Transcription and Translation

According to Beadle and Tatum's hypothesis, at a minimum how many genes are necessary for this pathway?

2

If a protein has 100 amino acids, what is the minimum length of the RNA required to code for this protein?

300

List all of the features of a mature mRNA in eukaryotes.

5' cap, 5'UTR, exons, 3'UTR poly A tail (tail is not encoded by the DNA)

The genetic code read from the mRNA in what manner?

5' to 3' in groups of three bases called codons

Consider the following pice of DNA 3'GATCCGGTT 5'CTAGGCCAA Using the top strand as template, what would be the corresponding RNA?

5'CUAGGCCAA

Consider the following piece of DNA 3'GATCCGGTT 5'CTAGGCCAA Using the top strand as template, what would be the corresponding RNA?

5'CUAGGCCAA

Functional RNA

A RNA molecule that functions without being translated. Carries out a job in the cell as RNA.

What does not occur in prokaryotic gene expression, but does occur in eukaryotic gene expression?

A cap is added to the 5' end of the mRNA.

The genetic code is essentially the same for all organisms. From this, one can logically assume which of the following?

A gene from an organism can be expressed by any other organism and the resulting protein is functional.

During translation elongation, which site in the ribosome represents the location where a codon is being read?

A site

What site in the ribosome is where the codon / anti-codon relationship tested?

A site

How does termination of translation take place?

A stop codon is reached.

What is the start codon for translation?

AUG

The codon on an mRNA will base pair with what on the tRNA?

Anticodon

What occurs in prokaryotes but not in eukaryotes?

Concurrent transcription and translation

The central dogma of Molecular Biology states that information flows in what order?

DNA to RNA to a function protein that could be either protein or RNA

Garrod hypothesized that "inborn errors of metabolism" such as alkaptonuria occur because

Genes dictate the production of specific enzymes, and affected individuals have genetic defects that cause them to lack certain enzymes.

Proper order of the phases of transcription

Initiation, Elongation, Termination

Which part of a mRNA is removed through splicing of the pre-mRNA?

Introns

Telomerase is sometimes called a ribo protein because?

It contains both RNA and poly-peptide elements

If a mutation of a single base occurs in an intron what would you predict would be a possible consequence to the protein that the gene encodes?

Nothing, as the RNA containing the mutation would be spliced out and not translated. As long as the mutation did not occur as the splice junction.

A mutation occurs in the the 5'UTR of a eukaryotic Gene. Predict what might occur to the protein encoded by this gene.

Nothing, this region is not translated so no change to the protein will occur.

Minimal media

One that contains only base materials such as inorganic salts, a carbon source, a nitrogen source, and some molecules that serve as vitamins. No macromolecules or amino acids or nucleotides are present.

Telomere shortening is a problem in which types of cells?

Only eukaryotic cells

Which site "holds onto" the growing poly peptide chain?

P site

According to the central dogma, what molecule should go in the blank? DNA → _____ → Proteins

RNA

In the process of transcription, _____.

RNA is synthesized

In eukaryotes there are several different types of RNA polymerase. Which type is involved in transcription of mRNA for a globin protein?

RNA polymerase II

The sigma sub unit of e. Coli Holo RNA polymerase is important for what function of the enzyme?

Recognition of the promoter -10 and -35 sequences

Transcription in eukaryotes requires which of the following in addition to RNA polymerase?

Several transcription factors

What occurs during the initiation phase of transcription in a prokaryote?

The Holo RNA polymerase recognizes the DNA promoter sequence and starts linking together NTP as directed by the template strand of the DNA.

What occurs during the Termination phase of transcription in a prokaryote?

The core RNA polymerase lets go of the RNA and transcription ends in response to either factor dependent termination or factor independent termination signals.

What occurs during the Elongation phase of transcription in a prokaryote?

The core RNA polymerase moves along the DNA synthesizing RNA in a 5' to 3' direction.

In prokaryotes, the consensus -10 promoter sequence is TATAAT. What would your predict might happen if this sequence was mutated to GAGAAT?

The rate or amount of transcription from the mutated promoter would be less than the wild type consensus sequence.

What occurs during the termination phase of translation?

The ribosome reaches the stop codon and a release factor enters the A site causing the ribosome to release the poly peptide and the two ribosome subunits come apart.

You have treated a region of chromatin with a nuclease (an enzyme that digests DNA) and you observe very little digestion or break down of the DNA. You conclude:

The the region is probably heterochromatin as it resists digestion.

How do amino acids get into the ribosome?

They are attached to tRNA molecules which can enter the ribosome.

How many bases are required to code for a single amino acid?

Three

What is the purpose of telomeres?

To protect the ends of linear chromosomes.

What are the stop codons for translation?

UAA, UAG, UGA

Linear Chromosomes shrink with each round of replication, because?

When the RNA primers are removed at the very end of the chromosome by DNA polymerase I, there is nothing to act as primer so no DNA is synthesized at that location.

A ribozyme is

an RNA molecule that function like an enzyme.

Alternative RNA splicing

can allow the production of proteins of different sizes and functions from a single mRNA.

One way that chromatin can change between the 30nMeter (condensed) filament and the 10nMeter (uncondensed) filament

is through the interaction of histone H1 with the linker DNA regions.

mRNA

messenger RNA; type of RNA that carries instructions from DNA in the nucleus to the ribosome

Eukaryotic Transcription:

requires a large set of protein factors to properly recruit the polymerase to the promoter.

rRNA

ribosomal RNA; type of RNA that combines with proteins to form ribosomes

What are the four types of RNA and which one does the ribosome read?

tRNA, mRNA, rRNA, functional RNA, and it reads the mRNA.

In the polymerization of DNA, a phosphodiester bond is formed between a phosphate group of the nucleotide being added and _____ of the last nucleotide in the polymer.

the 3' OH

In the structural organization of many eukaryotic genes, individual exons may be related to...

the various domains or regions of the polypeptide product.

tRNA

transfer RNA; type of RNA that transfers amino acids to the ribosome