chapter 2: the chemistry of life
DESCRIPTION
Chapter 2: The Chemistry of Life. Remember metabolism?. Those reactions involve chemicals and chemistry! Chemistry: the science of matter What it’s made of What it does- reactions Democritus’ question…. Atoms- the basic unit of matter. VERY small- 100 million = 1 centimeter! - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: Chapter 2: The Chemistry of Life](https://reader035.vdocument.in/reader035/viewer/2022062520/56815c1d550346895dc9f23d/html5/thumbnails/1.jpg)
S
Chapter 2:The Chemistry of
Life
![Page 2: Chapter 2: The Chemistry of Life](https://reader035.vdocument.in/reader035/viewer/2022062520/56815c1d550346895dc9f23d/html5/thumbnails/2.jpg)
Remember metabolism?
Those reactions involve chemicals and chemistry! Chemistry: the science of matter
What it’s made of What it does- reactions
Democritus’ question…
![Page 3: Chapter 2: The Chemistry of Life](https://reader035.vdocument.in/reader035/viewer/2022062520/56815c1d550346895dc9f23d/html5/thumbnails/3.jpg)
Atoms- the basic unit of matter
VERY small- 100 million = 1 centimeter! Subatomic particles
Protons (+) Neutrons (0) Electrons (-)*
Atomic number: # of protons Mass number: # of protons + # of neutrons
![Page 4: Chapter 2: The Chemistry of Life](https://reader035.vdocument.in/reader035/viewer/2022062520/56815c1d550346895dc9f23d/html5/thumbnails/4.jpg)
Element
A pure substance consisting of just one type of atom
Over 100 known- only about 24 commonly found in nature
![Page 5: Chapter 2: The Chemistry of Life](https://reader035.vdocument.in/reader035/viewer/2022062520/56815c1d550346895dc9f23d/html5/thumbnails/5.jpg)
Isotopes
Atoms of the same element that differ in the number of neutrons So they have a different what?
Same number of electrons means same chemical properties Radioactive isotopes
Used to date fossils and rocks Cure cancers/kill bacteria Tracers- “label” a substance and follow it thru the body
![Page 6: Chapter 2: The Chemistry of Life](https://reader035.vdocument.in/reader035/viewer/2022062520/56815c1d550346895dc9f23d/html5/thumbnails/6.jpg)
Chemical Compounds
A substance formed by the chemical combination of two or more elements in definite proportions
Formulas- ex: H20 and NaCl Chemical/physical properties of compounds are
very different than their individual elements
![Page 7: Chapter 2: The Chemistry of Life](https://reader035.vdocument.in/reader035/viewer/2022062520/56815c1d550346895dc9f23d/html5/thumbnails/7.jpg)
Chemical Bonds
Chemistry- what matter “does”- depends on the forming/breaking of bonds
Involve valence electrons 2 Main types of bonds
Ionic: transfer e- (ex: NaCl: Na+ and Cl- ions) Covalent: share e- (ex: H2O)
Molecule- the smallest unit of most compounds
![Page 8: Chapter 2: The Chemistry of Life](https://reader035.vdocument.in/reader035/viewer/2022062520/56815c1d550346895dc9f23d/html5/thumbnails/8.jpg)
Van der Waals forces
1. covalent bond “sharing” isn’t always “equal” 2. electrons are always in motion …therefore there are always + and – regions of a
molecule
Van der waals forces = intermolecular forces between + and – regions of molecules that attracts them together
![Page 9: Chapter 2: The Chemistry of Life](https://reader035.vdocument.in/reader035/viewer/2022062520/56815c1d550346895dc9f23d/html5/thumbnails/9.jpg)
http://www.youtube.com/watch?v=OoYeIsSkafI
![Page 10: Chapter 2: The Chemistry of Life](https://reader035.vdocument.in/reader035/viewer/2022062520/56815c1d550346895dc9f23d/html5/thumbnails/10.jpg)
![Page 11: Chapter 2: The Chemistry of Life](https://reader035.vdocument.in/reader035/viewer/2022062520/56815c1d550346895dc9f23d/html5/thumbnails/11.jpg)
2-3 Carbon Compounds
Organic chemistry: the study of all compounds with bonds between C atoms
4 macromolecules Carbohydrates Lipids Nucleic acids Proteins
![Page 12: Chapter 2: The Chemistry of Life](https://reader035.vdocument.in/reader035/viewer/2022062520/56815c1d550346895dc9f23d/html5/thumbnails/12.jpg)
Why is C so important?
