Biology Exam 1
- Natural selections is a process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than do other individuals because of those traits - The dead ends signify extinction of a particular organism
Be able to explain the argument for descent with modification and natural selection. Understand a history tree and what the dead ends signify (ch 22 and 25)
- If the pH, salt concentration, temperature, or other aspects of its environment are altered, the weak chemical bonds and interactions within a protein may be destroyed, causing the protein to unravel and lose its native shape, a change called denaturation. Because it is misshapen, the denatured protein is biologically inactive
Define denaturation and explain how proteins may be denatured (ch 5)
- A polymer is a long molecule consisting of many similar or identical building blocks linked by covalent bonds. The repeating units that serve as the building blocks of a polymer are smaller molecules called monomers. In addition to forming polymers, some monomers have functions of their own. - The reaction that connects a monomer to another monomer or a polymer is a "condensation reaction", a reaction in which two molecules are covalently bonded to each other with the loss of a small molecule. If a water molecule is lost, it is known as a dehydration reaction. Polymers are dissembled to monomers by hydrolysis, a process that is essentially the reverse of the dehydration reaction. Hydrolysis means water breakage. The bond between monomers is broken by the addition of a water molecule, with a hydrogen from water attaching to one monomer and the hydroxyl group attaching to the other.
Compare and contrast monomers and polymers. Compare condensation and hydrolysis (ch 5)
- atomic number: the number of protons in the nucleus of an atom, unique for each element and designated by a subscript - mass number: the total number of protons and neutrons in an atom's nucleus - isotopes: one of several atomic forms of an element, each with the same number of protons but a different number of neutrons, thus differing in atomic mass
Define atomic number, mass number, and isotopes (ch 2 and 3)
- The scientific study of life.
Define biology (ch 1)
- Isomers are compounds that have the same numbers of atoms of the same elements but different structure and hence different properties. - Structural isomers differ in the covalent arrangements of their atoms. - In cis-trans isomers (also known as geometric isomers), carbons have covalent bonds to the same atoms, but these atoms differ in their spatial arrangements due to the inflexibility of double bonds. Single bonds allow the atoms they join to rotate freely about the bond axis without changing the compound. In contrast, double bonds do not permit such rotation. - Enantiomers are isomers that are mirror images of each other and that differ in shape due to the present of an asymmetrical carbon, one that is attached to dour different atoms or groups of atoms.
Define isomer. Describe three types of isomer (ch 4)
- The study of carbon compounds (organic compounds)
Define organic chemistry (ch 4)
- Table salt is sodium chloride (NaCl), a compound composed of the elements sodium (Na) and chlorine (Cl) in a 1:1 ratio. Pure sodium is a metal, and pure chlorine is a poisonous gas. When chemically combined however, sodium and chlorine form an edible compound.
Describe a specific compound and explain the emergent property found (ch 2 and 3)
- Length: carbon skeletons cary in length - Branching: skeletons may be unbranched or branched - Double Bond Position: the skeleton may have double bonds, which can vary in location - Presence of Rings: some carbon skeletons are arranged in rings. IN the abbreviated structural formula for each compound, each corner represents a carbon and its attached hydrogens
Describe four examples of structural isomers (ch 4)
- He observed and collected thousands of plants and animals - He described features of organisms that made them well suited to such diverse environments as the humid jungles of Brazil, the expansive grasslands of Argentina, and the towering peaks of the Andes - He also noted that the plants and animals in temperate regions of South America more closely resembled species living in the South American tropics than species living in temperate regions of Europe. Furthermore, the fossils he found, though clearly different from living species, distinctly resembled the living organisms of South America
Describe how Darwin used his observations from the voyage of the HMS Beagle to formulate and support his theory of evolution (ch 22 and 25)
