BIOL 1406 Exam 1 Review PDF

BIOL 1406 Exam 1 Review Not completely comprehensive but does hit the most important points Concept 1.1 Living Organisms Share Similarities All life forms share common features: 1. Made of a common set of chemical compounds 2....

BIOL 1406 Exam 1 Review Not completely comprehensive but does hit the most important points Concept 1.1 Living Organisms Share Similarities All life forms share common features: 1. Made of a common set of chemical compounds 2. Made up of cells 3. Use molecules from the environment to synthesize new molecules. 4. Extract energy from the environment and use it to do work 5. Regulate their internal environments 6. Contain genetic information that enables them to develop, function, and reproduce 7. Use a universal genetic code to build proteins 8. Exist in populations that evolve (change) over time © Macmillan Learning Concept 1.1 Living Organisms Share Similarities In some eukaryotes, cells are specialized for different functions. Cell specialization allows multicellular organisms to get larger and become more efficient at gathering resources and adapting to specific environments. Similar cell types can develop together into tissues. Different tissue types develop together into organs for specific functions, and organs can be grouped into organ systems. There is a hierarchy of biological organization from atoms to organisms. © Macmillan Learning Concept 1.1 Living Organisms Share Similarities Organisms must regulate their internal environment. Maintenance of the narrow range of conditions in the internal environment is known as homeostasis. Self-regulation to maintain a constant internal environment is a general attribute of all life. © Macmillan Learning Concept 1.2 Genetics and Evolution Are Major Themes of Biology Charles Darwin proposed that all organisms are descended from a common ancestor. He argued that differential survival and reproduction in a population (natural selection) could account for much of the evolution of life. © Macmillan Learning Concept 1.2 Genetics and Evolution Are Major Themes of Biology If populations are isolated and evolve differences, they are eventually considered different species. Each species has a distinct scientific name, a binomial (genus and species). Example: Homo sapiens Genus: Group of species that share a recent common ancestor. Scaptia beyonceae Neopalpa donaldtrumpi Spongiforma squarepantsii © Macmillan Learning Concept 1.2 Genetics and Evolution Are Major Themes of Biology A phylogenetic tree illustrates the evolutionary histories of different groups. Trees are built by analyzing and quantifying similarities and differences among species, including genome sequences. © Macmillan Learning Figure 1.11 Phylogenetic Trees Depict Evolutionary Relationships © Macmillan Learning Concept 1.3 Biologists Investigate Life through Experiments That Test Hypotheses To answer questions, the scientific approach traditionally has 5 steps: 1. Make observations 2. Ask questions 3. Form hypotheses 4. Make predictions 5. Test the predictions © Macmillan Learning Concept 2.1 An Element’s Atomic Structure Determines Its Properties Element: fundamental substance containing only one kind of atom. The number of protons (atomic number) identifies an element. Number of protons and electrons determines how an element behaves in chemical reactions. © Macmillan Learning  Essential Elements of Life About 25 of the 92 naturally occurring elements are essential to life Carbon, hydrogen, oxygen, and nitrogen make up 96% of living matter (Also know Sulfur & Phosphorus) Most of the remaining 4% consists of calcium, phosphorus, potassium, and sulfur Trace elements are those required by an organism in minute quantities © Macmillan Learning Concept 2.1 An Element’s Atomic Structure Determines Its Properties Mass number = protons + neutrons Isotopes: Forms of an element with different numbers of neutrons, and thus different mass numbers. Example: carbon isotopes 12C has 6 neutrons 13C has 7 neutrons 14C has 8 neutrons © Macmillan Learning Concept 2.2 Atoms Bond to Form Molecules Chemical bond: Attractive force that links atoms together to form molecules. Covalent bonds: Atoms share one or more pairs of electrons so that the outer shells are filled. Each atom contributes one member of each electron pair. © Macmillan Learning Concept 2.2 Atoms Bond to Form Molecules Nonpolar covalent bond: Electrons are shared equally (atoms have similar electronegativity). Polar covalent bond: One atom has greater electronegativity, so electrons are drawn more to that nucleus. A molecule with a polar bond has a slightly negative charge on one end and a slightly positive charge on the other. © Macmillan Learning Concept 2.3 Chemical Reactions Transform Substances For all chemical reactions, matter and energy are neither created nor destroyed. The total number of carbon atoms on the left side of the equation (3) equals the total number of carbon atoms on the right (3); the equation is balanced. © Macmillan Learning Concept 2.4 The Properties of Water Are Critical to the Chemistry of Life Water has high specific heat (amount of energy needed to raise temperature of 1 gram of a substance by 1 degree C), because of hydrogen bonding. Ice requires a lot of energy to melt, to break the hydrogen bonds; when water freezes, a lot of energy is released to the environment. © Macmillan Learning Concept 2.4 The Properties of Water Are Critical to the Chemistry of Life Water has a high heat of vaporization: A lot of heat energy is required to change water from the