Transcript Chapter 12

Chapter 12
By: Cole, Symone and Mel
12.1 : DNA
•Grffith’s Experiment & Transformation
• Transformation is the process when the heat-killed bacteria had
passed their disease-causing ability to the harmless strain
Disease-causing bacteria = Dead Mouse
Harmless bacteria = Lives
Heat-killed Disease causing bacteria = Lives
BUT when you mix heat killed with harmless = Dies Of Pnuemonia
• Avery & DNA
• Avery and other scientists discovered that the
nucleic acid DNA stores and transmits the
genetic information from one generation of an
organism to the next
• Bacteriophage- its a kind of virus that infects
bacteria. To infect a bacteria the virus attaches to
the cell and injects its genetic information.
• Hershey & Chase did an experiment with viruses
and radioactive markers. They concluded that
the genetic material of the bacteriophage was
DNA, not protein.
The Components & Structure of DNA
• DNA is a long molecule made up of units
called nucleotides
Summary Of Scientists
• Griffith: Transformation
• Avery: Determines that genes are composed of
DNA
• Franklin: studied DNA molecule by using X-Ray
Diffraction
• Watson & Crick: double helix structure of DNA
• Brenner: Discover messenger RNA
• Gilbert: methods to read the DNA sequence
• Human Genome Project: completed attempt to
sequence all human DNA
12.2 : Chromosomes & DNA
Replication
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DNA molecule are located in the cytoplasm
Chromatin: DNA and protein in chromosomes
Histones: a type of protein
Replication: When a cell duplicates its DNA
During replication, the DNA splits into two
strands, and then produces two new strands,
which serves as a template.
• DNA polymerase: joins individual nucleotides to
produce DNA molecules
12.3 : RNA & Protein Synthesis
• Genes: coded DNA instructions that control
the production of proteins in a cell
• 3 types of RNA: Messenger RNA, Ribosomal
RNA, and Transfer RNA
• Transcription: a process when RNA molecules
are produced by copying part of the
nulceotide sequence of DNA into a sequence
of RNA
• Promoters: regions that the enzymes bind to
12.3...
• Introns (nucleotide) & Exons (proteins)
• Codon: consists of 3 consecutive nucleotides,
they represent the different amino acids
• Translation: when the cell uses info from the
messenger RNA to produce proteins