UMN Biol 1009 Exam 1 (Dean/Scott) Questions With Detailed Correct Answers 100% Verified Answers

anything that takes up space and has mass, made up of elements - correct answers matter cannot be broken into a simpler substance 92 naturally occurring - correct answers element substance consisting of two or more different elements in a fixed ratio eg: NaCl sodium chloride - correct answers compound properties of compounds are different than those of the elements which make it up - correct answers properties of compounds essential elements that make up 96% of human body - correct answers oxygen, carbon, hydrogren, nitrogen required by living organisms in small quantities - correct answers trace elements smallest unit of matter that still retains its properties - correct answers atom examples of subatomic particles protons (pos) neutrons (neutral) electrons (negative) - correct answers protons, neutrons, electrons protons and neutrons at the center of the atom. - correct answers atomic nucleus number of protons in an atom which is unique to the element. - correct answers atomic number sum of number of protons and neutrons, mass number approximates the atomic mass. - correct answers mass number, atomic mass atoms with differing numbers of neutrons. an element usually a combination of different isotopes - correct answers isotopes unstable isotope where the nucleus decays spontaneously giving off particles and energy - correct answers radioactive isotope capacity to cause change - correct answers energy energy possessed because of structure or location, electrons have potential energy given their arrangement around the nucleus - correct answers potential energy -electrons energy correlated with its average distance from the nucleus - changes in every levels only occur in fixed incriments - when electrons absorb energy they move to a more distant shell and falls in when loses energy - correct answers potential energy of electron depends largely on the number of electrons in the outermost shell valence shell - correct answers chemical behavior of an atom electrons in the outer shell aka valence shell - correct answers valence electrons 3D space where an electron can be found 90% of the time ( an electrons exact location cannot be known) - correct answers orbital sharing of a pair of valence electrons by two atoms, occurs when atoms are close enough for orbitals to overlap - correct answers covalent bond 2 or more atoms joined by a covalent bond - correct answers molecule sharing of two pairs of electrons between two atoms - correct answers double bond often thought of as bonding capacity, the number of unpaired electrons needed to complete the outer shell. - correct answers valence attraction of a particular atom for the electrons of of a covalent bond. - the greater the electronegativity the more strongly it pulls the shared pair of electrons towards itself. - correct answers electronegativity the electron pair is shared equally in a covalent bond because the elements have equal E-negativity - correct answers nonpolar covalent bond unequal sharing of the electron pair if one of the atoms is more E-neg than the other. - correct answers polar covalent bond oxygen has a high E-neg meaning it creates a partial charge by pulling the electrons closer to it. - correct answers E-negativity of Oxygen charged ion or particle. it has either gained or lost an electron. - correct answers ion positively charged ion - correct answers cation negatively charged ion - correct answers anion attraction between a cation and an anion. - correct answers ionic bond any compound created via ionic bonds, aka ionic compound - correct answers salt many salts are solid in dry environments but will dissolve in water - correct answers environment affects ionic bond strength when water molecules are close together, their positive and negative regions are attracted to the oppositely-charged regions of nearby molecules. this is a weak interaction - correct answers hydrogen bond ever-changing regions of positive and negative charges even within covalent molecules cause atoms and molecules to stick to each other - also a weak type of interaction - correct answers Van der Waals Interactions precise shape is generally very important to the function of the molecule.. these shapes are determined by the orbitals. hybrid orbitals are formed when covalent bonds occur. -shape is important for recognition and response - correct answers molecular shape and function ( 3 things) making and breaking of chemical bonds changing the composition of matter. - reactants and products - correct answers chemical reactions reactions offset each other exactly - correct answers chemical/ dynamic equilibrium wide V with two H bonded to one O by single covalent bonds - correct answers structure of H2O unequal sharing of electrons and its shape make it a polar implying that its overall charge is unevenly distributed with oxygen having partial neg and each H having partial positive. - correct answers water as a polar molecule slightly positive parts of one H2O are attracted to slightly