Chapter 15

Question 1

SEQ, HD flow of genetic information

Answer 1

Francis Crick

DNA → RNA → Protein
DNA(ds): A T C G
RNA(ss): A U C G

2 Processes

Transcription: DNA → RNA
Information in DNA used to synthesize RNA

Translation: RNA → Protein
Carried out by ribosomes, information in RNA used to make polypeptide

Question 2

CC types of RNA

Answer 2

mRNA: messenger RNA
Encodes AA sequence

rRNA: ribosomal RNA
Part of ribosome structure

tRNA: transfer RNA
Carries AA;s to ribosome during translation

Question 3

SEQ, CC, HD eukaryotic transcription

Answer 3

DNA → RNA

Initiation (1 strand Template = Transcribed)
Promoter: starter
RNA Polymerase: Binds promoter, unwinds helix, begins transcription

Elongation
RNA Synthesis: RNA polymerase makes a strand using codon on the template

Termination
DNA sequence signals RNA polymerase to stop (NOT Stop codon) = mRNA

mRNA Modification
Add 5’ cap, 3’ poly-A tail
RNA splicing: Removes Introns

Question 4

SEQ, HD eukaryotic translation

Answer 4

RNA → Protein

Initiation (Sandwich Large/ tRNA/mRNA/Small)
Ribosome: 2 parts = small subunit and Large subunit
1. mRNA arrives and attached by small subunit until start codon
2. tRNA (Amino acids) arrives and binds to start codon with anticodons
3. Large subunit arrives to cover

Elongation
Translocation - ribosome moves down one codon and stacks AA until stop codons

Termination
Polypeptide releases and ribosome subunits separate

Polypeptide adds other polypeptide to make Protien