DNA to RNA to Protein Flashcards
DNA is made of?
Nuclei acids
What’s the role of nucleotides and nucleosides?
- Transmission of genetic information
- Energy Storage
- Preservation of genetic information
- Energy Transmission
- Signaling
- Antioxidant
What are three parts of nucleotide ?
- Sugar: either ribose or deoxyribose
- Nitrogenous base (attached to carbon 1 in ring)
- One, two or three phosphate groups (on carbon 5)
What’s the difference between nucleotide and nucleoside structure?
Same except nucleotide has phosphate groups while nucleoside does not
What do ribonucleic acids (nucleotides with ribose sugars) do?
They attach to other ribose sugars to form RNA which makes proteins
What do deoxyribonucleic acid (nucleotides with deoxyribose) do?
They form DNA which makes up the genome found in all living cells
Nitrogenous bases (residues) can be categorized in two groups:
Purines: Two rings fused together
- Adenine (A)
- Guanine (G)
Pyrimidines: One six membered ring
- Cytosine (C)
- Uracil (U)
- Thymine (T)
What holds DNA strand helix together?
Intermolecular interactions (hydrogen bonds between nitrogenous bases)
Adenine and Thymine are paired with
Two hydrogen bonds
Guanine and Cytosine are paired with
Three hydrogen bonds
How do enzymes read DNA?
From 5’ end to 3’ end
What must happen to DNA in order to replicate?
Denaturation: process of separating two DNA strands into single strands
What is reannealing?
Process of two single DNA strands (that were separated by helicase or heat) coming back together to form original DNA
What’s hybridization of DNA?
Process in which two complementary single-stranded DNA form double stranded molecule
DNA makes RNA through what process
Transcription
RNA makes proteins though what process
Translation
Codon
The way nitrogenous bases are arranged to creat a genetic code
How many codons are possible?
64 as there are 4 nitrogenous bases involved i.e. 444*4 is 64
Point mutation
A mutation affecting only one nucleotide in a codon
Eg) Silent mutation
Missense mutation
Mutation where one amino acid is substituted for another
Nonsense Mutation (truncation mutation)
Serious because they change a codon for amino acid to a premature stop codon instead
What’s a start codon for translation
AUG
What’re the stop codons for translation?
UAA
UGA
UAG
What’s transcription?
Formation of RNA polymer which is done through RNA polymerase enzyme
What’re the three stages of transcription?
1) Initiation: where transcription starts
2) Elongation: this is where RNA strand is grown
3) Termination:
RNA starts with AUG which is _______ in DNA
ATG (Thymine is replace with Uracil in RNA) and this is called a sense strand
The complimentary DNA strand for ATG is ATC and it’s called
Antisense strand (as it is the opposite of sense strand)
What is operon in Prokaryotes?
A system where a group of genes can be turned on or off at same time
What are the three basic types of DNA segments?
- Structural genes: genes that operon works for
- Promoter: RNA polymerase binds here and can move through DNA to transcribe structural genes (promoter acts like a play button)
- Operator: a repressor (on/off) switch button binds here and stops RNA polymerase from traveling (pause button)
What are repressible operons?
Ones that keeps working unless stopped by something physically
What are inducible operon?
Ones that start working when induced by something
Positive control operon
Where RNA polymerase is asked to transcribe structural genes so something can be produced
Negative control operon
Where RNA polymerase is set to not transcribe structural genes so nothing can be produced
How does the cell alter the structure?
Cytosine and adenine bases in DNA can be methylated i.e. affect the ability of RNA polymerase to transcribe genes
RNA polymerase doesn’t know on its own where to bind so who helps?
Transcription factors help which bind to the specific DNA sequences
What’s a recombinant DNA?
DNA sequence created by combining genes from more than one source that wouldn’t occur naturally
What is transformation?
Introducing new genetic information into a host so it can integrate in host’s genome
What does PCR do and what goes in it?
PCR will create multiple copies of genes. It’s used in lab to create specific DNA.
A PCR test tube contain:
- DNA fragments
- dNTP (deoxynucleotide triphosphate- A, T, C, G)
- Enzymes (Polymerase)
- Target primers
What are the common genetic recombination techniques?
- PCR (to make multiple copies of same gene)
- Gel electrophoresis (to measure the size of DNA strand)
- Southern Blotting (used to identify if target genes are present)
- Restriction enzymes + plasmids (to integrate into new genome)
