Biology Final Study Guide PDF

Chapter 1 1.1 Biology is the scientific study of life. Biology is the scientific study of life. Properties of life include order, reproduction, growth and development, energy processing, regulation, response to the environment, and evolutionary adaptation. The cell is the structural and functional...

Chapter 1 1.1 Biology is the scientific study of life. Biology is the scientific study of life. Properties of life include order, reproduction, growth and development, energy processing, regulation, response to the environment, and evolutionary adaptation. The cell is the structural and functional unit of life. 1.2 Biologists arrange the diversity of life into three domains. Taxonomists name species and classify them into broader groups. Domains Bacteria and Archaea contain organisms with simple cells. Domain Eukarya includes various protists and the kingdoms Fungi, Plantae, and Animalia. 1.3 In life’s hierarchy of organization, new properties emerge at each level. Biological organization unfolds as follows: biosphere > ecosystem > community > population > organism > organ system > organ > tissue > cell > organelle > molecule. Emergent properties result from the interactions among component parts. 1.4 What is science? Science uses an evidence-based process of inquiry to investigate the natural world. The scientific approach involves observations, hypotheses, predictions, tests of hypotheses via experiments or additional observations, and analysis of data. A scientific theory is broad in scope and supported by a large body of evidence. 1.5 Hypotheses can be tested using controlled experiments. The use of control and experimental groups can demonstrate the effect of a single variable. Hypotheses can be tested in humans with clinical trials, as well as 1.6 Hypotheses can be tested using observational data. Scientists tested hypotheses about the evolutionary relationships of red pandas. Recent studies comparing DNA sequences classify the red panda as the only living species in its family. Definitions: Natural selection: process that results in the adaptation of an organism to its environment by means of selectively reproducing changes in its genotype, or genetic constitution. - bratanica Natural experiment – an experiment where the researcher compares variables under different natural conditions A Theory – is a well-tested and widely accepted explanation, validated by previous research Manipulative experiment – an experiment where the researcher actively manipulates a variable under controlled conditions Models–a physical, conceptual, or mathematical representation of a real phenomenon that is difficult to observe directly. Chapter 2 2.1 Organisms are composed of elements, usually combined into compounds. Oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus make up about 99% of living matter 1. 2.3 Atoms consist of protons, neutrons, and electrons. Full Alternative Text 2. 2.4 Radioactive isotopes can help or harm us. Radioactive isotopes are valuable in basic research and medicine. Chemical Bonds (2.5–2.9) 1. 2.5 The distribution of electrons determines an atom’s chemical properties. An atom whose outer electron shell is not full tends to interact with other atoms and share, gain, or lose electrons, resulting in attractions called chemical bonds. 2. 2.6 Covalent bonds join atoms into molecules through electron sharing. In a nonpolar covalent bond, electrons are shared equally. In polar covalent bonds, such as those found in water, electrons are pulled closer to the more electronegative atom. 3. 2.7 Ionic bonds are attractions between ions of opposite charge. Electron gain and loss create charged atoms, called ions. 4. 2.8 Hydrogen bonds are weak bonds important in the chemistry of life. The slightly positively charged H atoms in one polar molecule may be attracted to the partial negative charge of an oxygen or nitrogen atom in a neighboring molecule. 5. 2.9 Chemical reactions make and break chemical bonds. The composition of matter is changed as bonds are broken and formed to convert reactants to products. Water’s Life-Supporting Properties (2.10–2.16) 1. 2.10 Hydrogen bonds make liquid water cohesive. Cohesion creates surface tension and helps water to move from plant roots to leaves.  2. 2.11 Water’s hydrogen bonds moderate temperature. Heat is absorbed when hydrogen bond 3. 2.12 Ice floats because it is less dense than liquid water. Floating ice protects lakes and oceans from freezing solid, which in turn protects aquatic life. 4. 2.13 Water is the solvent of life. Polar or charged solutes dissolve when water molecules surround them, forming aqueous solutions. 5. 2.14 The chemistry of life is sensitive to acidic and basic conditions. A compound that releases H+ in solution is an acid, and one that accepts H+ is a base. The pH scale ranges from 0 (most acidic) to 14 (most basic). The pH of most cells is close to 7 (neutral) and is kept that way by buffers. 6. 