4 valence electrons How many bonds can it make?
4!
Can bond with other carbon atoms Long chains Rings Can form a variety of structures
![Page 13: Chapter 2: The Chemistry of Life](https://reader035.vdocument.in/reader035/viewer/2022062520/56815c1d550346895dc9f23d/html5/thumbnails/13.jpg)
Macromolecules
What does “macromolecule” mean? “giant” molecule
Monomers: small individual molecules Polymer: a bunch of smaller monomers together This process called: polymerization
![Page 14: Chapter 2: The Chemistry of Life](https://reader035.vdocument.in/reader035/viewer/2022062520/56815c1d550346895dc9f23d/html5/thumbnails/14.jpg)
Carbohydrates
C, H & O Living things use it for energy and structural
purposes (plants) Monomer: monosaccharides Polymer: polysaccharides
![Page 15: Chapter 2: The Chemistry of Life](https://reader035.vdocument.in/reader035/viewer/2022062520/56815c1d550346895dc9f23d/html5/thumbnails/15.jpg)
Carb Examples:
Animals: Starch and glucose- store excess sugar Fiber (from plants) helps with digestion
Plants: Cellulose- rigidity and strength (ex: paper!) Plant starch- store excess sugar
Carb N. Ergy!
![Page 16: Chapter 2: The Chemistry of Life](https://reader035.vdocument.in/reader035/viewer/2022062520/56815c1d550346895dc9f23d/html5/thumbnails/16.jpg)
Lipids
C and H Fats, oils, waxes Store energy in living things Makes up waterproof membranes (ex: in cells) Steroids
![Page 17: Chapter 2: The Chemistry of Life](https://reader035.vdocument.in/reader035/viewer/2022062520/56815c1d550346895dc9f23d/html5/thumbnails/17.jpg)
Lipids are NOT polymers
Structure: A glycerol molecule 3 fatty acid chains
Saturated fatty acids: single bonds btwn Cs maximum # H atoms possible
Unsaturated fatty acids: at least one double bond btwn Cs
Polyunsaturated: two or more double bonds btwn Cs
![Page 18: Chapter 2: The Chemistry of Life](https://reader035.vdocument.in/reader035/viewer/2022062520/56815c1d550346895dc9f23d/html5/thumbnails/18.jpg)
Lipids Examples
Saturated (mostly solids): butter, waxes Unsaturated (mostly liquids): olive oil Polyunsaturated (mostly liquids): cooking oils like
canola oil
![Page 19: Chapter 2: The Chemistry of Life](https://reader035.vdocument.in/reader035/viewer/2022062520/56815c1d550346895dc9f23d/html5/thumbnails/19.jpg)
Nucleic Acids
H, O, N, C and P Store and transmit genetic material
DNA and RNA Monomer: nucleotides
Made up of: 5C sugar, phosphate group, N base Polymer: nucleic acid Covalent bonds
![Page 20: Chapter 2: The Chemistry of Life](https://reader035.vdocument.in/reader035/viewer/2022062520/56815c1d550346895dc9f23d/html5/thumbnails/20.jpg)
Proteins
N, C, H and O Regulates cell processes/ rates of reaction
Transport substances in/out of cells Growth and repair of muscles and bone Fight diseases
![Page 21: Chapter 2: The Chemistry of Life](https://reader035.vdocument.in/reader035/viewer/2022062520/56815c1d550346895dc9f23d/html5/thumbnails/21.jpg)
Proteins (continued)
Monomers: amino acids (aa) Amino group Carboxyl group R group side chain (unique)
20+ found in nature
![Page 22: Chapter 2: The Chemistry of Life](https://reader035.vdocument.in/reader035/viewer/2022062520/56815c1d550346895dc9f23d/html5/thumbnails/22.jpg)
Protein Structure
4 Levels of organization: Primary- sequence of aa form a chain Secondary- aa form either a twist or folds within the chain Tertiary-the chain itself twists/folds Quaternary-how chain interacts with other chains
Attractive forces at work: Van der waals forces H- bonds Peptide bonds
![Page 23: Chapter 2: The Chemistry of Life](https://reader035.vdocument.in/reader035/viewer/2022062520/56815c1d550346895dc9f23d/html5/thumbnails/23.jpg)
![Page 24: Chapter 2: The Chemistry of Life](https://reader035.vdocument.in/reader035/viewer/2022062520/56815c1d550346895dc9f23d/html5/thumbnails/24.jpg)
Water!
