Gene Expression (DNA → RNA → Protein)

A nucleotide consists of:

a nitrogen base, sugar, and phosphate

RNA transcription and the role of RNA as the messenger

a section of DNA double helix is uncoiled and only one of the DNA strands serves as a template for RNA polymerase enzyme to guide the synthesis of RNA. DNA uses mRNA to send genetic information to the cell organelles to perform specific functions.

The "rungs" of the DNA ladder are made of:

bases

In order to transform to a virulent form of bacteria, non encapsulated bacteria must:

be exposed to killed capsulated bacteria

substitution mutation

in which a single nucleotide is substituted with (or exchanged for) a different nucleotide that may result in an altered sequence of amino acid during translation, which may render the newly synthesized protein ineffective.

protein translation and why proteins are important in the biological systems

is the process in which cellular ribosomes create proteins; they are important because some functions of proteins include: speeding up reactions, transporting substances across membranes and through fluids, nutrition, hormonal signals for changes in cell activity, and immunity.

Before the Hershey-Chase experiment, many scientists believed that ____ carried the hereditary information.

protein

genetic code and its role in protein synthesis

since the codon for the protein comes from the copied genetic code it is crucial that the order of the genetic code be identical so we can have the right protein

Codon Wheel

the first letter of the codon is one of the ones in the middle than the second is on the second wheel and so on.

connection between DNA and RNA in protein synthesis

the first step in protein synthesis is the transcription of mRNA from a DNA gene, than protein synthesis is iniatiated

Okazaki fragments form on the:

the lagging strand

RNA processing events

1.) addition of 5' methyl G cap 2.) removal of introns 3.) addition of 3' poly(A) tail As the 5' end of the RNA emerges from polymerase it is immediately capped. After transcription (or during if the strand is long enough) the introns are excised by spliceosomes. As soon as transcription of the entire strand is complete and polymerase disociates, the 3' end is rapidly polyadenilated. 4.) binding of codon to anticodon 5.) association of hnRNA with the ribosome happen in the cytoplasm

deletion mutation

A deletion changes the number of DNA bases by removing a piece of DNA. Small deletions may remove one or a few base pairs within a gene, while larger deletions can remove an entire gene or several neighboring genes. The deleted DNA may alter the function of the resulting protein(s).

insertion mutation

An insertion changes the number of DNA bases in a gene by adding a piece of DNA. As a result, the protein made by the gene may not function properly

how do nitrogen bases complement each other

A→T and G→C, each nitrogenous base only pairs up or matches up with its counterpart

The element that transformed the bacteria in Griffith's experiments was:

DNA

What is required for DNA replication to occur?

DNA helicase DNA ligase DNA polymerase

the structure of DNA

DNA is a double helix matter, which consists of 4 nitrogen bases

Which of the following must happen first in order for DNA replication to occur?

DNA is unwound

The Hershey-Chase research showed that:

DNA was the molecule of heredity

A DNA strand has the following bases: A A G C C A. What are the bases on its complimentary strand?

T T C G G T

different types of RNA and their functions

The three types of RNA are: - mRNA (messenger RNA) - carries genetic information from the nucleus to the cytoplasm - tRNA (transfer RNA) - brings amino acids to ribosomes during protein synthesis - rRNA (ribosomal RNA) - guides the translation of mRNA into a protein

frameshift mutation

This type of mutation occurs when the addition or loss of DNA bases changes a gene's reading frame. A reading frame consists of groups of 3 bases that each code for one amino acid. A frameshift mutation shifts the grouping of these bases and changes the code for amino acids. The resulting protein is usually nonfunctional. Insertions, deletions, and duplications can all be frameshift mutations.