Module 2 Section 3 - Genes and Protein Syntheisis Flashcards
What is a gene
A sequence of DNA nucleotides that codes for a polypeptide
Different proteins….
Have different number and order of amino acids
What determines the order of the amino acids in a particular protein
The order of the nucleotide bases in a gene
Each amino acids is coded for….
A sequence of three bases (triplet) in a gene
DNA contain genes which are….
Instructions for making proteins
The sequences of bases in a section of DNA ….
is a template that’s used to make proteins during protein synthesis
DNA is copied into what for protein synthesis
RNA
Where are DNA molecules found
In the nucleus
Where are the organelles that make proteins found
The ribosomes are found in the cytoplasm
Why can’t DNA be moved out of the nucleus
Because it is too large
DNA is too large to move out the nucleus so…..
A section is copied into mRNA - this is called transcription
After copying a section of DNA, what does the mRNA do
It leaves the nucleus and joins with a ribosome on the cytoplasm where it is used to synthesise protein - this is called translation
What are the three types of RNA
mRNA (Messenger RNA)
tRNA (Transfer RNA)
rRNA (Ribosomal RNA)
RNA is a single….
Polynucleotide strand
RNA contains what as a base instead of thymine
Uracil
Where is mRNA made
In the nucleus
What is the structure of mRNA
three adjacent bases called a codon
What is the function of mRNA
it carries the genetic code from the DNA in the nucleus to the cytoplasm where it is used to make a protein during translation
Where is tRNA found
Cytoplasm
What is the structure of tRNA
it has an amino acid binding site at one end and a sequence of 3 bases at the other end (anticodon)
What is the function of tRNA
It carries the amino acids that are used to make proteins to the ribosomes during translation
What does rRNA form
Forms the two subunits in a ribosomes (along with proteins)
How does rRNA work
The ribosomes move along the mRNA strand during protein synthesis. The rRNA in the ribosome helps to catalyse the formation of peptide bonds between amino acids
What is the genetic code
The sequence of base triplets (codons) in DNA or mRNA which codes for specific amino acids
The genetic code is…
non-overlapping
degenerate
universal
What is meaning by genetic code being non-overlapping
The base triplets don’t share their bases
What is meant by the genetic code is degenerate
Means there are more possible combinations of triplets than there are amino acids (some amino acids can be coded for more than one base triplet)
What is a start and stop codon
Some triplets are used to tell the cell when to start and stop production of the protein (found at beginning and end of gene)
What is meant by the genetic code being universal
The same specific base triplets code for the same amino acids in all living things (UAU codes for tyrosine in all organisms)
