Mircobiology Quiz Quiz

Eukaryotic DNA is primarily organized and packaged into nucleosomes which consists of DNA wrapped around histone proteins. Ribosomes are cellular particles involved in protein synthesis, chromosomes are structures composed of DNA and proteins that contain genetic information, and mitochondria are organelles responsible for energy production.

Linker DNA is the term used to describe the DNA found between nucleosomes, connecting them together. Spacer DNA, interstitial DNA, and connector DNA are not accurate terms for this specific region of DNA.

Core DNA refers to the DNA that tightly wraps around the histone core within a nucleosome. Supercoiled DNA is DNA that is over-twisted and more compact, free DNA is not associated with nucleosomes, and exon DNA is a specific region within a gene that codes for protein.

The histone core consists of H2A, H2B, H3, and H4 proteins which play a crucial role in DNA packaging within the cell nucleus.

Histone core is positively charged, which allows it to interact with the negatively charged DNA.

Histones are proteins involved in the packaging of DNA into nucleosomes within the cell nucleus. Lysine and arginine, both positively charged amino acids, are commonly found in histones due to their important role in binding to the negatively charged DNA. The incorrect answers provided do not match the characteristics required for amino acids found in histones.

Histone H1 is a structural protein that binds to the linker DNA regions between nucleosomes, helping to stabilize the overall chromatin structure.

The correct size of the fiber without H1 is 30nm, which is obtained by adding up the individual sizes without accounting for H1.

The 'N' terminal tails of core histones play a crucial role in the formation of 30nm fibers, which are important for chromatin compaction and regulation of gene expression.

Histone modification enzymes include those that add or remove phosphate, acetyl, or methyl groups to histone proteins, affecting gene expression and other cellular processes.

Histone acetyl transferase enzymes are responsible for adding acetyl groups to histone proteins, specifically to lysines on the N-terminal tails. This process is important for regulating gene expression levels by modifying chromatin structure.

Histone deacetylases are enzymes that remove acetyl groups from histone proteins, leading to chromatin condensation and gene repression.

Histone methyl transferase enzymes are responsible for adding methyl groups to specific amino acids on histone proteins, leading to changes in gene expression and chromatin structure.

Histone demethylases specifically function to remove methyl groups from histone proteins, influencing gene expression regulation.

Nucleosome remodeling and modification help to make the DNA more accessible for various cellular processes by altering the structure of nucleosomes, which are made up of histone proteins around which DNA is wrapped. This accessibility allows for transcription factors to bind to specific DNA sequences and regulate gene expression.

Epigenetics deals with changes in gene expression or cellular phenotype that can be inherited without changes to the underlying DNA sequence. These changes are often influenced by external factors and can be passed down from one generation to another.

Protein CAF-1 requires that DNA is being replicated to perform its function, and it also requires PCNA and a chaperone to function properly.

In DNA synthesis, the two main ingredients are deoxynucleoside triphosphates (dntps) and primer: template junctions. Amino acids, lipids, and carbohydrates are not directly involved in DNA synthesis.

During DNA synthesis, the TEMPLATE strand provides the ssDNA that will direct the addition of nucleotides, serving as a template for the creation of a complementary DNA strand.

In DNA synthesis, the ANNEALED PRIMER is a short piece of single-stranded DNA that is complimentary to the template strand it binds to, but is intentionally shorter in length. It provides the starting point for DNA polymerase to extend and replicate the template strand.