- Biogeography is the geographic distribution of species. The geographic distribution of organisms is influenced by many factors, including continental drift, the slow movement of Earth's movement over time, and the presence of endemic species, species that are found nowhere else in the world. - Darwin found fossils of ocean organisms high in the Andes, leading him to infer that the rocks containing the fossils must have been raised there by many earthquakes
Describe how biogeography influenced Darwin and know some examples used for proof of evolution (ch 22 and 25)
- Fossils are important evidence for evolution because they show that life on earth was once different from life found on earth today. Paleontologists can determine the age of fossils using methods like radiometric dating and categorize them to determine the evolutionary relationships between organisms. - Radiometric dating is a method used to date rocks and other objects based on the known decay rate of radioactive isotopes. The decay rate is referring to radioactive decay, which is the process by which an unstable atomic nucleus loses energy by releasing radiation. - Isotope: each of two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei, and hence differ in relative atomic mass but not in chemical properties; in particular, a radioactive form of an element. - Uranium-235, Lead-207: 10 million to origin of Earth - Carbon-14 Nitrogen-14: 0-100,000
Describe how the fossil record was and has been used for evidence of evolution. Understand radiometric dating. Understand what an isotope is and how it relates to fossil age records. Give some examples of isotopes used. Understand how the different half-lives of elements affect their use in fossil records (ch 22 and 25)
- Hydroxyl Group: Is polar due to electronegative oxygen. Forms hydrogen bonds with water, helping dissolve compounds such as sugars. (ex- ethanol, the alcohol present in alcoholic beverages) - Carbonyl Group: Sugars with ketone groups are called ketoses; those with aldehydes are called aldoses. (ex- acetone, the simplest ketone; proposal, an aldehyde) - Carboxyl Group: Acts as an acid (can donate H+) because the covalent bond between oxygen and hydrogen is so polar. (ex- acetic acid, which gives vinegar is sour taste) - Amino Group: Acts as a base; can puck up an H+ from the surrounding solution (water, in living organisms). (ex- glycine, an amino acid) - Sulfhydryl Group: Two—SH groups can react, forming a "cross-link" that helps stabilize protein structure. Hair protein cross-links maintain the straightness or curliness of hair; in hair salons, "permanent" treatments break cross-links, then re-form them while the hair is in the desired shape. (ex- cysteine, a sulfur-containing amino acid) - Phosphate Group: Contributes negative charge (1- when positioned inside a chain of phosphates; 2- when at the end). When attached, confers on a molecule the ability to react with water, releasing energy. (ex- glycerol phosphate, which takes part in many important chemical reactions in cells) - Methyl Group: Affects the expression of genes when bonded to DNA or to proteins that bind to DNA. Affects the shape and function of male and female sex hormones. (ex- 5-methylcytosine, cytosine, a component of DNA, had been modified by addition of a methyl group)
Describe or identify the structure of the seven functional groups. Explain one important function for each. Be able to draw and recognize the basic functional group (ch 4)
- Hydrogen, Carboxyl group, Amino group, R group - At the pH in a cell, the amino and carboxyl groups are usually ionized. - R group: A variable side chain; confers the unique physical and chemical properties of each amino acid. Side chains may be either nonpolar and hydrophobic, or polar or charged (acidic or basic) and thus hydrophilic.
Describe the basic structure of an amino acid. Explain how amino acids may be grouped, according to the physical and chemical properties of the side chains (R groups) (ch 5)
- Proteins make up over 50% of dry mass of most cells, important in every aspect of an organism. Serve for structural support, storage, transport, cellular communications, movement, and defense against foreign substances.
Describe the characteristics that distinguish proteins from the other major classes of macromolecules and explain the biologically important functions of this group (ch 5)
- Ethical issues raised by such questions have as much to do with politics, economics, and cultural values as with science and technology. All citizens—not only professional scientists—have a responsibility to be informed about how science works and about the potential benefits and risks of technology. The relationship between science, technology, and society increases the significance and value of any biology course.
