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DNA. Nucleic Acids. What are the types of Nucleic Acids?. Nucleic Acids. Types of Nucleic Acids: DNA (deoxyribonucleic acid) RNA (ribonucleic acid). Nucleic Acids. Types of Nucleic Acids: DNA (deoxyribonucleic acid) RNA (ribonucleic acid) mRNA (messenger) tRNA (transfer)
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Nucleic Acids • What are the types of Nucleic Acids?
Nucleic Acids • Types of Nucleic Acids: • DNA (deoxyribonucleic acid) • RNA (ribonucleic acid)
Nucleic Acids • Types of Nucleic Acids: • DNA (deoxyribonucleic acid) • RNA (ribonucleic acid) • mRNA (messenger) • tRNA (transfer) • rRNA (ribosomal)
Nucleic Acids • What are the building blocks of nucleic acids?
Nucleic Acids • Building blocks of nucleic acids: • Nucleotides
Nucleic Acids • Building blocks of nucleic acids: • Nucleotides: • Adenine • Thymine • Guanine • Cytosine • Uracil
Nucleic Acids • How would you recognize a nucleotide?
Nucleic Acids • How would you recognize a nucleotide?
Nucleic Acids • How do DNA and RNA compare?
DNA Structure • Double-stranded
DNA Structure • Double-stranded • Covalent bonds between phosphate and sugar
DNA Structure • Double-stranded • Covalent bonds between phosphate and sugar • Two strands held together by hydrogen bonding between complimentary base pairs
DNA Structure • Described as having two antiparallel strands (aligned in opposite directions)
DNA Replication • DNA must make copies of itself to prepare for cell division
DNA Replication • DNA must make copies of itself to prepare for cell division during Synthesis Phase of Interphase
DNA Replication • DNA must make copies of itself to prepare for cell division during Synthesis Phase of Interphase • Occurs in nucleus
DNA Replication • DNA must make copies of itself to prepare for cell division during Synthesis Phase of Interphase • Occurs in nucleus with the presence of • Enzymes (helicase and DNA polymerases)
DNA Replication • DNA must make copies of itself to prepare for cell division during Synthesis Phase of mitosis • Occurs in nucleus with the presence of • Enzymes (helicase and DNA polymerases) • Free nucleotides
DNA Replication Step 1: Helicase initiates the separation of double-stranded DNA into two single strands
DNA Replication Step 1: Helicase initiates the separation of double-stranded DNA into two single strands by breaking the hydrogen bonds between base pairs.
DNA Replication Now unpaired nucleotides are a template.
DNA Replication Step 2: A free-floating nucleotide finds a partner on one opened strand at one end
DNA Replication Step 2: A free-floating nucleotide finds a partner on one opened strand at one end and then a second nucleotide comes in and joins the first, etc.
DNA Replication Step 2: A free-floating nucleotide finds a partner on one opened strand at one end and then a second nucleotide comes in and joins the first, etc. DNA polymerase catalyzes the formation of a covalent bond between the two nucleotides.
DNA Replication Step 3: Other DNA polymerases proofread each nucleotide against the template and make corrections if needed.
DNA Replication Step 3: Other DNA polymerases proofread each nucleotide against the template and make corrections if needed. Before proofreading error rate: 1 in 100,000 After proofreading error rate: 1 in 10,000,000,000 (ten billion)
DNA Replication • New strands are identical to one another… why?
DNA Replication • New strands are identical to one another because of complementary base pairing
DNA Replication • Described as a “semiconservative” process
DNA Replication • Described as a “semiconservative” process because DNA after replication consists of one “old” and one “new” strand.