Introduction to Metabolism

• The flow of genetic information prepared in a cell makes all proteins necessary that would sustain life
• Metabolic pathway describes the interrelated reactions which are enzyme catalyzed in the metabolism of a living organism.
• Metabolic pathway occurs in the cell of an organism and is a series of chemical reactions that occur in the cell
• Enzymes are biological catalysts that speed up biochemical reactions without being consumed themselves
• The end product of central dogma, proteins, and enzymes are proteins
• Central dogma refers to the flow of genetic information from DNA to RNA to protein
• Before a cell divides, it has to replicate its genome for it to have a complete set of information which can be used in synthesizing the protein, for sustainability
• Genome refers to the organism's complete set of information, which is found in chromosomes
• Chromosomes is found in DNA
• Replication refers to the replicating the genome's DNA
• The main enzyme in replication is DNA polymerase
• The prokaryotic replication is different from eukaryotic replication
• Eukaryotes happen to replicate in the nucleus of the cell
• Prokaryotes does not have a nucleus, and the process of replication happens in the cytoplasm
• A complete set of DNA includes all its genes, which contains instructions to create RNA to proteins
• DNA replication happens to ensure that new cells get the same genetic information as the parent cell
• DNA when replicated, can be transcribed to RNA serving as a messenger to protein
• In some cases, the information is encoded through RNA
• The system has a special enzyme called reverse transcriptase that can convert RNA to cDNA
• Reverse transcriptase is commonly used to viruses or tumor
• DNA Replication takes place in the nucleus of a cell
• RNA transcription occurs in the nucleolus of a cell, which is inside the nucleus
• DNA is a double stranded helical structure, coiled around each other and its bases are perpendicular to the imaginary axis
• DNA are held in positions by Hydrogen - Bonding in between pairs
• The first initial step before replication is that the two strands in DNA are separated which can be used as a template with the DNA polymerase and to insert the correct nucleotide
• DNA has nucleotides, which are made of a base, a pentose sugar, and a phosphate group
• DNA polymerase create an exact copy of DNA each time a cell divides
• After strand separation, the strand will be initiated on a specific site called origin of replication
• The new template strand is assembled and elongated forming a DNA
• DNA is transcribed to RNA and translated to protein synthesis by an enzyme RNA polymerase
• Translation refers to the message of sequence of bases to sequence of amino acids
• The site of protein synthesis happens to ribosomes, in which DNA cannot leave in nucleus
• Ribosomes gain protein by releasing RNA from the nucleus through the nuclear pore
• Nuclear pore complexes are pores in the nuclear envelope that allow macromolecules like RNA and proteins to enter and exit the nucleus
• Nuclear envelope separates the nucleus from the cytoplasm which gives the structural framework of the nucleus
• Ribosome is the site of protein synthesis
• Translation happens to ribosomes
• Ribosomes are made of rRNA and proteins
• Mature rRNA is created in the nucleolus, and it goes to the ribosomes
• rRNA is transcribed in the nucleolus to pre rRNA, which later forms mature rRNA