DNA - Ácidos Nucleicos - Compostos Orgânicos - Aula Completa

New Section

This section introduces the topic of nucleic acids, focusing on DNA and RNA, their discovery in cells, and their acidic nature.

Introduction to Nucleic Acids

• Nucleic acids include DNA and RNA, discovered in the cell nucleus due to their acidic properties.

• Apart from the nucleus, nucleic acids are also found in bacteria and organelles like chloroplasts and mitochondria.

• Nucleic acids store genetic information determining traits such as muscle predisposition, hair color, and height.

DNA Structure and Function

This section delves into the structure of DNA, explaining genes, chromosomes, chromatin formation, and gene function.

DNA Structure Breakdown

• DNA forms a double helix structure by wrapping around histone proteins to create chromatin.

• Chromosomes consist of condensed DNA molecules that carry genetic information.

Gene Function

• Genes are segments of DNA containing instructions for protein synthesis through specific nucleotide sequences.

• DNA is a polymer composed of repeating monomers called nucleotides consisting of a sugar-phosphate backbone and nitrogenous bases (adenine, guanine, cytosine, thymine/uracil).

Nucleotide Composition

This part explores the composition of nucleotides in DNA and RNA along with differences between them.

Nucleotide Components

• A nucleotide comprises a sugar (ribose in RNA), phosphate group, and nitrogenous base (adenine, guanine, cytosine/uracil).

• Bases adenine-guanine-cytosine-thymine/uracil differ between DNA (thymine) and RNA (uracil), crucial for distinguishing between the two.

Base Pairing in DNA

Discusses base pairing rules in DNA involving purines (guanine/adenine) with two rings and pyrimidines (cytosine/thymine) with one ring.

Base Pairing Rules

• Purines (guanine/adenine) pair with pyrimidines (cytosine/thymine) based on hydrogen bonding specificity.

• Understanding purines have two rings while pyrimidines have one aids in differentiating them during problem-solving scenarios.

New Section

In this section, the speaker discusses the sequence of nucleotides in DNA and various mnemonic devices to remember them.

Nucleotide Sequence Mnemonics

• The speaker finds it easier to remember the sequence of nucleotides as "CGE HÁ Vestígios de ATER CGPJ até seja."

• Purines are classified as Adenine (A) and Guanine (G), while pyrimidines include Cytosine (C) and Thymine (T).

• Three hydrogen bonds exist between DNA bases Adenine-Thymine, while Guanine-Cytosine have two hydrogen bonds.

• DNA strands are antiparallel, with one running in a 5' to 3' direction and the other in a 3' to 5' direction.

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This segment delves into the discovery of DNA's double helix structure by Watson and Crick.

Watson and Crick's Discovery

• Watson and Crick discovered the double helix structure of DNA, earning them fame and Nobel recognition.

• The Chargaff's rule states that Adenine pairs with Thymine (A=T), while Guanine pairs with Cytosine (G=C).

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Here, the discussion centers on the replication process of DNA.

DNA Replication Process

• The ratio of Adenine to Thymine should be equal in a strand of DNA for stability.

• Before cell division, DNA must replicate to ensure each daughter cell receives a complete set of genetic information.

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This part explores the conservative nature of DNA replication.

Conservative Replication

• During conservative replication, one original strand remains intact in each new double-stranded DNA molecule.