Lesson Overview

1. Lesson Overview 2.3 Carbon Compounds

2. THINK ABOUT IT • In the early 1800s, many chemists called the compounds created by organisms “organic,” believing they were fundamentally different from compounds in nonliving things. • We now understand that the principles governing the chemistry of living and nonliving things are the same, but the term “organic chemistry” is still around. • Today, organic chemistry means the study of compounds that contain bonds between carbon atoms, while inorganic chemistry is the study of all other compounds.

3. The Chemistry of Carbon • Carbon atoms have four valence electrons, allowing them to form strong covalent bonds with many other elements, including hydrogen, oxygen, phosphorus, sulfur, and nitrogen. • Living organisms are made up of molecules that consist of carbon and these other elements.

4. The Chemistry of Carbon • Carbon atoms can also bond to each other, which gives carbon the ability to form millions of different large and complex structures. • Carbon-carbon bonds can be single, double, or triple covalent bonds. • Chains of carbon atoms can even close up on themselves to form rings.

5. Macromolecules • Many organic compounds in living cells are macromolecules- “giant molecules,” made of many smaller molecules. • Macromolecules are formed by polymerization

6. Macromolecules • The smaller units, or monomers, join together to form polymers. • The monomers in a polymer may be identical or different.

7. Polymerization • Dehydration synthesis: Building polymers from monomers! • Lose :

8. HYDROLYSIS • Hydrolysis: using water to separate the monomers!

9. Macromolecules What are the four groups of macromolecules? • video • A. Carbohydrates • B. Lipids • C. Proteins • D. Nucleic Acids

10. Carbohydrates • Living things use carbohydrates as their main source of energy. Plants, some animals, and other organisms also use carbohydrates for structural purposes.

11. Carbohydrates • Carbohydrates : • carbon, hydrogen, oxygen, usually in a ratio of 1 : 2 : 1. • Carbohydrates: main source of energy: supplies immediate energy for cell activities. • Plants, some animals, and other organisms also use carbohydrates for structural purposes.

12. Simple Sugars • monosaccharides- Single sugar molecules • Ex: glucose • galactose (milk) • fructose(fruit) • disaccharides- • sucrose (table sugar) glucose + fructose

13. Complex Carbohydrates • The large macromolecules formed from monosaccharides are known as polysaccharides.

14. Carbohydrates • Plants store extra glucose as a complex carbohydrates known as starch.

15. Complex Carbohydrates • Plants also make another important polysaccharide called cellulose, which gives plants much of their strength and rigidity.

16. Complex Carbohydrates • Humans store excess sugar in a polysaccharide called glycogen. • When the level of glucose in your blood runs low, glycogen is broken down for energy

17. Lipids • Lipids can be used to store energy. Some lipids are important parts of biological membranes and waterproof coverings.

18. Lipids • Lipids are made mostly from carbon and hydrogen atoms and are generally not soluble in water. • lipids are fats, oils, and waxes. • Lipids can be used to store energy. Some lipids are important parts of biological membranes and waterproof coverings. • Steroids synthesized by the body are lipids as well. Many steroids, such as hormones, serve as chemical messengers.

19. Lipids • Many lipids are formed when a glycerol combines with a fatty acid.

20. Lipids • If each carbon atom in a lipid’s fatty acid chain is joined to another carbon atom by a single bond, the lipid is said to be saturated. • If there is at least one carbon-carbon double bond in a fatty acid, the fatty acid is said to be unsaturated. • Lipids whose fatty acids contain more than one double bond are said to be polyunsaturated.

21. Lipids • Lipids that contain unsaturated fatty acids, such as olive oil, tend to be liquid at room temperature. • The data in the table illustrate how melting point decreases as the degree of unsaturation (number of double bonds) increases.

22. Macromolecules • Nucleic acids store and transmit hereditary, or genetic, information.

23. Nucleic Acids • Nucleic acids are macromolecules containing hydrogen, oxygen, nitrogen, carbon, and phosphorus. • individual monomers are nucleotides.

24. Nucleic Acids • Nucleotide :consists of three parts • 5-carbon sugar • phosphate group (–PO4) • nitrogenous base.

25. Nucleic Acids • Individual nucleotides are joined by covalent bonds to form a polynucleotide, or nucleic acid. • There are two kinds of nucleic acids: • ribonucleic acid (RNA) • RNA contains the sugar ribose • deoxyribonucleic acid (DNA) • DNA contains the sugar deoxyribose.

26. Macromolecules Proteins 1. control the rate of reactions and regulate cell processes. 2. form important cellular structures 3. transport substances into or out of cells 4. help to fight disease

27. Protein • Proteins are macromolecules that contain nitrogen, carbon, hydrogen, and oxygen. • monomers of amino acids. • Functions: controlling the rate of reactions, regulating cell processes, forming cellular structures, transporting substances into or out of cells, and helping to fight disease.

28. Protein • Amino acids • amino group (–NH2) on one end • carboxyl group (–COOH) other end. • Covalent bonds called peptide bonds link amino acids together to form a polypeptide. • A protein is a functional molecule built from one or more polypeptides.

29. Structure and Function • Amino acids differ from each other in a side chain called the R-group, which have a range of different properties. • More than 20 different amino acids are found in nature. • This variety results in proteins being among the most diverse macromolecules.

30. Levels of Organization • Proteins have four levels of structure. • A protein’s primary structure is the sequence of its amino acids.

31. Secondary structure •  hydrogen bonds are always between C=O and H-N groups, the exact pattern of them is different in an alpha-helix 

32. Levels of Organization • Tertiary structure is the complete, three-dimensional arrangement of a polypeptide chain.

33. Quaternary Structure is the combination of two or more chains, to form a complete unit.