2.15 Scientists study the effects of rising atmospheric CO2 on coral reef ecosystems. The acidification of the ocean threatens coral reefs and other marine organisms. Vocabulary: compound is a substance consisting of two or more different elements in a fixed ratio. atom is the smallest unit of matter that still retains the properties of an element. Chemical bond an atom whose outer electron shell is not full tends to interact with other atoms and share, gain, or lose electrons, resulting in attractions ion is an atom or molecule with an electrical charge resulting from gain or loss of one or more electrons. Polar non balenced non-polar balenced Cohesion- The tendency of molecules of the same kind to stick together is adhesion The clinging of one substance to another surface tension—a measure of how difficult it is to break the surface of a liquid. solution is a liquid consisting of a uniform mixture of two or more substances. solvent water’s versatility as a a dissolving agent, results from the polarity of its molecules. solutes dissolve when water molecules surround them. atomic number is the number of protons found in the nucleus of an atom atomic mass combined mass of the protons and neutrons in the nucleus Chapter 3 3.1 Life’s molecular diversity is based on the properties of carbon. Carbon’s ability to bond with four other atoms is the basis for building large and diverse organic compounds. Hydrocarbons are composed of only carbon and hydrogen. Isomers have the same molecular formula but different structures. 3.2 A few chemical groups are key to the functioning of biological molecules. Hydrophilic functional groups give organic molecules specific chemical properties. 3.3 Cells make large molecules from a limited set of small molecules. Full Alternative Text Carbohydrates (3.4–3.7) 3.4 Monosaccharides are the simplest carbohydrates. A monosaccharide has a formula that is a multiple of CH2O and contains hydroxyl groups and a carbonyl group. 3.5 Two monosaccharides are linked to form a disaccharide. 3.6 Are we eating too much sugar? The FDA recommends that only 10% of daily calories come from added sugar. Research supports the correlation between high sugar intake and adverse health effects. 3.7 Polysaccharides are long chains of sugar units. Starch and glycogen are storage polysaccharides; cellulose is structural, found in plant cell walls. Chitin is a component of insect exoskeletons and fungal cell walls. Lipids (3.8–3.11) 3.8 Fats are lipids that are mostly energy-storage molecules. Lipids are diverse, hydrophobic compounds composed largely of carbon and hydrogen. Fats (triglycerides) consist of glycerol linked to three fatty acids. Saturated fatty acids are found in animal 3.10 Phospholipids and steroids are important lipids with a variety of functions. Phospholipids are components of cell membranes. Steroids include cholesterol and some hormones. 3.12 Proteins have a wide range of functions and structures. Proteins are involved in almost all of a cell’s activities; as enzymes, they regulate chemical reactions. 3.13 Proteins are made from amino acids linked by peptide bonds. Protein diversity is based on different sequences of amino acids, monomers that contain an amino group, a carboxyl group, an H atom, and an R group, all attached to a central carbon. The R groups distinguish 20 amino acids, each with specific properties. 3.15 Nucleic acids DNA and RNA are information-rich polymers of nucleotides. Nucleotides are composed of a sugar, a phosphate group, and a nitrogenous base. DNA is a double helix; RNA is a single polynucleotide chain. DNA and RNA serve as the blueprints for proteins and thus control the life of a cell. DNA is the molecule of inheritance Chapter 4 4.1 Microscopes reveal the world of the cell. The light microscope can display living cells. The greater magnification and resolution of the scanning and transmission electron microscopes reveal the ultrastructure of cells. 4.2 The small size of cells relates to the need to exchange materials across the plasma membrane. The microscopic size of most cells provides a large surface- to-volume ratio. The plasma membrane is a phospholipid bilayer with embedded proteins. 4.3 Prokaryotic cells are structurally simpler than eukaryotic cells. All cells have a plasma membrane, DNA, ribosomes, and cytosol. Prokaryotic cells lack organelles. 4.4 Eukaryotic cells are partitioned into functional compartments. Membrane- enclosed organelles compartmentalize a cell’s activities. The Nucleus and Ribosomes (4.5–4.6) 4.5 The nucleus contains the cell’s genetic instructions. The nucleus houses the cell’s DNA, which directs protein synthesis via messenger RNA. Subunits of ribosomes are assembled in the nucleolus. 4.6 Ribosomes make proteins for use in the cell and for export. Composed of ribosomal RNA and proteins, ribosomes synthesize proteins according to directions from DNA. The Endomembrane System (4.7–4.12) 4.7 Many organelles are connected in the endomembrane system. 4.8 The endoplasmic reticulum is a biosynthetic workshop. The ER is a membranous network of tubes and sacs. Smooth ER synthesizes lipids and processes toxins. Rough ER produces membranes, and ribosomes on its surface 4.9 The Golgi apparatus modifies, sorts, and ships cell products. The Golgi apparatus consists of stacks of sacs in which products of the ER are processed and then sent to other organelles or to the cell surface. 4.10 Lysosomes are digestive compartments within a cell. Lysosomes house enzymes that break down ingested substances and damaged organelles. 4.11 Vacuoles function in the general maintenance of the cell. Some protists have contractile vacuoles. Plant cells contain a large central vacuole that stores molecules and wastes and facilitates growth. 