Describe the ethical concerns scientists need to consider and have some specific examples of how ethical concerns are safeguarded (ch 1)
- Evolution is "descent with modification" by which species accumulate differences from their ancestors as they adapt to different environments over time - Averred catastrophes defined strata. Said different organisms in overlying strata hadn't evolved but migrated - Hutton. Current gradual processes can explain land forms. Deep time: Earth millions and millions of years old. Lyell. Uniformitariamism: mechanisms are constant over time= the opposite of catastrophism. Darwin proposed evolution by slow, gradual change - Darwin realized that the capacity to reproduce was characteristic of all things after reading this essay. The essay was about human suffering (disease, famine, was, etc.) and how it was an inescapable consequence of the human population;s potential to increase faster that food supplies and other resources.
Describe the historical context of evolutionary theory. Be able to trace the early thoughts of Western culture up to and including natural theology. Explain how Cuvier and his followers used the concept of catastrophism to oppose the theory of evolution. Explain how the principle of gradualism and Charles Lyell's theory of uniformitarianism influenced Darwin's ideas about evolution. Explain how an essay by the Rev. Thomas Malthus influenced Charles Darwin (ch 22 and 25)
- biosphere - ecosystem - community - population - organisms - organ - tissue - cell - organelles - molecule - reductionism: an approach that reduces complex systems to simpler components that are more manageable to study - emergent properties: New properties that arise with each step upward in the hierarchy of life, owing to the arrangement and interactions of parts as complexity increases. - Because such correlations of structure and function are common in all living things, analyzing a biological structure gives us clues about what is does and how it works
Describe the levels of biological organization. Define reductionism. Explain what emergent properties means. Describe what "structure and function are related" means (ch 1)
- order - energy processing - evolutionary adaptation - growth and development - response to the environment - regulation - reproduction
Describe the properties of life (ch 1)
- data - scientific method - variables
Describe the types of items you would use to judge the validity of a scientific study (ch 1)
- A fat consists of a glycerol molecule joined to three fatty acids. Glycerol is an alcohol; each of its three carbons bears a hydroxyl group - A phospholipid is similar to a fat molecule but had only two fatty acids attached to glycerol rather than three. The third hydroxyl group of glycerol is joined to a phosphate group, which has a negative electrical charge in the cell - Steroids are lipids characterized by a carbon skeleton consisting of four fused rings. Different steroids are distinguished by the particular chemical groups attached to this ensemble of rings
Describe the unique properties, building-block molecules, and biological importance of the three important groups of lipids: fats, phospholipids, and steroids (ch 5)
- The finches of the Galápagos islands are one example of natural selection because over time, the birds's beaks evolved for whatever type of food the bird eats. Another example of natural selection is: in an ecosystem, some giraffes have long necks and others have short ones. If something caused low-lying shrubs to die out, the giraffes with short necks would not get enough food. After a few generations, all the giraffes would have long necks.
Describe the various examples used as evidence for evolution and natural selection (ch 22 and 25)
- The blood disease Sickle-cell anemia is caused by a simple substitution mutation. In the mutation, a single nucleotide is replaced in the portion of DNA which codes for a unit of hemoglobin. Hemoglobin is a multi-protein complex, responsible for carrying oxygen and supporting the shape of blood cells. The substitution mutation causes a glutamic acid in the protein to be changed to a valine amino acid
Describe what occurs when a mutation occurs and there is a substitution of amino acids. Give a specific example (ch 5)
- Molecular shape is crucial: It determines how biological molecules recognize and respond to one another with specificity. Biological molecules often bind temporarily to each other by forming weak interactions, but only if their shapes are complementary. Consider the effects of opiates, drugs such as morphine and heroin derived from opium. Opiates relieve pain and alter mood by weakly binding to specific receptor molecules on the surfaces of the brain cells.
