Unit 2 The Chemistry Of Life

10,619 views

Published on

2 Comments
5 Likes
Statistics
Notes
No Downloads
Views
Total views
10,619
On SlideShare
0
From Embeds
0
Number of Embeds
4,747
Actions
Shares
0
Downloads
418
Comments
2
Likes
5
Embeds 0
No embeds

No notes for slide

Unit 2 The Chemistry Of Life

  1. 1. KEY CONCEPTCarbon-based molecules are the foundation of life.<br />
  2. 2. Carbon atoms have unique bonding properties.<br />Carbon forms covalent bonds with up to four other atoms, including other carbon atoms.<br /><ul><li>Carbon-based molecules have three general types of structures.
  3. 3. straight chain
  4. 4. branched chain
  5. 5. ring</li></li></ul><li>Many carbon-based molecules are made of many small subunits bonded together.<br /><ul><li>Monomers are the individual subunits.
  6. 6. Polymers are made of many monomers.</li></li></ul><li>Four main types of carbon-based molecules are found in living things.<br />Carbohydrates are made of carbon, hydrogen, and oxygen.<br />
  7. 7. Four main types of carbon-based molecules are found in living things.<br />Carbohydrates are made of carbon, hydrogen, and oxygen.<br /><ul><li>Carbohydrates include sugars and starches.
  8. 8. Monosaccharides are simple sugars.
  9. 9. Polysaccharides include starches, cellulose, and glycogen.</li></li></ul><li>Polymer (starch)<br />Starch is a polymer of glucose monomers that often has a branched structure.<br />Polymer (cellulose)<br />Cellulose is a polymer of glucose monomers that has a straight, rigid structure<br />monomer<br />Carbohydrates can be broken down to provide energy for cells.<br /><ul><li>Some carbohydrates are part of cell structure.</li></li></ul><li>Triglyceride<br /><ul><li>Lipids are nonpolar molecules that include fats, oils, and cholesterol.
  10. 10. Many contain carbon chains called fatty acids.
  11. 11. Fats and oils contain fatty acids bonded to glycerol.</li></li></ul><li>Lipids have several different functions.<br /><ul><li>broken down as a source of energy
  12. 12. make up cell membranes
  13. 13. used to make hormones</li></li></ul><li>Fats and oils have different types of fatty acids. <br /><ul><li>saturated fatty acids
  14. 14. unsaturated fatty acids</li></li></ul><li>Phospholipid<br />Phospholipids make up all cell membranes.<br /><ul><li>Polar phosphate “head”
  15. 15. Nonpolar fatty acid “tails”</li></li></ul><li>Proteins are polymers of amino acid monomers.<br /><ul><li>Twenty different amino acids are used to build proteins in organisms.</li></li></ul><li><ul><li>Proteins are polymers of amino acid monomers.
  16. 16. Twenty different amino acids are used to build proteins in organisms.</li></ul>Amino acids differ in side groups, or R groups.<br />
  17. 17. <ul><li>Proteins are polymers of amino acid monomers.
  18. 18. Twenty different amino acids are used to build proteins in organisms.
  19. 19. Amino acids differ in side groups, or R groups.</li></ul>Amino acids are linked by peptide bonds.<br />
  20. 20. hydrogen bond<br />Hemoglobin<br />Proteins differ in the number and order of amino acids.<br /><ul><li>Amino acids interact to give a protein its shape.
  21. 21. Incorrect amino acids change a protein’s structure and function.</li></li></ul><li>Nucleic acids are polymers of monomers called nucleotides.<br />
  22. 22. nitrogen-containing molecule,called a base<br />A phosphate group<br />deoxyribose (sugar)<br /><ul><li>Nucleic acids are polymers of monomers called nucleotides.</li></ul>Nucleotides are made of a sugar, phosphate group, and a nitrogen base.<br />
  23. 23. DNA<br />RNA<br /><ul><li>Nucleic acids are polymers of monomers called nucleotides.
  24. 24. Nucleotides are made of a sugar, phosphate group, and a nitrogen base.</li></ul>DNA stores genetic information.<br /><ul><li>RNA builds proteins.</li></li></ul><li>KEY CONCEPT Life depends on chemical reactions.<br />
  25. 25. Bonds break and form during chemical reactions.<br />Chemical reactions change substances into different ones by breaking and forming chemical bonds.<br />Reactants are changed during a chemical reaction.<br /><ul><li>Products are made by a chemical reaction.</li></li></ul><li>Bond energy is the amount of energy that breaks a bond.<br /><ul><li>Energy is added to break bonds.
  26. 26. Energy is released when bonds form.
  27. 27. A reaction is at equilibrium when reactants and products form at the same rate.</li></ul>CO2 + H2O H2CO3<br />
  28. 28. Chemical reactions release or absorb energy.<br />Activation energy is the amount of energy that needs to be absorbed to start a chemical reaction.<br />
  29. 29. Exothermic reactions release more energy than they absorb.<br /><ul><li>Reactants have higher bond energies than products.
  30. 30. Excess energy is released by the reaction.</li></li></ul><li>Endothermic reactions absorb more energy than they release.<br /><ul><li>Reactants have lower bond energies than products.
  31. 31. Energy is absorbed by the reaction to make up the difference.</li></li></ul><li>KEY CONCEPTEnzymes are catalysts for chemical reactions in living things.<br />
  32. 32. A catalyst lowers activation energy.<br />Catalysts are substances that speed up chemical reactions.<br />decrease activation energy<br />increase reaction rate<br />
  33. 33. Enzymes allow chemical reactions to occur under tightly controlled conditions.<br />Enzymes are catalysts in living things.<br />Enzymes are needed for almost all processes.<br /><ul><li>Most enzymes are proteins.</li></li></ul><li>Disruptions in homeostasis can prevent enzymes from functioning.<br /><ul><li>Enzymes function best in a small range of conditions.
  34. 34. Changes in temperature and pH can break hydrogen bonds.
  35. 35. An enzyme’s function depends on its structure.</li></li></ul><li>substrates (reactants)<br />enzyme<br />Substrates bind to anenzyme at certain places called active sites.<br />An enzyme’s structure allows only certain reactants to bind to the enzyme.<br /><ul><li>substrates
  36. 36. active site</li></li></ul><li>Substrates bind to anenzyme at certain places called active sites.<br />The enzyme bringssubstrates together and weakens their bonds.<br />The catalyzed reaction formsa product that is releasedfrom the enzyme.<br />The lock-and-key model helps illustrate how enzymes function.<br /><ul><li>substrates brought together
  37. 37. bonds in substrates weakened</li>

×