75% of earth is water! 60% of the human body is water! 70% of your brain is water! You will die in a few days without water!
![Page 25: Chapter 2: The Chemistry of Life](https://reader035.vdocument.in/reader035/viewer/2022062520/56815c1d550346895dc9f23d/html5/thumbnails/25.jpg)
2-2 Properties of Water
Density Polarity Cohesion Adhesion High specific heat
![Page 26: Chapter 2: The Chemistry of Life](https://reader035.vdocument.in/reader035/viewer/2022062520/56815c1d550346895dc9f23d/html5/thumbnails/26.jpg)
Density
Mass per unit volume Water expands when frozen Ice is less dense than water
What does this mean? Why is this important in nature?
![Page 27: Chapter 2: The Chemistry of Life](https://reader035.vdocument.in/reader035/viewer/2022062520/56815c1d550346895dc9f23d/html5/thumbnails/27.jpg)
Density Rainbow Test
At your lab tables, work with your group to make your hypothesis…
Place the following substances in order from MOST dense to LEAST dense. Corn syrup Water Vegetable oil Dish soap Alcohol Honey
![Page 28: Chapter 2: The Chemistry of Life](https://reader035.vdocument.in/reader035/viewer/2022062520/56815c1d550346895dc9f23d/html5/thumbnails/28.jpg)
Check your hypothesis…were you correct?
![Page 29: Chapter 2: The Chemistry of Life](https://reader035.vdocument.in/reader035/viewer/2022062520/56815c1d550346895dc9f23d/html5/thumbnails/29.jpg)
Polar
Uneven distribution of electrons between O and H atoms
O has 8 protons H has only 1 proton Covalent bonds
![Page 30: Chapter 2: The Chemistry of Life](https://reader035.vdocument.in/reader035/viewer/2022062520/56815c1d550346895dc9f23d/html5/thumbnails/30.jpg)
Hydrogen bonds
attraction between H and an electronegative atom (like O!)
![Page 31: Chapter 2: The Chemistry of Life](https://reader035.vdocument.in/reader035/viewer/2022062520/56815c1d550346895dc9f23d/html5/thumbnails/31.jpg)
Cohesion
The ability of water molecules to “stick together” Surface tension
*Jesus Christ lizard!
![Page 32: Chapter 2: The Chemistry of Life](https://reader035.vdocument.in/reader035/viewer/2022062520/56815c1d550346895dc9f23d/html5/thumbnails/32.jpg)
Adhesion
The ability of water molecules to “stick” to other surfaces
Ex: capillary action in plants
![Page 33: Chapter 2: The Chemistry of Life](https://reader035.vdocument.in/reader035/viewer/2022062520/56815c1d550346895dc9f23d/html5/thumbnails/33.jpg)
High Specific Heat
Water takes a long time to heat up and cool down Have you ever gone surfing in Oct? Swimming in
April?
![Page 34: Chapter 2: The Chemistry of Life](https://reader035.vdocument.in/reader035/viewer/2022062520/56815c1d550346895dc9f23d/html5/thumbnails/34.jpg)
Mixtures
Mixture- 2 or more elements physically but not chemically combined What does this mean? Ex: salt and pepper Ex: gases in the atmosphere
![Page 35: Chapter 2: The Chemistry of Life](https://reader035.vdocument.in/reader035/viewer/2022062520/56815c1d550346895dc9f23d/html5/thumbnails/35.jpg)
Solutions and Suspensions
2 types of mixtures: Solutions: when the molecules of a mixture are
evenly distributed Solute: substance being dissolved Solvent: usually water
Suspensions: a mixture of water and nondissolved material These materials are “suspended” in the mixture
![Page 36: Chapter 2: The Chemistry of Life](https://reader035.vdocument.in/reader035/viewer/2022062520/56815c1d550346895dc9f23d/html5/thumbnails/36.jpg)
Acids, Bases and pH
A water molecule can react to form ions H2O H+ + OH-
(Water H ion + hydroxide ion) # of H+ ions = # of OH- ions (water is” neutral”)
pH: concentration of H+ ions in a solution
![Page 37: Chapter 2: The Chemistry of Life](https://reader035.vdocument.in/reader035/viewer/2022062520/56815c1d550346895dc9f23d/html5/thumbnails/37.jpg)
pH Scale
Scale from 1 to 14 Water is neutral: pH of 7 Acids: any compound that forms H+ ions in a solution
1-6 on the scale Bases: any compound that forms OH- ions in a solution
8-14 on the scale aka: alkaline solutions
![Page 38: Chapter 2: The Chemistry of Life](https://reader035.vdocument.in/reader035/viewer/2022062520/56815c1d550346895dc9f23d/html5/thumbnails/38.jpg)
pH Buffers
Fluids in human body must be between 6.5 and 7.5
Sharp increases or decreases will effect chemical reactions
So we must maintain internal conditions… Hmm, what is THAT called?
