Biolab

• Biochemistry is the application of chemistry to the study of biological processes at the cellular and molecular level.
• Centrioles are normally oriented perpendicular to each other.
• Cells are highly organized and require a constant source of energy to maintain the ordered state.
• Living processes contain thousands of chemical reactions, and precise regulation and integration of these reactions are required to maintain life.
• All organisms use the same type of molecules: CHO, proteins, lipids and nucleic acids.
• Instructions for growth, reproduction and developments for each organism is encoded in their DNA.
• Inorganic chemistry deals with substances that do not contain carbon and lacks carbon-hydrogen bonds.
• Organic chemistry is the study of carbon-containing substances, with a few exceptions such as O2, which is a small, nonpolar, inorganic molecule consisting of two oxygen atoms bound together by a double covalent bond.
• Oxygen (O2) makes up about 21% of the gas in the atmosphere and is essential for most living organisms.
• Water (H2O) is formed when an atom of oxygen forms polar covalent bonds with two atoms of hydrogen.
• Organic molecules have various purposes: as energy molecules for synthesis of ATP, as structural components of the cell, and as regulatory molecules.
• Carbon atoms bound together by covalent bonds constitute the “backbone” of many large molecules.
• The four major groups of organic molecules essential to living organisms are carbohydrates, lipids, proteins, and nucleic acids.
• The term “cell” was coined by a microscopist Robert Hooke.
• Organisms such as bacteria, amoebae and yeasts, for example, may consist of as few as one cell, while a typical human body contains about a trillion cells.
• Active transport requires energy in the form of ATP; if ATP is not available, active transport stops.
• Facilitated diffusion is a mediated transport process, involving membrane proteins such as channels or carrier proteins, to move substances across the cell membrane.
• Active transport processes accumulate substances on one side of the cell membrane at concentrations many times greater than those on the other side.
• Secondary active transport involves the active transport of one substance, such as Na+, across the cell membrane, establishing a concentration gradient, which then provides the energy for moving a second substances across the membrane.
• Specialized cells (sperm cells and oocytes) transmit genetic information to the next generation.
• Passive membrane transport mechanisms include diffusion, osmosis, and facilitated diffusion.
• Active membrane transport mechanisms include active transport, secondary active transport, endocytosis, and exocytosis.
• Endocytosis and exocytosis are processes where large water-soluble molecules that cannot be transported by carrier molecules, small pieces of matter, and even whole cells can be transported across cell membranes in membrane-bound sacs called vesicles.
• Active transport is a process that utilizes membrane proteins to move substances across the cell membrane from regions of lower concentration to those of higher concentration, against a concentration gradient.
• Osmosis is the diffusion of water across a selectively permeable membrane, such as the cell membrane, from a region of higher water concentration to one of lower water concentration.
• Diffusion is a process where a solute tends to move from an area where it is in higher concentration to an area where it is in lower concentration in solution.
• Passive membrane transport does not require the cell to expend energy.
• Cell membranes are selectively permeable, allowing some substances, but not others, to pass into or out of the cells.
• Substances such as enzymes, glycogen, and potassium ions (K+) are found in greater concentrations inside the cell, whereas Na+, Ca2+, and Cl− are found in greater concentrations in the extracellular fluid.
• Cytoplasmic material has a different composition than extracellular material, and the cell’s survival depends on maintaining the difference.
• Active membrane transport does require the cell to expend energy, usually in the form of ATP.
• Within cells, the nucleus is an organelle containing the cell’s genetic material, the cytoplasm is living material surrounding the nucleus, and it contains many types of organelles, and the cell membrane encloses the cytoplasm.
• Cells may be prokaryotic or eukaryotic.
• The nucleoid region contains the DNA in prokaryotic cells, while the cell membrane and cell wall contain ribosomes to make proteins in their cytoplasm.
• There are two main types of eukaryotes: unicellular and multicellular.
• Cell functions include cell metabolism and energy use, synthesis of molecules, communication, and reproduction and inheritance.
• Cell metabolism involves the chemical reactions that occur within cells, and the energy released during metabolism is used for cell activities such as the synthesis of new molecules, muscle contraction, and heat production, which helps maintain body temperature.
• Cells synthesize various types of molecules, including proteins, nucleic acids, and lipids.
• Cells produce and receive chemical and electrical signals that allow them to communicate with one another.
• Secretory vesicles pinch off from the Golgi apparatus and move to the cell membrane.