Unit 1 Ch 4 - Molecular Information Flow and Protein Processing Flashcards
from Unit 1 -The Foundations of Microbiology
Amino acid
one of the 22 different monomers that make up proteins; chemically, a two-carbon carboxylic acid containing an amino group and a characteristic substituent on the alpha carbon
Aminoacyl-tRNA synthetase
an enzyme that catalyzes attachment of an amino acid to its cognate tRNA
Anticodon
a sequence of three bases in a tRNA molecule that base-pairs with a codon during protein synthesis
Antiparallel
in reference to double stranded DNA, the two strands run in opposite direction (one runs 5’ to 3’ and the complementary strand 3’ to 5’)
Bacteriocin
a toxic protein secreted by bacteria that inhibits or kills other, related bacteria
Chaperone
a protein that helps other proteins fold or refold from a partly denatured state
Chromosome
a genetic element, usually circular in prokaryotes, carrying genes essential to cellular function
Codon
a sequence of three bases in mRNA that encodes an amino acid
Codon bias
nonrandom usage of multiple codons encoding the same amino acid
Complementary
nucleic acid sequences that can base-pair with each other
Denaturation
loss of the correct folding of a protein, leading (usually) to protein aggregation and loss of biological activity
DNA (deoxyribonucleic acid)
a polymer of deoxyribonucleotides linked by phosphodiester bonds that carries genetic information
DNA gyrase
an enzyme found in most prokaryotes that introduces negative supercoils in DNA
DNA helicase
an enzyme that uses ATP to unwind the double helix of DNA
DNA ligase
an enzyme that seals nicks in the backbone of DNA
DNA polymerase
an enzyme that synthesizes a new strand of DNA in the 5’ to 3’ direction, using an antiparallel DNA strand as a template
Exons
the coding DNA sequences in a split gene (contrast with intron)
Gene
a segment of DNA specifying a protein (via mRNA), a tRNA, an rRNA, or any other noncoding RNA
Genetic code
the correspondence between nucleic acid sequence and amino acid sequence of proteins
Genetic element
a structure that carries genetic information, such as a chromosome, as plasmid, or a virus genome
Genome
the total complement of genes contained in a cell or virus
Informational macromolecule
any large polymeric molecule that carries genetic information, including DNA, RNA and protein
Introns
the intervening noncoding DNA sequences in a split gene (contrast with exon)
Lagging strand
the new strand of DNA that is synthesized in short pieces and then joined together
Leading strand
the new strand of DNA that is synthesized continuously during DNA replication
Messenger RNA (mRNA)
an RNA molecule that contains the genetic information to encode one or more polypeptides