Biology Lecture Exam 1 Study Guide PDF

**Scientific Thinking Study Guide** **1. Introduction to Science and Biology** - **What is science?**\ Science is not just a body of knowledge or a list of facts to memorize, but an intellectual activity that involves observation, description, experimentation, and explanation of natu...

**Scientific Thinking Study Guide** **1. Introduction to Science and Biology** - **What is science?**\ Science is not just a body of knowledge or a list of facts to memorize, but an intellectual activity that involves observation, description, experimentation, and explanation of natural phenomena. - **How does science help us understand the world?**\ Science is a pathway by which we can come to discover and better understand our world. - **What is biology?**\ Biology is the study of living things. **2. The Nature of Scientific Thinking** - **Key Elements of Scientific Thinking**\ Scientific thinking is empirical, meaning it is based on experience and observations that are rational, testable, and repeatable. It is also self-correcting, meaning it can be adjusted as new evidence is found. - **What question underlies scientific thinking?**\ The fundamental question of scientific thinking is: \"How do you know that is true?\" **3. Scientific Literacy** - **What is scientific literacy?**\ Scientific literacy is the ability to think scientifically, use knowledge to make wise decisions, and integrate scientific knowledge into decision-making. - **Why is scientific literacy important?**\ It is increasingly important in our lives, especially in matters of biology. **4. The Scientific Method** - **Step 1: Make Observations**\ Scientific thinking begins by making observations about the world. For example, people observed that consuming echinacea extract seems to reduce the likelihood of catching the common cold. - **Step 2: Formulate a Hypothesis**\ A hypothesis must establish an alternative explanation for a phenomenon and generate testable predictions. - **Step 3: Devise a Testable Prediction**\ The goal is to propose a situation that will give a particular outcome if your hypothesis is true but a different outcome if your hypothesis is not true. This often involves making \"If\... then\...\" predictions. - **Step 4: Conduct a Critical Experiment**\ A critical experiment makes it possible to decisively determine whether a particular hypothesis is better than an alternative hypothesis. A well-known example involves the reliability of eye-witness testimony. - **Step 5: Draw Conclusions and Make Revisions**\ After conducting an experiment, conclusions are drawn, and hypotheses may be revised based on the evidence. **5. Hypotheses and Theories** - **What is a hypothesis?**\ A hypothesis is a proposed explanation for a phenomenon that leads to testable predictions. - **What is a theory?**\ A theory is not just a guess but a hypothesis that has been repeatedly tested and supported by empirical data. **6. Elements of a Well-Designed Experiment** - **What are the key components of an experiment?** - **Treatment:** Any experimental condition applied to individuals. - **Experimental Group:** The group exposed to a particular treatment. - **Control Group:** The group that is treated identically to the experimental group, except they are not exposed to the treatment. - **Variables:** Characteristics of the experiment that can change; they are described as independent or dependent. - **Why is controlling variables important?**\ Controlling variables helps ensure that differences in outcomes between groups are due to the treatment itself. **7. The Placebo Effect and Experiment Design** - **What is the placebo effect?**\ The placebo effect is the phenomenon in which people respond favourably to any treatment, highlighting the need for a proper control group. - **What is the Clever Hans effect?**\ The Clever Hans effect illustrates how the outcome of an experiment can be influenced by subtle body cues, stressing the importance of blind or double-blind experimental designs. **8. Avoiding Pseudoscience** - **What is pseudoscience?**\ Pseudoscience involves making scientific-sounding claims that are not supported by trustworthy, methodical scientific studies. - **What are anecdotal observations?**\ Anecdotal observations are based on only one or a few observations, leading to erroneous conclusions about links between two things. **Atoms Form Molecules Study Guide** **1. Basics of Atoms and Elements** - **What is an element?**\ An element is a substance that cannot be broken down chemically into any other substances. It consists of atoms, which are the smallest units that retain the element\'s properties. - **What is an atom?**\ An atom is a bit of matter that cannot be subdivided any further without losing its essential properties **2. Atomic Structure** - **What is the nucleus of an atom composed of?