Frameshift

Develop a model which explains how point and frameshift mutations can impact a protein.

Frameshift mutations include deletions and additions. With the addition/deletion of one nucleotide pair in a gene, this can cause a shift in an entire series of codons, leading to the creation of an incorrect or malfunctioning protein.

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Modifying RNA

Explain how eukaryotic cells modify RNA after transcription and why it is necessary.
Both ends of the transcript are altered to include a 5’ cap on the 5” end, and a poly-A tail on the 3’. These modifications facilitate the export of mRNA from out of the nucleus into the cytoplasm, protect mRNA from hydrolytic enzymes, and help ribosomes attach to the 5’ end of the strand. Enzymes that modify the original RNA transcript into mRNA within the nucleus also cut out interior sections of the molecule before allowing it to exit the nucleus.

Process of Transcription and Translation

Develop a model and explain the process of transcription and translation.
In an eukaryotic cell:

Transcription occurs in the nucleus of the cell. There are three steps; initiation, elongation, and termination. RNA polymerase attaches to the promoter segment of DNA and moves downstream, laying down corresponding RNA bases along the template strand of DNA in the 5’ to 3’ direction. Once the segment of DNA has been transcribed, the RNA polymerase detaches and the DNA rewinds, leaving a completed RNA transcript.

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Translation typically occurs in ribosomal units that are free floating within the cytoplasm. mRNA is fed through the ribosomal complex, and tRNA brings corresponding

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Gene Expression, Transcription, Translation

Compare and contrast the key terms gene expression, transcription, and translation.
Gene Expression: Process that includes transcription and translation; this is the process by which DNA directs protein synthesis

Transcription: Creating RNA from DNA; mRNA coding

Translation: Creating a polypeptide using information coded in mRNA

Wiggly Purple Guys

Develop a model and explain how DNA is packaged into a chromosome.

DNA is wound around histones, and these histone packages condense to form a chromosome.

Mastering Biology | Pearson; Campbell Biology

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Replication, Transcription, Translation

Compare and contrast the difference between replication, transcription, and translation.
Replication: Copying DNA

Transcription: Creating RNA from DNA; mRNA coding

Translation: Creating a polypeptide using information coded in mRNA

Replication Bubble

Develop a model which explains the major steps to replication, specifically a replication bubble.

To form a replication bubble, Helicase will come in first at the origin point of said replication bubble, and will unwind the two strands by breaking hydrogen bonds between nitrogenous bases. Single-strand binding proteins keep the fork open, and topoisomerase makes sure the DNA strands do not become damaged from the stress of unwinding. Topoisomerase does its job by breaking and swiveling pieces of DNA, which will later be rejoined. Next, primase comes in and places an RNA primer at the 5’ end of the leading strand, and on the 5’ end of each Okazaki fragment of the lagging strand. This allows new DNA to be created in the 5’-3’ direction. DNA polymerase III places new nucleotides on the parental DNA that complements the template in the 3’ to 5’ direction. So, the new DNA is formed in the 5’-3’ direction, but the new nucleotides are placed starting at the 3’ end of the old DNA strand that is being used as a template. DNA polymerase II removes any RNA nucleotide primers that were placed in the leading and lagging strand(s), replacing them with DNA nucleotides. Lastly, DNA ligase will clean up the disjointed areas and make sure all the Okazaki fragments, breaks in DNA sequencing, etc. are glued and smoothed out. At this point, the DNA strand will be fully replicated. Multiple replication bubbles occur at the same time, which is why DNA can be replicated so quickly, otherwise the time it would take for this to happen via one single replication bubble would be too great.

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Structure of DNA and Nucleotides

Explain the structure of DNA and nucleotides. Include a model of your explanation.

DNA is shaped as a twisted ladder; a double helix. Hydrogen bonds connect corresponding nitrogenous bases with one another, forming the rungs of the ladder.

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Rosalind Franklin took a photograph of the X-ray diffraction of DNA. This photo is what helped Watson and Crick understand that DNA has a helical shape, and the width of this helix suggested that the molecule is made up of two strands. The width also provided a basis which allowed Watson was able to estimate the spacing of nitrogenous bases along DNA.

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Nucleotides are subunit of DNA that build up the twisted helical shape, each nucleotide consists of a sugar-phosphate group attached to a nitrogenous base.

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