Bio107 Test 1/2025: Key Concepts and Definitions, Exams of Biology

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Bio107 Test 1/2025 LATEST UPDATE WITH VERIFIED Questions And Answers GRADED A+) atom ✔✔smallest functional units of matter that form all chemical substances anion ✔✔negatively charged atom cation ✔✔positively charged atom organic chemistry ✔✔chemistry of carbon-based molecules Biochemistry ✔✔organic chemistry of living organisms hydroxl group ✔✔OH- carbonyl group ✔✔C=O carboxylic acid group ✔✔COOH electronegative atom ✔✔has a slightly negative charge and its partner(s) has a slightly positive charge oxidation reaction ✔✔a molecule becomes more dependent on oxygen and loses hydrogens; releases energy reduction reaction ✔✔molecule becomes less dependent on oxygen and gains hydrogens; outside energy required monomer ✔✔basic subunit oligomer ✔✔2-10 monomers linked together polymer ✔✔more than 10 monomers linked together Carbohydrates ✔✔structural building blocks: most abundant biochemicals on the planet; poly hydroxy aldehyde or ketone monosaccharides ✔✔sugars - may have 3-8 carbons; 6 and 5 C most common disaccharide ✔✔two monosaccharides linked together by a glycosidic bond ex. lactose Raffinose ✔✔indigestible oligosaccharide made of 3 monosaccharides (galactose-glucose- fructose) - beans, cabbage, whole grains - when eaten galactose can't be broken down in the gut, leading to gas production trans fats ✔✔An unsaturated fat, formed artificially during hydrogenation of oils, containing one or more trans double bonds. cholesterol ✔✔fatty substance that is waxy and exists as small molecules within the human body - found in all cells of the body - an essential component that makes hormones, bile acids, vitamin D, and substances that help in the digestion of food high density lipoprotein (HDL) ✔✔good cholesterol - build and maintain cell membranes, manufacture bile, necessary to absorb fat and vitamins, insulates nerve fibers, production of adrenal gland hormones, production of sex hormones - regulates LDL storage and promotes excretion low density lipoprotein (LDL) ✔✔bad cholesterol - clog arteries, lead to coronary heart disease, heart attack, strokes, death phospholipids ✔✔A molecule that is a constituent of the inner bilayer of biological membranes, having a polar, hydrophilic head and a nonpolar, hydrophobic tail - amphipathic and biological membranes proteins ✔✔Nutrients the body uses to build and maintain its cells and tissues - biological catalysts; amino group, side chain, carboxyl group peptide bonds ✔✔Bonds between amino acids; n terminus and c terminus protein ✔✔a functional unit composed of one or more polypeptides - have unique structure with different levels of organization primary structure protein ✔✔sequence of amino acids secondary structure protein ✔✔folding of sequence by hydrogen bonds; alpha helix, beta pleated sheets tertiary structure ✔✔The third level of protein structure; the overall, three-dimensional shape of a polypeptide due to interactions of the R groups of the amino acids making up the chain. quaternary structure ✔✔The fourth level of protein structure; the shape resulting from the association of two or more polypeptide subunits. nucleic acids ✔✔the source of genetic information - dna and rna nucleotides ✔✔Basic units of DNA molecule, composed of a sugar, a phosphate, and one of 4 DNA bases nitrogenous bases ✔✔cytosine - guanine, adenine-thymine (uracil) phosphodiester linkages ✔✔The bonds that join nucleotides in DNA - link between sugars with bases projecting out RNA ✔✔single-stranded nucleic acid that contains the sugar ribose and uracil instead of thymine cell ✔✔large and diverse set of biochemicals that interact to perform life's processes compartmentalization ✔✔Membrane-bound organelles allow different parts of the cell to perform different functions at the same time biological membranes ✔✔selectively permeable membranes that help maintain homeostasis in the cell phospholipid membrane ✔✔Cell membrane composed of phospholipids, proteins (transport), cholesterol, and aquaporins. - forms an effective barrier in an aqueous environment glycoprotein (membrane) ✔✔A protein with one or more carbohydrates covalently attached to it. glycolipid (membrane) ✔✔lipid with a carbohydrate attached to it facilitated diffusion ✔✔Movement of specific molecules across cell membranes through protein channels active transport ✔✔Energy-requiring process that moves material across a cell membrane against a concentration difference gates ✔✔proteins that form channels for movement of materials (controlled by hormones and neurotransmitters) transporters ✔✔proteins that undergo transformational changes when binding and transporting material across a membrane - used for