negative parts of another H2O, these bonds form and break a lot. - correct answers Hydrogen bonds and H2O hydrogen bonds cause water to hold together, contributes to transport of nutrients in plants - correct answers cohesion: property of water clinging of one substance to another - correct answers Adhesion how difficult it is to stretch or break the surface of a liquid. - correct answers surface tension energy of motion - correct answers kinetic energy measure of heat intensity and also represents the average kinetic energy of molecules. - correct answers temperature heat passes from warmer to cooler substances until the two are the same temperature. - correct answers heat transfer the amount of heat that must be absorbed or lost for 1 g of substance to change temp 1 deg C - thought of howe well substance resists changing temperature in response to absorption or release of heat. - correct answers specific heat - due to hydrogen bonding - important because keeps both land and water at temperature that can support and permit life. - correct answers high specific heat of H2O transformation from a liquid to gas - correct answers evaporation quantity of heat a liquid must absorb for 1 g of it to be converted from liquid to gaseous state. - correct answers heat of vaporization moderates global climate, keep organisms from overheating. think of cooling down when you sweat. - correct answers heat of vape and evaporative cooling water hydrogen bonds cause ice to be less dense than liquid water causing it to float. this occurs because of hydrogen bonding which keep molecules "at arms length" - correct answers Ice floats homogeneous mixture of two or more substances - correct answers solution dissolving agent within a solution - correct answers solvent substance that is dissolved in the solvent. - correct answers solute the sphere of water molecules around each dissolved ion in a solution - correct answers hydrogen shell any substance that has an affinity for water, - correct answers hydrophilic large molecules that do not dissolve in water but rather remain suspended in the aqueous solution. - correct answers colloid substances without an affinity for water, generally nonionic and nonpolar eg oil - correct answers hydrophobic represents the exact number of objects 6.23 * 10^23. - correct answers mole (mol) the number of moles of solute per liter of solution - correct answers molarity a single proton with charge +1, H+1 - correct answers hydrogen ion OH- , the water molecule that lost a proton - correct answers hydroxide ion H3O+, the other water molecule that the proton joins. - correct answers hydronium ion substance that increases the hydrogen ion concentration of a solution. - correct answers acid substance that reduces the hydrogen ion concentration of a solution. - correct answers base pH declines as H+ increases and vice versa. neutral pH is at 7 - correct answers pH scale substances that minimizes changes in concentrations of H+and OH-. Most buffers contain a weak acid and its corresponding base - correct answers buffer when CO2 dissolves in sea water, it reacts to form carbonic acid which lowers ocean pH - correct answers ocean acidification branch of chemistry which focuses on study of carbon compounds - correct answers organic chemistry C, H, O, N, S, P - correct answers major elements of life carbon has valence of 4, usually bonds covalently with up to 4 atoms to fill its shell - correct answers formation of bonds with carbon for the skeleton of organic molecules and they vary in shape (straight, ring,..) - correct answers carbon chain organic molecule consisting of only carbon and hydrogen. H is attached wherever electrons are available. - correct answers hydrocarbon 1. length 2. branching e bond position 4. presence of rings - correct answers four ways that carbon skeletons can vart compounds with the same numbers of the same elements but have a different shape and therefore different properties. - correct answers isomer differ in the covalent arrangement of their atoms - correct answers structural isomer covalent bonds to the same atoms, but atoms differ in spatial arrangement due to the inflexibility of the double bonds cis has H's on same side trans has H on opposite side - correct answers cis/trans isomer isomers that are mirror images of each other but differ due the the presence of an asymmetric carbon ( one that is attached to 4 different atoms or groups of atoms) two enantiomers may have very different properties. - correct answers Enantiomers the properties of organic molecules depend not only on the arrangement of the carbon skeleton but also on the number and arrangement of chemical groups attached. - correct answers functional groups are key to the functioning of molecules visible light passed through the specimen and then through glass lenses, which magnify the image as it is projected into the eye or into a camera. - correct answers light microscope ratio of an objects image size to its real size - correct answers magnification measure of clarity of the image. it is the minimum distance two points can