Translation Flashcards
What do letters U, C, A, G represent
nucleotides in RNA
what do the abbreviations such as phe, lle.ala, gly represent
amino acids
The language of mRNA is often described as a triplet code. explain the significance of this reference
Three nucleotides are needed to code for one amino acid
If an RNA molecule had 300 nucleotides in the coding region of the strand, how many amino acid would be in the polypeptide that was synthesized
300/3 equals 100 amino acids
how many different codons code for the amino acid proline
4
compare all of the codons for proline. what is similar and different
all the proline codes start with CC. only the 3rd pase is different
considering the mistakes that can occur during transcription and DNA replication, what advantage is there for an organism to have multiple mRNA sequences code for the same amino acid
If a mistake occured during the transcription or replication the codon in mRNA may still translate to the same amino acid.
what amino acid is at the beginning of evry polypeptide
methionine
The codons shown in model one are used in all species on Earth with little variation. what might scientist conclude from this
This supports the theory of evolution, that these systems have been passed down through generations of animals eve through changes in species
what are the 3 stages of translation
Initiation, elongation and termination
define each of the terms used in your answer to part a as they are used in everyday language
initiation- to start
elongation- to make longer to add on
termination- to end
Whe the mRNA leaves the nucleus to which organelle does it attach
ribosome
the mRNA attaches to the organelle at the sequence AUG. What is the significance of this sequence of nulceotides
this is the start codon
describe the movement of the ribosome as translation occurs
the ribosomes move along the mRNA chain from the 5’ end to the 3’ end
Find the tRNA in model 2 that is carrying the histidine. what is the sequence of nucleotides make the anticodon on this tRNA molecule
GUA
what codon on mRNA would match this anticodon
CAU
The t in tRNA is short for transfer. In a complete sentence explain why this molecule is called transfer RNA
It is transferring the correct amino acids in the correct sequence to the ribosome to produce the functional protein
During elongation how many tRNA molecules that are held in the ribosomes at the same time
2
what will happen to the unattached tRNA once it has delivered its amino acid
it is released from the ribosome and is free to pick up and carry another amino acid
describe 2 things that occur during termination
a release factor binds the last codon which stops the process of adding more amino acids to the polypeptide. A water molecule is added to the end of the amino acid chain
explain how the term translation applies to the synthesis of proteins from the DNa instructions
the language of DNA is in the format of nitrogen bases read in set of 3 called codons is being translated into the language of the proteins ie.. amino acids
the codons of mRNA are
3 nucleotides and four possible base combinations
show mathematically that there are 64 permutations possible when 3 basses are used
444=64
show mathematically that two bases as a codon would not be sufficient to code for all 20 known amino acids
4*4=16
in prokaryotic cells translation begins before transcription is finished. give 2 reasons why this would not be possible in eukaryotic cells
eukaryotic cells have a nucleus, and transcription takes place in the nucleus while translation takes place on the ribosomes in the cytoplasm of the cells. Eukaryotic cells have introns that need to be removed from the pre-mRNA before translation can happen
purpose
to synthesize proteins
definition
the process of synthesizing a specific polypeptide on a ribosome
product preocessing
codons are translated into the proteins that are needed
location
cytoplasm ( ribosomes in the cytoplasm)
initiation
a complex is formed between an mRNA molecule, the first tRNA and the ribosomal sununits
termination
occurs when a stop codon
completed protein
takes place in the ribosomes
elongation
involves the covalent bonding of amino acids to each other, one at a time to produce a polypeptide (proteins)
antibiotics
some antibiotics which are chemicals that inhibits the growth of certain microorganisms, bind only to bacterial ribosomes and inhibit translation
bacteria has a cell wall
antibiotics destroy the cell wall
what does ribosome do
it consists of 2 subunits. the smaller subunit binds to the mRNA strand and the larger subunit holds the tRNA molecules in place while the covalent peptide bond is formed between the amino acids
the tRNA molecules in a cell are short sequences of nucleotides about ( about 80 bases) that contains an ___ and carry a specific amino acid
anticodon
