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Biomolecules a.k.a

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Biomolecules a.k.a organic compounds The Chemical Building Blocks of Life * The Chemistry of Carbon Organic molecules contain carbon Carbon s ____ valence ... – PowerPoint PPT presentation

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Title: Biomolecules a.k.a


1
Biomoleculesa.k.a organic compounds
The Chemical Building Blocks of Life
2
The Chemistry of Carbon
  • Organic molecules contain carbon
  • Carbons ____ valence electrons allow it to form
    up to ____ covalent bonds. WHY???
  • It can easily bond to itself and form long chains
  • Linear - Cyclic - Branched
  • Make ethane (CH4)
  • Make a cyclical benzene C6H6

3
Functional Groups
  • Chemical properties and reactivity are a result
    of functional groups- a configuration of atoms
    attached to the carbon skeleton
  • Functional groups maintain chemical properties no
    matter where they occur
  • Polar molecules are hydrophilic
  • Nonpolar molecules are hydrophobic
  • The degree to which organic molecules interact
    with water affects their function
  • Hydroxyl group (-OH) is one of the most common
    functional groups, it will make a molecule
    soluble in water

4
Macromolecules The Sum of the Parts
  • Many complex biological activities require large
    macromolecules
  • Macromolecules are polymers built by linking
    together small subunits called monomers
  • Proteins are polymers of amino acids
  • Nucleic acids are polymers of nucleotides
  • Polysaccharides (starch and glycogen) are
    polymers of simple sugars (monosaccharides)

5
CondensationIts not just for the water cycle
anymore
  • Macromolecules are constructed by covalently
    bonding monomers by condensation reactions where
    water is removed from the functional groups of
    the monomers
  • Dehydration synthesis (water is removed)
  • A hydroxyl (-OH) from one monomer and a hydrogen
    (-H) from another are removed

6
Condensation reactions are anabolic This means
smaller, lower energy, less complex molecules are
built up into larger, higher energy, and more
complex molecules. This requires a net input of
energy.
7
Hydrolysis
  • Hydrolysis is the reverse of condensation
  • Results in the break down of polymers
  • Hydration reactions add water and break bonds
    releasing energy

animation
8
Hydrolysis reactions are catabolic This means
larger, higher energy, and more complex molecules
are broken down into smaller, lower energy, less
complex molecules.This requires a net release
of energy.
9
Macromolecules
  • Perform complex tasks with precision
  • Basic structure and function of each family
    similar in all organisms (bacteria humans)

10
Families of Biomolecules
  • Carbohydrates
  • Lipids
  • Proteins
  • Nucleic Acids

11
Basic Function
Carbos Lipids N. Acids Proteins
Energy Storage Structure Long term storage Insulation Protection Inheritance Blueprint for metabolism Catalysts Hormones Structure
Starch Glycogen Glucose Sucrose Cellulose Lipid Fats Oils Waxes DNA RNA ATP Proteins Enzymes
12
CarbohydratesHow Sweet It Is!
  • General formula (CH2O)n
  • Simple sugars or large molecules made of sugar
    monomers
  • Monosaccharides (monomer) are covalently linked
    by condensation reaction to form polysaccharides
    (polymers)

13
Sugars
  • Monosaccharides
  • Five carbon Ribose
  • Six carbon glucose and fructose
  • Disaccharides
  • Sucrose
  • Lactose
  • Polysaccharides
  • Starch
  • Cellulose
  • Glycogen

14
Polysaccharides
  • Three Types
  • Glycogen animal storage product that
    accumulates in the liver
  • - Highly branched
  • Glucose?Glycogen?glucose?bloodstream
  • Starch plant energy storage
  • - Helical
  • - Easily digested by animals through hydrolysis

15
Cellulose
  • Polysaccharide found in plant cell walls
  • For humans cellulose is indigestible and forms
    dietary fiber
  • Made up entirely of ß glucoses
  • Structure is constrained into straight
    microfibrils
  • Not an energy source for animals
  • Chitin insect exoskeletons

16
Lipids
  • Long-term energy storage
  • Generally insoluble in water
  • nonpolar
  • hydrophobic
  • Structural components of cells (phospholipids)
  • Cellular messengers (hormones)

17
More FAT
  • Triglycerides are composed of three fatty acids
    covalently bonded to one glycerol molecule
  • Fatty acids are composed of CH2 units and are
    hydrophobic
  • Fatty acids can be saturated (all single bonds)
    or unsaturated (one or more double bonds)
  • A fat (mostly saturated) is solid at room temp.,
    while an oil (mostly unsaturated) is liquid at
    room temp.

