chap 8 Flashcards
*genetics
study of what genes are,
how they carry information,
how infomation is expressed,
how genes are replicated
*gene
a segment of DNA encodes a functional product = protein
*chromosome
containing DNA that physically carries hereditary information; contain the genes
*genome
every DNA in cell. all the genetic information in the cell
plasmid
extra piece of chromosomal self-replicating structure in bacterial cells that carries genes; not essential for cell growth
*genomics
molecular study of genomes
*genotype
genes of an organism
*phenotype
expression of the genes
horizontal transfer
transfer genes from parent cell to daughter cell
DNA structure:
Polymer of nucleotides
adenine, thymine, cytosine, guanine
DNA structure:
double helix
associated with proteins
DNA structure:
backbone is
deoxyribose-phosphate
DNA structure:
- strands are held together by
- stands are:
- hydrogen bonds
between A=T and C=G - antiparallel
DNA replicates
semiconservative
half
DNTP=Deoxy Nucleotide Tri Phosphate serves as;
DNTP serves as energy source and building blocks for DNA replication
DNA is copied by;
DNA polymerase = make polymers, cannot start a new strand
DNA polymerase (many issues) copies RNA from DNA template
- 5’ to 3’ direction
- initiated by RNA primer
- leading strand is synthesized continuously
- lagging strand is synthesized discontinuously
- Okazaki fragments
- RNA primers are removed and Okazaki fragments joined by a DNA polymerase and DNA ligase(=tie pieces together)
DNA Ligase
= glue bottle = makes covalent bonds to join DNA strands; joins Okazaki fragments and new segments in expression repair
DNA Gyrase
relaxes supercoiling ahead of the replication fork
Helicase
“un-zip” unwinds double stranded DNA
RNA Primase
RNA polymerase that makes RNA primers from a DNA template
Enzyme adds…“un-zip”
bacterial DNA replication:
bidirectional
Topoisomerase remove supercoils in DNA molecule
flattens, uncoils, keep off making knots
bacterial DNA replication:
DNA is methylated = functional maturation
- bacteria methylate Adenine
- methylation plays ole in variety of processes;
control of genetic expression,
initiation of DNA replication
protection against viral infection
repair of DNA