nuclear DNA

Each chromosome contains a single double-stranded piece of DNA along with the aforementioned packaging proteins. Figure 1: Chromatin condensation changes during the cell cycle. During cell division, for example, they become more tightly packed, and their condensed form can be visualized with a light microscope.

prophase

Cell cycle, the ordered sequence of events that occur in a cell in preparation for cell division. The cell cycle is a four-stage process in which the cell increases in size (gap 1, or G1, stage), copies its DNA (synthesis, or S, stage), prepares to divide (gap 2, or G2, stage), and divides (mitosis, or M, stage).

DNA can be highly compacted Yet during mitosis and meiosis, this DNA molecule is compacted into a chromosome approximately 5µm long. Although this compaction makes it easier to transport DNA within a dividing cell, it also makes DNA less accessible for other cellular functions such as DNA synthesis and transcription.

DNA is tightly packed up to fit in the nucleus of every cell. As shown in the animation, a DNA molecule wraps around histone proteins to form tight loops called nucleosomes. Chromatin, in turn, loops and folds with the help of additional proteins to form chromosomes.

In mitosis, the nuclear DNA of the cell condenses into visible chromosomes and is pulled apart by the mitotic spindle, a specialized structure made out of microtubules. Mitosis takes place in four stages: prophase (sometimes divided into early prophase and prometaphase), metaphase, anaphase, and telophase.

During mitosis, the chromosomes condense so that each chromosome is a distinct unit. Prior to mitosis, the cell copies its DNA so that it contains two copies of each chromosome. Condensing the DNA into tightly packed chromosomes makes the process of chromosome alignment and separation during mitosis more efficient.

The DNA is packaged by special proteins called histones to form chromatin. The chromatin further condenses to form chromosomes….

Chromatin is a substance within a chromosome consisting of DNA and protein. The DNA carries the cell’s genetic instructions. The major proteins in chromatin are histones, which help package the DNA in a compact form that fits in the cell nucleus.

There are 22 homologous pairs and two sex chromosomes (the X and Y chromosomes). One chromosome in each pair is inherited from one’s mother and one from one’s father. Each chromosome is a single molecule of DNA.

Genes are segments of deoxyribonucleic acid (DNA) that contain the code for a specific protein that functions in one or more types of cells in the body. Chromosomes are structures within cells that contain a person’s genes. Genes are contained in chromosomes, which are in the cell nucleus.

When DNA gets coiled, it becomes smaller in size just in order to fit the nucleus of the cell. This is known as DNA packaging. So, we can say that the chromosome when present, is bigger than the DNA because millions of nucleotides of DNA add up to form a Chromosome.

DNA is expressed as a gene which determines the expressed trait of the organism. DNA is expressed as a gene which determines the genetic make-up of the organism. DNA is expressed as a chromosome which determines the genetic make-up of the organism. Q.

DNA carries the genetic information for making proteins. The four bases A, T, C and G make up the genetic code. The base sequence determines amino acid sequence in protein.

During transcription, the DNA of a gene serves as a template for complementary base-pairing, and an enzyme called RNA polymerase II catalyzes the formation of a pre-mRNA molecule, which is then processed to form mature mRNA (Figure 1).

DNA contains the genetic information of all living organisms. Proteins are large molecules made up by 20 small molecules called amino acids. So in a living being nucleic acids contain the information that is passed to the proteins that are in charge of many functions, including rebuilding these nucleic acids.

When biologists first started to ponder how life arose, the question seemed baffling. In all organisms alive today, the hard work is done by proteins. However, the information needed to make proteins is stored in DNA molecules. You can’t make new proteins without DNA, and you can’t make new DNA without proteins.

DNA or deoxyribonucleic acid is a long molecule that contains our unique genetic code. Like a recipe book it holds the instructions for making all the proteins in our bodies.

The information to make proteins is stored in an organism’s DNA. Each protein is coded for by a specific section of DNA called a gene. A gene is the section of DNA required to produce one protein.

The type of RNA that contains the information for making a protein is called messenger RNA (mRNA) because it carries the information, or message, from the DNA out of the nucleus into the cytoplasm. A type of RNA called transfer RNA (tRNA) assembles the protein, one amino acid at a time.

Answer. Cells use genes to make proteins for critical jobs like carrying oxygen and contracting muscles. Explore the steps of proteinsynthesis, the process by which DNA is transcribed and translated into the tens of thousands of different types of proteins thatmake us what we are.

DNA makes RNA makes Protein. As you have learned, DNA is the genetic material of your cells and holds the information for making all the different proteins of your body. Translation converts the information in a series of three letter words in the mRNA into a sequence of amino acids, the building blocks of proteins.

Messenger RNA (mRNA) molecules carry the coding sequences for protein synthesis and are called transcripts; ribosomal RNA (rRNA) molecules form the core of a cell’s ribosomes (the structures in which protein synthesis takes place); and transfer RNA (tRNA) molecules carry amino acids to the ribosomes during protein …

The four roles DNA plays are replication, encoding information, mutation/recombination and gene expression.

Protein synthesis is the process in which cells make proteins. It occurs in two stages: transcription and translation. Transcription is the transfer of genetic instructions in DNA to mRNA in the nucleus. It includes three steps: initiation, elongation, and termination.

Terms in this set (12)

• DNA unzips in the nucleus.
• mRNA nucleotides transcribe the complementary DNA message.
• mRNA leaves nucleus and goes to ribosome.
• mRNA attaches to ribosome and first codon is read.
• tRNA brings in proper amino acid from cytoplasm.
• a second tRNA brings in new amino acid.

Terms in this set (5)

1. Unzipping. – DNA double helix unwinds to expose a sequence of nitrogenous bases.
2. Transcription. A copy of one of the DNA strand is made.
3. Translation (Initiation) mRNA couples w/ ribosome & tRNA brings free amino acids to ribosomes.
4. Elongation. – Anticodon of tRNA recognizes codon on mRNA.
5. Termination.

Transcription