Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Photosynthesis wikipedia , lookup
Protein–protein interaction wikipedia , lookup
DNA-encoded chemical library wikipedia , lookup
Evolution of metal ions in biological systems wikipedia , lookup
Protein adsorption wikipedia , lookup
Abiogenesis wikipedia , lookup
Biomolecular engineering wikipedia , lookup
Chemical biology wikipedia , lookup
History of molecular biology wikipedia , lookup
AP Biology Unit 1--Chemistry of Life-- Study Guide Chapters 2, 3, & 6 1. Basic Chemistry 2. Water 3. Organic molecules in organisms 4. Enzymes Key Terms 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. Hydrogen bond Cohesion Adhesion Capillary action Heat capacity Carbohydrate Hydrolysis Starch Cellulose Amino acids Dehydration synthesis 12. Peptide bond 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. Protein Lipids Nucleic acids Phospholipids Hydrophilic head Phosphate Hydrophobic tails Lipid bilayer Saturated Unsaturated exergonic reaction 24. endergonic reaction 25. enzyme 26. activation energy 27. enzyme-substrate complex 28. competitive inhibitor 29. noncompetitive inhibitor 30. feedback inhibition Recommended Work For Chapters 2 & 3: 1. Concept Checks 2. Testing Your Understanding Levels 1 & 2 =============================================== AP Biology Unit 1- The Chemistry of Life ELEMENTS Although all of the substances in the universe are chemically diverse, they all have one thing in common: They’re all made up of elements. Elements, by definition, are substances that cannot be broken down into simpler substances by chemical means. There are 92 naturally occurring elements found in nature. THE ESSENTIAL ELEMENTS OF LIFE Although there are 92 different elements in the known universe, 99% of all living matter is made up of just six of them. These are considered the essential elements of life: Write out the names of the six elements essential to life. 1 AP Biology Unit 1—Chemistry of Life C H O N P S SUBATOMIC PARTICLES If you break down an element into smaller pieces, you’ll eventually come to an atom. Define atom:_____________________________________________________________ Atoms are the building blocks of the physical world. Within atoms, there are even smaller subatomic particles called protons, neutrons, and electrons. Draw and label a diagram of a carbon atom, include the subatomic particles: In your own words describe the atomic structure of an atom and the interactions of the subatomic particles. COMPOUNDS Define compound: You’ll sometimes find that a compound has different properties from those of its elements. For instance, hydrogen and oxygen exist in nature as gases. Yet when they combine to make water, they often pass into a liquid state. When hydrogen atoms get together with oxygen atoms to form water, we’ve got a chemical reaction: 2 AP Biology Unit 1—Chemistry of Life Write out the chemical reaction for the above reaction: Label the reactants and the products. The atoms of a compound are held together by chemical bonds, which may be ionic bonds, covalent bonds, or hydrogen bonds. Define the following terms and give examples of each: a. ionic bond b. covalent bond c. nonpolar covalent bond d. polar covalent bond 3 AP Biology Unit 1—Chemistry of Life WATER: THE VERSATILE MOLECULE One of the most important substances in nature is water. Did you know 70% of your body weight consists of water? Water is considered a unique molecule because it plays an important role in chemical reactions. Draw and label a diagram of water: Explain why water is a polar molecule, include partial charges both negative and positive. Define hydrogen bond and is it a strong or weak bond? Draw and label a diagram of six water molecules engaging in hydrogen bonds. Hint: start with a central water molecule and work outward. Hydrogen bonds are not actually bonds, but strong intermolecular forces that act in a bond-like way. It’s this property that makes water a great solvent- it can dissolve many kinds of substances. The hydrogen bonds that hold water molecules contribute to a number of special properties: 4 AP Biology Unit 1—Chemistry of Life Describe and explain the significance to life, the following properties that water has do to hydrogen bonding: a. cohesive forces b. cohesion c. adhesion d. capillary action e. heat capacity 5 AP Biology Unit 1—Chemistry of Life THE ACID TEST Water is important because most reactions occur in watery solutions. Reactions are also influenced by whether the solution in which they occur is acidic, basic, or neutral. What makes a solution acidic or basic? What is the difference between acidity and alkalinity? The acidity and alkalinity of a solution can be measured using a pH scale. Draw and label a pH scale ranging from 0 to 14, include what pH’s are considered acids, what pH’s are considered bases, what pH is neutral, and where the following would fall on the pH scale: concentrated nitric acid, stomach acid, lemon juice, cola drinks, vinegar, black coffee, distilled water, blood, seawater, laundry bleach, ammonia, oven cleaner, and drain cleaner. ORGANIC MOLECULES Most of the chemical compounds in living organisms contain a skeleton of carbon atoms. These molecules are called organic compounds. By contrast, molecules that do not contain carbon atoms are called inorganic compounds. For example, salt (NaCl) is an inorganic compound. 