be separated but still distinguished. - correct answers resolution accentuates differences in the parts of a sample - correct answers contrast membrane enclosed structures within eukaryotic cells - correct answers organelles focuses a beam of electrons through the specimen or onto its surface. - correct answers electron microscope good for the detailed study of topography . electron beam scans the surface and excites the electrons - correct answers scanning electron microscope used to study internal structure of cells. aims an E beam through a very thin section of specimen which has been stained with heavy metals.. this has revealed many organelles. - correct answers transmission EM separates cells into their different components using a centrifuge. allows scientists to prepare cell components in bulk for study. - correct answers cell fractation 1. bounded by a plasma membrane 2. cytosol 3. contain chromosomes 4. ribosomes - correct answers basic features shared by all cells DNA concentrated in a region but is not bound, occurs in prokaryotic cells. - correct answers nucleoid means true nucleus in greek aka they have a real nucleus. - correct answers "eukaryote" region generally between the nucleus and the plasma membrane. organelles are suspended in euks. - correct answers cytoplasm eukaryotic cells tend to be larger than prokaryotic cells. - correct answers cell size selective barrier found in all cells that allows for the passage of enough oxygen, nutrients, and wastes to service cell. - correct answers plasma membrane crucial in cells in order to get enough nutrients in the cell. the surface area ratio is highest in small cells such as bacteria. - correct answers surface area to volume ratio long thin projections from the surface which increase cellular surface area. - correct answers microvilli lysosomes centrosomes with centrioles flagella - correct answers in animal cells but not in plant cells contains most of the genes of a eukaryotic cell. - correct answers nucleus encloses the nucleus and separates the contents from the cytoplasm. this is a double membrane. envelope is perforated by pore structure - correct answers nuclear envelope a netlike array of protein filaments that maintains the shape of the nucleus by supporting the envelope. also potential evidence for a nuclear matrix which would be protein fibers extending throughout the nucleus. - correct answers nuclear lamina structures that carry the genetic information. each eukaryotic species has a unique number of chromosomes - correct answers chromosomes complex of DNA and proteins making up chromosomes - correct answers chromatin -dense granules and fibers adjoining part of the chromatin. -this is where ribosomal RNA (rRNA) is synthesized. -proteins and rRNA join form subunits that will combine to form ribosomes - correct answers nucleolus consist of rRNA and proteins; carry out protein synthesis. free ribosomes are in cytosol bound ribosomes are attached to ER or nuclear envlp. proteins function in the area that the ribosome was in when synthesized. - correct answers ribosomes nuclear envelope, endoplasmic reticulum, golgi apparatus, lysosomes, vesicles, vacuoles, plasma membrane. - correct answers endo-membrane system synthesis of proteins transport of proteins into membranes/organelles/out of cell metabolism & movement of lipids detox of poisons - correct answers functions of endo-membrane system little sacs made out of membrane material which is transports stuff - correct answers vesicles network of membranous tubules and sacs called cisternae. ER membrane is continuous with the nuclear envelope. "lume" is the inside cavity part of the membrane. - correct answers endoplasmic reticulum lacks ribosomes functions include 1. synthesis of lipids 2. metabolism of carbohydrates 3. detox of drugs and poison 4. storage of calcium ions - correct answers smooth ER studded with ribosomes functions include the production of secretory proteins. teh rough ER keeps these separate from proteins that will remain in the cytosol. also membrane factory of the cell by adding phospholipids and proteins to its own membrane - correct answers rough ER many secretory proteins are these. - correct answers glycoproteins warehouse for receiving, sorting, shipping, and some manufacturing. products from the ER are modified, stored and sent out to other areas. manufacturing of some macromolecules such as polysaccharides - correct answers golgi apparatus cis - cisternae is the receiving side of the golgi trans - cisternae is the shipping side cisternae move in a cis to trans direction and products are modified during this time. different cisternae have different teams of enzymes - correct answers cis and trans golgi membraneous sac of hydrolytic enzymes that an animal cell uses to digest (hydrolyze) macromolecules. - work best in acidic environments - phagocytosis and then food vacuole fuses with lysosome whose enzymes digest food. - correct answers lysosomes engulfing smaller organisms or food particles by pinching in from the cell membrane forming a food vacuole - correct answers