Chapter 4 Nucleic Acids and the RNA World. Key Concepts Nucleotides consist of a sugar, a phosphate...
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Transcript of Chapter 4 Nucleic Acids and the RNA World. Key Concepts Nucleotides consist of a sugar, a phosphate...
Chapter 4Nucleic Acids and the RNA World
Key Concepts
• Nucleotides consist of a sugar, a phosphate group, and a nitrogen-containing base. Ribonucleotides polymerize to form RNA. Deoxyribonucleotides polymerize to form DNA.
• DNA’s primary structure consists of a sequence of nitrogen-containing bases. Its secondary structure consists of two DNA strands, running in opposite directions, that are held together by complementary base pairing and twisted into a double helix. DNA structure allows organisms to store and replicate the information needed to grow and reproduce.
Key Concepts, cont’d
• RNA’s primary structure consists of a sequence of nitrogen-containing bases. Its secondary structure includes short regions of double helices and structures called hairpins.
• Because RNA molecules can carry information as well as catalyze chemical reactions, it is likely that RNA was the first self-replicating molecule and a forerunner to the first life-form.
DNA Structure
http://highered.mcgraw-hill.com/sites/0073383198/student_view0/chapter2/animation_quiz_-_dna_structure.html
RNA Structure & the Origin of Life
http://www.nature.com/scitable/content/rna-has-a-primary-and-secondary-structure-105312
http://exploringorigins.org/rnaworld.html
Website Questions(send questions to [email protected])
1. Describe 3 structural differences between DNA and RNA.
2. Describe 1 functional difference between DNA and RNA.
3. What is a ribozyme? How is it similar AND different than an enzyme?
4. Why do scientists say that RNA was important in the creation of life on earth?