1 / 26

Ch.2

Ch.2 . The chemical basis of life. What is this picture illustrating? Spider capturing a moth What does the male moth do for the female? It receives chemicals that repel the spider. What level does everything in biology begin at? Everything in biology starts at the chemical level

adamma
Download Presentation

Ch.2

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Ch.2 The chemical basis of life

  2. What is this picture illustrating? • Spider capturing a moth • What does the male moth do for the female? • It receives chemicals that repel the spider

  3. What level does everything in biology begin at? • Everything in biology starts at the chemical level • What molecules make up muscle? • Actin and myosin

  4. Which four elements do we need the most of? • O,C,H, and N • What are trace elements? • Elements that we need in very small amounts

  5. What is causing the bulge in her neck? • A lack of iodine in her diet • How much do we need each day and where do we usually get it? • 0.15mg and it is added to salt

  6. What two elements combine to form the salt crystals on the far right? • Na and Cl combine to make the compound NaCl or table salt • Define a compound • Two or more elements in a fixed ratio • Is H2O a compound? • Yes, it has 2 Hydrogens for every oxygen all the time

  7. What do we call the center of the atom? • Nucleus • What particles are in the nucleus? • Protons and Neutrons • What is around the outside of the atom? • Electrons • What are the charges of protons, electrons and neutrons? • Protons are +, electrons are - and neutrons have no charge.

  8. Sodium in wateractin and myosin

  9. What is an isotope? • An atom with a different number of neutrons • What is a radioactive isotope? • An isotope that gives off particles and energy

  10. What is the glowing area showing? • Cancer picked up by a radioactive isotope.

  11. What information does the atomic number give? • The number of protons and the number of electrons • How many electrons does oxygen need to complete its outer shell? • 2, the outer shell can hold eight but only has six

  12. Why is the sodium atom giving up an electron? • To complete it’s outer shell it would need 7 more electrons, it is easier to give it to chlorine. • Why is chlorine willing to take it? • To complete it’s outer shell it needs one more electron • What kind of bond (attraction) is this? • Ionic

  13. What is keeping the sodium and chloride together? • The charged particles are attracted to each other forming an ionic bond

  14. How are the attractions between these molecules different from ionic bonds? • The atoms are sharing electrons instead of transferring them. • What are these bonds called? • Covalent bonds involve sharing electrons

  15. What is this picture showing? • In a water molecule the oxygen pulls the electrons toward itself making the oxygen negative and the hydrogens positive • What type of bond is this? • A polar covalent bond

  16. What are the dashed lines representing? • A hydrogen bond between one water and another • What causes these bonds to form? • The attraction between the negative oxygen of one water and the positive hydrogen of another

  17. What are the 3 states of water? • Solid, liquid and gas • What allows for this property? • Hydrogen bonding

  18. What allows this insect to walk on water? • Hydrogen bonding between water molecules creates surface tension

  19. What makes it difficult to heat up water? • It takes a lot of energy to break the hydrogen bonds • What happens when we sweat? • The hottest water molecules evaporate leaving the cooler ones behind, (evaporative cooling)

  20. What are some other properties of water? • Large bodies of water can store huge amounts of heat. • Water molecules stick together (cohesion)

  21. water and ice • Why does ice float? • The hydrogen bonds are stuck in place making it less dense so it floats

  22. Does this look familiar? • What do you think was going on in this demonstration? • The solution on the right is not liquid water but something that is less dense than ice

  23. What happens to salt in water? • It dissolves • Does it disappear? • No, the ions are attracted to the different parts of the water molecule, breaking the ionic bonds

  24. What are solutes and solvents? • The solute is what dissolves in a solution, the solvent is the solution. • What do you see as the difference between an acid and a base? • Acids have more H ions and bases have more Oh ions

  25. What has happened to this statue? • Acid rain has caused it to deteriate • What causes acid rain? • Sulfur and nitrogen oxides produced in factories

  26. C6H12O6 + ____ O2 -------> ___ CO2 + __ H2O C6H12O6 + 6O2 -------> 6 CO2 + 6 H2O

More Related