Describe, with a specific example, how molecular structure affects function (ch 2 and 3)
- A pyrimidine had one six-membered ring of carbon and nitrogen atoms. The members of the pyrimidine family are cytosine (C), thymine (T), and uracil (U). - Purines are larger, with a six-membered ring fused to a five-membered ring. The purines are adenine (A) and guanine (G). The specific pyrimidines and purines differ in the chemical groups attached to the rings. Adenine, guanine, and cytosine are doing in both DNA and RNA; thymine is found only in DNA and uracil only in RNA
Distinguish between a pyrimidine and a purine (ch 5)
- At room temperature, the molecules of a saturated fat, such as the fat in butter, are packed closely together, forming a solid - At room temperature, the molecules of an unsaturated dat such as olive oil cannot pack together closely enough to solidify because of the kinks (caused by double bonds) in some of their fatty acid hydrocarbon chains
Distinguish between a saturated and an unsaturated fat and list some unique emergent properties that are a consequence of these structural differences (ch 5)
- Monosaccharides generally have molecular formulas that are some multiple of the unit CH2O. Disaccharides consist of two monosaccharides joined by a glycosidic linkage, a covalent bond formed between two monosaccharides by a dehydration reaction. - Polysaccharides are macromolecules, polymers with a few hundred to a few thousand monosaccharides joined by glycosidic linkages. Some polysaccharides serve as storage material, hydrolyzed as needed to provide monosaccharides for cells. Other polysaccharides serve as building material for structures that protect the cell or the whole organism. The architecture and function of a polysaccharide are determined by its monosaccharides and by the positions of its glycosidic linkages.
Distinguish between monosaccharides and disaccharides. Identify a glycosidic linkage and describe how it is formed. Describe the structure and functions of polysaccharide (ch 5)
- In starch, all the glucose monomers are in the alpha configuration; in contrast, the glucose monomers of cellulose are all in the beta configuration, making every glucose monomer "upside down" with respect to its neighbors - The differing glycosidic linkages in starch and cellulose give the two molecules distinct three-dimensional shapes
Distinguish between the glycosidic linkages found in starch and cellulose and explain why the difference is biologically important (ch 5)
- Descent with Modification: Darwin attributed the unity of life to the descent of all organisms from an ancestor that lived in the remote past - Artificial Selection, Natural Selection, and Adaptation: humans have modified other species over many generations by selecting and breeding individuals that possess desired traits, a process called artificial selection. As a result, organisms often bear little resemblance to their wild ancestors
Explain Darwin's two major points from "The Origin of the Species" (ch 22 and 25)
- In 1953, Stanley Miller, a graduate student of Harold Urey at the University of Chicago, designed an experiment on the abiotic (nonliving) synthesis of organic compounds to investigate the origin of life. From his results, Miller concluded that complex organic molecules could Aris spontaneously under conditions thought at that time to have existed on early Earth. These experiments support the idea that abiotic synthesis of organic compounds, perhaps near volcanoes, could have been an early stage in the origin of life
Explain a possible origin of organic molecules. Describe any evidence for this idea (ch 4)
- Each functional group has certain properties, such as shape and charge, that cause it to participate in chemical reactions in a characteristic way. - Hydroxyl Group: Is polar due to electronegative oxygen. Forms hydrogen bonds with water, helping dissolve compounds such as sugars. (ex- ethanol, the alcohol present in alcoholic beverages)
Explain how functional groups add to the distinctive properties of organic molecules. Give a specific molecular example (ch 4)
- As a polypeptide folds into its functional shape, amino acids with hydrophobic (non polar) side chains usually end up in clusters at the core of the protein, out of contact with water. This, a "hydrophobic interaction" is actually caused by the exclusion of non polar substances by water molecules. Once nonpolar amino acid side chains are close together, van der Waals interactions help hold them together. Meanwhile, hydrogen bonds between polar side chains and ionic bonds between positively and negatively charged side chains also help stabilize tertiary structure. These are all weak interactions in the aqueous cellular environment, but their cumulative effect helps give the protein a unique shape - Covalent bonds called disulfide bridges may further reinforce the shape of a protein. Disulfide bridges form where two cysteine monomers, which have sulfhydryl groups (-SH) on their side chains, are brought close together by the folding of the protein. The subduer of one cysteine bonds to the sulfur of the snood, and the disulfide bridge (-S-S-) rivets parts of the protein together. All of these different kinds of interactions can contribute to the tertiary structure of a protein
Explain how weak interactions and disulfide bridges contribute to tertiary protein structure (ch 5)
- Small organic molecules were thought to have formed in the early oceans due to the abiotic synthesis of organic monomers. Oparin and Haldane postulated that conditions on earth favored chemical reactions that synthesized organ compounds from inorganic precursors present in the early atmosphere and seas - In the 1950's, biochemists Stanley Miller and Harold Urey, conducted an experimentwhich demonstrated that several organic compounds could be formed spontaneously by simulating the conditions of Earth's early atmosphere.
