Biology Chapter Summaries PDF

### **hapter 1: What is Life?** **Describe the common characteristics of living things:** 1. **Organization:** Living things have a complex and organized structure, starting from cells, the basic unit of life. 2. **Metabolism:** They acquire and use energy to carry out life processes....

### **hapter 1: What is Life?** **Describe the common characteristics of living things:** 1. **Organization:** Living things have a complex and organized structure, starting from cells, the basic unit of life. 2. **Metabolism:** They acquire and use energy to carry out life processes. 3. **Homeostasis:** Living organisms maintain stable internal conditions. 4. **Growth and Development:** They grow by increasing cell size or number and develop according to specific instructions in their DNA. 5. **Reproduction:** Living things can produce new organisms, passing on their genetic material. 6. **Response to Stimuli:** Organisms react to environmental changes. 7. **Evolution:** Populations of living organisms adapt and evolve over time. ### **Chapter 2: Atomic Structure and Bonding** **Compare and contrast polar covalent bonds and non-polar covalent bonds:** - **Polar Covalent Bonds:** Electrons are shared unequally due to differences in electronegativity between the atoms, creating partial charges (e.g., H2O). - **Non-Polar Covalent Bonds:** Electrons are shared equally because the atoms have similar electronegativities (e.g., O2). **Describe how ionic bonds are formed:\ **Ionic bonds form when one atom donates an electron to another, creating oppositely charged ions that attract each other (e.g., NaCl). **Describe how hydrogen bonds are formed:\ **Hydrogen bonds form when a hydrogen atom covalently bonded to an electronegative atom (e.g., O or N) is attracted to another electronegative atom nearby. **Compare the relative strengths of covalent, ionic, hydrogen bonds, and van der Waals forces:** - **Covalent Bonds:** Strongest; electrons are shared between atoms. - **Ionic Bonds:** Strong in dry conditions but weaker in water. - **Hydrogen Bonds:** Weaker than ionic and covalent bonds but critical in biological molecules. - **Van der Waals Forces:** Weakest; temporary attractions between electron clouds. **Define hydrophilic and hydrophobic:** - **Hydrophilic:** Substances that interact well with water (e.g., polar molecules, ions). - **Hydrophobic:** Substances that do not interact well with water (e.g., non-polar molecules like oils). **Describe hydrophobic interactions:\ **Hydrophobic interactions occur when non-polar molecules cluster together in an aqueous environment to minimize contact with water. ### **Chapter 2: The Chemistry of Water** **List some of the properties that water has due to its hydrogen bonds:** 1. High specific heat. 2. High heat of vaporization. 3. Cohesion (water molecules stick together). 4. Adhesion (water sticks to other surfaces). 5. Excellent solvent for polar and ionic substances. 6. Solid water (ice) is less dense than liquid water. **Describe what the pH scale measures:\ **The pH scale measures the concentration of hydrogen ions (H⁺) in a solution, ranging from 0 (acidic) to 14 (basic), with 7 being neutral. ### **Chapter 3: Proteins, Carbohydrates, and Lipids** **List the four types of macromolecules found in cells and the monomers or building blocks from which they are constructed:** 1. **Proteins:** Built from amino acids. 2. **Carbohydrates:** Built from monosaccharides. 3. **Lipids:** Built from glycerol and fatty acids (not true polymers). 4. **Nucleic Acids:** Built from nucleotides. **Describe condensation/dehydration reactions:\ **Condensation reactions join monomers by removing water (H₂O), forming covalent bonds. **Be able to identify an amino acid and be able to point out its amino, carboxyl, and R groups, as well as its α (alpha) carbon:** - Amino group: NH₂. - Carboxyl group: COOH. - R group: Variable side chain unique to each amino acid. - α-Carbon: Central carbon atom bonded to the amino, carboxyl, R group, and hydrogen. **Identify peptide bonds, N terminus, and C terminus of a polypeptide:** - **Peptide Bond:** Covalent bond between the amino group of one amino acid and the carboxyl group of another. - **N Terminus:** Free amino group at one end of a polypeptide. - **C Terminus:** Free carboxyl group at the other end. **Describe what is meant by primary, secondary, and tertiary protein structure:** 1. **Primary Structure:** Linear sequence of amino acids. 2. **Secondary Structure:** Folding into α-helices or β-sheets stabilized by hydrogen bonds. 3. **Tertiary Structure:** 3D shape due to interactions between R groups. **Identify environmental factors that affect protein structure:** - Temperature changes. - pH levels. - Salt concentrations. **Describe the general structure of carbohydrates:\ **Carbohydrates consist of carbon, hydrogen, and oxygen in a 1:2:1 ratio (e.g., C₆H₁₂O₆). **Recognize glycosidic bonds:\ **Glycosidic bonds form between monosaccharides during dehydration reactions. **Define monosaccharides, oligosaccharides, and polysaccharides:** - **Monosaccharides:** Single sugar units (e.g., glucose). - **Oligosaccharides:** Short chains of monosaccharides (3--10 units). - **Polysaccharides:** Long chains of monosaccharides (e.g., starch, cellulose). **Explain how triglycerides are constructed from glycerol and fatty acids:\ **A triglyceride forms when three fatty acids bind to a glycerol molecule through ester bonds in a dehydration reaction. **Describe what makes a fatty acid saturated or unsaturated:** - **Saturated:** No double bonds between carbon atoms; straight chains. - **Unsaturated:** One or more double bonds; bent chains. **Describe phospholipids and how they arrange themselves to form a membrane:\ **Phospholipids have a hydrophilic head (phosphate group) and hydrophobic tails (fatty acids). In water, they form bilayers with heads facing outward and tails inward, creating a cell membrane.