phagocytosis recycling of the cells own organic material. a damaged organelle becomes surrounded by a double membrane which then fuses with a lysosome. the organic monomers are returned to the cytosol. - correct answers autophagy larges vesicles derived from golgi and ER. due to its selectivity, the vacuole solution has a different composition than the cytosol. - correct answers vacuoles food vacuole: formed by phagocytosis contractile vacuoles: pump excess water out of the cell maintaining a suitable concentration. in plant cells: enzymatic hydrolysis for digestion. other plant vacuoles separate poisonous products, others hold pigments etc - correct answers different types of vacuoles and their functions contains cell sap which is the plant cells main repository of inorganic ions including K and Cl. also plays a major role in growth bc enlarges as water is absorbed. - correct answers central vacuole mitochondrion and chloroplasts, these both contain double membranes too. - correct answers which organelles are involved in energy conversion contains out and inner membrane. the inner membrane has the mitochondrial matrix which contains mitochondrial DNA and ribosomes - the location of cellular respiration, the conversion of sugar into energy ATP - correct answers mitochondria contain chlorophyl as well as enzymes and other molecules that participate in photosynthesis. double membrane. move along the tracks of the cytoskeleton. - correct answers chloroplasts flattened interconnecting sacs within the chloroplasts. can be stacked called granum - correct answers thylakoids fluid surrounding the thylakoids which contains the chloroplast DNA, ribosomes, and other enzymes. - correct answers stroma single membrane bounded region which remove H atoms from various substrates and add them to O2 creating H2O2 functions include: -breaking down fatty acids which can be used for energy in respiration. - detoxifying alcohol and other harmful compounds by transferring H from them to O - correct answers peroxisome produced by peroxisome and is actually toxic by itself. - correct answers H2O2 network of fibers extending throughout the cytoplasm along which materials travel around the cell. composed of : microtubules, microfilaments, intermediate filaments. - correct answers cytoskeleton provide mechanical support for the cell and help it maintain its'e shape. also provides anchorage for other organelles. - correct answers function of cytoskeleton assist with cell motility which includes changes in cell location as well as parts of the cell. motor proteins allow flagella and cilia to move and move the cell. allow vesicles to "walk " along a microtubule - correct answers motor proteins hollow tubes, shape and support the cell and serves as tracks along which organelles equipped with motor proteins can travel - correct answers microtubules microtubule organizing center located near the nucleus and . contains a pair of centrioles - correct answers centrosome both are microtubule containing extensions ( flagella is like one larger tale and cilia is more like hairs) but they differ in their beating patterns cillium may also serve s antennas - correct answers flagella and cilia two single microtubules surrounded by a larger ring consisting of 9 microtubules. - correct answers 9+2 pattern solid rods, built from actin. functions to form certain structural networks. also important is their ability to bear tension pulling forces within the cell. network of microfilaments give the outer cytoplasm layer called the cortex. muscle contraction - correct answers microfilaments (actin filaments) specialized for bearing tension and are more permanent structures. (the others tend to disassemble and reassemble often) formation of the nuclear lamina - correct answers intermediate filaments extracellular structure of plant cells that distinguishes it from animal cell. much thicker than a plasma membrane. - correct answers cell wall young cell first secretes this thin and flexible cell wall - correct answers primary cell wall thin layer rich in sticky polysaccharides called "pectins" and this glues adjacent cells togtether. - correct answers middle lamella some cells add a second cell wall (rather than just strengthening the original) - correct answers secondary cell wall consists of glycoproteins and other carbohydrates containing molecules secreted by the cells. - correct answers Extracellular matrix in animal cells most abundant glycoprotein which forms strong fibers outside the cell. - correct answers collegen consists of a small core protein with many carb chains covalently attached. may be up to 95% carb - correct answers proteoglycan bind to cell surface receptors called integrins that are built into the cell membrane - correct answers fibronectin span membrane and bind on their cytoplasmic side to associated proteins attached to microfilaments on the cytoskeleton side. - correct answers integrins a narrow thread of cytoplasm that passes through the cell walls of adjacent plant cells and allows communication between them. - correct answers plasmodesmata