Topic 4A- DNA,RNA and Protein Synthesis Flashcards
gene
section of DNA, codes for the sequence of amino acids that forms a particular polypeptide (primary structure)
in eukaryotic cells, where is DNA found
in a nucleolus within the nucleus
in eukaryotic cells, what if the shape of the DNA
linear strands
in eukaryotic cells, what type are the proteins other DNA contains
histone proteins
in prokaryotic cells, where is the DNA found
free floating in cytoplasm
in prokaryotic cells, what shape is the DNA
circular loop
does prokaryotic cells have histone proteins
no
in some prokaryotic cells, what other structure of DNA do they contain
plasmid
is the DNA structure always the same in different organisms
yes, nucleotides are always the same
means they are known as universal
how many naturally occurring aminos acids are there
20
how many nucleotides code 1 amino acid
3
why aren’t nucleotides in pairs
because there wouldn’t be enough combinations of nucleotides to make up the amino acids
what is it called when the same n-bases code for the same amino acid
degenerate
what does non-over lapping mean
that only each base is read once
what is at the end of a gene before a new gene
a STOP triplet
does a STOP triplet code for anything
no
does DNA have non-coding proteins, if so why
yes they do, we don’t know why
what is protein synthesis (short answer)
making proteins
what are the 3 types of RNA
mRNA, tRNA and ribosomal RNA
what does DNA contain
the sequence of nucleotides that code for all proteins
what are the two stages of protein synthesis
transcription and translation
simplify what transcription is
making a copy of the target gene
-copys
-cuts out unwanted
-sticks extrons back together
simplify what translation is
reading the information from the mRNA, and reading it with the appropriate amino acids
what does DNA helicase do
unwinds the DNA, breaking the hydrogen bonds
what are the two stands of DNA called when unravelled
sense strand and antisense strand
what is the promotor region
marks the start of a gene
what does RNA polymerase do
moves along antisense strand forming phosphodiester bonds between complementary RNA nucleotides
when doe RNA polymerase stop and release off the DNA strand
reaches a stop triplet at the end of a gene
what is an intron
non-coding sections of RNA
what is splicing
an enzyme cutting out the introns and sticking the exons back together
once spliced, where does the mRNA go
exits the nucleus out of pores and goes into the cytoplasm to ribosomes
how is the mRNA protected to travel through the cytoplasm
a polyadenine tail and a cap on the other end
what is the structure of tRNA
a single stranded piece of RNA, folded into a ‘clover leaf’ shape
what holds tRNA in its shape
hydrogen bonds
what is on tRNA that is complementary for a specific amino acid it carries
anticodon
what is formed between the amino acids once read i the ribosome
peptide bond
