Chapter Twelve: Gene Expression at the Molecular Level Flashcards
Whose work on genetics, in the early 1900s, was rediscovered and finally understood?
Gregor Mendel
What British Physician in 1908, who was studying the inheritance of the disease Alkaptonuria, proposed a link between genes and the production of enzymes?
Archibald Garrod
By 1908, biochemists understood that metabolic pathways consisted of a series of…each one converting one chemical to another
enzymes
Garrod applied Mendel’s theory on genes to the pathway for the breakdown of Phenylalanine and the disease…
Alkaptonuria
Garrod was the first to link genes with…production
enzyme
What did Garrod term defective genes?
Inborn Errors of Metabolism
Garrod began the field of…
Human or Medical Genetics
Beagle and Tatum saw Garrod’s work while working on the nutritional needs of a mold called…
Neurospora
After Beadle and Tatum exposed the mold spores to….(to produce mutations) they isolated a number of mutant strains which could not produce certain nutrients
X-rays
Beadle and Tatum were working on the inheritance or genetics of…strains
mutant
The metabolic pathway for Arginine production was known to be controlled by how many enzymes?
three
Beadle and Tatum found several straight of Neurospora that could not produce…
Arginine
Beadle and Tatum found that different stains had different mutations which prevented…synthesis, but at different steps in the pathway
Arginine
What theory was proposed by Beadle and Tatum in which each gene controls a separate enzyme?
One Gene, One Enzyme Theory
One Gene, One Enzyme Theory
1. Genes control the…of enzymes, but not all genes encode enzymes
production
One Gene, One Enzyme Theory
2. Not all enzymes consist of a single polypeptide. Some multimeric enzymes are formed by the product of multiple genes, each producing a separate…which combines to form the enzyme
polypeptide
One Gene, One Enzyme Theory
3. some genes are alternatively…to produce multiple proteins, or versions of a protein. So some genes produce multiple proteins - 20,000 human genes produce more than 2 million proteins
spliced
The “Central Dogma” of Biology: traces the path of…flow within cells
information
Transcription is DNA-directed…synthesis
RNA
RNA Polymerase is the one molecule that is concerned with…
Transcription
What is this?
- region of gene where RNA Polymerase attaches to Transcribe gene
Promoter
What are the three types of RNA?
mRNA
tRNA
rRNA
Are all types of RNA transcribed the same way?
yes
What type of RNA?
- carries the information from DNA to the Ribosome
mRNA
What type of RNA?
- a component of Ribosomes
rRNA
What type of RNA?
- escorts amino acids to the Ribosome
tRNA
What is a precursor for Transcription?
Ribonucleoside Triphosphate
Mechanism of Ribonucleoside Triphosphate:
- removal of…and polymerization of…to 3’ end of growing RNA chain
Pyrophosphate
Polymerization
Transcription occurs on…strand only
template
Transcription occurs on…gene only
one
RNA Polymerase attaches to DNA and…DNA
denatures
In Eukaryotes, a variety of…are involved in the attachment of RNA Polymerase and DNA
proteins
Proteins involved in the attachment between RNA Polymerase and DNA are termed Initiation and…factors
Transcription
What lines up opposite DNA Template stand and RNA Polymerase connects them together in the 5’ to 3’ direction?
Ribonucleoside Triphosphates
Within a chromosome, different strands of the double stranded DNA form the…strand
template
…occurs in a variety of ways in different RNAs. The final product (Primary Transcript), however is not the finished product
Termination
…are all Post-transcriptionally modified in a variety of ways
RNAs
The addition of a 5’ 7-methyl Guanosine “cap” occurs in…only
mRNA
Addition of a Poly-A tail occurs in…only
mRNA
Splicing: The removal of…can occur to any type of RNA, from the action of Spliceosomes, a complex of RNA and Proteins
Introns
….is a complex of RNA and proteins involved in the action of splicing
Spliceosomes
The removal of introns results in an RNA Transcript much…than the corresponding gene (DNA)
shorter
Alternative Splicing:
Not all…are included in the final mRNA
exons