Lecture 12 - Structure of RNA Flashcards
What does RNA stand for?
Ribonucleic acid
What is RNA a product of?
Product of transcription from a DNA template
How much RNA is in a cell?
10x more than DNA
10pg RNA
In what 3 ways is RNA different to DNA?
Chemical structure
Physical properties
Biological role
How is RNA different to DNA in terms of chemical structure?
Uses ribose not deoxyribose
Uracil is used not thymine
RNA is less stable
How is RNA different to DNA in terms of physical properties?
Single stranded
Can base pair with itself and fold into complex structures
How is RNA is different to DNA in terms of biological role?
Transfer of info from DNA to protein
Synthesis of proteins
Processing of messenger
Processing and modification of ribosomal RNA
Catalytic RNA
How does an RNA secondary structure form?
RNA is a palindromic sequence
It can do self complementary base pairing which means it can fold in half and bind to itself
How is the regulation of RNA usage controlled?
Synthesis
Regulated degradation
Translation efficiency
How is synthesis used to regulate RNA usage?
Transcription can be turned on or off rapidly
eg Lac operon
How is regulated degradation used to regulate the usage RNAs?
Transferrin receptor mRNA
How is translation efficiency used to regulate RNA usage?
Proteins can control the usage of some RNAs
How does the transferrin receptor work?
- Iron in the blood binds to transferrin
- Its transported into the cells by a receptor
- If theres enough intracellular iron, the transferrin receptor mRNA is degraded
How is the transferrin receptor regulated?
- RNA 2 structure regulates transferrin receptor mRNA degradation
- If theres no iron, the iron response element binding protein will bind to 3’-UTR
- RNA is stable so the receptor is made in the presence of iron
- Iron response element binding protein binds to iron and the protein dissociates form 3’-UTR
- The RNA is degraded so the receptor is not made
