Chemistry Concepts: Atomic Weight, Bonds, Water, Acids, Bases, Proteins, Nucleic Acids, Exams of Biology

Download Chemistry Concepts: Atomic Weight, Bonds, Water, Acids, Bases, Proteins, Nucleic Acids and more Exams Biology in PDF only on Docsity! Biology 189: Exam 1 (Chapter 1-4) Questions and Answers). *Chapter 1* Summarize the five characteristics of life - Correct answer 1. Organization: atoms make up molecules, which make up cells, which make up tissues, and so on. 2. energy use: a kitten uses the energy from its mothers milk to fuel its own groth 3. maintenance of internal consistency (homeostasis): your kidneys regulate your body's water balance by adjusting the concentration of your urine 4. Reproduction, growth, and development: an acorn germinates, developed into an oak seedling, and, at maturity, reproduces sexually to produce its own acorns 5. Evolution: increasing numbers of bacteria survive treatment with antibiotic drugs. all of the following are characteristics of life EXCEPT: a. evolution b. reproduction c. homeostasis d. multicellularity - Correct answer d. multicellularity the concentration of salts in blood remains relatively steady, regardless of a person's diet. This situation best illustrates: a. homeostasis b. life organizational hierarchy c. autotrophy d. evolution - Correct answer a. homeostasis illustrate life's organizational hierarchy - Correct answer - atom - molecule - organelle - cell - tissue - organ - organ system - organism - population - community - ecosystem - biosphere atom - Correct answer smallest chemical unit of a pure substance molecule - Correct answer A group of atoms bonded together organelle - Correct answer a membrane bound structure that has a specific function within a cell cell - Correct answer fundamental unit of life, multicellular or unicellular tissue - Correct answer collection of specialized cells that function in a coordinated fashion organ - Correct answer structure consisting of tissues organized to interact and carry out specific functions organ system - Correct answer organs connected physically or chemically that function together organism - Correct answer An individual living thing Population - Correct answer a group of the same species of organisms living in the same place and time community - Correct answer all populations that occupy the same region ecosystem - Correct answer living and nonliving things in an area biosphere - Correct answer the global ecosystem, the parts of the planet and its atmosphere where life is possible which of the following is smaller than an organelle? a. an organ b. a molecule standardized variable - Correct answer any factor held constant for all subjects in an experiment Control - Correct answer untreated group used as a basis for comparison with a treated group in an experiment in an experiment to test the effect of temperature on the rate of bacterial reproduction, temperature would be the... - Correct answer indépendant variable Placebo - Correct answer an inert substance that resembles the treatment given to the experimental group epidemiological studies - Correct answer advantages: comparatively inexpensive potential to study harmful factors statistical power: - sample number one time Theory - Correct answer an explanation of a natural phenomenon supported by many observations and experiments over time Can a theory be proven wrong? - Correct answer Yes, a new observation or interpretation of data could disprove a theory. Hypothesis - Correct answer a tentative explanation for one or more observations limitations to science inquiry - Correct answer - evidence may lead to multiple interpretation - experiments can fail to give a definitive answer - researchers may interpret observations or results - scientific community may be slow to accept new evidence that suggests unexpected conclusions Filing drawer syndrome - Correct answer failure to share negative results data image manipulation - Correct answer scientists editing photos releasing fake results *which of the following statements is false? a. emergent properties are function that arise from the interaction between an organisms parts. b. two fo the three domains contain prokaryotic organisms c. when medical researchers test the effectiveness of a new drug, they typically compare the new drug to a placebo d. for a scientific study to be considered valid, the researchers myst conduct experiments * - Correct answer asexual reproduction vs sexual reproduction - Correct answer Asexual reproduction generates offspring that are genetically identical to a single parent. In sexual reproduction, two parents contribute genetic information to produce unique offspring. Why is the cell considered the basic unit of life? - Correct answer because every organism consists of one or more cells emergent properties - Correct answer new functions that arise from interactions among a system's components give an example of emergent properties from everyday life. - Correct answer brain cell -> interacting brain cells -> brain -> memory *Chapter 