What is the sugar in RNA?
What are the bases in RNA?
How is RNA stranded?
Does RNA have base pairing?
Does RNA have a double helix?
What is the sugar in DNA?
What are the bases in DNA?
How is DNA stranded?
Does DNA have base pairing?
Is DNA a double helix?
What is DNA Replication?
is the process of copying a DNA molecule
Replication is semi-conservative, what does this mean?
each strand of the original double helix serves as a model for a new strand in a molecule
What is Unwinding in DNA Replication?
Hydrogen bonds are "unzipped" and broken by the enzyme helicase
What is Complementary Base Pairing in DNA Replication?
This process is catalyzed by DNA polymerase
What is Joining in DNA Replication?
Complementary nucleotides bond to each other to form new strands, each DNA molecule contains an old strand and a new strand
What is the process of DNA Replication?
Unwinding, Complementary Base Pairing, and Joining
Bacteria have a single circular loop
Begins at a special site on a bacterial chromosome, called the origin of replication.
Replication moves around the circular DNA molecule in both Directions
Replication moves arou
Produces two identical circles
Only proceeds in one direction, from 5'to3'.
Cell divides between circles, as fast as every 20 minutes.
DNA replication begins at numerous points along linear chromosome.
DNA unwinds and unzips into two strands.
Each old strand of DNA serves as a template for a new strand
Complementary base-pairing forms a new strand.
Requires enzyme polymerase.
DNA Replication proceeds in two directions at many sites simultaneously.
DNA replication occurs in the 5'->3' direction
Replication is continuous on....
the 3'->5' template
Replication is discontinuous on...
the 5'->3' template forming short segments
What is a Mutation?
Is a permanent change in the sequence of bases in DNA
Where does germ-line mutations occur?
Occur in sec cells
Where does somatic mutations occur?
Occur in body cells.
DNA can undergo a chemical change.
Movement of transposons from one chromosomal location to another.
Mutagens such as radiation, organic chemicals.
Are carcingens (cancer causing)
1 in 1,000,000,000 replications
What happens in DNA Polymerase?
Proofreads new strands and generally corrects errors.
What are some Environmental Mutagens?
Ultraviolent Radiation and Tobacco Smoke
Involves change in a single DNA molecule
Changes one codon to a different codon.
What affects does Point Mutations have?
Nonfunctional, Reduced functionality, Unaffected.
One or two nucleotides are either inserted or deleted from DNA.
Protein always rendered nonfunctional