Comparison of Ionic, Polar Covalent, and Nonpolar Covalent Bonds

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Comparison of Ionic, Polar Covalent, and Nonpolar
Covalent Bonds
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Formation of an Ionic Bond

• A valance electron from Na is transferred to Cl
• Cl now has 18e and 17p resulting in a charge
• Na has 10e and 11P resulting in a charge.

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Nonpolar and Polar Covalent Bonds
Non polar covalent Bonds equally share electrons
Polar covalent bonds share electrons unequally
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Hydrogen Bonds

• Too weak to bind atoms together
• (intra-molecular bonds within molecule)
• Important as inter-molecular bonds
• between to different molecules
• Important for giving proteins (enzymes) and DNA
  both shape and functionality.
• Hold water molecules together
• Responsible for surface tension in water

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Hydrogen Bonds in Water
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Hydrogen Bonds
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Properties of Water

• Water makes up to 50-80 of all living cells.
• Water stabilizes internal temperature of the body
• Hydrogen bonds stabilize large shifts in
  temperature
• Evaporate cooling (sweating) is critical from
  maintaining 98.6 degrees temperature in hot
  environments or increased physical workloads.
• Water is necessary for all biochemical reactions
  that take place in the body.

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Polarity of Water

• Oxygen has a greater electronegativity.
• Hydrogens one electron spend more time in
  Oxygen's outermost energy level.
• The result is more electrons around the oxygen
  making it more negative.
• Hydrogen losses its electron. Its proton is
  unopposed making it more positive.

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Properties of Water

• Water makes up to 50-80 of all living cells.
• Water stabilizes internal temperature of the body
• Hydrogen bonds stabilize large shifts in
  temperature
• Evaporate cooling (sweating) is critical for
  maintaining 98.6 degrees temperature in hot
  environments or increased physical workloads.
• Water is necessary for all biochemical reactions
  that take place in the body.

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Properties of Water

• Water is a powerful splitting agent. (Hydrolysis)
  means water splitting. Occurs in breaking down
  reactions
• Is known as the universal solvent. ( Polarity
  allows it to dissolve stuff.) water molecules
  slit the ionic bonds in NaCl-

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Polarity

• Polar molecules associate with water and will
  dissociate from lipids (fats) .
• Polar hydrophilic (philic loving)
• Lipophobic (lipid fearing)
• Non-polar molecules associate with lipids will
  not associate with water and are considered to be
  
• Non-polar hydrophobic (water fearing)
• Lipophilic Lipid loving

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Organic Compounds

• Organic compounds contain carbon as the
  backbone.
• It has the ability to create 4 covalent bonds
  which is important for making large complex
  structures.
• Organic compounds include
• Carbohydrates (sugars)
• Lipids (fats and oils)
• Proteins ( muscle, enzymes)
• Nucleic acids (DNA and RNA)
• They may be built up or broken down depending on
  what the system requires.
• May have a variety of functional groups

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Dehydration Synthesis

• Dehydrate( remove water)/ Synthesis( Build)
• Monomers bond together to form a polymer with the
  removal of a water molecule (dehydration)
• Removal OH of one and H of the other hydroxyl
  group forms the water.
• A covalent bond will result.

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Hydrolysis

• