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Chapter 2

Chapter 2. THE CHEMISTRY OF LIFE. California State Standards. 1h: most macromolecules in cells and organisms are synthesized from a small collection of simple precursor 4e: proteins can differ from one another in the number and sequence of amino acids

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Chapter 2

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  1. Chapter 2 THE CHEMISTRY OF LIFE

  2. California State Standards • 1h: most macromolecules in cells and organisms are synthesized from a small collection of simple precursor • 4e: proteins can differ from one another in the number and sequence of amino acids • 1b: enzymes are proteins that catalyze biochemical reactions without altering the reactions equilibrium and the activities of enzymes depend on the temperature, ionic conditions, and the pH of the surroundings

  3. I Q #1 • What is an atom? • What are the components (parts) of an atom? Where are they found? • What is an element?

  4. CHAPTER 2: THE CHEMISTRY OF LIFE • The first job of a biologist is to understand the chemistry of life. • 2-1 The Nature of Matter • A. Atoms • · ___________= the basic unit of matter (has volume and mass; solid, liquid, gas, and plasma) ·Atoms are made Atoms subatomic particles called protons, neutrons, and electrons

  5. Carbon Atom = electrons - - - Electronegative charge 1/1840 amu = protons - - electrons travel in regions outside the nucleus called orbitals Positivelycharged 1amu = neutrons - - Nucleus _______________= center of an atom. Home to protons and neutrons. No charge 1 amu protons electrons neutral If the # of _________ = # of _________ the atom is _____________ (no overall charge) Ex. 6 protons = ++++++ 6 electrons = ------

  6. B B. Elements · Elements= · More than _____known kinds; · Found on the pure substances that consists entirely of one type of atom 2 dozen are common in living organisms 100 Periodic table

  7. Reading the Periodic TableExample: The element Carbon (only made of carbon atoms) Atomicnumber = Number of protons in an atom; different for each element SYMBOL ____________ usually 1-2 letters ____________ of the element NAME _______________= # Protons + # neutrons in an atom; the average of one elements isotopes MASS NUMBER Isotopes are the various forms of an atom that differ based on the number of neutrons in the nucleus such as C 14. The isotopes that differ from the most common form are often radioactive or unstable.

  8. C. Chemical Compounds 1. Chemical compound= Example: Sodium Chloride = Table salt Forms when sodium and chlorine combine in a 1:1 ratio 2. Chemical formula= Example: Sodium Chloride= NaCl 3. ____________________________ of a molecule Example: = white crystalline solid = a soft silvery metal that reacts explosively with water = poisonous greenish gas a substance formed by the combination of 2 or more elements in definite proportions. a short hand that shows chemical composition Chemical properties NaCl Na Cl

  9. Chemical Bonds • Atoms in compounds are • Involves the • 2 main types of bonds are: ___________ and _________ held together by links called chemical bonds. interaction of electrons covalent ionic

  10. 1. Ionic Bonds a. b. ion= are formed by the transfer of one or more electrons from one atom to another. an atom that has a positive or negative charge as a result of gaining or losing electrons.

  11. Figure 2 - 3 Ionic Bonding Section 2 - 1 Sodium atom (Na) Chlorine atom (Cl) Sodium ion (Na ) Chloride ion (Cl ) + - Transfer of electron Protons +11 Protons +17 Protons +11 Protons +17 Electrons - 11 Electrons - 17 Electrons - 10 Electrons - 18 Charge Charge Charge Charge FORMING AN IONIC BOND 0 0 +1 -1 c. Opposite charges attract creating a bond between the ions

  12. 2. Covalent Bonds a. formed by the b. Sharing means c. atoms sharing 2 electrons= __ electrons=double bond 6 electrons= d. _________________= The smallest unit of most chemical compounds (those joined with covalent bonds) sharing of electrons between 2 atoms. that the moving electrons are actually traveling in the orbitals of both atoms. single bond 4 triple bond Molecule

  13. IQ #3 Mini Lab • Predict the number of drops of water on one side of a penny. • Predict the number of drops of alcohol on one side of a penny. • Copy data table on IQ sheet. • Do Lab 3 times for validity/repeatability. • Explain your results using the properties of water.

  14. Water Molecule Creates polar nature of water

  15. Hydrogen Bonds Water can create up to 4 H-bonds per molecule Create the 6 sided crystalline structure when solid.

  16. Mixtures and solutions • Mixture is two or molecules in combination • Solution involves mixture in which one compound dissolves in another. • The compound that dissolves is the solute • The compound dissolved in is the solvent • “ the solute dissolves in the solvent”

  17. Ionic solutions Ionic compounds dissociate in water to become their individual ions. Note how H’s of water are nearest Cl- and O of water is nearest Na+ Solute: Solvent:

  18. pH Scale More Hydroxide ions (OH-) BASE (Alkaline) More Hydrogen ions (H+) Acid

  19. 2-2 Properties of Water- Refer to reader’s guide 2-3 Carbon Compounds A. The Chemistry of Carbon 1. Carbon has ________________ which means carbon can form _________________ 2. Living organisms are made up of molecules that consist 3. Carbon can bond with itself forming 4 valence electrons 4 covalent bonds. of carbon, hydrogen, oxygen, phosphorus, nitrogen and sulfur. chains of unlimited length and form, rings, and complex structures.