**\ The nucleus is made up of protons, which have a positive charge, and neutrons, which have no charge. - **What surrounds the nucleus?**\ The nucleus is surrounded by electrons, which have a negative charge and move quickly around the nucleus. **3. Atomic Numbers and Isotopes** - **What determines the identity of an element?**\ The number of protons in the nucleus of an atom determines what element it is. This number is called the atomic number. - **What are isotopes?**\ Isotopes are atoms of the same element that have the same number of protons but a different number of atomic mass. **4. Radioactive Atoms** - **What are radioactive atoms?**\ Radioactive atoms have unstable nuclei that break down spontaneously, releasing energy and sometimes particles. This process is useful in determining the age of fossils and in medical treatments. **5. Elements in the Human Body** - **What are the \"Big Four\" elements in the human body?**\ The \"Big Four\" elements---oxygen, carbon, hydrogen, and nitrogen---make up about 96% of your body mass. **6. Electron Shells and Bonding** - **What determines an atom\'s bonding behavior?**\ Electrons move around the nucleus in designated areas called electron shells. Atoms become stable when their outermost shell is filled to capacity. - **What is a covalent bond?**\ A covalent bond is formed when two atoms share electrons. **7. Types of Chemical Bonds** - **What are the three principal types of bonds?** 1. **Covalent Bonds:** Involves the sharing of electrons between atoms. 2. **Ionic Bonds:** Formed when one atom transfers electrons to another, resulting in oppositely charged ions attracting each other. 3. **Hydrogen Bonds:** A weak bond between a slightly positive hydrogen atom and a slightly negative atom in another molecule. **8. Properties of Water** - **Why is water important to life?**\ Water\'s properties such as cohesion, high heat capacity, low density as a solid, and being a good solvent are critical to life. These properties are primarily due to cohesive bonds between water molecules. - **What happens to water when it freezes?**\ When water freezes, it becomes less dense because the hydrogen bonds form a crystaline lattice that keeps the molecules slightly farther apart. **9. pH and Acidity** - **What does the pH of a solution indicate?**\ The pH of a solution measures its acidity, which is determined by the concentration of H+ ions. Solutions with a pH less than 7 are acidic, while those with a pH greater than 7 are basic. - **Why is the pH scale logarithmic?**\ The pH scale is logarithmic, meaning a change of 1 unit on the scale represents a 10-fold change in the concentration of H+ ions. **Carbohydrates and Lipids Study Guide** **1. Introduction to Macromolecules** - **What are the four types of macromolecules essential to life?**\ The four types of macromolecules are carbohydrates, lipids, proteins, and nucleic acids. - **What role do these macromolecules play in organisms?**\ These macromolecules are essential for building and fueling the functions of living organisms. **2. Carbohydrates** - **What are carbohydrates?**\ Carbohydrates are macromolecules composed of carbon, hydrogen, and oxygen that serve as the primary energy source for cellular activities and as structural components in cells. - **What is the basic structure of glucose?**\ Glucose, a simple sugar, has the chemical formula CH1206, and is an important energy source for cells. **3. Monosaccharides, Disaccharides, and Polysaccharides** - **What are monosaccharides?**\ Monosaccharides are the simplest form of carbohydrates, consisting of single sugar units such as glucose, fructose, and Galactose. - **What happens to glucose in the body?**\ Glucose in the blood has three potential fates: it can be used as fuel for cellular activity, stored temporarily as glycogen, or converted to fat for long-term energy storage. - **What are disaccharides and polysaccharides?**\ Disaccharides are formed by the union of two monosaccharides, while polysaccharides are complex carbohydrates formed by the union of many simple sugars. **4. The Role of Glycogen in Energy Storage** - **How does glycogen contribute to weight loss during dieting?**\ When glycogen is broken down for energy, the water molecules bound to it are also lost, leading to a significant loss of water weight during the initial phase of dieting. **5. The Indigestibility of Certain Carbohydrates** - **What are chitin and cellulose?**\ Chitin and cellulose are complex carbohydrates that serve as structural materials in invertebrates and plants, respectively. They are indigestible by humans. - **Why is cellulose important in our diet?**\ Although indigestible, cellulose, known as fiber in our diet, helps clear the digestive tract and reduces the risk of colon cancer. **6. Lipids** - **What are lipids?**\ Lipids are a diverse group of macromolecules that are insoluble in water and serve various functions, including energy storage, insulation, and forming cell membranes. - **What are the three types of lipids?