Explain the abiotic synthesis theory of Oparin and Haldane and explain the Miller & Urey experiment that examined that theory (ch 22 and 25)
- Darwin's explanation of how adaptations arose centered on natural selection, a process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than do other individuals because of those traits - Lamarck thought organisms evolved by "use and disuse" (idea that parts of the body that are used extensively become larger and stronger; ex- giraffe's neck grows because it stretches its neck to reach high branches), and by "inheritance or acquired characteristics" (an organism could pass these modifications to its offspring)
Explain the differences between Darwin and Lamarck's theories (ch 22 and 25)
- covalent bond: a type of strong chemical bond in which two atoms share one or more pairs of valence electrons - ionic bond: a chemical bond resulting from the attraction between two oppositely charged ions - hydrogen bond: a type of weak chemical bond that is formed when the slightly positive hydrogen atom of a polar covalent bond in one molecule is attracted to the slightly negative atom of a polar covalent bond in another molecule or in another region of the same molecule - Van der Waals forces: weak attractions between molecules or parts of molecules that result from transient local partial charges
Explain the differences between covalent, ionic, hydrogen bonds, and Van der Waals forces (ch 2 and 3)
- organization: reductionism is an approach that reduces complex systems to simpler components that are more manageable to study - information: within cells, structures called chromosomes contain genetic material in the form of DNA - energy and matter: moving, growing, reproducing, and the various cellular activities of life are work, and work requires energy. The input of energy, primarily from the sun, and the transformation of energy from one form to another make life possible - interactions: at any level of the biological hierarchy, interactions between the components of the system ensure smooth integration of all the parts, such that they function as a whole - evolution: as the fossil record demonstrates, life has been evolving for billions of years, resulting in a vast diversity of past and present organisms; along with the diversity there is also unity, in the form of shared features
Explain the five unifying themes of biology (ch 1)
- Molecular chaperones are diverse families of multidomain proteins that have evolved to assist nascent proteins to reach their native fold, protect subunits from heat shock during the assembly of complexes, prevent protein aggregation or mediate targeted unfolding and disassembly. - Protein folding is the process by which a protein structure assumes its functional shape or conformation. All protein molecules are heterogeneous unbranched chains of amino acids. By coiling and folding into a specific three-dimensional shape they are able to perform their biological function.
Explain the function of chaparones and the importance of protein folding (ch 5)
- 130,000: Anatomically modern humans evolve. Seventy thousand years later, their descendents create cave paintings — early expressions of consciousness. - 4 million: In Africa, an early hominid, affectionately named "Lucy" by scientists, lives. The ice ages begin, and many large mammals go extinct. - 65 million: A massive asteroid hits the Yucatan Peninsula, and ammonites and non-avian dinosaurs go extinct. Birds and mammals are among the survivors. - 130 million: As the continents drift toward their present positions, the earliest flowers evolve, and dinosaurs dominate the landscape. In the sea, bony fish diversify. - 225 million: Dinosaurs and mammals evolve. Pangea has begun to break apart. - 248 million: Over 90% of marine life and 70% of terrestrial life go extinct during the Earth's largest mass extinction. Ammonites are among the survivors. - 250 million: The supercontinent called Pangea forms. Conifer-like forests, reptiles, and synapsids (the ancestors of mammals) are common. - 360 million: Four-limbed vertebrates move onto the land as seed plants and large forests appear. The Earth's oceans support vast reef systems. - 420 million: Land plants evolve, drastically changing Earth's landscape and creating new habitats. - 450 million: Arthropods move onto the land. Their descendants evolve into scorpions, spiders, mites, and millipedes. - 500 million: Fish-like vertebrates evolve. Invertebrates, such as trilobites, crinoids, brachiopids, and cephalopods, are common in the oceans. - 555 million: Multi-cellular marine organisms are common. The diverse assortment of life includes bizarre-looking animals like Wiwaxia. - 3.5 billion: Unicellular life evolves. Photosynthetic bacteria begin to release oxygen into the atmosphere. - 3.8 billion: Replicating molecules (the precursors of DNA) form. - 4.6 billion: The Earth forms and is bombarded by meteorites and comets.