18
  • Glycerol is a molecule with three carbons in a
    row, each with a hydroxide group
  • Fatty acid chains are hydrocarbons
  • that is, they are composed of mostly carbons and
    hydrogens.
  • This is a molecule that is VERY hydrophobic.
  • When glycerol combines with the fatty acid chains
    it forms a carboxyl group between them
  • They link by the loss of a water molecule.

Carbon can bond to four different substances, but
sometimes it will share more than one pair of
electrons.
animation
19
Phospholipids
  • Important structural component of cell membranes
  • Phosphate group (head) is polar and water soluble
    (hydrophilic)
  • Two fatty acid tails are hydrophobic
  • This allows the phospholipids to
  • form bilayers and membranes

20
Other Lipids
  • Steroids
  • Insoluble in water
  • Built around a four ringed skeleton
  • Cholesterol
  • Component for animal cell membranes
  • Formation of myelin sheath covering nerves
  • Hormones
  • Chemical messengers
  • Waxes
  • Many fatty acids linked to a long backbone
  • Waterproofing in plants, ears, beehives

overview
21
Proteins
  • 50 dry weight of body
  • Mammal cell contains 10,000 proteins
  • Control elements (enzymes)
  • Organic catalysts
  • Mediators of metabolism
  • Direct development, maintenance, and growth
  • Structural elements (cell membrane, muscles,
    ligaments, hair, fingernails)
  • Regulate what goes into/out of cells

22
Building Blocks of ProteinsAmino Acids
  • Amino acids (monomers) are linked together to
    form proteins (polymers)
  • Each unique sequence of amino acids forms a
    different protein
  • All living things (even viruses) use the same 20
    amino acids
  • 20 different Amino Acids
  • Amino end (NH2)
  • Carboxyl end (COOH)
  • Hydrogen
  • R group variable component

23
Amino Acids
  • Amino Acids are grouped by whether R- group is
    polar or non-polar
  • Positively charged side chain
  • Negatively charged side chains
  • Polar but uncharged side chains
  • Hydrophobic side chains
  • Special cases

24
Protein Assembly
  • AAs are linked together by joining the amino end
    of one molecule to the carboxyl end of another
  • Peptide bond forms a chain called a polypeptide

http//www.biotopics.co.uk/as/aminocon.html
25
Protein Structure
  • Primary structure
  • Specific linear sequence of AAs in a
    polypeptide
  • Determined from code in inherited genetic
    material
  • Changes in primary structure can alter proper
    functioning of the protein

26
  • Secondary structure
  • the tendency of the polypeptide to coil or
  • pleat due to H-bonding between R- groups
  • ?-helix, ?-pleated sheet, or random coil

27
  • Tertiary structure
  • shape of entire chain folded, twisted, or
  • globular
  • shape related to function and properties

28
  • Quaternary structure
  • more than one polypeptide chain

29
Nucleic Acids
  • Polymers composed of monomer units known as
    nucleotides
  • Information storage
  • DNA (deoxyribonucleic acid)
  • Protein synthesis
  • RNA (ribonucleic acid)
  • Energy transfers
  • ATP (adenosine tri-phosphate) and NAD
    (nicotinamide adenine dinucleotide)

30
Nucleotides
  • Nucleotide structure
  • Phosphate
  • Nitrogenous base
  • Purines (double-rings)
  • Adenine and Guanine
  • Pyrimidines (single-rings)
  • Cytosine, Thymine, and Uracil
  • Sugar either ribose or deoxyribose
  • pentoses in ring form
  • Deoxyribose lacks one oxygen

31
Functions of Nucleic Acids
  • DNA Physical carrier of genetic information
  • Restricted to nucleus
  • RNA key component of protein synthesis
  • Messenger RNA (mRNA) blueprint for construction
    of a protein
  • Ribosomal RNA (rRNA) construction site where
    the protein is made
  • Transfer RNA (tRNA) truck delivering the proper
    AA to the site of construction

32
The End
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