**\ The three types of lipids are fats, sterols, and phospholipids. - **How do fats differ in structure from carbohydrates?**\ Fats contain significantly more C-H bonds than carbohydrates, resulting in more stored energy. **7. Saturated and Unsaturated Fats** - **What is the difference between saturated and unsaturated fats?**\ Saturated fats have no double bonds in their fatty acid chains, making them solid at room temperature, while unsaturated fats have one or more double bonds, making them liquid at room temperature. - **What are trans fats?**\ Trans fats are a type of unsaturated fat that has been artificially hydrogenated, leading to a less healthful "trans" orientation of the double bonds. **8. Sterols and Phospholipids** - **What role does cholesterol play in the body?**\ Cholesterol is an important component of cell membranes and is used to build steroid hormones like estrogen and testosterone. - **What are phospholipids and their function?**\ Phospholipids are the major component of cell membranes, with a hydrophilic "head" and hydrophobic "tails" that align to form a bilayer, controlling the flow of chemicals into and out of the cell. **9. Waxes** - **What is the role of waxes in nature?**\ Waxes, being strongly hydrophobic, repel water and serve as a protective coating on the surface of many plants and animals, preventing water loss **Proteins and Nucleic Acids Study Guide** 1. **Proteins: The Bodybuilding Macromolecules**\ **What are proteins and what functions do they serve?**\ Proteins are the chief building blocks of all life, performing a variety of functions including structure, protection, regulation, contraction, and **transportation**.\ **What are proteins made of?**\ Proteins are made of amino acids, which are composed of carbon, hydrogen, oxygen, and **nitrogen**. 2. **Amino Acids: The Building Blocks of Proteins**\ **What are amino acids?**\ Amino acids are the building blocks of proteins. There are **20** different amino acids, each with a unique side chain that determines its properties.\ **What is the significance of the side chain in amino acids?**\ The side chain is the unique part of each amino acid and determines the amino acid's **chemical** properties, such as whether it is polar or nonpolar. 3. **Protein Structure and Function**\ **What is the primary structure of a protein?**\ The primary structure of a protein is the **sequence** of amino acids in a polypeptide chain.\ **How does a protein\'s three-dimensional shape affect its function?**\ A protein's function is influenced by its **three-dimensional** shape. Changes in this shape can lead to denaturation and loss of function. 4. **Dietary Proteins and Essential Amino Acids**\ **What are essential amino acids?**\ Essential amino acids are those that must be obtained from our **diet** because the body cannot synthesize them.\ **What is the difference between complete and incomplete proteins?**\ Complete proteins contain all essential amino acids and are typically found in animal products, while incomplete proteins lack one or more essential amino acids and are often found in **plant** sources. 5. **Enzymes: Catalysts of Life**\ **What are enzymes and what role do they play in the body?**\ Enzymes are proteins that initiate and speed up chemical **reactions**. They lower the activation energy required for reactions to occur.\ **What factors can affect enzyme activity?**\ Factors such as enzyme and substrate concentration, **temperature**, pH, and the presence of inhibitors or activators can influence enzyme activity. 6. **Nucleic Acids: Information Storage and Transfer**\ **What are nucleic acids and what are they composed of?**\ Nucleic acids are macromolecules that store information. They are composed of nucleotides, which consist of a sugar molecule, a phosphate group, and a **nitrogenous** base.\ **What are the two types of nucleic acids?**\ The two types of nucleic acids are DNA (deoxyribonucleic acid) and **RNA** (ribonucleic acid). 7. **DNA: The Blueprint of Life**\ **What is the structure of DNA?**\ DNA is composed of two sugar-phosphate backbones that spiral around each other to form a **double** helix. The bases adenine (A), thymine (T), guanine (G), and cytosine (C) pair together in specific ways.\ **How is information stored in DNA?**\ The information in DNA is stored in the sequence of **bases** along the sugar-phosphate backbone. 8. **RNA: The Messenger of DNA**\ **What are the key differences between RNA and DNA?**\ RNA differs from DNA in three main ways: RNA contains the sugar ribose instead of deoxyribose, has the base **uracil** (U) instead of thymine, and is single-stranded rather than double-stranded.\ **What role does RNA play in protein synthesis?**\ RNA acts as a middleman, taking instructions from DNA and directing the **synthesis** of proteins in the cell.