6 AP Biology Unit 1—Chemistry of Life Explain why carbon is important for life. FOUR CLASSES OF ORGANIC COMPOUNDS CENTRAL TO LIFE. Carbohydrate Describe a carbohydrate. What is the function of carbohydrates? What is a monosaccharide? What are the two most common sugars? Draw the ring form and linear form of glucose. 7 AP Biology Unit 1—Chemistry of Life What is a disaccharide? Draw the reaction of two glucose molecules that combine to form maltose. (Draw the structures) What is a dehydration synthesis reaction or a condensation reaction. What is a hydrolysis? Write out a reaction to demonstrate hydrolysis. What are polysaccharides? Describe the structure and function of starch, cellulose and glycogen. 8 AP Biology Unit 1—Chemistry of Life These are important functional group to know. Complete the following chart of functional groups. Name of Group Structural Formula Examples Amino (amine) Methyl (methylated compound) Carboxyl (carboxylic acid) Hydroxyl (alcohol) Carbonyl-Aldehyde Carbonyl-Keto Sulfhydryl (thiol) Phosphate (organic phosphate) 9 AP Biology Unit 1—Chemistry of Life Proteins Amino acids are organic molecules that serve as building blocks of proteins. They contain carbon, hydrogen, oxygen, and nitrogen atoms. There are 20 different amino acids commonly found in proteins. You don’t have to memorize the 20 amino acids. But you do have to remember that every amino acid has four important parts: Draw the structure of a typical amino acid and label the four important parts: amino group, carboxyl group, a central carbon with a hydrogen, and R group. Draw the structure of the amino acid glycine and phenylalanine. Identify the R groups. What is a polypeptide? 10 AP Biology Unit 1—Chemistry of Life Proteins can be grouped according to their function. Some major categories follow: Define the function and give examples of the following types of proteins: 1. Structural proteins 2. Storage proteins 3. Transport proteins 4. Defensive proteins 5. Enzymatic proteins 6. Hormonal proteins 7. Contractile and Motor proteins 8. Receptor proteins 11 AP Biology Unit 1—Chemistry of Life There are four levels that describe the structure of a protein: Describe each of the following levels of protein structure; include the types of bonds involved at each level: 1. Primary structure 2. Secondary structure 3. Tertiary structure 4. Quaternary structure Lipids Like carbohydrates, lipids consist of carbon, hydrogen, and oxygen atoms, but not in the 1:2:1 ratio typical of carbohydrates. The most common examples of lipids are fats, oils, phospholipids, and steroids. Draw the structure of a typical fat consisting of three fatty acids and one glycerol molecule. This molecule is called a triglyceride. 12 AP Biology Unit 1—Chemistry of Life Explain the difference between saturated fatty acids, monounsaturated fatty acids, and polyunsaturated fatty acids. Draw the structure of each molecule. Phospholipids Draw, label, and describe the structure of a phospholipid. Include the head region, the tail region, hydrophobic region, and hydrophilic regions. Steriods Draw the structure of a typical steroid. Describe the function of steroids. 13 AP Biology Unit 1—Chemistry of Life Nucleic Acids Like proteins, nucleic acids contain carbon, hydrogen, oxygen, and nitrogen, but nucleic acids also contain phosphorus. Nucleic acids are molecules that are made up of simple unit called nucleotides. You need to know about two kinds of nucleic acids: deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). List the four bases of DNA and identify the two purines and the two pyrimidines. List the four bases of RNA and identify the two purines and the two pyrimidines. Draw the structure of a nucleotide of DNA with the base adenine. Draw the structure of a nucleotide of RNA with the base cytosine. The Energy of Life: An Introduction to Metabolism Chemical reactions that occur in biological systems are referred to as metabolism. Metabolism includes catabolism, anabolism, and the transferring of energy from one substance to another. An organism’s metabolism transforms matter and energy and is subject to the laws of thermodynamics. Define Catabolism: 14 AP Biology Unit 1—Chemistry of Life Define Anabolism: The free-energy change of a reaction tells us whether or not the reaction occurs spontaneously. Define free energy: What is the symbol for a change in free energy?