Chapter 3 Biochemistry Modern Biology Textbook Holt

1. Chapter 3 BiochemistryModern Biology TextbookHolt

2. Section 1 Carbon Compounds Chapter 3 Objectives • Distinguish between organic and inorganic compounds. • Explain the importance of carbon bonding in biological molecules. • Identify functional groups in biological molecules. • Summarize how large carbon molecules are synthesized and broken down. • Describe how the breaking down of ATP supplies energy to drive chemical reactions.

3. Section 1 Carbon Compounds Chapter 3 Carbon Bonding • The study of carbon-based molecules is called organic chemistry • Organic compoundscontain carbon atoms and are found in living things. • Most inorganic compoundsdo not contain carbon atoms.

4. Section 1 Carbon Compounds Chapter 3 Carbon Bonding, continued • Carbon has 4 electrons in its outer shell • So it readily forms 4 covalent bonds

5. Organic Molecules • Hydrocarbons are the simplest organic molecule that contain onlycarbon and hydrogen (for example, methane, CH4) • Methane is one of the most abundant hydrocarbons in natural gas • formed by bacteria that live in swamps and intestines of grazing animals like cows • Larger hydrocarbons, like octane (8 carbons) are found in gasoline that we use in cars

6. Section 1 Carbon Compounds Chapter 3 Functional Groups • Functional groups are groups of atoms that influence the properties of molecules and the chemical reactions in which the molecules participate. • Condensation reactions join monomers (small simple molecules) to form polymers. A condensation reaction releases water as a by-product. • In a hydrolysis reaction, water is used to split polymers into monomers.

7. Large Carbon Molecules • Many carbon compounds Monomers Polymers Macromolecules • Ex: carbohydrates, lipids, protein and nucleic acid

8. Polymer Example

9. Section 1 Carbon Compounds Chapter 3 Energy Currency • Adenosine triphosphate (ATP) stores and releases energy during cell processes, enabling organisms to function.

10. Section 2 Molecules of Life Chapter 3 Objectives • Distinguish between monosaccharides, disaccharides,and polysaccharides. • Explain the relationship between amino acids and protein structure. • Describe the induced fit model of enzyme action. • Compare the structure and function of each of the different types of lipids. • Compare the nucleic acids DNA and RNA.

11. Section 2 Molecules of Life Chapter 3 Carbohydrates • Carbohydrates are organic compounds composed of carbon, hydrogen, and oxygen in a ratio of: • 1 carbon: 2 hydrogen :1 oxygen • Carbohydrates are a source of energy and are used as structural materials in organisms.

12. Section 2 Molecules of Life Chapter 3 Carbohydrates, continued • Monosaccharides • Carbohydrates are made up of monomers called monosaccharides. • Ex: fructose – the sugar found in fruit • Disaccharides and Polysaccharides • Two monosaccharides join to form a double sugar called a disaccharide. • A complex sugar, or polysaccharide, is made of three or more monosaccharides.

13. Section 2 Molecules of Life Chapter 3 Proteins • Proteins are organic compounds composed mainly of carbon, hydrogen, oxygen, and nitrogen. • Many structures such as hair and horns are made of proteins • Also skin and muscles

14. Proteins • Most elaborate molecule on earth • There are tens of thousands of different types of proteins in the body each has a specific structure and function • 4 types of protein • Structural – provide support ( hair, connective tissue) • Storage – provide amino acid source (eggs) • Contractile – allow for muscle contraction • Transport – allow for oxygen to be transported through the body (hemoglobin RBC)

15. Section 2 Molecules of Life Chapter 3 Proteins, continued • Amino Acids • Proteins are made up of monomers called amino acids. The sequence of amino acids determines a protein’s shape and function. • Dipeptides and Polypeptides • Two amino acids are joined by peptide bonds to form a dipeptide. • A long chain of amino acids is called a polypeptide.

16. Section 2 Molecules of Life Chapter 3 Enzyme Activity • Enzymes speed up chemical reactions and bind to specific substrates.