liquid to gaseous state (evaporation). The heat energy must be absorbed from the environment in contact with the water, and results in cooling (e.g., when humans sweat). © Macmillan Learning Concept 2.4 The Properties of Water Are Critical to the Chemistry of Life Cohesion: Hydrogen bonds between water molecules cause them to stick together: ▪ Helps water move through plants ▪ Results in surface tension Adhesion: Attraction of water molecules to other molecules of a different type. © Macmillan Learning Figure 2.16 Water in Biology © Macmillan Learning Concept 2.4 The Properties of Water Are Critical to the Chemistry of Life Acids release hydrogen ions (H+) in water: HCl → H+ + Cl− H+ concentration is increased; the solution is acidic. H+ ions can attach to other molecules and change their properties. © Macmillan Learning Concept 2.4 The Properties of Water Are Critical to the Chemistry of Life Bases accept H+ ions. NaOH is a strong base. + − NaOH → Na + OH OH− + H+ → H2O Weak bases include bicarbonate ion (HCO3–), ammonia (NH3), and compounds with amino groups (NH2). © Macmillan Learning Concept 2.4 The Properties of Water Are Critical to the Chemistry of Life Living organisms maintain constant internal conditions (homeostasis). Buffers help maintain constant pH. Buffer: a weak acid and its corresponding base, e.g., carbonic acid (H2CO3), and bicarbonate ion (HCO3–) HCO3 − + H+ → H2CO3 © Macmillan Learning Figure 3.1 Some Functional Groups Important to Living Systems © Macmillan Learning Figure 3.4 Condensation and Hydrolysis of Polymers (Part 2) © Macmillan Learning Figure 3.5 An Amino Acid Memorize This © Macmillan Learning Concept 3.2 Proteins Are Polymers with Highly Variable Structures Oligopeptides, or peptides: short polymers of 20 or fewer amino acids. Polypeptides: longer polymers. Amino acids bond together covalently in a condensation reaction by peptide linkages (peptide bonds). © Macmillan Learning Figure 3.8 The Four Levels of Protein Structure (Part 1) © Macmillan Learning Concept 3.3 Carbohydrates Are Made from Simple Sugars Carbohydrates: (C1H2O1)n. Sources of stored energy Used to transport stored energy Carbon skeletons for many other molecules Form extracellular structures such as cell walls © Macmillan Learning Concept 3.3 Carbohydrates Are Made from Simple Sugars Monosaccharides bind together in condensation reactions to form glycosidic bonds to form disaccharides. Oligosaccharides: several monosaccharides linked by glycosidic bonds; often covalently bonded to proteins and lipids on cell surfaces, where they serve as recognition signals. © Macmillan Learning Concept 3.3 Carbohydrates Are Made from Simple Sugars Polysaccharides are large polymers of monosaccharides connected by glycosidic bonds; some are branched. Starch: storage of glucose in plants Glycogen: storage of glucose in animals Cellulose: very stable, good for structural components © Macmillan Learning Concept 3.4 Lipids Are Defined by Their Insolubility in Water Lipids are nonpolar hydrocarbons; insoluble in water. If close together, weak but additive van der Waals forces hold them together in aggregates. © Macmillan Learning Concept 3.4 Lipids Are Defined by Their Insolubility in Water Types of lipids: Fats and oils store energy. Phospholipids—structural role in cell membranes. Carotenoids and chlorophylls—capture light energy in plants. Steroids and modified fatty acids—hormones and vitamins. Animal fat—thermal insulation. Lipid coating around nerves provides electrical insulation. Oil and wax on skin, fur, and feathers repel water and slows evaporation. © Macmillan Learning Concept 3.4 Lipids Are Defined by Their Insolubility in Water Fats and oils are triglycerides: three fatty acids plus glycerol. Fatty acid: Nonpolar hydrocarbon chain with a polar carboxyl group. Carboxyls bond with hydroxyls of glycerol in ester linkages (condensation reactions). © Macmillan Learning Concept 3.4 Lipids Are Defined by Their Insolubility in Water Saturated fatty acid: No double bonds between carbons—it is saturated with H atoms (animal fats; solid at room temperature). Unsaturated fatty acid: One or more double bonds in the carbon chain result in kinks that prevent packing (plant oils; liquid at room temperature). © Macmillan Learning Concept 4.1 Nucleic Acids Are Informational Macromolecules Nucleic acids: polymers specialized for storage, transmission, and use of genetic information. DNA = deoxyribonucleic acid RNA = ribonucleic acid Monomers are nucleotides: pentose sugar + nitrogenous base + phosphate group. © Macmillan Learning Figure 4.1 Nucleotide Chemistry DNA vs. RNA “AGs” are Pure Concept 4.1 Nucleic Acids Are Informational Macromolecules Nucleotides are linked by phosphodiester bonds. Phosphate groups link the 3′ carbon in one sugar to the 5′ carbon in another sugar. Nucleic acids grow in the 5′-to-3′ direction. Concept 4.1 Nucleic Acids Are Informational Macromolecules DNA bases: – Purines: Adenine (A) & Guanine (G) – Pyrimidines: Cytosine (C) & Thymine (T) Complementary base pairing: Purines pair with pyrimidines by hydrogen bonds. DNA bases: Purines: Adenine (A) & Guanine (G) Pyrimidines: Cytosine (C) & Thymine (T) Complementary base pairing: Adenine Thymine Purines pair with pyrimidines (A) (T) by hydrogen bonds. Hydrogen Bonding between nitrogenous bases explains Chargaff’s Rule (A = T and G=C) Suppose an organism had 15% Adenine in its DNA. Calculate the percentages for Guanine Cytosine the remaining 3 bases. (G) (C) Figure 4.5 DNA Figure 4.6 DNA, RNA, and Protein The “central dogma” of molecular biology