongation, RNA continues unwind DNA and use the ___ strand as a template to synthesize RNA in the __ to ___ direction
antisense, 5’ 3’
Transcription termination occurs when RNA polymerase encounters the __ ___ which is usually a long sequence of ___ nucleotides, and ____ ___
stop point, adenine, falls off
mRNA ____ is a process by which pre-mRNA is modified before translation into a protein product. It occurs only in _____.
processing, eukaryotes
The 5’ cap is a ____ sequence that is added to the __ end of the mRNA. It provides __ for the mRNA and a point of attachment for ____
5;-G-P-P-P, 5’, ribosomes
The poly-A tail is the addition of ___ nucleotides to the end of an mRNA transcript which provides _____ and prevents it from ____
adenine, stability, degradation
RNA sequences that are translated into a final protein product
exons
RNA sequences that are removed before the RNA is translated
introns
___ and proteins form a ___ complex which helps to remove introns, and __ together exons.
snRNA, spliceosome, splice
process of removing introns and joining together exons
RNA splicing
__ ___ is a term used when the remaining exons can be combined in different ways to create different __ from the same __ ___. It allows a gene to code for multiple ____
alternative splicing, mRNA, RNA transcript, multiple proteins
sit on or near the promoter sequence and help the transcription factors and RNA polymerase to assemble
activator
Prevents transcription factors from assembling and blocks transcription
repressor
The most effective way to prevent gene expression is to __ the promoter region.
delete
siRNA or ____ RNA, is loaded with a sequences that matches an existing mRNA sequence the body wants to ___. It will bind to it, and ___ it into small ineffective pieces that cannot be translated
small-interfering, silence, chop
miRNA or ____ RNA, also has a matching sequence to the mRNA needing to be silenced, but acts as a physical ___ that prevents translation
micro, block
the process of creating proteins by using the genetic information from mRNA
translation
The genetic code is __ or ___, but it does not contain any ____. This allows possible mistakes in the ____ process to possibly be coded for by the same amino acid
redundant, degenerate, ambiguity, transcription
The stop codons that do not code for an amino acid
UAA, UAG, AGA
The start codon is always ___ and results in a ____ amino acid
AUG, methionine
The 3 letter codon that is read at a time
reading frame
A clover shaped molecule responsible for transporting nucleotide triplets called anticodons and their associated amino acid; each is designated to carry a specific amino acid
tRNA
Ribosomes function in the binding of a ___ __ with its associated mRNA codon. It has ___ binding sites for tRNA and an additional site for the ____ molecule being translated
tRNA anticodon, 3, mRNA
Ribosomes that are free floating directly in the cytosol
free ribosome
