Module 4 (Intro. to Cell Structure of Animal and Plant Cell)

• Cells have often been referred to as "the building blocks of life", and indeed they are.
• In both animals and plants, cells generally become specialized to perform certain functions.
• Nerve cells, bone cells, and liver cells, for example, all develop in ways that enable them to better perform their specific functions.
• The first organelle is the cell wall.
• Cell wall is the covering of the plant cell which is present only in plants. It is predominantly made up of cellulose. The cell wall has a rigid covering that protects the cell, provides structural support, and gives shape to the cell.
• The plasma membrane is a phospholipid bilayer with embedded proteins that separates the internal contents of a cell from its surrounding environment.
• Plasma Membrane is a semi-permeable membrane that controls the passage of organic molecules, ions, water, and oxygen into and out.
• Wastes such as carbon dioxide and ammonia also leave the cell by passing through the plasma membrane.
• Plasma membrane guards the entrance to the cell and controls what goes in and out.
• Endoplasmic reticulum is a series of interconnected membranous sacs and tubules within the cytoplasm that collectively modifies proteins and synthesizes lipids.
• The rough endoplasmic reticulum and smooth endoplasmic reticulum functions are performed in different areas of ER.
• The endoplasmic reticulum becomes rough due to the ribosomes attached to the membrane.
• The function of RER is for protein synthesis.
• The smooth endoplasmic reticulum is a network of tubular sacs without ribosomes on the membrane.
• Functions of SER include the synthesis of carbohydrates, lipids, and steroid hormones.
• Cytoplasm is the entire region of the cell between the plasma membrane and the nuclear envelope.
• Cytoplasm is the fluid portion of the cell approximately 70%-80% water where all organelles appear to be floating.
• Cytosol is the fluid portion of the cytoplasm. Its functions are to maintain the shape of the cell, bear cell organelles, and carry out different metabolic processes such as glycolysis, cell division, protein synthesis, and many more.
• Ribosomes are another cellular organelle found in the cell. It appears either as a cluster (polyribosomes) or single, tiny dots that float freely in the cytoplasm.
• The function of the ribosomes is for protein synthesis.
• Protein synthesis is an essential function of all cells including enzymes, hormones, antibodies, pigments, structural components, and surface receptors.
• Ribosomes are particularly abundant in cells that synthesize large amounts of proteins.
• If the ribosome does not function normally or is not present in the cell, definitely there will be no production of proteins which are the most important macromolecules in the body to support the daily activity of the organisms.
• Golgi body or Golgi apparatus is a series or stacks of flattened membrane-bound organelle that forms a complex structure.
• Golgi body was named after the Italian physician Camillo Golgi, who discovered it in 1890.
• Sorting, tagging, packaging, and distribution of lipids and proteins destined to leave the cell and for use within the cell takes place in the Golgi bodies.
• A golgi body has a front and back, the front or the receiving end is called the cis face and the opposite side is called the trans face, where lipids and proteins enter and exit to allow further modification.
• Lysosomes is a membrane-bounded digestive vesicle that arises from the Golgi apparatus and contains high levels of degrading enzymes, which catalyze the rapid breakdown of proteins, nucleic acids, lipids, and carbohydrates.
• The organelle 'lysosomes' can only be found in animal cells.
• Lysosome use their hydrolytic enzyme to destroy pathogens that might enter the cell through phagocytosis or endocytosis.
• Lysosomal also breaks down old organelles and recycles their component molecules, this makes room for newly formed organelle.
• Peroxisomes are small, round organelles enclosed by single membranes.
• Peroxisomes carry out enzymes that involve oxidation reactions that break down fatty acids and amino acids.
• Peroxisomes detoxify many poisons that may enter the body, like oxidation reactions that release hydrogen peroxide which would be damaging to the cells; however, these reactions are confined to peroxisomes, and enzymes safely break down the toxic H2O2 into oxygen and water.
• Lysosome is called a suicidal bag of cells because it contains hydrolytic enzymes that are capable of degrading or breaking down macromolecules, destroying pathogens that may enter the cell, and breaking down old organelles and apoptosis to recycle.
• The similarity between lysosome and peroxisome is they both used enzymes for the degradation and breaking down of chemical down of chemical components.
• Mitochondria are called the powerhouse of the cell or energy factories because they are responsible for making adenosine triphosphate (ATP).
• Adenosine triphosphate is the cell's energy-carrying molecule.
• ATP represents the short-term stored energy of the cell.
• ATP is produced through cellular respiration, the process of making ATP using the chemical energy found in glucose and other nutrients.