Chemistry of Life Essential Questions

Transcription

1 Chemistry of Life Essential Questions VMHS Standards 8.6b; 8.6c; 1h; 4e; 4f; 5a;1b; 1. What is an atom? What are elements? An atom is the basic unit of o Consist of,, and An element is a type of atom o Ex. gold,, hydrogen,, etc. 2. Describe the 3 subatomic particles that make up an atom.,, and Different numbers of make different atoms ( charged) held in energy levels determine the properties of atoms ( charged) have no charge 3. What are the 6 most abundant elements in the human body? 4. What is a compound? How is it different from an element? A compound is a substance made of atoms that are together. The properties of a are often different than the than make it up. o Ex. H 2 O is made of and 5. What is an ion? Describe the formation of an ionic compound. An ion is an atom that has or one or more electrons An ionic compound forms through the force between two charged ions. o Ex. Na+ and Cl- (table salt) 6. What is the difference between an ionic bond and a covalent bond? Ionic bonds form through the force between two charged ions. Covalent bonds form when atoms a pair of 7. What is a molecule? A molecule is two or more held together by bonds. 8. What is the chemical formula for water? What are hydrogen bonds? Hydrogen bonds are attractions between + Hydrogen atoms and Oxygen atoms 9. Draw 3 H 2 O molecules with hydrogen bonds.

2 10. What are the 8 chemical properties that make water unique? 1 st. H2O is a molecule It has separated 2 nd. Water is a It will dissolve almost anything 3 rd. Water is and (capillary action) It sticks to itself and to other things 4 th. Water has a specific heat Able to absorb a lot of heat energy without a large change in temperature 5 th. Water has a high heat of It takes a lot of heat to turn liquid water into a gas 6 th. Water has a high heat of It takes a lot of heat removed to turn water into ice 7 th. Water has high surface H2O molecules stick together and form a membrane on the surface of water 8 th. Water loses density and expands upon Ice floats 11. Why do microwaves cook the food, but not the container? of water!! The wave has an alternating + and which alternatively attracts the and + ends of the water molecule, causing molecules to shake back and forth. The shaking molecules collide and generate through. 12. What is ph? ph is a measure of the hydrogen ion [H+] H2O H + + OH - Pure water = ph 7 = ph less than 7 = ph more than What is the ph of normal rainwater? What is the ph of acid rain? Rainwater is slightly = because of CO 2 in the air Acid rain has a ph of to (could be as low as in some places) 14. Why is Carbon so important to life? Carbon has unpaired electrons in its outer energy level, so it can bond with other atoms This makes carbon able to form of different. o Ex. Straight,, branched 15. What is nanotechnology? Nanotechnology is a field of science that seeks to design useful materials at the level. Materials could be used to help humans at the level (ex. repair tissues) and build more portable technology. o Carbon-carbon bonds are often used because of carbon s unpaired electrons Ex. Carbon nanotubes 16. How are monomers and polymers related? A polymer is a molecule made of many small, called monomers, that are bonded together. 17. What are the 4 major carbon-based molecules found in all living things? 18. Fill in the following table on carbon-based molecules. (at the end) 19. Name the following molecules of life. (at the end)

3 20. How is a protein s structure related to its function? Explain protein denaturation. different amino acids ( ) make up proteins ( ) Proteins differ in the and of the amino acids A protein s of amino acids, of amino acids, of polypeptides, and determine its function Protein occurs when a protein looses its structure (by a change in temp, ph, or ionic conditions) o Ex. Cooking eggs 21. What is a chemical reaction? What are 2 major biochemical reactions in living things? Chemical reactions change substances into other substances by and/or chemical bonds. Cellular and are two very common biochemical reactions. 22. What are the reactants and the products in a biochemical reaction? Reactants are the substances that are during the reaction. Products are the substances during the reaction. 23. What are bond energies? When is energy needed in reactions? When is energy released in reactions? Bond energy is the mount of energy needed to a chemical bond Energy is needed in a reaction in order to bonds. Energy is released in a reaction when bonds. 24. Explain the activation energy in a biochemical reaction. Activation energy is the amount of energy needed to a reaction. 25. How do endothermic and exothermic reactions differ? Endothermic reactions more energy than they release. Exothermic reactions more energy than they absorb. 26. What is a catalyst? How does it affect a biochemical reaction? A catalyst is a substance (often an enzyme) that lowers the needed to a chemical reaction. Catalysts the rate of chemical reactions. 27. What are enzymes? Why are enzymes important in biochemical reactions? Enzymes are for biochemical reactions in living things. Enzymes cause biochemical reactions to happen up to a times faster than it normally would. o Ex. Breaking down to. 28. What is the lock-and-key model of enzymes? enzymes work only on substrates, just like only specific keys fit specific locks. If an enzyme s changes, it may not work at all. o Like a key no longer fitting a lock 29. What kinds of conditions can affect the shape and function of enzymes?,, and condition changes can change the shape of an enzyme. If the of the enzyme is changed, it won t work. o Like changing the of a key will make it no longer fit the lock.

4

5