Physiology

• The nucleus is the control center of the cell, enveloped by a pair of membrane enclosing a lumen that is continuous to ER, and is also penetrated by several nuclear pores, constructed from nucleoporins.
• Agranular ER has no attached ribosome, functions in the synthesis of lipid substances and other enzymatic process.
• Peroxisomes detoxify alcohol and peroxidase- catalase catalyze the breakdown of fatty acid into acetyl- CoA.
• Endoplasmic Reticulum is a network of tubular and flat vesicular structure with walls constructed of lipid bilayer.
• Mitochondria, the powerhouse of the cell, produce ATP and are composed of 2 lipid bilayer protein membrane.
• Apoptosis, or programmed cell death, is a highly regulated process that allows a cell to self- degrade in order for the body to eliminate unwanted or dysfunctional cells.
• Apoptosis is essential to embryonic development, maintenance of tissue homeostasis, elimination of unwanted DNA, control of cell number.
• Granular endoplasmic reticulum has ribosomes attached to the outer surface, which functions for protein synthesis.
• Substances produced from different parts of the cell enter the space of ER before being conducted to other parts of the cell.
• Cellular respiration: Formation of ATP involves ATP, Adenosine triphosphate, which is a nucleotide composed of adenine base, pentose sugar.
• Golgi Apparatus is a secretory apparatus composed of stacked layers of thin, flat vesicles lying near the nucleus.
• Secretory granules either form lysosomes or secretory vesicles.
• Endoplasmic Reticulum contains various enzymes along the surface of its membrane.
• Proteins extruded from ribosomes enter the ER matrix and are glycosylated to form glycoproteins.
• Endoplasmic Reticulum controls glycogen breakdown and detoxifies substances.
• Lysosomes provide nutrition via cellular autophagy, lysis of organelles during cellular differentiation and metamorphosis, destruction of aged RBC or dead cells, dissolution of blood clot or thrombi, bone resorption, defense against invading organism.
• Peroxisomes are formed from sER and contain oxidases which is capable of combining oxygen with hydrogen ions to form H2O2.
• Secretory products include integral proteins, lysosomes, mucopolysaccharides, hyaluronic acid and chondroitin sulfate, and hormones/ neuro- transmitters.
• Transport vesicles from ER fuse with Golgi for further processing.
• Lysosomes provide an intracellular digestive system with more than 40 hydrolases that digest proteins, nucleic acid, mucopolysaccharides, lipids, glycogen.
• Cells require a complete set of genetic instructions to survive, which are coded in the DNA of cells.
• Genetic instructions are used to direct life processes and produce required molecules.
• Genes are the basic unit of genetic material, which are a sequence of DNA that acts as a unit controlling the formation of polypeptide chain.
• Nucleic Acids are very large and complex molecules that store information in the cell.
• Nucleic Acids use four compounds to store hereditary information.
• Transcription is the formation of RNA from DNA to enable the formation of protein in the cytoplasm.
• Translation is the process of protein synthesis in the ribosomes.
• Mitosis is cell division that produces a genetically similar cell.
• DNA and RNA are nucleic acids that store information necessary for the protein synthesis and reproduction of cell.
• Chromosomes contain the genes through the chemical known as nucleic acids.
• Replication is the duplication of DNA necessary for cell reproduction.
• DNA, Deoxyribonucleic acid, contains the information for all cell activities, including cell division, and is a double-stranded helical molecule.
• RNA, Ribonucleic acid, stores and transfers information for making proteins, and is a polymer composed of thousands of linked monomers.
• Nucleotides are the monomers of DNA and RNA, each composed of three main components: phosphate group, five-carbon sugar, and ring-shaped nitrogen base.
• Chromatin are loosely arranged DNA molecules, which allow easy reading of the codes in the DNA and is the template for transcription, replication, recombination, and repair.
• Chromosomes are DNA that are coiled into compact bodies wrapped tightly around proteins called histones, each chromosome consists of two identical halves called chromatids, chromatids form as DNA copies itself to prepare for cell division, and chromatids are held together by a centromere until separation at cell division.
• Sex Chromosomes (In mammals = X or Y; Male = XY, Female = XX) determine male or female and can carry genes for other characteristics.
• Autosomes are all other chromosomes, and include 44 in humans, 78 in dogs, 62 in cattle, 40 in swine, 40 in horses, 64 in ass, 62 in ewe.
• Homologues are two copies of each autosome: one from each parent during sexual reproduction, they are the same size and shape and carry the same genes for the same traits, and if one chromosome in a pair contains a gene for hair color, the other does also.
• Interphase is when a cell is not engaged in mitosis.