Buffers: weak acids/bases that can react with strong acids/strong acids/bases to prevent sharp changes in pH
![Page 39: Chapter 2: The Chemistry of Life](https://reader035.vdocument.in/reader035/viewer/2022062520/56815c1d550346895dc9f23d/html5/thumbnails/39.jpg)
2-4 Chemical Reactions and Enzymes
Chemistry: what things are made of WHAT THEY DO!
This depends on chemical reactions!
Chemical reaction: a process that changes one set of chemicals into another Mass and energy are conserved
![Page 40: Chapter 2: The Chemistry of Life](https://reader035.vdocument.in/reader035/viewer/2022062520/56815c1d550346895dc9f23d/html5/thumbnails/40.jpg)
Chemical Reactions
Involve a change in the bonds Quick or slow Reactants (in) products (out) Ex: carbon dioxide as a waste product
CO2 + H2O H2CO3 (carbonic acid) H2CO3 H2O + CO2 (as we exhale)
![Page 41: Chapter 2: The Chemistry of Life](https://reader035.vdocument.in/reader035/viewer/2022062520/56815c1d550346895dc9f23d/html5/thumbnails/41.jpg)
Energy in Reactions
All reactions release/absorb energy Release energy- occur spontaneously Absorb energy- require energy Living things must have a source of energy
Plants- store energy from sun Animals- digested good (metabolism!)
![Page 42: Chapter 2: The Chemistry of Life](https://reader035.vdocument.in/reader035/viewer/2022062520/56815c1d550346895dc9f23d/html5/thumbnails/42.jpg)
Activation Energy
Activation energy: the energy needed to get a reaction started
Ex: cellulose will react with oxygen and burn So why don’t our books burst into flames?
![Page 43: Chapter 2: The Chemistry of Life](https://reader035.vdocument.in/reader035/viewer/2022062520/56815c1d550346895dc9f23d/html5/thumbnails/43.jpg)
Enzymes
Specific type of proteins Some vital reactions take a long time to start Catalyst: a substance that speeds up a chemical reaction
Lowers the activation energy Enzymes are biological catalysts!
Speed up chemical reactions in cells Specific!
![Page 44: Chapter 2: The Chemistry of Life](https://reader035.vdocument.in/reader035/viewer/2022062520/56815c1d550346895dc9f23d/html5/thumbnails/44.jpg)
Why is this important?
Carbonic acid example Too much CO2 in blood will kill you Enzyme (carbonic anhydrase) speeds up reaction
so it happens right away
![Page 45: Chapter 2: The Chemistry of Life](https://reader035.vdocument.in/reader035/viewer/2022062520/56815c1d550346895dc9f23d/html5/thumbnails/45.jpg)
How enzymes work…
Must form an enzyme-substrate complex Substrate = reactants Substrate meet at active site
“lock and key” = very specific Lowers activation energy needed for reaction to occur
![Page 46: Chapter 2: The Chemistry of Life](https://reader035.vdocument.in/reader035/viewer/2022062520/56815c1d550346895dc9f23d/html5/thumbnails/46.jpg)
Enzyme Action
5. enzyme available for use again
1. reactants/substrates 2. enzyme-substrate complex
4. products produced
3. *activation energy lowered *chemical reaction occurs
active site
![Page 47: Chapter 2: The Chemistry of Life](https://reader035.vdocument.in/reader035/viewer/2022062520/56815c1d550346895dc9f23d/html5/thumbnails/47.jpg)
Regulation of Enzyme Activity
Affected by changes in temp., pH, etc. Proteins can turn enzyme on/off Roles:
Regulate chemical pathways Make materials Release energy Transfer information