Bio 1320 ch 7

What describes a substitution mutation?

1 DNA base is replaced with another

Translation initiation and elongation events in order from the first step at the top to the last step at the bottom

1. The 5' end of the mRNA molecule binds with the small ribosomal subunit 2. The first tRNA binds to the start codon on the mRNA molecule 3. The large ribosomal subunit binds to the small ribosomal subunit 4. The second tRNA molecule binds to the second codon on the mRNA molecule 5. A covalent bond is formed between the 2 amino acids 6. The ribosome releases an empty tRNA

Events that led to our understanding of DNA in chronological order

A harmless bacteria strain was found to cause disease after receiving DNA (not protein) from another bacterial strain An experiment using radioactive compounds revealed that viruses inject DNA into bacteria X-ray diffraction revealed the 3D shape of DNA A model of DNA was created showing how it's subunits form its double helical shape The human genome was sequenced

Eukaryotic Gene Regulation

A transcription factor binds to the TATA box Alternate patterns of intron removal Chromatin unwinding Genes are regulated by enhancers located far away from the gene

The term genome refers to

All the genetic material in an organisms cell

Mutations can lead to genetic variability because they create new — or variants of genes

Alleles

What gene regulation mechanism allows for the production of different proteins from the same mRNA?

Alternative splicing of exons

On a tRNA molecule, the — is a 3-base sequence that is complementary to and binds to an mRNA codon during translation.

Anticodon

What 3-base site of a tRNA molecule is complementary to an mRNA codon?

Anticodon

Regulating gene expression allows cells to produce

Certain proteins only when they are needed

Agents or processes that can cause mutations

Chemical mutagens Errors in DNA replication Some forms of radiation

In an RNA molecule, a — is a genetic code word that corresponds to one amino acid.

Codon

The genetic code specifies what amino acid is matched to each three-nucleotide — in the mRNA

Codon

Hershey and Chase showed that the part of a virus that could enter bacterial cells and cause the production of more viruses was

DNA

The information that each cell needs to produce proteins is stored in a molecule called

DNA

Likely effect of shorter protein mutation

Deletion of 12 bases in the 2nd exon

Affected by epigenetic modifications in eukaryotes

Developmental patterns Gene expression Cell division

Modifications to DNA, such as methylation, that do not change the nucleotide sequence but do affect gene expression are called — modifications

Epigenetic

After translation is complete, the newly synthesized polypeptide must — , as determined by some regions of the amino acid chain

Fold into its functional shape

Prokaryotic gene regulation

Genes of the lac operon are transcribed when lactose is present Repressor protein binds to operator region of DNA

The — describes the correspondence of 3-nucleotide codons to specific amino acids or directions for starting and stopping translation.

Genetic code

A — mutation is one that occurs in the cells that give rise to sperm or egg

Germline

All of the correct statements regarding the results of Frederick Griffiths 1928 experiment involving streptococcus pneumoniae

Heat killed S strains mixed with live R strains caused pneumonia in mice Live S strains caused pneumonia in mice

Likely effect of protein of same size with different sequence mitation

Insertion of 6 bases in exon #1 and deletion of 6 bases in exon #2

Likely effect of longer protein mutation

Insertion of 6 bases in the 2nd exon

Likely effect of no change to protein mutation

Insertion of 9 bases in the 2nd intron Deletion of 3 bases in the 2nd intron

An — is a portion of RNA that averages about 1000 nucleotides

Intron

In eukaryotes, a part of an mRNA that is removed before translation is called an

Intron

The lab operon in E. Coli bacteria includes 3 genes that produce

Lactose-degrading proteins

When Griffith mixed together live strain R bacteria and heat killed S bacteria and injected them into mice, and — bacteria were isolated from the mice, indicating that something could pass between cells and transform them.

Live S strain

A change in a protein-encoding DNA sequence or a regulatory DNA sequence, such as an enhancer, is called a

Mutation

A — is a change in a cells DNA sequence

Mutation

Because of — , the language gene (FOXP2) in humans has 2 unique amino acids compared to other primates

Mutations

— in DNA May arise spontaneously as errors in replication, or they can be induced by external agents, like chemicals and radiation

Mutations

Genes and Exons encode many more these just one amino acid and include many more

Nucleotides than just three

Parts of a DNA molecule

Phosphate group Purine Hydrogen bond Complementary pair Deoxyribose Pyrimidine

Components of nucleotides

Phosphorus-containing groups Sugar Nitrogen-containing base

Likely effect of no protein produced mutation

Point mutation in start codon

Enzymes and chaperone proteins assist in — that takes place after translation is complete

Polypeptide folding

Splicing of different exons together from the same mRNA molecules can result in

Production of different proteins

The— is a sequence of DNA that signals the start of a gene and is the site where RNA polymerase binds to begin transcription

Promoter

Prokaryotic and eukaryotic gene regulation

Promoter region of genes Transcription can be affected by the environment

In the central dogma, information flows from DNA to RNA to

Proteins

Central dogma/ parts and processes of eukaryotic gene expression in chronological order

RNA polymerase binds to gene Transcription elongation occurs A complete mRNA strand detached from RNA polymerase Introns are removed Translation occurs Functional protein is formed

In the Hershey and Chase experiment, — was found inside the infected bacteria, indicating that the labeled viral — had entered the bacterial cells to direct new virus production.

Radioactive phosphorus; DNA

Utilized in the process of translation

Ribosome mRNA tRNA amino acids

In his experiments with S. Pneumoniae bacteria and mice, Frederich Griffith found that

Something in heat-killed S bacteria could transform type R bacteria.

What role does DNA play in the cell?

Store genetic information

A — mutation is caused by the replacement of 1 nucleotide with another

Substitution

Transcription

Synthesis of RNA Nucleotides are joined together Occurs in the nucleus DNA is the template Requires RNA polymerase

Translation

Synthesis of polypeptides Amino acids are joined together Occurs on a ribosome Occurs after RNA processing

At the beginning of transcription, RNA polymerase binds to

The promoter

True about codons

They are composed of three mRNA bases They correspond to one amino acid

Reasons a cell regulates gene expression

To respond to changing conditions To have a specialized function

In eukaryotic cells, proteins called — factors bind at specific DNA sequences, which allows RNA polymerase to initiate transcription

Transcription

In the central dogma describing the flow of genetic information from DNA to protein, DNA is copied to RNA in a process called —, and the information in RNA is used to direct the synthesis of a protein in a process called —.

Transcription Translation

In eukaryotes, what regulatory proteins are required for RNA polymerase to bind to the promoter and initiate transcription?

Transcription factors

Transcription factors are eukaryotic proteins that are required for RNA polymerase to bind to a promoter and initiate

Transcription of genes

All of the genetic material that is within a cell is called its

genome

As described by Jacob and Monod, what E. Coli genes and regulatory sequences are only produced when the bacteria need to break down lactose in the immediate environment

lac operon

During production of a protein, the info encoded in a DNA base sequence is transcribed to produce a molecule of — ,which is then processed and translated to produce the sequence of — acids in a protein.

mRNA Amino

In transcription, the genetic info in DNA is copied into a — molecule, and in translation, the message in an mRNA molecule is translated into an — sequence.

mRNA; amino acid

During the elongation stage of translation, the ribosome exposes codons on the — one at a time; each codon determines what — will bring it's attached amino acid to the ribosome to be added to the polypeptide chain

mRNA; tRNA

Subunits called _____ are the building blocks of nucleic acids, as determined by scientists by about 1930.

nucleotides