B1 DNA And Protein Synthesis Flashcards
(22 cards)
What is DNA made up of?
Nucleotides
How many nucleotides are there in DNA?
Four
What molecules form the backbone to the DNA strand?
One sugar molecule, one phosphate molecule.
They are the same in all DNA nucleotides.
What joins to sugar molecule in a nucleotide?
A base
List the four different bases found in a DNA molecule
Adenine (A)
Thymine (T)
Cytosine (C)
Guanine (G)
How does a base link on the opposite side of the helix?
To a base on the opposite side.
What is complementary base pairing?
Adenine (A) pairs with thymine (T)
Cytosine (C) pairs with guanine (G)
What is genetic code?
The order of bases in all of an organisms DNA (genome).
What decides the order of amino acids in a protein?
The order of the bases in a gene.
How are minor acids coded for?
By a sequence of three bases in the gene called a triplet.
What does the triplet AGG code for?
Amino acid arginine.
What does the sequence AGGCTT code for?
Arginine then leucine.
What determines how amino acids are joined together to make various proteins?
The order of the bases in the gene.
How are the properties of each protein determined?
By the particular amino acid sit contains and theories they’re present in.
Where is DNA found?
In the cell nucleus.
Why can’t DNA move out of the cell nucleus?
Because it’s really big.
Where does the cell need to move information from the DNA to and why?
To the cell cytoplasm, so proteins can be synthesised.
How is information moved from the DNA to the cytoplasm?
Using a molecule called messenger RNA (mRNA)
How does mRNA differ from DNA?
It is shorter and only a single strand.
It uses uracil (U) instead of thymine (T) as a base.(U still pairs with A)
How is DNA the same as mRNA?
Both polymers of nucleotides.
Describe how proteins are made (5)
In the nucleus, the two strands of DNA unzip.
The DNA is used as a template to make mRNA (base pairing ensures the mRNA is complementary to the opposite DNA strand)
The mRNA molecule moves out of the nucleus and into the cytoplasm, where it attaches to a ribosome.
Amino acids are then joined together in the correct order by the ribosomes, following the order of the triplets in the mRNA.
This makes the protein coded for by the gene.
Explain how a gene codes for a protein (2 marks)
Each triplet of bases in a gene codes for an amino acid (1 mark)
The order of the triplets in a gene determines the order of amino acids in a protein (1 mark)
