DNA Flashcards
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What is the full name of DNA?
Deoxyribonucleic acid
What is DNA?
An important information carrying molecule.
Why can’t the DNA leave the nucleus?
Because it’s too big >:( to go through the nucleus pores
Fill in the blanks:
The DNA itself is a —— with 2 — chains held together by — bonds between specific —— pairs
The DNA itself is a double helix with 2 polynucleotide chains held together by hydrogen bonds between specific complimentary base pairs.
True or false, DNA is the genetic material in all living and non living organisms.
True ye
Is DNA parallel?
no, its anti parallel
Does DNA have codes?
yes (oui)
What are the components of DNA?
deoxyribose, a phosphate group and one of the 4 organic bases
Fill in the blanks:
In terms of structure, DNA has a – – made up of the repeated joining of the sugar and phosphate group of each –.
- phosphate backbone
- nucleotide
What does the DNA code tell the cell?
What to do, what proteins to make.
What is the name of the study of genomes?
Genomics
What is the difference between eukaryotic DNA and prokaryotic DNA?
In eukaryotes, DNA is found mainly in the nucleus as it is a membrane bound organelle, but there is some DNA in chloroplasts and mitochondria.
In prokaryotes, DNA is not enclosed in a membranous envelope, it sits freely as a loop of DNA in the cytoplasm.
Who created the first x-ray of the structure of DNA?
Rosalind Franklin, but she did not receive a noble prize due to her dying of cancer from her own experiment.
Which technique was used to find the first x-ray of DNA?
X-ray diffusion
Why was the discovery of DNA important?
Because it explained how DNA was copied and provided information on evolution, gene theory, medicines, etc.
Why did scientists initially deny the DNA structure?
Because it was a chemically simple molecule
What are the 4 organic bases?
Adenine (A)
Thymine (T)
Guanine (G)
Cytosine (C)
What are the pairs of the organic bases?
Adenine always binds with thymine.
Guanine always binds with Cytosine.
What bonds are between the organic bases? How many for each pair?
- Hydrogen bonds
- 3 between G and C, 2 between A and T
Which of the organic bases are purine and pyrimidine?
Adenine and Guanine are purine.
Cytosine and Thymine are pyrimidine.
Which enzyme:
Breaks down the hydrogen bonds between the bases, causing the two strands of DNA to separate and expose the nucleotides base in that region?
DNA helicase
What does DNA polymerase do?
It is an enzyme that joins DNA nucleotides together in a condensation reaction, forming phosphodiester bonds, during DNA replication
What are the carbon atoms of a sugar molecule numbered at?
1’ to 5’
What is the bond called to the hydroxyl group of the 5’ carbon of one sugar group and the hydroxyl group of the 3’ carbon of the sugar group of the next nucleotide?
5’-3’ phosphodiester linkage
What are the 4 steps of transcription?
Step 1:
- DNA Helicase breaks the hydrogen bonds on a section of DNA containing the gene for the desired protein. Nucleotides are exposed.
Step 2:
- RNA polymerase moves along one of the two DNA strands (the template strand). It joins complementary nucleotides on the exposed template strand to from a pre-mRNA strand.
Step 3:
- The DNA bases re-join as the RNA polymerase moves along.
Step 4:
- Pre-mRNA can then be spliced before it leaves the nuclear pores.
Describe and explain the Splicing of pre-mRNA
DNA contains regions which code for proteins (called exons) and introns which are the regions of DNA that do not code for proteins.
In pre-mRNA both exons and introns are present but the introns must be removed or ‘spliced out’ to only leave exons.
- Introns INterrupt the exons to they are removed.
