RNA and Protein Synthesis Flashcards
RNA stands for….
Ribonucleic Acid
3 Types of RNA
- Messenger RNA (mRNA)
- Ribosomal RNA (rRnNA
- Transfer RNA (tRNA)
mRNA
long strands of RNA nucleotides that are complementary to DNA
rRNA
associated with formation of ribosomes in cytoplasm
tRNA
segments of RNA nucleotides that transport amino acids to ribosomes
RNA vs. DNA
sugars:
Sugars:
DNA - deoxyribose
RNA - ribose
RNA vs. DNA
structure:
Structure:
DNA - double stranded
RNA - single stranded
RNA vs. DNA Nitrogenous Bases: DNA RNA DNA's A binds to...
Nitrogenous Bases:
DNA - A, T, C, G
RNA - A, U (uracil), C, G
DNA’s A binds to RNA’s U
Transcription
The process of making a protein.
DNA must be transcribed into messenger RNA.
What happens in Transcription?
- RNA polymerase attaches to DNA at a certain point. This point is called the prometer.
- RNA polymerase copies the DNA strand until it reaches the end of that particular message (the terminator).
- The copy is mRNA
What happens in Transcription - part 2?
- mRNA is “cleaned up.”
~ introns removed, leaving exons - the coding portion - spliced together
~ protective “caps” put on each end (lots of A’s).
~ mRNA leaves the nucleus
Translation
decoding the RNA message and making it into a polypeptide chain (protein).
What happens in Translation?
- mRNA attaches to the ribosome - top & bottom subunits join
- Ribosome “reads” mRNA - codon is the 3-base code for a specific amino acid
- tRNA brings over the corresponding amino acid - anticodon is the complementary sequence on tRNA
Codon
Amino Acid
What happens in Translation ( part 2)?
- Anticodon & codon bind. The amino acid is transferred and a peptide bond forms between the two strands
- Ribosome will move along mRNA until “stop” codon is reached
~ protein is realeased
~ subunits detach