Explain the key events in the timeline of life evolving (ch 22 and 25)
- The key to an atom's chemical characteristics is its electron configuration. This configuration determines the kinds and number of bonds an atom will form with other atoms. Recall that it is the valence electrons, those in the outermost shell, that are available to form bonds with other atoms
Explain the key to an atom's chemical characteristic (ch 4)
- An electron can move from one shell to another, but only by absorbing or losing an amount of energy equal to the difference in potential energy between its position in the old shell and that in the new shell. When an electron absorbs energy it moves to a shell farther out from the nucleus. When an electron loses energy, it "falls back" to a shell closer to the nucleus, and the lost energy is usually released to the environment as visible light or ultraviolet radiation.
Explain the movement of electrons from one shell (orbital) to another (ch 2 and 3)
- The pH of a solution is defined as the negative logarithm (base 10) of the H+ concentration: pH = -log [H+] - For a neutral aqueous solution, [H+] is 10^-7 M, giving us -log 10^-7 = -(-7) = 7
Explain the pH scale (ch 2 and 3)
- When ionic compounds dissolve in water, their ions separate from one another in a process called dissociation. One interesting feature of water and many other covalent compounds is that they too can dissociate into ions.
Explain the process of water dissociation (ch 2 and 3)
- A "parent" isotope decays into its "daughter" isotope at a fixed rate, expressed as the half-life of the isotope—the time it take for 50% of the parent isotope to decay. Each radioactive isotope has a characteristic half-life that is not affected by temperature, pressure, or any other environmental variable. Using a process called radiometric dating, scientists measure the ratio of different isotopes and calculate how many half-lives (in years) have passed since an organism was fossilized or a rock was formed. - Labeling each data point with the corresponding fractions will help orient you to the graph. Draw an arrow to the data point for half-life = 1 and write the fraction of the element that will remain after one half-life. Calculate the fraction of the element remaining at each half-life and write the fractions on the graph near arrows pointing to the data points. Convert each fraction to a decimal and write the decimal in scientific notation.
Explain what a half-life is and how to interpret a radioactive isotope decay curve (ch 2 and 3)
- The sequence of amino acids is what determines a proteins conformation. A protein's conformation gives it its function, and any small change can make the protein ineffective. - Primary structure is simply the sequence of amino acids in a polypeptide. Determined by inherited genetic information. - The two types of secondary protein structures are the alpha helix, and the beta pleated sheets. Hydrogen bonds connect the R groups together, maintaining its shape. - The two types of secondary protein structures are the alpha helix, and the beta pleated sheets. Hydrogen bonds connect the R groups together, maintaining its shape. - Quaternary structure occurs in proteins that are made up of more than one polypeptide chain. Combining different polypeptides leads to a greater range of biological activity.
Explain what determines protein conformation and why it is important. Define primary structure and describe how it may be deduced in the laboratory. Describe the two types of secondary protein structure. Explain the role of hydrogen bonds in maintaining the structure. Explain the quaternary protein structure (ch 5)
- Lipids are the one class of large biological molecules that dos not include true polymers, and they are generally not big enough to be considered macromolecules
Explain what distinguishes lipids from other major classes of macromolecules (ch 5)
- Although the atom is the smallest unit having the properties of an element, these tiny bits of matter are composed of even smaller parts, called subatomic particles. The number of protons in an element determines the atomic number of that element; when the number of protons increases or decreases, the element changes, and therefore so too does the structure.