transporting sugars, amino acids, nucleotides, hormones, etc electrochemical gradients ✔✔The combined difference in concentration and charge; influences the distribution and direction of diffusion of ions. microscopy goals ✔✔magnification, resolution, contrast, versatility, cost limit of resolution ✔✔point of magnification in a microscope beyond which images become blurry and lose detail - defined by wavelength of the energy used to illuminate specimen - shorter wavelength - better resolution fluorescence ✔✔the capacity of a molecule to absorb a wavelength of light and subsequently release it as light at a longer wavelength immunolabeling ✔✔Labeling technique which makes use of antibody-antigen complexes to mark biological molecules or structures polyclonal antibodies ✔✔Antibodies produced by injecting animals with a specific antigen. A series of antibodies are produced responding to a variety of different sites on the antigen. fluorescent proteins ✔✔proteins that are fluorescent, or absorb and emit light at different wavelengths or colors confocal laser scanning microscopy ✔✔A type of fluorescence microscopy in which the excitation and emitted light are laser beams focused together, producing high-resolution images. electron microscopy ✔✔use electrons generated by superheating a metal - use electromagnetic lenses to focus electrons on specimen and capture/magnify electrons resulting from interaction with specimen scanning electron microscopy ✔✔view electrons that bounce off a specimen - used for looking at surfaces transmission electron microscopy ✔✔image electron that pass through a specimen - used to view internal structures of cells: fixation - chemicals or cryofixation - electrons do not penetrate deeply prokaryotes ✔✔simplest and most primitive of cellular life nucleoid ✔✔main site of dna in prokaryotes cell wall ✔✔A rigid layer of nonliving material that surrounds the cells of plants and some other organisms - peptidoglycan and lipid - fibrillar framework embedded in complex matrix capsule/glycocalyx ✔✔thick gelatinous covering prokaryotes pilli/fimbriae ✔✔Allow prokaryotes to attach to surfaces and exchange genetic material ribosome ✔✔protein synthesis flagellum ✔✔A long, hairlike structure that grows out of a cell and enables the cell to move plasmid ✔✔circular DNA molecule found in bacteria cisternae ✔✔flattened stacked membrane folds - golgi apparatus vesicles ✔✔arise form endomembrane components - carry cargo to plasma membrane, fuse with the plasma membrane and release cargo endocytosis ✔✔process by which a cell takes material into the cell by infolding of the cell membrane - invaginations of plasma membrane pinch off internally and recycle membrane and bring in key external molecules phagocytosis ✔✔A type of endocytosis in which a cell engulfs large particles or whole cells pinocytosis ✔✔A type of endocytosis in which the cell ingests extracellular fluid and its dissolved solutes. receptor-mediated endocytosis ✔✔The movement of specific molecules into a cell by the inward budding of membranous vesicles containing proteins with receptor sites specific to the molecules being taken in; enables a cell to acquire bulk quantities of specific substances. lysosomes ✔✔animal cells - where macromolecules are degraded vacuoles ✔✔Cell organelle that stores materials such as water, salts, proteins, and carbohydrates - plants: tonoplast, sap, turgor, waste and storage peroxisome ✔✔where hydrogen peroxide and other toxins are broken down microfilaments (actin) ✔✔changes the cell shape; contraction; movement of cell - cytoplasmic streaming, muscle movement, cell division microtubules ✔✔Spiral strands of protein molecules that form a tubelike structure - cell division spindle, cellulose synthesis cytosol/cytoplasm ✔✔ground substance or fluid/gel in which the organelles float - site of many metabolic processes glycocalyx ✔✔The external surface of a plasma membrane that is important for cell-to-cell communication - eukaryotic cells are usually coated with carbs on their surface primary cell wall ✔✔In plants, a relatively thin and flexible layer first secreted by a young cell - first wall, surrounds growing cells - cellulose, hemicellulose, pectins hemicellulose ✔✔polysaccharides that tether cellulose microfibrils - synthesized in the golgi, packaged in secretory vesicles and secreted to the outside pectins ✔✔complex polysaccharides that constitute 30-35% of the cell wall in higher plants - maintenance of cell wall structure, adhesion, cell expansion, ion uptake, pollen tube growth, leaf abscission, fruit development lignins ✔✔complex phenolics found in secondary cell wall middle lamella ✔✔the space between cell walls of adjacent cells plasmodesmata ✔✔connection between plant cells that traverse cell walls