Ribosomes are organelles located inside the animal, human cell, and plant cells. They are situated in the cytosol, some bound and free-floating to the membrane of the coarse endoplasmic reticulum.

Ribosome, particle that is present in large numbers in all living cells and serves as the site of protein synthesis. Ribosomes occur both as free particles in prokaryotic and eukaryotic cells and as particles attached to the membranes of the endoplasmic reticulum in eukaryotic cells.

In eukaryotes, ribosomes can commonly be found in the cytosol of a cell, the endoplasmic reticulum or mRNA, as well as the matrix of the mitochondria. Proteins synthesized in each of these locations serve a different role in the cell.

The nucleus (plural, nuclei) houses the cell’s genetic material, or DNA, and is also the site of synthesis for ribosomes, the cellular machines that assemble proteins.

Ribosomes are large complexes of protein and ribonucleic acid (RNA) responsible for protein synthesis when DNA from the nucleus is transcribed.

RNA/DNA can leave the nucleus. mRNA is made during transcription/translation. mRNA is made in the cytoplasm/nucleus.

DNA, which contains our genetic code, is located inside the nucleus of eukaryotic organisms. DNA cannot leave the nucleus, and so to send instructions to the rest of the cell it has to be replicated, creating mRNA, which can leave the nucleus.

cytoplasm

RNA is much shorter than DNA. DNA contains the code for making lots and lots of different proteins.

Ribonucleic acid (RNA) is a molecule similar to DNA. Unlike DNA, RNA is single-stranded. An RNA strand has a backbone made of alternating sugar (ribose) and phosphate groups.

If we talk about the uncoiled DNA, then DNA is larger than the chromosome. And if we talk about the coiled DNA, then DNA is smaller than the chromosome. When DNA gets coiled, it becomes smaller in size just in order to fit the nucleus of the cell.

2) CsCl centrifugation method as RNA is more denser i.e. 1.8g as compared to DNA i.e. 1.7g.

The diploid human genome is thus composed of 46 DNA molecules of 24 distinct types. Because human chromosomes exist in pairs that are almost identical, only 3 billion nucleotide pairs (the haploid genome) need to be sequenced to gain complete information concerning a representative human genome.

Like DNA, RNA is made up of nucleotides. There are two differences that distinguish DNA from RNA: (a) RNA contains the sugar ribose, while DNA contains the slightly different sugar deoxyribose (a type of ribose that lacks one oxygen atom), and (b) RNA has the nucleobase uracil while DNA contains thymine.

DNA contains the genetic information of all living organisms. Proteins are large molecules made up by 20 small molecules called amino acids. All living organisms have the same 20 amino acids, but they are arranged in different ways and this determines the different function for each protein.

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.

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.

DNA tells a cell how to make proteins through the genetic code. Both DNA and proteins are long molecules made from strings of shorter building blocks. While DNA is made of nucleotides, proteins are made of amino acids, a group of 20 different chemicals with names like alanine, arginine, and serine.

Uracil

A human cell contains about 6 pg of DNA.

Genes are made up of DNA. Some genes act as instructions to make molecules called proteins.

The chemicals come in four types A, C, T and G. A gene is a section of DNA made up of a sequence of As, Cs, Ts and Gs. Your genes are so tiny you have around 20,000 of them inside every cell in your body! Human genes vary in size from a few hundred bases to over a million bases.

Type I genes tend to be involved in immune response or sensory receptors while type III genes are involved in cell to cell signalling and type II genes are a complex mix of all three types.

Chromatin is a complex of DNA and proteins that forms chromosomes within the nucleus of eukaryotic cells. Each nucleosome is composed of DNA wrapped around eight proteins called histones. …

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.

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

DNA methylation is a biological process by which methyl groups are added to the DNA molecule. Methylation can change the activity of a DNA segment without changing the sequence. When located in a gene promoter, DNA methylation typically acts to repress gene transcription.

DNA methylation is catalyzed by a family of DNA methyltransferases (Dnmts) that transfer a methyl group from S-adenyl methionine (SAM) to the fifth carbon of a cytosine residue to form 5mC (Figure 1).

DNA methylation, a process of adding a methyl group to DNA done by a DNA methyltransferase is a heritable (epigenetic) alteration leading to cancer, atherosclerosis, nervous disorders (Imprinting disorders), and cardiovascular diseases.

Eukaryote ribosomes are produced and assembled in the nucleolus. The ribosome units leave the nucleus through the nuclear pores and unite once in the cytoplasm for the purpose of protein synthesis. When protein production is not being carried out, the two subunits of a ribosome are separated.

Deoxyribonucleic Acid