BIOLOGYYY

• Macromolecules are large, carbon-based organic molecules found in living organisms.
• The fusion of the vesicle and cell membranes to release substances outside of the cell.
• Macromolecules contain carbon and most of them are polymers.
• Polymers are chains of molecules that form through dehydration synthesis (or the loss/elimination of a water molecule).
• A monomer is a single repeating unit in a larger molecule (polymer).
• Carbohydrates are used for energy storage (glucose, starch, cellulose) and are broken down through glycolysis.
• Carbohydrates are energy-storing molecules containing carbon, hydrogen, oxygen in a 1:2:1 ratio.
• Monosaccharides such as glucose are single-sugar subunits often found as rings.
• Disaccharides have two monosaccharide subunits.
• Polysaccharides (such as starch, glycogen, and cellulose) are long chains of sugars and are aka complex carbohydrates.
• Carbohydrates are used for short-term energy storage, structural support, and a component of cell walls.
• Proteins are long polymer chains called polypeptides built from amino acid subunits linked by peptide bonds.
• Every amino acid contains a central carbon with an amino group.
• Proteins constitute more than half of the cell’s dry weight.
• Peptide bonds are a type of covalent bonds.
• An amino acid is a building block of protein that consists of a central atom with the following units bonded to it – an amino group (-NH2), a carboxyl group (-COOH), and a side chain.
• Generally, proteins contain C, H, N, and O.
• Enzymes are proteins capable of speeding chemical reactions without being consumed.
• Enzymes lower the activation energy of a reaction but do not affect the free energy charge.
• Enzymes react with substrates (the molecules they interact with) to create products.
• Plant cells contain several additional components: chloroplasts, which contain chlorophyll and have a double membrane, a vacuole used to store water, proteins, and wastes, a cell wall, and chloroplasts.
• Animal cells have centrosomes (or a pair of centrioles) and lysosomes whereas plant cells do not.
• The nucleus is a membrane-bound storage site of genetic information that determines heredity and directs the activities of a cell.
• Prokaryotes include the simplest unicellular organisms and earliest cells to evolve (bacteria).
• Centrioles are involved in organizing microtubules during cell division (mitosis and meiosis) and play a role in forming the spindle fibers necessary for chromosome segregation.
• Plant cells have a cell wall, chloroplasts, plasmodesmata, and plastids used for storage, and a large central vacuole whereas animal cells do not.
• The cells of multicellular organisms contain membrane-bound organelles, each of which performs specific functions and increases efficiency.
• Lysosomes are vesicles of digestive enzymes that degrade old cellular components.
• Vesicles are sacs in which substances (fluid) are transported or stored.
• Eukaryotic cells reproduce via mitosis or meiosis, while prokaryotic cells reproduce asexually through binary fission.
• Exocytosis is the extrusion of material from a cell by discharge from vesicles at the surface.
• Prokaryotic cells have no nucleus, DNA is present in the nucleoid, and they lack membrane-bound organelles; simple structures.
• Prokaryotes have a genetic material that floats in the cytoplasm in a concentrated but unbounded region called the nucleoid, and lack membrane-bound organelles.
• Eukaryotic cells are larger and more complex than prokaryotic cells, contain a nucleus enclosed in the nuclear membrane that houses DNA in the form of chromosomes, and have membrane-bound organelles.
• Passive mechanisms include diffusion, where molecules move freely across a membrane to balance a concentration gradient, and facilitated diffusion, where molecules move across an impermeable or semipermeable membrane down their concentration gradient but must do so via special channels.
• Multicellular organisms include plants and animals, and some unicellular protists.
• The Golgi apparatus is an organelle that packages and exports proteins and lipids produced in the endoplasmic reticulum, involved in carbohydrate synthesis.
• Mitochondria are double-membraned power plants of the cell and the location of aerobic respiration (ATP production!).
• The nucleolus is located within the nucleus, site for ribosome synthesis.
• The endoplasmic reticulum is a network of membranes where lipids and proteins are synthesized, with the smooth ER being for lipid synthesis and the rough ER being covered with ribosomes for protein synthesis.