6. BACTERIAL GENETICS Flashcards
discovered DNA
Frederick Miescher(1869)
discovered that DNA contained phosphates, five-carbon sugars (cyclic pentose), and nitrogen containing bases
Phoebus A. T. Levine (1920s)
→ discovered the helical structure by x-ray crystallography
Rosalind Franklin
described the three-dimensional structure of the DNA molecule
James Watson and Francis Crick (1950s )
What does genetics study?
Heredity and variation
What determines an organism’s ability to maintain viability, adapt, multiply, and cause disease?
Genetic composition
What are the three major aspects of microbial genetics?
Structure and organization of genetic material,
replication and expression of genetic information,
mechanisms of genetic information alteration and exchange
What is the structure of a DNA molecule?
Double helical chain of nucleotides
How is the DNA helix described?
Double strand twisted together, referred to as a “spiral staircase”
What determines the information contained in DNA?
Base sequence (Genetic Code)
What process involves DNA in the production of RNA?
Genetic information processing
What are the components of a nucleotide?
A phosphate group (PO4),
a cyclic five-carbon pentose sugar (deoxyribose),
and a nitrogen-containing base
What are the two types of nitrogen-containing bases in nucleotides?
Purine and pyrimidine
What is the structure and length of an RNA molecule compared to DNA?
RNA is single-stranded and short
What sugar is present in RNA molecules?
Ribose
What are the three major types of RNA?
Messenger RNA (mRNA),
Transfer RNA (tRNA),
Ribosomal RNA (rRNA)
A DNA sequence that encodes for a specific product (RNA or protein)
gene
What term refers to all the genes in an organism?
Genome
What organizes the genome into discrete elements?
Chromosomes
What type of chromosome do bacteria have?
Single, unpaired (haploid), double-stranded, closed, circular
What are double-stranded, closed, circular, autonomously replicating genetic elements called?
Plasmids
What are the size ranges of plasmids?
1 to 2 kilobases up to 1 megabase
What do plasmids encode for?
Replication and transfer products, specialized functions
Do plasmids encode essential viability products?
No