QUESTION 12The leucine zipper domain of transcription factors is not involved in DNA recognition but rather in facilitating dimerization. Given the chemical properties of the amino acid leucine, dimerization of transcription factors via this domain by (select the correct option). Facilitating hydrogen bonding with the aqueous environment. Chelation of bivalent ions such as Zn2+. Formation of coiled-coils through hydrophobic non-covalent interactions between evenly spaced Leu residues in alpha-helical domains. Physically connecting the two transcription factor subunits through unstructured loops. **Benzo(a)pyrene: A Well-Known Carcinogen**Benzo(a)pyrene is a chemical compound recognized for its carcinogenic properties. This compound and others like it are considered dangerous mutagens due to their chemical structure and behavior. **Chemical Structure:**The molecular structure of benzo(a)pyrene consists of five interlocked benzene rings, forming a polycyclic aromatic hydrocarbon (PAH). These rings are represented as hexagons with alternating single and double bonds, typical of aromatic compounds. The structure is stable due to resonance, allowing electrons to move freely across the rings.**Why Benzo(a)pyrene is Dangerous:**1. **Interaction with DNA:** - Benzo(a)pyrene can intercalate between DNA bases. This insertion can disrupt the normal base pairing, leading to mutations during DNA replication.2. **Metabolic Activation:** - Within the body, benzo(a)pyrene undergoes metabolic activation to form reactive epoxides. These epoxides can covalently bind to DNA, causing permanent damage.3. **Mutagenicity:** - The structural arrangement and electron distribution enable benzo(a)pyrene to cause errors in DNA replication and transcription, promoting mutations and oncogenic transformations in cells.Understanding the molecular intricacies of benzo(a)pyrene helps elucidate its role in carcinogenesis and underscores the need for awareness and regulation of exposure to such compounds.

Answered: QUESTION 12 The leucine zipper domain…

Human Anatomy & Physiology (11th Edition)

11th Edition

ISBN:9780134580999

Author:Elaine N. Marieb, Katja N. Hoehn

Publisher:Elaine N. Marieb, Katja N. Hoehn

Chapter1: The Human Body: An Orientation

Section: Chapter Questions

Problem 1RQ: The correct sequence of levels forming the structural hierarchy is A. (a) organ, organ system,...

See similar textbooks

QUESTION 12

The leucine zipper domain of transcription factors is not involved in DNA recognition but rather in facilitating dimerization. Given the chemical properties of the amino acid leucine, dimerization of transcription factors via this domain by (select the correct option).

		Facilitating hydrogen bonding with the aqueous environment.
		Chelation of bivalent ions such as Zn²⁺.
		Formation of coiled-coils through hydrophobic non-covalent interactions between evenly spaced Leu residues in alpha-helical domains.
		Physically connecting the two transcription factor subunits through unstructured loops.

**Benzo(a)pyrene: A Well-Known Carcinogen**

Benzo(a)pyrene is a chemical compound recognized for its carcinogenic properties. This compound and others like it are considered dangerous mutagens due to their chemical structure and behavior.

**Chemical Structure:**

The molecular structure of benzo(a)pyrene consists of five interlocked benzene rings, forming a polycyclic aromatic hydrocarbon (PAH). These rings are represented as hexagons with alternating single and double bonds, typical of aromatic compounds. The structure is stable due to resonance, allowing electrons to move freely across the rings.

**Why Benzo(a)pyrene is Dangerous:**

1. **Interaction with DNA:**
- Benzo(a)pyrene can intercalate between DNA bases. This insertion can disrupt the normal base pairing, leading to mutations during DNA replication.

2. **Metabolic Activation:**
- Within the body, benzo(a)pyrene undergoes metabolic activation to form reactive epoxides. These epoxides can covalently bind to DNA, causing permanent damage.

3. **Mutagenicity:**
- The structural arrangement and electron distribution enable benzo(a)pyrene to cause errors in DNA replication and transcription, promoting mutations and oncogenic transformations in cells.

Understanding the molecular intricacies of benzo(a)pyrene helps elucidate its role in carcinogenesis and underscores the need for awareness and regulation of exposure to such compounds.

Expert Solution

Step 1

Leucine zipper is formed by the dimerization of two specific alpha helix monomers bound to DNA.

The two α helices which contains the leucines coil together into a coil in which the helices are hold together by hydrophobic interactions between the leucines. The interaction between the two subunits forms a DNA binding domain made up of the basic motif region of each subunit.