Explain why a biologist is interested in the atomic structure of an atom (ch 2 and 3)
- Carbon has 6 electrons, with 2 in its first electron shell and 4 in the second shell; thus, it has 4 valence electrons in a shell that can hold up to 8 electrons. A carbon atom usually completes its valence shell by sharing its 4 electrons with other atoms so that 8 electrons are present. Each pair of shared electrons constitutes a covalent bond. In organic molecules, carbon usually forms single or double covalent bonds. Each carbon atom acts as an intersection point form which a molecule can branch off in as many as four directions. This enable carbon to form large, complex molecules.
Explain why carbon is able to form such diverse molecules (ch 4)
- An atom with a completed valence shell is unreactive; that is, it will not interact readily with other atoms. At the far right of the periodic table are helium, neon, argon, krypton, xenon, and radon, all of which have full valence shells. These elements are inert, meaning chemically unreactive.
Explain why inert elements are so stable (ch 2 and 3)
- When two amino acids are positioned so that the carboxyl group of one is adjacent to the amino group of the other, they can become joined by a dehydration reaction
Identify a peptide bond and explain how it is formed (ch 5)
- Cohesion/Adhesion: Hydrogen bonds attract water molecules to other water molecules (for example, this allows certain insects to tread on water or brings water up through plants) - Moderation of temperature: Hydrogen bonds cause water's high specific heat due to the energy needed to break these bonds - Floating ice: Hydrogen bonds get locked into crystal structures that is less dense than the liquid state - Solvent: Polar water molecules surround & dissociate ionic compounds (+other polar molecules) - Hydrophilic= Water loving / Hydrophobic= Water fearing (tend to be nonionic & nonpolar) - Acid: 1-6 / Base 9-14
List the four emergent properties of water and explain how each come about (ch 2 and 3)
- Carbohydrates - Proteins - Nucleic Acids - Lipids
List the four major classes of macromolecules (ch 5)
- The amino acid sequence go a polypeptide is programmed by a discrete unit of inheritance know as a gene. Genes consist of DNA, which belongs to the class of compounds called nucleic acids. Nucleic acids are polymers made of monomers called nucleotides - A nucleotide, in general, is composed of three parts: a five-carbon sugar (a pentose), a nitrogen-containing (nitrogenous) bade, and one to three phosphate groups - Each nitrogenous base has one or two rings that include nitrogen atoms. Add sugar to which the nitrogenous is attached. So far, we have built a nucleoside (base plus sugar). To complete the construction of a nucleotide, we attach one to three phosphate groups to the 5' carbon of the sugar. With one phosphate, this is a nucleoside monophosphate, more often called a nucleotide
Summarize the functions of nucleic acids. List the major components of a nucleotide, and describe how these monomers are linked to form a nucleic acid (ch 5)
- The number of electrons required to fill the valence shell of an atom is generally equal to the atom's valence.
Why is the valence shell important (ch 4)
- Hydrophobic interactions between sickle-cell hemoglobin proteins lead to their aggregation into a fiber; capacity to carry oxygen is greatly reduced - Fibers of abnormal hemoglobin deform red blood cell into sickle shape - Since the structure is altered, so too is its function
Using hemoglobin as an example, describe quaternary protein structure (ch 5)
- Mutations are the source of new variation. Natural selection itself does not create new traits; it only changes the proportion of variation that is already present in the population. The repeated two-step interaction of these processes is what leads to the evolution of novel adaptive features. - Antibiotic resistance is the ability of bacteria or other microbes to resist the effects of an antibiotic. Antibiotic resistance occurs when bacteria change in some way that reduces or eliminates the effectiveness of drugs, chemicals, or other agents designed to cure or prevent infections. - When a pesticide is first used, a small proportion of the pestpopulation may survive exposure to the material due to their distinct genetic makeup. These individuals pass along thegenes for resistance to the next generation.
Using some "contemporary examples", explain how natural selection results in evolutionary change. Describe antibiotic resistance and pesticide resistance and how they came about (ch 22 and 25)