quick review
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Quick Review. What is genetic information stored as? What organelle is this information found in?. First Model of DNA. 1953: James Watson, Francis Crick and Maurice Wilkins examined an amazing photograph made by Rosalind Franklin using a technique she developed called X-ray crystallography - PowerPoint PPT PresentationTRANSCRIPT
Quick Review
1. What is genetic information stored as?
2. What organelle is this information found in?
First Model of DNA
• 1953: James Watson, Francis Crick and Maurice Wilkins examined an amazing photograph made by Rosalind Franklin using a technique she developed called X-ray crystallography
• With what they had discovered about the composition of DNA and Franklin's photographs, Watson & Crick developed and proposed the first model for the structure of DNA
Watson and Crick Model
• consisted of two nucleotide chains that wrap around each other to form a double spiral.
• This shape is called a double helix.
DNA• DeoxyriboNucleic Acid
• Genetic code of life
• Located inside the nucleus
• NEVER leaves the nucleus
• Double Stranded
• Shape of DNA is a double helix
• Made of nucleotides
Primary functions of DNA:
1. Store and Transmit genetic information
2. Direct its synthesis/replication
3. Code for protein synthesis
So, what is RNA?
• RiboNucleic Acid
• Copy of a gene in DNA
• Responsible for delivering genetic information from the DNA in the cell nucleus to the ribosome in the cytoplasm
• Located outside the nucleus
• Responsible for completion of the process of protein synthesis
• Single stranded
• 3 Types of RNA: Messenger, Transfer, Ribosomal
• Made of nucleotides
Sugar
• Deoxyribose - a 5-carbon sugar in DNA
• Ribose - a 5-carbon sugar in RNA. • This sugar has more oxygen than the sugar in DNA.
Notice: Oxygen placement
DEoxy (de means to remove. DNA has an Oxygen removed!!!
Nitrogen Base
Purines– have a double ring of
carbon and nitrogen atoms.
– Adenine & Guanine
Pyrimidines• have a single ring of carbon
and nitrogen atoms.• Thymine & Cytosine (in DNA)• Uracil & Cytosine ( in RNA)
The sugar and phosphate groups form the "backbone" or outer support of the
DNA ladder-like double helix.
Sugar phosphate backbone
Base Pairing RulesBase Pairing RulesThese rules describe the behavior of the bases.
1. Cytosine always bonds with guanine by forming three hydrogen bonds. (C - G)
2. Adenine always bonds with thymine by forming two hydrogen bonds. (A - T) In the RNA nucleotide, thymine is replaced by Uracil (A – U).
3. A pair of bases that always bond together is known as a complementary base pair.
Celebration of Learning Moment!
You are to create a comparison between RNA and DNA.
Be sure to include:
1. Type of Sugar
2. Type of nucleotides
3. Strand type