Question

1. One way that gene expression is regulated is in the remodeling of chromatin. Describe the three mechanisms of changes in the structure of the nucleosome as well as the effect of acetylation and methylation on gene expression?

2. Describe the impact of deletion, duplication, inversion and translocation on chromosome structure and gene expression of those chromosomes?

3. Explain how ATP is produced in respiration?

Please help with this picture below as well! It’s a gram positive and negative bacteria.

Answer 1

Ans 1. When DNA wraped around a protein core of 8 histone protein forms a nucleosome. The formation of molecule convert that DNA into nucleosome. This is first leven of DNA packing. Various histone modification occurs during this process are

Acetylation

Phosphorylation

Methylatiom

Ubiquitination

Sumoylation

The interaction between DNA molecule and histone protein is considerable for some cellular process such as transduction, transcription hence gene expression

Chromatin remodeling complex exhibit these functions

• Change or loosen DNA hence also change in protein interaction in nucleosomes.
• Mediate ATP dependent confirmational changes in nucleosome structure.
• Closely interact with histone linked enzymes.

Methylation can increase or decrease transcription depending upon which amino acid gets methylated, hence affect gene expression. Acetylation is known to increase gene expresstion of gene because of gene transcription.

Ans 2. These are variation in chrosomosome structure. All of them leads to mutation at varying degree.

Deletion - loss of a segement of chromosome.

Duplication- repetition of a particular segment of chromosome.

Inversion- change in direction of DNA along a chromosome.

Translocation- when a part of chromosome get attached with nonhomologus chromosome.

These all process leads to alter gene expression.

Ans 3. ATP is currency of energy which is used for cellular work. ATP or energy is yielded via respiration from breakdown of glucose into simpler form. In cellular reapiration ATP is released in glycolysis and oxidative phosphorylation. In later, ATP is produced from electron flow from NADH and FADH. It is formed when ADP gains a phosphate group.

Ans 4. It is gram stained bacteria. The violet membrane containg is gram positive bacteria, because it have high amount of peptidoglycan which is responsible to retain crystal violet dye. The right hand side image is of gram negative bacteria. The pink color in gram negatibe bacteria is due to counterstrain dye safranin.