BIO 201 - Anatomy and Physiology Exam 1 With All Questions and Answers

BIO 201 - Anatomy and Physiology Exam 1 With All Questions and Answers In a covalent bond, the bond can be either polar or... - ANSWER Nonpolar. Polarity deals with the _______ of electrons. - ANSWER Sharing Each atom can have a slight _______. These dictate how each atom will share ________. - ANSWER Charge Electrson Nonpolar bonds means there is __________ sharing of electrons. Polar bonds have ____________ sharing. - ANSWER Equal Nonequal Endocytosis - ANSWER What many single-celled eukaryotes use to ingest food particles. The plasma membrane surrounds/engulfs the food particle. There are three types of endocytosis: phagocytosis, pinocytosis, and receptor mediated endocytosis. Phagocytosis - ANSWER Used when the material being taken in is "particulate", like a bacterial cell or an organic fragment Pinocytosis - ANSWER Used when the material being taken in is liquid Receptor Mediated Endocytosis - ANSWER Used when the material being taken in needs to be transported across the plasma membrane via receptors. The molecules will bind to a specific site embedded in the plasma membrane. These receptor molecules are in a concentrated location coated by the protein clathrin. When enough material molecules accumulate, the pit deepens and seals up to be incorporated into the cell as a vesicle. Exocytosis - ANSWER Opposite of endocytosis. The process results in the discharge of materials from membrane-bound packages that migrate to the inner surface of the plasma membrane, fuse with the membrane and then release the contents outside of the cell. Protein Denaturation - ANSWER Changes the solubility of individual protein molecules, entrapping solvent water into a semisolid gel structure What is Jell-O a good example of? - ANSWER The process of coagulation of proteins into a 3D latticework that entraps water molecules to produce a semisolid gel How are proteins synthesized? - ANSWER By polymerizing amino acids. This occurs by repeatedly forming peptide bonds that link individual amino acids together into a chain. What three features influence the 3D shape of a water soluble protein? - ANSWER Primary structure Secondary structure Tertiary structure Primary Structure - ANSWER The peptide bond between individual amino acids that creates a long chain of connected amino acids These include hydrophilic and hydrophobic projections (that are oriented perpendicular to the chain) Secondary Structure - ANSWER The helix that the protein chain curls into as a result of hydrogen bonds and other weak forces Tertiary Structure - ANSWER Created when the protein molecules fold back on themselves outside of the helical segments Putting the hydrophobic portions on the inside and the hydrophilic portions on the outside Denaturation - ANSWER When natural proteins are subjected to physical/chemical treatment and their structures change They become "un-native or "unnatural" What does heating proteins do to them? - ANSWER Imparts energy to the molecules This added energy breaks the relatively weak forces that hold the protein together (in tertiary and secondary structures) As the heat continues, the protein molecule unfold more and more The hydrophilic regions are now exposed to the outside of the molecule Are peptide bonds hydrophilic or phobic? - ANSWER Hydrophilic What happens when protein molecules are denatured and unwound? - ANSWER They attract water molecules This traps the water molecules in close proximity to the protein strands What happens when hydrophobic molecules are exposed? - ANSWER They become unstable in aqueous environments They will then associate with other hydrophobic molecules on other protein molecules What is the end result of heating proteins? - ANSWER Water molecules adhere to the surface of hydrophilic regions and hydrophobic regions dissolve into each other to provide the energy to retain the structure of the protein It becomes a large insoluble mass with randomly organized structural framework What is frying an egg an example of? - ANSWER Irreversibly denatured proteins resulting in the formation of a solid gel The gel entraps water molecules into a semi solid structure How does the negative feedback go for thirst? - ANSWER -Situation: during a hot day, water is lost through sweat and produces a condition of decreasing blood/fluid volume -Response: blood (fluid) volume decreases, can also be stated as increasing the osmolarity (or concentration of solutes) of blood -Detection: increasing osmolarity of the blood is detected by the osmoreceptors in the hypothalamus -Trend: the sense of thirst is enhance partially as a result of antidiuretic hormone -Effect: drinking of fluids reverses the declining water volume What are enzymes? - ANSWER Proteins that speed up chemical reactions in the cell What is the active site on an enzyme for? - ANSWER Meant to be a specific shape to bind to substrate molecules How does an enzyme work? - ANSWER By binding to one+ specific molecules or substrates (this occurs at the active site) This creates an enzyme-substrate complex What happens when the enzyme and the substrates interact? - ANSWER The chemicals bonds in the substrate are put under stress and begin to weaken This stress aids the substrates in forming into a different molecule completely (a new product is formed) After this new molecule is created, it leaves the active site and the enzyme is free to do it all again Homeostasis - ANSWER The body has the ability to detect change, activate mechanisms that oppose it, and maintain relatively stabl e internal conditions.