Chapter 17 Flashcards
What is the link between genotype and phenotype
Proteins
What is gene expression
the process DNA directs protein synthesis, including transcription and translation
Basic principles of transcription and translation
- Transcription is the synthesis of RNA using DNA info to make mRNA.
- Translation is the synthesis of polypeptide (proteins) using mRNA.
Process to produce mRNA
- Initiation
- Elongation
- Termination
What preRNA is altered to become mRNA
- 5’ CAP added
- Poly-A-tail added
Splicing of coding regions together
What’s the difference of coding region between eukaryote and prokaryoteq
Prokaryote just have coding sequences, eukaryote preRNA has both coding and noncoding sequences.
What do addition of the 5’Cap and Poly-A-tail help for eukaryote RNA processing
- provide stability for mRNA
- export mRNA to the cytoplasm
- Help ribosomes to attach to the 5’ end.
What are coding sequences
Extrons (expressed sequences)
What are noncoding sequence
Introns (intervening sequences)
What is triplet code
A nonoverlapping, three-nucleotide words
What thing helps transport the triplet code from mRNA to make amino acids in ribosomes
tRNA
What is the basic structure of tRNA
- Has an L shape, link together by H-bond
- one site of it will bind to a specific amino acid
- one site (anticodon) will bind to an mRNA codon
What are the three steps of translation
- Initiation
- Elongation
- Termination
What happens during initiation
- Small unit of ribosomes first binds with the start codon (AUG) of the mRNA
- Large subunit completes the initiation complex
When will elongation in translation stop
When a stop codon in the mRNA reaches the A site of the ribosome, which dissociates ribosomal subunits and other components.