2* Why is chemistry important to understand biology? - Correct answer It allows us to understand nutrition, allows us to test for drugs, sugars, hormones, and indicate pregnancy. General structure of atoms - Correct answer - electrons: rotating around the nucleus, negative charge -protons: in the nucleus, positive charge - neutrons: in the nucleus, natural charge Elements that make up most of the mass of all living organisms - Correct answer - Nitrogen - carbon - hydrogen - oxygen - phosphorus - sulfer How is the periodic table related to atomic structure - Correct answer elements are arranged by atomic number (number of protons) ion - Correct answer atom that has gained or lost electrons cation - Correct answer lost an electron (Na+) anion - Correct answer gain an electron, F- isotope - Correct answer atoms of the same element that have the same atomic number but different atomic masses atomic number - Correct answer the number of protons in the nucleus of an atom atomic mass - Correct answer calculated by adding the number of protons and neutrons a neutral hydrogen atom with a mass number of 1 has ___ neutrons, ___ protons, and ___ electrons - Correct answer 0; 1; 1 how many neutrons foes carbon -14 have in its nucleus? - Correct answer 8 atomic weight - Correct answer the average atomic mass of all atoms of an element chemical reaction - Correct answer interactions between atoms in which electrons are involved nuclear reaction - Correct answer A reaction that involves a change in the nucleus of an atom isotopes are unstable ionic bond - Correct answer - one atom donated - a more electronegative atom steals the other atoms electron, no sharing - an electrical attraction occurs between two atoms of different charte Properties of carbon that make this element the chemical basis of all life - Correct answer - strong and stable - can form single, double or triple bonds - biological molecules are built on a carbon framework - has unique electron configuration *describe the variety and chemical characteristics of common functional groups or organic compounds* - Correct answer diagram dehydration synthesis and hydrolysis reactions - Correct answer *diagram* dehydration: joins monomers into polymers hydrolysis: breaks polymers into monomers structure and function of carbohydrates - Correct answer - organic molecules that consist of carbon, hydrogen, and oxygen (1:2:1) structural material and energy source called sugars/saccharides structure and function of lipids - Correct answer - fat - desiccation - cell membrane - insulation - energy - include fatty acids, triglycerides, phospholipids, steroids, and waxes structure and function of proteins - Correct answer the basic building blocks of proteins are amino acids structure: slide 76 how are amino acids joined to form a polypeptide - Correct answer a protein is a chain of amino acids linked by peptide bonds (covalent bond) links the carboxyl group with the amino group explain the four levels of protein structure - Correct answer - primary: amino acid sequence of a polypeptide - secondary structure: localized areas of coils, sheets, and loops within a polypeptide - tertiary structure: overall shape of one polypeptide - quaternary structure: overall protein shape arising from interaction between multiple polypeptides that make up the functional protein what factors determine protein shape and function - Correct answer - amino acid sequence - denaturing (loss of function) structure and functions of nucleic acids - Correct answer - information bearing molecules of all life on earth Structure: on page 39 ands lide 101 different types of nucleotides - Correct answer - adenine - guanine - thymine - cytosine DNA vs. RNA - Correct answer DNA: deoxyribose sugar, thymine, double strand RNA: ribose sugar, uracil, single strand how do certain nucleotides base pair with each other - Correct answer through hydrogen bonding central dogma of biology - Correct answer *slide 107* Monosaccharides - Correct answer usually contain five or six carbon atoms Disaccharide - Correct answer two monosaccharides bonded together through dehydration synthesis Polysaccharides - Correct answer complex sugars huge molecules consisting of hundreds or thousands of monosaccharide monomers A sugar is an example of a _________, whereas DNA is a _________. - Correct answer carbohydrate; nucleic acid ____ are monomers that form polymers called _____ - Correct answer nucleotides; nucleic acids Relate the functions of plant and animal polysaccharides to their structure. - Correct answer starch used to store energy by plants glycogen is the energy storage molecule in animals in their muscle cellulose is used for structure in plant cell wall Diagram the structure of a triglyceride, and explain how it is formed and how its structure is affected by the presence of saturated and unsaturated fatty acids - Correct answer 65 Explain why some fats are solid at room temperature and others are liquid - Correct answer saturated: have maximum possible number of hydrogens, no double bonds (solid) unsaturated: have one or more double bonds (liquid) Explain why phospholipids form a bilayer when dissolved in water - Correct answer because of the hydrophilic head and the hydrophobic tail. the tails move away from the water and connect with the other tails while the heads move towards the water *Describe the chemical nature of steroids, and give an example of their biological importance* - Correct answer - have four fused carbon rings *Chapter 3* Three principles of cell theory - Correct answer 1. cells are the fundamental units of life 2. all living things are composed of cells 3. all cells come from. pre-existing cells Biological components range in size *slide 6) - Correct answer light microscopes - Correct answer - ideal for generating true-color views of living or preserved cells - uses two or more lenses to focus visible light through a specimen - can magnify up to 1600 times and resolve objects that are 200 nanometers apart Transmission Electron Microscope (TEM) - Correct answer - send a beam of electrons through a very thin slice of specimen which organelles are associated with the job of cellular digestion? - Correct answer lysosomes and peroxisomes Within a single cell, which of the following is physically the smallest? - Correct answer phospholipid molecule a human nerve cell that has an abnormal shape most likely has a defective - Correct answer cytoskeleton *different types of components that are associated with each type of organelle* - Correct answer explain the consequences to the cell if a specific type of organelle malfunctions or is absent - Correct answer without each of the organelles the cell would not be able to maintain homeostasis and would die *How does the central dogma of biology tie into cellular location and cellular processes* - Correct answer components of the cytoskeleton - Correct answer microtubules, microfilaments, intermediate filaments functions of the cytoskeleton - Correct answer supports eukaryotic cells transportation system provides physical support necessary to maintain the cells characteristics three dimensional shape locations of the cytoskeleton - Correct answer throughout the cell cilia flagella how do plant cells directly communicate with their neighbors - Correct answer - interconnected by plasmodesmata - membrane is lined with channels - water ion, small molecules, RNAs and proteins can go through How do animal cells communicate? - Correct answer - connected by junctions - tight - gap - anchoring what type of cellular junction prevents stomach acid from leaking into the abdomen and digesting internal organs ? - Correct answer tight junctions diagram the components involved in animal cell connections - Correct answer page 64 *Chapter 4* Autotroph vs. heterotroph - Correct answer autotroph: organisms that make their own food heterotroph: organisms that obtain energy by consuming other organisms categorize energy into accurate categories - Correct answer Radiant: sunlight Kinetic: moving energy Chemical: chemical bonds Potential: stored energy *Process of energy transformation* - Correct answer first law of thermodynamics - Correct answer energy can be transformed. it can NOT be created or destroyed total amount of energy in the universe is constant it just changes forms relationship between entropy and temperature - Correct answer Entropy increases as temperature increases solid melts, liquid is heated, evaporation of liquid, heating vapor Relationship between entropy and chemical reactions (The second law of thermodynamics) - Correct answer entropy increases when larger molecules are broke down into many simpler molecules - 2nd law: the release of energy will result in a greater amount of disorder entropy decreases when many simpler molecules are organized into a more complex molecule anabolism vs catabolism - Correct answer anabolism is the energy driven synthesis of complex molecules from smaller ones. catabolism is the energy releasing degradation of complex molecules into smaller ones Endergonic vs. Exergonic - Correct answer - Endergonic: absorbs energy from environment energy of product higher than reactant - Exergonic releases free energy into environment energy of product lower than reactant Diagram an oxidation-reduction (redox) reaction - Correct answer slide 28 describe the role of ATP in short term energy storage - Correct answer This molecule acts as the short-term energy currency of the cell and provides the source of energy used in individual synthetic (nonspontaneous) reactions. ATPcollects small packets of energy from the food-burning power plants of the cell and transports this energy to where it is needed. Diagrams the structure of ATP - Correct answer slide 30 Describe why coupled chemical reactions work (endergonic/exergonic) - Correct answer In an exergonic reaction, energy is released to the surroundings. The bonds being formed are stronger than the bonds being broken. In an endergonic reaction, energy is absorbed from the surroundings. The bonds being formed are weaker than the bonds being broken.