Cell structure

• The Golgi apparatus is involved in the modification, sorting, packaging, and transport of proteins.
• Smooth ER is responsible for lipid metabolism, detoxification, and calcium storage.
• Protein synthesis occurs at ribosomes attached to rough endoplasmic reticulum (RER).
• Cell theory: Every organism consists of one or more cells. Cells are the smallest unit with properties of life. New cells arise by division of previously existing cells.
• Fluid mosaic model: The model that describes the structure of the cell membrane.
• Integral proteins must be amphipathic (hydrophobic inside bilayer, hydrophilic ends)
• Phospholipids flip flop once a month, and laterally move many times per second.
• Warmer temperatures means more fluid, as well as unsaturated fats = more fluid
• Cholesterol decreases fluidity of the membrane and prevents the membrane from being permeable.
• Passive transport is the movement of substances from an area of high concentration to an area of low concentration. No energy is needed.
• Diffusion is the net movement of particles from an area of high concentration to an area of low concentration.
• Facilitated diffusion is the movement of molecules across a membrane with the help of a protein, is used for hydrophilic and/or large molecules
• Aquaporins help polar water molecules move across the cell membrane.
• Osmosis is the diffusion of water molecules across a membrane to a higher solute concentration
• Hypotonic is a solution with a lower solute concentration
• Hypertonic is a solution with a higher solute concentration
• Isotonic is where 2 solutions have equal concentrations
• Animal cells when hypotonic are called lysed and burst, while hypertonic is called crenation and they shrink.
• Plant cells stay the same size through osmosis because of the cell wall, but plasmolysis (hypertonic) is when the cell body shrinks, and turgid (hypotonic) is where the cell body swells.
• Active transport is the movement of molecules from an area of low concentration to an area of high concentration against a concentration gradient
• Bulk transport is packaging of large materials in vesicles for movement across the membrane.
• Endocytosis is entering into the cell and exocytosis is exiting out of the cell
• Eukaryotes have cytoskeleton
• Smooth ER is for lipid synthesis.
• Rough ER is for collecting, modifying, and distributing proteins and lipids
• Lysosomes are degrading enzymes that eat stuff
• Golgi apparatus transports, modifies, and packages proteins and lipids.
• free ribosomes are found in the cytoplasm and are not associated with a membrane. They make proteins for cytoplasm
• Bound ribosomes -> rough ER -> transport vesicle -> golgi (can go to lysosome) -> transport vesicle -> plasma membrane -> out of cell
• Endosymbiotic theory is the idea that the mitochondria and chloroplasts evolved from symbiotic bacteria