Transcription (Lecture 11) Flashcards
What is a lethal allele?
A lethal allele: causes death at an early stage of development, and so some genotypes may not appear among the progeny
A lethal allele:
Heterozygotes are ______, one or the other homozygotes are not
What does it affect and at what time?
Heterozygotes are viable, one or the other homozygotes are not.
Affects the Mendelian genotypic and phenotypic ratios in progeny at birth
A single gene may control several traits
Given this P generation and F1 generation, what is the conclusion?
Conclusion: YY mice die, and so
2/3 of progeny are Yy, yellow
1/3 of progeny are yy, nonyellow
Multiple genes contribute to a phenotype:
A mutation in Gene A or Gene B can generate the same mutant phenotype. This is very different from what?
A mutation in Gene A or Gene B can generate the same mutant phenotype. This is very different from alleles of the same gene!
The Expression of a Genotype May Be Influenced By Environmental Effects
What is a temperature-sensitive allele?
Temperature-sensitive allele: an allele whose product is functional only at a certain temperature.
Example: a fruit fly has a mutation in a wing development gene. At low temperatures, the protein is non-functional but is functional at warmer temperatures. This would be a cold-sensitive mutation.
Intro in Transcription
- The central dogma of molecular biology
- What are the stages of transcription and translation (basic)?
DNA → RNA → Protein
Transcription Translation
Our Wonderful Genome
- How many bases of DNA are distributed over how many pairs of chromosomes?
- What percentage actually codes for protein?
- 3 billion bases of DNA distributed over 23 pairs of chromosomes.
- Only 3-5% actually codes for protein
An RNA molecule folds to form secondary structures owing to what?
An RNA molecule folds to form secondary structures owing to hydrogen bonding between complementary bases on the same strand
Class or RNA: Ribosomal RNA (rRNA)
Cell Type?
Location of Function in Eukaryotic Cells?
Function?
Ribosomal RNA (rRNA)
Cell Type: Prokaryotic and eukaryotic
Location of Function in Eukaryotic Cells: Cytoplasm
Function: Structural and functional components of the ribosome (translation)
Class or RNA: Messenger RNA (mRNA)
Cell Type?
Location of Function in Eukaryotic Cells?
Function?
Class or RNA: Messenger (mRNA)
Cell Type: Prokaryotic and eukaryotic
Location of Function in Eukaryotic Cells: Nucleus and cytoplasm
Function: Carries genetic code for proteins
Class or RNA: Transfer RNA (tRNA)
Cell Type?
Location of Function in Eukaryotic Cells?
Function?
Class or RNA: Transfer RNA (tRNA)
Cell Type: Prokaryotic and eukaryotic
Location of Function in Eukaryotic Cells: Cytoplasm
Function: Helps incorporate amino acids into polypeptide chain (translation)
13.2 Is the Synthesis of an RNA Molecule from a DNA Template?
The template:
- What is the transcribed strand called?
- The transcription unit consists of 3 parts what are they?
The template:
- The transcribed strand: template strand
- The transcription unit
- A promoter
- RNA-coding sequence
- Terminator (end)
How many of the DNA strands will be the template for RNA?
Only one of the DNA strands will be the template for RNA
- RNA synthesis is _______ and ______ to the template strand
- New nucleotides are added to the ______ of the growing RNA; so transcription proceeds in a _________ direction
- The ________ strand is not usually transcribed
- RNA synthesis is complementary and antiparallel to the template strand
- New nucleotides are added to the 3’-OH group of the growing RNA; so transcription proceeds in a 5’ → 3’ direction
- The nontemplate strand is not usually transcribed
- Template strand is in _______ orientation
- The Template strand is _________ (or read by the polymerase)
- RNA strand is synthesized in the _________ direction
- RNA strand is ___________to the Template strand
- RNA strand is similar to the ____________ (excepts U’s are substituted for T’s)
- Template strand is in 3’ → 5’ orientation
- The Template strand is transcribed (or read by the polymerase)
- RNA strand is synthesized in the 5’ → 3’ direction
- RNA strand is complementary to the Template strand
- RNA strand is similar to the non-template strand (excepts U’s are substituted for T’s)
Eukaryotic Transcription
- What region binds to transcription factors that are specific for initiating transcription of that particular gene? (ie, not every gene is turned on all of the time)
- Transcription factors recruit what to initiate transcription?
- This is a __________ process
- Promoter region binds to transcription factors that are specific for initiating transcription of that particular gene.(ie, not every gene is turned on all of the time).
- Transcription factors recruit the polymerase to initiate transcription.
- Highly organized and regulated process.
What is RNA polymerase II responsible for?
RNA polymerase II is the enzyme responsible for generating the majority of RNA for making proteins
