Genetics Chapter 7 + 8 Test Flashcards
What are the ends of linear chromosomes called? Why are bits of the ends lost with each cycle?
Telomeres, bits are lost bc do not replicate as easy the middle of cells
Lengths of telomeres decrease as we age. The effects of aging within cells is known as _______.
senescence
What is central dogma?
Central dogma describes how information flows in a cell.
The first step of information flow is transcription. What is transcription?
Process of copying gene (DNA) into a short mRNA sequence
What is the main enzyme involved in transcription? This enzyme uses single-stranded DNA to synthesize a complementary strand of ________.
RNA polymerase. Complementary strand of RNA
RNA polymerase reads DNA in the ____ to ____ direction. But, it builds an RNA strand in the _____ to _____ direction, adding each new nucleotide to the _____ end of the strand.
3’ to 5’ . It builds RNA 5’ to 3’, new nucleotides added to the 3’ end
Since only one strand of DNA can be transcribed, choose the one that starts w __ ______ (hint: its a number and 3 letters)
3’ TAC
mRNA is the intermediary between ____ and ________. From ribosomes, it is translated into _________.
DNA, ribosomes, protein
Translation is responsible for building a protein’s _______ structure. It assembles _____ _____ using the nucleotide sequence of _____.
primary, amino acids, mRNA
Every three nucleotides is called a _____. The codon chart is specific to ______.
codon, mRNA
What region does RNA polymerase bind to on DNA?
Promoter region
How do DNA and RNA compare location wise?
DNA: nucleus RNA: nucleus and cytosol
The promoter region is high in the bases adenine and thymine.
Adenine and thymine only have two H bonds.
What does RNA polymerase do?
It unwinds and unzips DNA and transcription begins
The start of the bases on DNA is 3’ TAC. Therefore, the first 3 bases of RNA are __ _____.
5’ AUG
The product of transcription is always ________ RNA. It is ______ length to a gene.
immature, equal
Immature RNA (aka _______) will undergo which two modifications?
- Splicing
- Addition of a cap and tail
What is splicing of pre-mRNA? What are the regions that are removed called? The regions that stay?
Splicing is when regions of the pre-mRNA are cut out. The regions that stay are called exons, those that stay are called introns.
An active __________ forms when the enzymes _______ bind to an intron and loop it out.
splicesome, SnRNPs
When two _______ are spliced together to form mRNA, the cleaved ______ and _______ are released.
exons, introns, snRNPs
mRNA can be spliced in many different ways. This is known as ____________ ________.
alternative splicing
After splicing, a ______ and ______ are added to mRNA
cap and tail
A cap contains 7 ________ nucleotides and is added to the ____ end. It aids in the bonding to a _______ and gives mRNA ________.
guanine, 5, ribosome, direction
A tail is added to the ____ end of mRNA. It consists of approximately _____ adenine nucleotides, known as a Poly A Tail.
3 end, 200
Both the cap and tail extend the life of mRNA is the cytosol. Why?
The pre-mRNA needs to last long enough to be translated by the ribosomes before it is recycled.
The translation of a new mature mRNA into a protein is accomplished by a _________. It is a _____ and protein hybrid, and composed of 2 subunits. What are they known as?
ribosome, RNA
Ribosomes bind to the RNA _________ initiation sequence and build a new _________ in the ___ to ___ direction.
translation, polypeptide, 5’ to 3’
The first amino acid on the polypeptide chain has a free amino group, it is called the ____ terminal. The last amino acid has a free acid group, it is called the ____ terminal.
N terminal, C terminal,
Transfer RNA is the adaptor between the three bases of ______ and its corresponding ______ _____.
codon, amino acid
tRNAs are only 70 to ____ base pairs long and have a signature _______ pattern.
90, cloverleaf
Each tRNA has 3 bases that make up its ______. These bases pair w the three bases of codon on the mRNA sequence during _________ (translation/transcription)
anticodon, translation
Each tRNA has an amino acid attached to its ___ end. The aminoacyl RNA _________ are used to charge the tRNA w the proper ______ acid.
3’, synthetases, amino
The third base of an anticodon is called the ________ position. What does it do?
wobble position, it forms base pairs w several different nucleotides
In eukaryotes, ribosomes bind to the 5’ cap, then move down the mRNA until they reach the first ______ (three letter codon)
AUG