Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
41 Cards in this Set
- Front
- Back
|
what is the point of DNA
|
it's a code that gives us the order for a sequence of amino acids
|
|
|
what is the reaction that combines amino acids
|
condensation
|
|
|
what do amino acids joined together form
|
A polypeptide chain
|
|
|
where is DNA found
|
the nucleus
|
|
|
where are proteins synthesized
|
cytoplasm
|
|
|
what is 'central dogma'
|
the production of mRNA which is read by ribosomes to position tRNA into a particular sequence forming a particular protein.
|
|
|
what is the role of mRNA
|
A messenger molecule, it transfers the DNA code from the nucleus to the cytoplasm because it is small enough to leave through the nuclear pores.
|
|
|
what are the structural differences between DNA and RNA
|
RNA remains single stranded
RNA contains uracil RNA has ribose sugar back bone DNA contains thymine DNA has deoxyribose back bone |
|
|
when is mRNA produced
|
the first step of protein synthesis
|
|
|
where is mRNA produced
|
in the nucleus when DNA is unraveled exposing a template stand for free RNA nucleotides to assemble
|
|
|
what enzyme is responsible for the unraveling of DNA
|
DNA helicase
|
|
|
How many nucleotides are exposed at any one moment
|
No more than 20
|
|
|
is mRNA identical or complementary to the DNA template from which it has been formed
|
complementary
|
|
|
after pre-mRNA is formed what happens
|
pre-mRNA leaves the nucleus through a nuclear pore where it attaches to ribosome which acts as a scaffold to form proteins on.
|
|
|
what do the bases of mRNA indicate
|
the order of amino acids in the polypeptide chain (protein) that is being made
|
|
|
what is a codon
|
3 nucleotide bases that code for an amino acid
|
|
|
what is a degenerate code?
|
when an amino acid has more than one cousin
|
|
|
what mark the end of a polypeptide chain
|
A stop codon, for which there are three.
|
|
|
the triplet code prevents
|
overlapping of amino acids
|
|
|
the triplet code is universal, what does this mean
|
the same codon codes for the same amino acid in all organisms.
|
|
|
structural features of tRNA
|
single stranded and folded into a cover leaf shape, contains uracil, very small
|
|
|
what is the role of tRNA
|
to bring amino acids to a ribosome during protein synthesis.
|
|
|
the process of producing a protein from DNA
|
|
|
|
what is transcription
|
the production of mRNA by using DNA as a template
|
|
|
what is translation
|
translating the base sequence of mRNA into an amino acid sequence.
|
|
|
what is the function of RNA polymerase
|
to form phosphodiester bonds (sugar phosphate backbone) to produce a single stand of pre-mRNA complementary to the DNA base sequence
|
|
|
when does RNA polymerase detach from the DNA and pre mRNA
|
when it reaches a stop codon, pre-mRNA is complete
|
|
|
what bonds does DNA helicase break
|
hydrogen bonds between bases
|
|
|
what happens when ends polymerase detaches?
|
the DNA rewinds forming hydrogen bonds between it's bases
|
|
|
does all DNA code for proteins?
|
No, only 2% is coding DNA the other 98% is non-coding
|
|
|
exons are...
|
coding sections of DNA and pre-mRNA
|
|
|
introns are...
|
non coding sections of DNA and RNA
|
|
|
what happens to separate introns and exons
|
useful exons are removed from pre-mRNA and spliced together to form a final strand of mRNA.
|
|
|
what is translation
|
the synthesis if the polypeptide
|
|
|
tRNA contains a complementary _ _ _ _ _ _ _ _ _ to the mRNA
|
anticodon
|
|
|
what is attached to the tRNA
|
the amino acid that is specific to the anticodon.
|
|
|
what is the job of the ribosome in translation
|
to bring complementary tRNA molecules to the mRNA, it brings two tRNA molecules at a time.
|
|
|
what bond is formed between amino acids in a condensation reaction
|
A peptide bond
|
|
|
what is used to join amino acids?
|
an enzyme and ATP
|
|
|
once the amino acids are bonded what happens to the tRNA
|
it is released so it can collect another amino acid.
|
|
|
what is the process called when many ribosomes travel laying the mRNA at the same time
|
polysome
|
