The following statements are about the control of chromatin condensation. Select True or False for each.
T/F Reducing histone acetylase activity is likely to decrease gene transcription.
T/F Mutations that reduce the number of positively charged amino acids on histones should promote open chromatin.
T/F Chromatin remodeling complexes add chemical groups to histones.
T/F Adding an inhibitor of DNA methylation is likely to reduce gene transcription.

Verified step by step guidance

1. Understand the role of histone acetylation: Histone acetylation typically reduces the positive charge on histones, decreasing their affinity for DNA and promoting a more open chromatin structure, which facilitates gene transcription. Therefore, reducing histone acetylase activity would likely decrease gene transcription.
2. Consider the impact of mutations on histone charge: Histones are proteins that can have positively charged amino acids, which interact with the negatively charged DNA. Mutations that reduce the number of positively charged amino acids on histones would decrease their interaction with DNA, promoting a more open chromatin structure and potentially increasing gene transcription.
3. Evaluate the function of chromatin remodeling complexes: Chromatin remodeling complexes are involved in repositioning nucleosomes and altering chromatin structure, but they do not typically add chemical groups to histones. Instead, they facilitate access to DNA by changing the physical arrangement of chromatin.
4. Analyze the effect of DNA methylation inhibitors: DNA methylation generally suppresses gene transcription by adding methyl groups to DNA, which can lead to a more condensed chromatin structure. Adding an inhibitor of DNA methylation would likely increase gene transcription by preventing this suppression.
5. Review each statement based on the explanations provided: Use the understanding of histone acetylation, histone mutations, chromatin remodeling, and DNA methylation to determine the truth value of each statement regarding chromatin condensation and gene transcription.

Key Concepts

Histone Acetylation

Histone acetylation involves the addition of acetyl groups to histone proteins, which reduces the positive charge on histones and decreases their affinity for negatively charged DNA. This process generally leads to a more relaxed chromatin structure, promoting gene transcription. Therefore, reducing histone acetylase activity would likely decrease gene transcription by maintaining a more condensed chromatin state.

Histone Charge and Chromatin Structure

Histones are proteins that help package DNA into chromatin, and their positive charge allows them to bind tightly to the negatively charged DNA. Mutations that reduce the number of positively charged amino acids on histones can decrease this binding affinity, leading to a more open chromatin structure. This open structure is associated with increased accessibility for transcription machinery, thus promoting gene transcription.

DNA Methylation and Gene Transcription

DNA methylation involves the addition of methyl groups to DNA, typically at cytosine bases, which can lead to a more condensed chromatin structure and reduced gene transcription. Inhibitors of DNA methylation can prevent this modification, potentially leading to a more open chromatin state and increased transcription. However, the effect can vary depending on the context and specific genes involved.