__________________ Define an exergonic reaction and is ∆G negative or positive? Define an endergonic reaction and is ∆G negative or positive? ATP powers cellular work by coupling exergonic reactions to endergonic reactions. A key feature in the way cells manage their energy resources to do work is energy coupling, the use of an exergonic process to drive an endergonic one. The primary source of energy for cells in energy coupling is ATP (adenosine triphosphate). Draw the structure of ATP and the hydrolysis reaction of ATP to ADP. Describe the role of ATP and this hydrolysis reaction in metabolic reactions. Enzymes speed up metabolic reactions by lowering energy barriers. Define catalyst, enzyme, and activation energy. How are they related? 15 AP Biology Unit 1—Chemistry of Life Draw a diagram that graphically depicts how enzymes function. Include free energy, progress of the reaction, and the reaction rate with and without an enzyme. Describe the function of enzymes, include the terms substrate, induced-fit model, active site. Are enzymes changed as a result of a reaction? What affects the efficiency of an enzyme? The activity of an enzyme can be affected by several factors. Environmental factors affect enzyme activity. Describe how pH affects enzyme activity, and then draw a graph to illustrate this affect. 16 AP Biology Unit 1—Chemistry of Life Describe how temperature affects enzyme activity, and then draw a graph to illustrate this affect. Describe the role of cofactors in chemical reactions, include coenzymes and inorganic cofactors. How do living systems regulate chemical reactions? How do they know when to start a reaction and when to shut it off? One way of regulating a reaction is by regulating its enzyme. Here are four common ways in which this is done: Describe how allosteric enzymes work, include allosteric effector, allosteric activator, allosteric inhibitor, and feedback inhibitor. Describe competitive inhibition. 17 AP Biology Unit 1—Chemistry of Life Describe noncompetitor inhibitor. Regulation of enzyme activity helps control metabolism. Describe Feedback Inhibition. Give two examples for negative feedback. Grid-In Questions 1. If nine molecules of a monosaccharide with the formula C6H12O6 are assembled to produce a complex carbohydrate, how many atoms of hydrogen will be in the final polymer? Answer:___________ 2. Compare the number of H+ ions in a solution with a pH of 2 to a solution with a pH of 6. If appropriate, include a negative sign in your answer. Answer:___________ 18 AP Biology Unit 1—Chemistry of Life Unit 1 Essay #1 The selectively permeable plasma membrane is composed of phospholipids and proteins, which allow for its unique functions. (a) Describe the structure and properties of phospholipids and explain the important roles of phospholipids in the plasma membrane. (b) Predict how the normal function of the plasma membrane would be altered if all phospholipids were saturated, resulting in fatty acid tails without kinks or bends. Explain the effect this would have on plants located in very cold regions. (c) Proteins are an important component of the cell membrane. Describe two specific functions of proteins in the membrane. (d) Explain the role of each type of protein you selected for part (c) based on the structure and properties of a protein. 19 AP Biology Unit 1—Chemistry of Life Unit 1 Essay #2 Describe why water is an ideal medium for living things. Explain two properties of water and their significance to life. 20 AP Biology Unit 1—Chemistry of Life Unit 1 Essay #3 Proteins are complex molecules important to the function of every living organism, and their chemical properties make them susceptible to conditions in the environment. (a) Discuss the chemical composition of proteins and the chemical reactions involved in protein synthesis. (b) Discuss protein structure and the structure and function of proteins in relation to environmental factors. (c) Discuss the role of proteins in the intracellular exchange of information. 21 AP Biology Unit 1—Chemistry of Life Unit 1 Essay #4 When you hard-boil an egg, the clear liquid part surrounding the yolk becomes white and solid. Describe, in detail, why this happens. 22 AP Biology Unit 1—Chemistry of Life Unit 1 Essay #5 Vertebrate hormones travel through the bloodstream to reach their cells. Hormones can be a variety of kinds of molecules. Insulin is a hormone that is protein derivative and testosterone is a steroid molecule. (a) Describe the structure of a protein hormone and give one more example. (b) Describe the structure of a steroid hormone and give one more example. (c) Compare and contrast the response to protein hormones and steroid hormones. Use specific hormones as examples. These hormones can be ones that are mentioned or provided or different hormones. (d) Describe what happens on the target cell when the hormone reaches its surface. 23