Chapter 8 - Microbial Genetics Flashcards
Gene
-a segment of DNA
-produces a functional product (usually a protein or an RNA - mRNA, rRNA, tRNA)
Genome
-the genetic information in a cell
-includes genes and nucleotide sequences
Chromosomes
-structures containing DNA that physically carry hereditary information
-contain the genes
DNA
-macromolecule comprised of repeating units call nucleotides (GCAT)
Antiparallel Nature of DNA
-the sugar in one strand is upside down
-creates stability (hydrogen bonds)
-allows the bases to remain close together
Leading Strand
-Carbon #5 is at the top and is in line with carbon #3 at the bottom
-synthesized continuously in the same direction
Lagging strand
-Carbon #3 is at the top and carbon #5 is in line with it at the bottom
-synthesized discontinuously in fragments of about 1000 nucleotides
Okazaki Fragments
-lagging strand
-the discontinuously synthesized fragments that are later joined to make a continuous strand
Genetic Code
-set of rules that determines how a nucleotide sequence is converted to the amino acid sequence
Importance of Complementary Base Pairs
- linear sequence provides information
- allows for DNA replication during cell division
Genotype
-genetic makeup of an organism
Phenotype
-actual, expressed properties
Central Dogma of DNA
-describes how DNA is transcribed into mRNA
-mRNA is in turn translated into proteins that carry out functions
Base Substitution Mutations
-single DNA base pair is altered
Frameshift Mutations
-DNA base pairs are added or removed from sequence causing a shift in the reading
DNA Replication
-one double stranded DNA molecule is converted to two identical offspring molecules