Mod 5: Heredity - DNA and Polypeptide Synthesis Flashcards
what are genes
short segments of DNA that provide instructions on how to make proteins
process of protein
DNA –> RNA (transcription –> translation) –> Polypeptide –> Protein
differences between DNA and RNA
- DNA is double stranded and RNA is single stranded
- Deoxyribose sugar and ribose sugar
- Thymine and uracil
what are the three types off RNA
- mRNA
- rRNA
- tRNA
process of transcription
- DNA to mRNA
- protein coding DNA –> mRNA –> transcription process –> polypeptides
- unwinding of DNA
- RNA polymerase attaches to promoter region
- codes in the 5’ - 3’ direction
- stops at terminator region
- introns and spliced and taken out
- 5’ cap and poly-A tail added
- mRNA ready
- complementary to template strand and same as coding strand
where does mRNA go when ready
into the cytoplasm to bind to a ribosome
what are exons
segments of RNA that code for something and are expressed
what are introns
non-coding regions that do other stuff that are non-expressed
how many stages of protein folding
4 - primary, secondary, tertiary, quarternary
what are proteins
a chain of amino acids folded into a 3D structure
what RNA is used in translation
tRNA
what RNA is used in transcription
mRNA
transcription process
- finds the start site - AUG
- ribosomes read mRNA as codons
- each codon corresponds to a different amino acid
- tRNA has anticodons with the amino acid attached and corresponds to the mRNA strand
- once attached, the amino acid gets connected to the growing chain
- when ribosomes goes to terminating codon, ribosomes detaches from mRNA
- polypeptide chain is further processed
why can several codon code for the same amino acid
to prevent more mistakes or mutatiosn from happening if there is a mistake in the codon
what are phenotype
an expressed genotype
genotype + environment –> phenotype
why is polypeptide synthesis important
- unless gene is transcribed into mRNA –> pigment will not be produced
what happens in primary structure of protein folding
- arrangement of amino acid in peptide chain
- amino acids held via peptide bonds
what happens in secondary structure of protein folding
- result of an alpha helix or a beta-pleated sheet
- caused by the hydrogen bonding across the amino acid backbone
what happens in the tertiary structure of protein folding
- folding is due to amino acid R-groups
what happens in the quarternary structure of protein folding
- composed of multiple polypetide subunits
what is the final structure of a protein
- fibrous - long strand shapes - generally structural
- globular - rounder or compact - generally functional
