Biology Chapter 6: Translation Basics

Study Notes

Amino acids are held together by a bond formed during translation.
The anticodon loop is found within a tRNA molecule.
The anticodon is complementary to a codon.
tRNA has a double-stranded stem-loop secondary structure.
The amino acid is attached to the 3' end of the tRNA.
An enzyme charges tRNA with an amino acid.
A degenerate code has more codons than amino acids.
The wobble hypothesis explains the flexibility in the third base of a codon-anticodon pairing.
The typical start codon in bacteria is AUG, which codes for methionine.
Archaea and eukaryotes typically begin proteins with methionine.
The Shine-Dalgarno sequence in mRNA helps ribosomes bind to the mRNA.
A stop codon signals the end of protein synthesis.
In bacteria, (and many archaea and eukaryotes), an open reading frame on mRNA starts with the codon AUG and ends with a stop codon.
The three stages of translation are initiation, elongation, and termination; translation requires energy.
Prokaryotic and eukaryotic ribosomes have differing structures.
2 rRNA components have crucial roles in translation.
The bacterial initiation complex includes mRNA, initiator tRNA, and the ribosome.
The first tRNA binds to the ribosome's P site.
Newly charged tRNAs enter the A site.
Peptide bond formation occurs at the ribosome's P site.
Polyribosomes are multiple ribosomes translating a single mRNA.
Translation terminates with a stop codon.

Viruses are obligate intracellular parasites.
A virion is a complete virus particle.
Virus infection is the invasion of a host cell by a virus.
Capsids, nucleocapsids, naked viruses, and enveloped viruses are defined.
Enveloped viruses gain their membrane from the host cell.
A viral genome can have 4 different configurations.
Viruses have a size range.
A capsid is the protein coat surrounding the viral genome.
Protein molecules that make up viral capsids are defined.
3 common viral symmetries (shapes) are described and one is more efficient than the others and why.
Enveloped viruses typically enter/exit host cells differently than naked viruses.
Viral enzymes carried within the viral capsid are defined and their functions.
Enzymes copy RNA to RNA, RNA to DNA, and DNA to DNA.
Animal viruses are cultivated in host cells or host cell lines.
Infectious units/volume is a virus concentration measurement.
Viral replication has 5 phases.
The major difference between prokaryotic and eukaryotic viral penetration is discussed.
Receptors on host cells are described.
Enzymes involved in viral entry and exit are described.
3 types of anti-viral mechanisms in prokaryotes are described.
3 general types of viral proteins are classified and their roles.
Virus life cycles (lytic and lysogenic) are defined and differentiated.
Factors that induce the lytic pathway in lysogenic viruses occur.
Lysogenic conversion is defined.