Chemistry of Life

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Chemistry of Life

• Chapter 2

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• How are living things (biotic) and non-living
  (abiotic) things different?
• How are they the same?
• All composed of Atoms

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• Element substance that cant be broken down
  into simpler chemical substances.
• Represented by 1 or 2 letter code
• (H, O, Na, Cl, He, Ne)
• Made up of atoms
• Atoms smallest particle of an element that has
  characteristics of that element.

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Structure of an Atom

• In the Nucleus mass of the atom
• Protons (p) positive charge
• Neutrons (n0) no charge (neutral)
• In the Electron Cloud space of atom
• Electrons (e-) negative charge in constant
  motion revolving around nucleus
• 7 different energy levels each can only hold a
  set amount of electrons

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IONS

• Atoms or group of atoms with a positive or
  negative charge
• Formed by loss or gain of electrons

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Combination of Substances

• Mixture
• Physical combination of 2 or more things.
• Each substance keeps its original properties.
• Compound
• Chemical combination of 2 or more elements.
• The substances lose their original properties and
  form something new.

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Bonding

• Combination of elements with electrons to become
  more stable
• Atoms want to have full outer e- level
• 2 e- in 1st level
• 8 e- in 2nd through 7th levels

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• Covalent Bonding
• Sharing of electrons between atoms
• example Water (H2O)
• Ionic Bonding
• Transferring of electrons between atoms
• Example Table Salt (NaCl)

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Chemical Reactions

• forming or breaking of bonds between atoms
• causes substances to combine and recombine to
  form molecules or compounds.
• Occur only when conditions are right
• Metabolism chemical reactions that occur over
  and over inside our cells

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Measuring Acids and Bases

• chemical reactions depend on how acidic or basic
  the environment is
• Indicators pH paper, litmus, and other
  substances that change color
• pH a measure of how acidic or basic a solution
  is.
• Scale from 0 to 14
• 0 strongest acid (lots of Hydrogen ions)
• 7 neutral
• 14 strongest base (few hydrogen ions)

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ACIDS and BASES

• Acids
• Sour taste (fruits)
• forms hydrogen ions (H) in water
• abundance of H ions
• pH below 7, the lower the pH the stronger the
  acid (Strong Acid pH 1 Weak Acid pH 6.9)
• ex HCl, H2SO4, HC2H3O2

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• Bases
• Bitter taste, slippery, good cleaners
• forms hydroxide ions (OH-) in water
• abundance of OH- ions
• Has a pH above 7, higher the pH the stronger the
  base (Strong base pH 14 Weak base pH 7.1)
• Ex NaOH, NH3

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Organic Molecules

• Molecules involved in life
• HONC 1234 rule to describe most common organic
  elements and their bonding patterns.
• H hydrogen - 1 bond
• O oxygen 2 bonds
• N Nitrogen 3 bonds
• C carbon 4 bonds

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Role of Carbon in Organisms

• Properties of Carbon
• Natures tinker toy
• 4 electrons in outer shell
• Forms 4 covalent bonds to become stable (single,
  double, or triple bonds)
• Forms chains, branched chains, and rings

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• Image of carbon skeletons

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Isomers

• Molecules with same chemical formula, but
  different structural arrangements.
• Each has different properties
• Ex Glucose and Fructose (C6H12O6)

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Building Blocks

• 50 common building blocks to carry out lifes
  functions
• Monomer small molecule building block of life
• Ex glucose
• Polymer molecule formed when monomers are
  linked together
• Ex cellulose is a polymer of glucose

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• Condensation and
• Hydrolysis Reactions

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Condensation Reaction

• Chemical reaction that occurs when monomers are
  linked together to form polymers.
• Creates 1 water (H2O) molecule per link
• Also called synthesis or dehydration

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Hydrolysis Reaction

• Chemical reaction that occurs when polymers are
  broken down into monomers
• Addition of 1 water (H2O) for each broken link
• Occurs during digestion, decomposition

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• Condensation and
• Hydrolysis Reactions

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Types of Organic Molecules

• Carbohydrates
• Lipids
• Proteins
• Nucleic Acids

• These 4 groups of organic molecules, their
  monomers, polymers, and functions, are basic and
  essential to biology!

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CARBOHYDRATES (starches and sugars)

• Function store energy for short term sometimes
  used for structural support
• Structure
• Composed of C, H, and O
• Ratio of 2 H for every 1 O
• Monosaccharide single sugar
• Glucose (blood sugar), fructose (fruit sugar)

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• Disaccharide two sugars
• Sucrose (table sugar glucose fructose)
• Polysaccharide many sugars
• Starch storage in plants (potatoes)
• Glycogen storage in animal muscle and liver
  cells
• Cellulose fiber in plants (wood, paper)

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LIPIDS (fats, oils, waxes, steroids)

• Functions
• Long term energy storage
• Insulation, cushioning of organs
• Waterproofing (waxes)
• Chemical messengers in body (steroids)

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• Properties
• Composed of C, H, and O
• Much less oxygen than carbon or hydrogen
• Beef fat C57H110O6
• Nonpolar no net electrical charge
• Insoluble in water

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• Triglycerides type of fat
• Composed of 3 fatty acids (monomers) and 1
  glycerol (sugar)
• Saturated fat solid at room temp, lacks double
  bonds between carbons.
• Unsaturated fat liquid at room temp (oils), at
  least 1 double bond between carbon atoms
  somewhere in fatty acid chain

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Triglyceride
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• Steroids
• 4 connected carbon ring structures
• Used as chemical messengers in body
• Ex sex hormones (testosterone and estrogen)
• Phospholipids
• Composed of 2 fatty acids, glycerol, and a
  phosphate group
• Major component of cell membrane

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• A Steroid

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• Phospholipid

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PROTIENS
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• Functions
• Structure hair, finger nails, skin
• Antibodies
• Hormones
• Movement muscles
• Enzymes proteins that speed up chemical
  reactions in the body
• 10,000 types of enzymes, each has a different
  function

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• Structure
• Composed of C, H, O, N, and sometimes S
• Made of monomers called amino acids (20 different
  types)

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• Amino acids consist of central carbon with the
  following attached
• Hydrogen
• Amine group, NH2
• Carboxyl group COOH
• R-group What makes the A.A. different from the
  rest. (R can be one of 20 different groups, from
  a simple H to a ringed structure)
• Peptide Bond covalent bond formed when amino
  acids link together to form proteins.

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• Polypeptide formation

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NUCLEIC ACIDS(DNA and RNA)

• Structure
• Composed of C, H, O, N, and P
• Monomers nucleotides
• Sugar ribose or deoxyribose
• Phosphate group
• Nitrogen Base A, T, G, C, and U

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• Function
• Information Storage
• Heredity DNA is used to pass genetic info to
  next generation
• Direct cell activities RNA directs synthesis of
  proteins

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• Nucleotide

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Double helix
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Revisiting Enzymes

• 28 days to digest food without enzymes, only 2-4
  hours with enzymes!
• Catalyst - substance that speeds up chemical
  reactions w/o being consumed by the reaction
  (recycled)
• substrate - molecule(s) going through chemical
  reaction
• product -new molecule(s) formed after chemical
  reaction

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• active site - place on enzyme where substrate
  fits, like a hand in a glove.
• substrate specific - each enzyme will only react
  with the substrate that fits the active site
• denaturation - a change in the active site so it
  no longer reacts with the substrate, may be
  caused by extremes in temperature, pH, or toxins

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Protein denaturation