FoB Exam 4

Who originally identified how genes work in the one-gene, one-enzyme hypothesis

Beadle and Tatum

a mutation in an allele that does not produce a functional gene product

null allele

the hypothesis of gene function that proposed each gene is responsible for making one enzyme

one gene, one-enzyme hypothesis

Who did an experiemtnt to test the one-gene, one-enzyme hypothesis using N. crassa

Srb and Horowitz

Who proposed that sequences of bases in DNA acted as a code?

Crick

What is used to convert DNA to proteins?

mRNA

an enzyme that uses DNA to synthesize a complementary RNA molecule

RNA polymerase

What base is present in RNA but not DNA

uracil

What is the central dogma of molecular biology?

DNA → RNA → Proteins

using a DNA template to make an RNA molecule that has a base sequence complementary to the DNA

transcription

using the information in the base sequence of mRNA to synthesize proteins

translation

RNA polymerase uses monomers called ______

NTPs

Only one of the two DNA strands is used a template and transcribed by RNA polymerase

True

the strand read by RNA polymerase

template strand

the strand of RNA synthesized from DNA

coding strand

Do RNA polymerases need a primer to begin transcription?

No

What are the sites of DNA where transcription begins called?

promoters

the direction from a reference point in which RNA polymerase moves along a DNA strand

downstream

the opposite to the direction from a reference point in which RNA polymerase moves along a DNA strand

upstream

a DNA sequence in eukaryotic promoters that assembles general transcription factors and RNA polymerase

TATA box

any class of proteins that assemble on promoters and help RNA polymerase intiate transcription

transcription factors

What are the five biological omes

genome, epigenome, transcriptome, proteome, and metabolome

ome describing the proteins that can be made

genome

ome describing the 3D structure of DNA

epigenome

ome describing what genes are being expressed

transcriptome

ome describing what proteins are being made

proteome

ome describing how cell function is changing

metabolome

process of going from genome to epigenome

transcription

process of going from epigenome to transcriptome

expression

process of going from transcriptome to proteome

translation

process of going from proteome to metabolome

function

What kind of sugar is present in RNA

ribose

is RNA double or single stranded

single stranded

What are the four steps of transcription?

initiation, elongation, termination, and processing

material that is a combination of DNA and histones

chromatin

actively transcribed region of DNA that is open

euchromatin

unactively transcribed portion of DNA that is closed

heterochromatin

proteins that bind to DNA to regulate gene expressions, can either be repressors or activators, and recognize specific sequences and fit to them

Transcription Factors

transcription factors that bind to upstream of all genes TATA boxes at the promoter

general transcription factors

what kind of transcription factors act as a beacon

general transcription factors

What steps occur in transcript processing

alternative splicing, and addition of a 5’ methylG cap and polyA tail

parts of the gene that are removed in alternative splicing

introns

parts of the gene that stay and are joined together on an mRNA strand

exons

proteins that bind to DNA sequences and mark exon boundaries for removal

snRNP

What end of the RNA gets the Methyl G cap?

5’

What end of the RNA gets a long string of adenine nucleotides added to it?

3’

what acts as the beacon instead of GTF’s in prokaryotes to call over polymerase

sigma factor

in which type of cell do the sequences pair up with complimentary base pairs to make a hairpin structure at the end of an mRNA?

prokaryotes

What are the six properties of genetic code?

triplet, non-overlapping, redundant, unambiguous, puncuated, and universal

What are the three stop codons?

UAA, UAG, UGA

what sequence in the template strand should you look for when translating mRNA

TAC

what three RNA molecules are used in translation

mRNA, tRNA, and rRNA

what type of RNA links the genetic code with an amino acid

tRNA

what region of tRNA binds to the mRNA codon

anticodon

what direction is mRNA read

5’ to 3’

what enzyme attaches the amino acid to the tRNA molecule

tRNA synthetase

what type of RNA makes proteins

rRNA

which kind of RNA mediates tRNA binding to mRNA and catalyzes the condensation reaction between amino acids to make peptide bonds

rRNA

What are the three rRNA binding sites?

E,P,A

which of the rRNA sites is where the anticodon of charged tRNA binds with its complementary codon in mRNA?

A site

which of the rRNA sites is where a new amino acid is added to the growing chain?

P site

which of the rRNA sites is where tRNA is being released from the ribosome?

E site

what direction are proteins synthesized in?

N to C

what catalyzes the peptide bonds between amino acids?

large rRNA subunit

what binds to the stop codon in termination and makes the ribosome fall off the mRNA transcript?

release factors

changes of the nucleotide sequence of the genome

mutations

what causes mutations?

DNA replication, spontaneous chemical changes, mutagens

What mutations occur in body cells and is not passed to offspring?

somatic mutations

what kind of mutations occur in sex cells and are passed to offspring?

germ line mutations

How many bases are changed in point mutations?

1 nucleotide

a mutation that occurs when have a change in the DNA sequence that codes for the same amino acid

silent mutation

a mutation where the amino acid does change

missense mutation

type of missense mutation where the chemical property of the new amino acid is the same as the original

conservative missense mutation

what are the types of chemical properties of amino acids?

non polar-aliphatic, polar-uncharged, aromatic, positively charged and negatively charged

type of missense mutation where the chemical property of the new amino acid is different from the original

non-conservative missense

what kind of mutation involves the amino acid changes to a stop codon

nonsense mutation

what kind of mutation involves a truncated protein

nonsense mutations

what type of mutation involves the addition of deletion of a DNA base which changes how the mRNA is read

Frameshift Mutation

frameshift mutations only impact the gene if it is in the ________ region of the gene

protien coding

mutations ____ impact alternative splicing of mRNA

can

Transcription factors bind by recognizing the _______ between the base pairs

hydrogen bonds

what are the three types of postranslational modifications

phosphorylation, glycosylation and proteolysis

added phosphate groups alter the shape of the protein

phosphorlyation

posttranslation modification where adding sugars is important for targeting and recognition

glycosylation

type of posttranslational modification where cleaving the polypeptide allows the fragments to fold into different shapes

proteolysis

what are the three types of gene expression control in prokaryotes

transcription, translation, and posttranslational control

a group of genes that are transcribed together and regulated by a shared promoter and operator

operon

small molecule that triggers transcription of a gene

inducer

sequence of DNA that a transcription factor binds to

operater

transcription factor protein that promotes transcription

activator

transcription factor protein that decr4eases transcription

repressor

what encodes the enzyme beta galactosidase

Lac Z

the enzyme that breaks bonds between sugar monomers

galactosidase

what encodes the galactosidase permeate?

Lac Y

an enzyme that creates a channel protein in the cell membrane to transport sugar molecules

galactosidase permease

what gene encodes the repressor that suppresses transcription factor protein

Lac I

when lactose is not present what binds to the operator?

the repressor

what is the inducer in the lac operon

lactose

when lactose is present what does it bind to

repressor

the e-coli experiment proved that what prevents expression of the gene for beta galactosidase

glucose