  20. B. Macromolecules • 1. Macromolecules= • 2. Polymerization= • 3. Monomers= • 4.  The _____ groups of organic compounds found in living things are: are giant molecules consisting of 1000+ smaller molecules. process of joining small molecules to form large molecules small units that form polymers (large molecules) 4 carbohydrates lipids nucleic acids proteins

  21. SINGLE SUGAR GLYCOGEN STARCH POLYSACCHARIDE PLANT CELL WALLS (CELLULOSE) CHITIN (INSECT EXOSKELETON) FATS OILS WAXES STEROIDS NO DOUBLE BONDS IN FATTY ACID AT LEAST ONE DOUBLE BOND

  22. DNA/RNA 5-C SUGAR PHOSPHATE GROUP NITROGENOUS BASE 20 KINDS HELPS CONTROL RATE OF REACTIONS (ENZYMES)

  23. Carbohydrates Lipids Nucleic acids Proteins Sugars and starches Fats and oils Nucleotides Amino Acids Carbon, hydrogen, oxygen Carbon, hydrogen, oxygen Carbon, hydrogen,oxygen, nitrogen, Carbon,hydrogen, oxygen, nitrogen, phosphorus Concept Summary Section 2-3 Carbon Compounds include that consist of that consist of that consist of that consist of which contain which contain which contain which contain Go to Section:

  24. Warm-up 1. What is a catalyst? 2. What are enzymes? 3. How do catalyst work? 4. What affects the activity of an enzyme?

  25. 2-4 Chemical Reactions and Enzymes A. Chemical Reactions =process that changes, or transforms one set of chemicals into another. Always involves changes in chemical bonds. 1. Reactants= 2. Products= elements or compounds that enter a reaction elements or compounds produced by a reaction EXAMPLE: HCl H + Cl

  26. energy that is needed to get a reaction started B. Energy in Reactions • Activation Energy= C. Enzymes 1. Catalyst= a substance that speeds up the rate of a chemical reaction without changing itself.

  27. 2. Catalysts ___________________________in a chemical reaction. lower the activation energy Reaction with no enzyme AE without enzyme AE with enzyme reactants Reaction with an enzyme products

  28. 3. ______________ are ___________________ that speed up favorable (spontaneous) reactions. 4. Enzymes _____________ chemical reactions that take place in cells. 5. Enzymes are Enzymes biological catalysts speed up very specific D. Enzyme Action 1. The Enzyme-Substrate Complex a. Enzymes provide a site where reactants can be brought together to react (increasing the rate of reaction by reducing the activation energy)

  29. Figure 2 - 21 Enzyme Action Active site= Enzyme Activity Site on the enzyme where the substrate attaches Section 2 - 4 Enzyme Glucose (hexokinase) The reactants of a catalyzed reaction Substrates ADP Products Glucose - 6 - ATP phosphate Products are released Substrates bind to enzyme Substrates Enzyme-substrate complex are converted into products

  30. Figure 2-21 Enzyme Action Section 2-4 Enzyme (hexokinase) Glucose Substrates ADP Products Glucose-6- phosphate ATP Products are released Active site Substrates bind to enzyme Enzyme-substrate complex Substrates are converted into products Go to Section:

  31. Figure 2-21 Enzyme Action Section 2-4 Enzyme (hexokinase) Glucose Substrates ADP Products Glucose-6- phosphate ATP Products are released Active site Substrates bind to enzyme Enzyme-substrate complex Substrates are converted into products Go to Section:

  32. Figure 2-21 Enzyme Action Section 2-4 Enzyme (hexokinase) Glucose Substrates ADP Products Glucose-6- phosphate ATP Products are released Active site Substrates bind to enzyme Enzyme-substrate complex Substrates are converted into products Go to Section:

  33. Figure 2-21 Enzyme Action Section 2-4 Enzyme (hexokinase) Glucose Substrates ADP Products Glucose-6- phosphate ATP Products are released Active site Substrates bind to enzyme Enzyme-substrate complex Substrates are converted into products Go to Section:

  34. b. Enzymes are not 2. Regulation of Enzyme Activity - Enzyme activity depends on environmental factors such as: · (enzymes in the stomach function best around pH=2) · (human enzymes function best around 37°C) consumed in the reaction; after products are formed, the enzyme is recycled. pH temperature • -Ionic conditions (coenzymes) • -Substrate concentration (greater the concentration the greater the rate of the reaction)

  35. Warm-up 1. What are the 4 organic macromolecules which make up living organisms. 2. What are the monomers (building blocks) to these macromolecules.

  36. IQ Quiz: Chapter 2 • What kind of compounds did we test in the lab? • What chemical was used to test for simple sugars? • What was a positive result? • If we want to see if peanuts have fat in them what could we do? • How do we know if it is positive? • What did copper sulfate and sodium hydroxide test for? • What was a positive result? • If I had a bowl of cereal and Iodine fell into my cereal and turned a blue-black color what do I know is in my cereal? • Name a food that had more than 1 compound in it? (tested positive for more than 1 test) • What are the four most common elements in living things?

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