17. Section 2 Molecules of Life Chapter 3 Lipids • Lipids are nonpolar molecules that store energy, but are slow to burn and are an important part of cell membranes. • Fats are stored in adipose tissue, for energy reserve and protection for vital organs

18. Section 2 Molecules of Life Chapter 3 Lipids, continued • Fatty Acids • Most lipids contain fatty acids, unbranched carbon molecules that have a hydrophilic (“water loving”)end and a hydrophobic (“water fearing”) end. • Triglycerides • Triglycerides consist of three fatty acids and one molecule of glycerol.

19. Section 2 Molecules of Life Chapter 3 Lipids, continued • Phospholipids • Phospholipids, which make up cell membranes, consist of two fatty acids and one glycerol molecule. • Waxes • A wax is made of one long fatty acid chain joined to one long alcohol. • Waterproof and in plants • forms a protective coating

20. Lipids, continued • Steroids are classified as lipids because they are hydrophilic, but they are very different structurally and functionally • Steroids • Cholesterol is steroid used to make other steroids • Ex: testosterone, estrogen • Anabolic steroids are a synthetic version of testosterone - used as a performance enhancing drug

21. Section 2 Molecules of Life Chapter 3 Structure of Nucleic Acids • A nucleic acid is a large and complex organic molecule that stores and transports information. • Ex: Deoxyribonucleic Acid (DNA) – contains genetic activity

22. Section 2 Molecules of Life Chapter 3 DNA Overview

23. Chapter 3 Standardized Test Prep Multiple Choice 1. Which of the following is not a function of polysaccharides? A. energy source B. energy storage C. structural support D. storage of genetic information

24. Chapter 3 Standardized Test Prep Multiple Choice, continued 2. Which of the following statements is false? F. A wax is a lipid. G. Starch is a lipid. H. Saturated fats are solid at room temperature. J. Unsaturated fats are liquid at room temperature.

25. Chapter 3 Standardized Test Prep Multiple Choice, continued 3. Which of the following molecules stores hereditary information? A. ATP B. DNA C. protein D. carbohydrates

26. Chapter 3 Standardized Test Prep Multiple Choice, continued 4. What is the name of the molecule in plants that stores sugars? F. starch G. protein H. cellulose J. glycogen

27. Chapter 3 Standardized Test Prep Multiple Choice, continued The figure below illustrates the basic structure of a cell membrane. Use the figure to answer the questions that follow. 5. Which of the following molecules make up the basic structure of a cell membrane? A. waxes B. steroids C. fatty acids D. phospholipids

28. Chapter 3 Standardized Test Prep Multiple Choice, continued The figure below illustrates the basic structure of a cell membrane. Use the figure to answer the questions that follow. 6. The “tails” of the molecules in the figure orient away from water. Which of the following describes the tail’s movement away from water? F. polar G. adhesive H. hydrophilic J. hydrophobic

29. Chapter 3 Standardized Test Prep Multiple Choice, continued 7. simple sugars : carbohydrates :: amino acids : A. lipids B. proteins C. nucleic acids D. amino acids

30. Chapter 3 Standardized Test Prep Multiple Choice, continued The figure below represents the structural formula of a molecule. Use the figure to answer the question that follows. 8. What is the name of the functional group circled in the structural formula? F. amino G. hydroxyl H. phosphate J. carboxyl

31. Chapter 3 Standardized Test Prep Short Response, continued Proteins are affected by environmental conditions such as heat and pH. Explain why the process of cooking an egg cannot be reversed. Answer: The heat that is added to the egg changes the bonds in the proteins and other molecules that make up the egg to such a large extent that the original protein shape can no longer be distinguished.

32. Chapter 3 Standardized Test Prep Extended Response Enzymes are essential for the functioning of all cells. Part A Explain what enzymes do that is essential for cell function. Part B Explain the induced fit model of enzyme action. Answer: Part A Enzymes catalyze chemical reactions that are involved in important cell processes. Part B Bonding of the substrates to enzymes causes a slight change in the enzyme’s shape, thereby weakening some of the bonds and lowering activation energy.