Genetics Module 3

Gene expression

the process by which information in the DNA is transcribed into RNA and often translated into protein

Central Dogma

DNA→RNA→Protein

Transcription

the process of copying information from DNA to RNA

Translation

the stage of gene expression where nucleotides in mRNA are translated into amino acids

DNA

deoxyribose nucleic acid

RNA

ribose nucleic acid

Template Strand

the DNA strand that is being complemented by the newly synthesized RNA (NOT identical to the new RNA)

Coding Strand

the DNA strand that is opposite to the newly synthesized RNA and is IDENTICAL to the newly synthesized RNA

RNA polymerase

an enzyme that binds to DNA and makes RNA

Promoter

the DNA sequence onto which proteins and enzymes involved in transcription bind to initiate the process

TATA box

a conserved DNA sequence that is found in the promoter region of many genes. Helps recruit RNA polymerase to initiate transcription

Consensus Sequence

an average/idealized sequence derived from comparing many similar functional sites. It is determined by selecting the most common nucleotide at each position across all promoter sequences

Upstream

before a specific gene- toward the 5’ direction of a reference point

Downstream

towards the 3’ end of a the coding strand

Transcription start site

where transcription begins

termination sequence

the codon that signals for DNA transcription to stop

Gene

a sequence that is transcribed

protein-coding gene

a gene that codes a protein

RNA gene

genes that are transcribed to produce a functional RNA

RNA transcript

the section of RNA that is transcribed from the template strand of DNA

Messenger RNA (mRNA)

the RNA that is transported into the ribosome to form amino acids/ proteins

Transfer RNA (tRNA)

functional RNA molecules that serve as adapters in translation

Ribosomal RNA (rRNA)

RNA molecules that are components of the ribosome

Cis-acting element

DNA sequences that regulate genes on the same DNA molecules

ex. promoters, enhancers

Trans-acting element

motile proteins that bind cis-acting elements to regulated gene expression

Transcription factor

proteins that (once activated) bind to enhancers or promoters (TFs) to increase or decrease the transcription of target genes

Enhancer

a cis-acting element that regulate (increase) gene expression

Silencer

decrease gene expression when bound by repressors (TF)

Activator

transcription factors that bind enhancers to increase transcription

Repressor

transcription factors that bind silencers to reduce transcription

TATA-binding protein (TBP)

the main transcription factor that binds promoters. helps recruit additional TFs and RNA pol II

Signal transduction pathway

the pathway that TFs must go through in order to be activated

Band-shift assay (EMSA)

a technique used to detect protein DNA interactions by observing of BNA through a gel when bound to a protein. - the fragment that has bound to a protein would be closer to the wells compared to the fragment that has not bound to a protein

Protein-DNA interaction

proteins interact with DNA by binding to

Gel electrophoresis

Post-transcriptional modification

5’ cap

poly A tail

polyadenylation

Poly A binding protein (PABP)

Splicing

Intron

Exon

Spliceosome

Amino acid

Polypeptide

Peptide bond

Peptide group

Protein

Primary structure

secondary structure

alpha helix

beta pleated sheet

tertiary structure

quaternary structure

ribosome

large ribosomal unit

small ribosomal unit

A site (aminoacyl site)

P site (peptidyl site)

E site (exit site)

Initiation

Elongation

Termination

Start codon

stop codon

Kozak sequence

methionine

peptidyl transferase

elongation factor

translocation

release factor

polysome

Genetic code

codon

anticodon

redundant genetic code

synonymous codon

nonsynonymous codon

isoaccepting tRNA

Wobble hypothesis

third-base wobble

tRNA

aminoacylation

aminoacyl-tRNA synthetase

reading frame

Frameshift mutation

poly-U rna

Nirenberg experiment

universal genetic code