4.12 A review of the structures involved in manufacturing and breakdown. The organelles of the endomembrane system are interconnected structurally and functionally. Energy-Converting Organelles (4.13–4.15) 4.13 Mitochondria harvest chemical energy from food. 4.14 Chloroplasts convert solar energy to chemical energy. 4.15 Mitochondria and chloroplasts evolved by endosymbiosis. These organelles originated from prokaryotic cells that became residents in a host cell. 4.21 Cell walls enclose and support plant cells. Plant cell walls are made largely of cellulose. Plasmodesmata are connecting channels between cells. 4.22 Review: Eukaryotic cell structures can be grouped on the basis of four main functions. These functions are (1) genetic control; (2) manufacturing, distribution, and breakdown; (3) energy processing; and (4) structural support, movement, and communication between cells. Chapter 5 5.1 Membranes are fluid mosaics of lipids and proteins with many functions. The proteins embedded in a membrane’s phospholipid bilayer perform various functions. 5.2 The spontaneous formation of membranes was a critical step in the origin of life. 5.3 Passive transport is diffusion across a membrane with no energy investment. Solutes diffuse across membranes down their concentration gradients. 5.4 Osmosis is the diffusion of water across a membrane. 5.5 Water balance between cells and their surroundings is crucial to organisms. Cells shrink in a hypertonic solution and swell in a hypotonic solution. In isotonic solutions, animal cells are normal, but plant cells are flaccid. 5.6 Transport proteins can facilitate diffusion across membranes. 5.8 Cells expend energy in the active transport of a solute. 5.9 Exocytosis and endocytosis transport large molecules across membranes. A vesicle may fuse with the membrane and expel its contents (exocytosis), or the membrane may fold inward, enclosing material from outside the cell (endocytosis). Energy and the Cell (5.10–5.12) 5.10 Cells transform energy and matter as they perform work. Kinetic energy is the energy of motion. Potential energy is energy stored in the location or structure of matter and includes chemical energy. According to the laws of thermodynamics, energy can change form but cannot be created or destroyed, and energy transfers or transformations increase disorder, or entropy, with some energy being lost as heat. 5.11 Chemical reactions either release or store energy. Exergonic reactions release energy. Endergonic reactions require energy and yield products rich in potential energy. Metabolism encompasses all of a cell’s chemical reactions. 5.12 ATP drives cellular work by coupling exergonic and endergonic reactions. The hydrolysis of ATP and, often, the transfer of a phosphate group is involved in chemical, transport, and mechanical work. How Enzymes Function (5.13–5.16) 5.13 Enzymes speed up the cell’s chemical reactions by lowering energy barriers. Enzymes are catalysts (usually proteins) that decrease the activation energy needed to begin a reaction. 5.14 A specific enzyme catalyzes each cellular reaction. An enzyme’s s 5.15 Enzyme inhibition can regulate enzyme activity in a cell. Inhibitors can be either competitive or noncompetitive. Feedback inhibition helps regulate metabolism. 5.16 Many drugs, pesticides, and poisons are enzyme inhibitors. Chapter 6 6.1 Photosynthesis and cellular respiration provide energy for life. Photosynthesis uses solar energy to produce organic molecules and O2 from CO2 and H2O. In cellular respiration, O2 is consumed during the breakdown of organic molecules to CO2 and H2O, and energy is released. 6.2 Breathing supplies O2 for use in cellular respiration and removes CO2. 6.3 Cellular respiration banks energy in ATP molecules. 6.4 The human body uses energy from ATP for all its activities. 6.5 Cells capture energy from electrons “falling” from organic fuels to oxygen. Electrons removed from fuel molecules (oxidation) are transferred to NAD+ (reduction). NADH passes electrons to an electron transport chain. As electrons “fall” from carrier to carrier and finally to O2, energy is released. Stages of Cellular Respiration (6.6–6.13) 6.6 Overview: Cellular respiration occurs in three main stages. Gylocosis, citric acid cycle and oxidative phosphorylation. 6.7 Stage 1: Glycolysis harvests chemical energy by oxidizing glucose to pyruvate. ATP is used to prime a glucose molecule, which is split in two. These three-carbon intermediates are oxidized to two molecules of pyruvate, yielding a net of 2 ATP and 2 NADH. ATP is formed by substrate-level phosphorylation, in which a phosphate group is transferred from an organic molecule to ADP. 6.8 Multiple reactions in glycolysis split glucose into two molecules. Steps 1–4 consume energy, while steps 5–9 yield energy. 6.9 Stage 2: The citric acid cycle completes the energy-yielding oxidation 6.10 The multiple reactions of the citric acid cycle finish off the dismantling of glucose. 6.11 Stage 3: Most ATP production occurs by oxidative phosphorylation. In mitochondria, electrons from NADH and FADH2 are passed down the electron transport chain to O2, which picks up H+ to form water. Energy released by these redox reactions is used to pump H+ into the intermembrane space. In chemiosmosis, the H+ gradient drives H+ back through ATP synthase complexes in the inner membrane, synthesizing ATP.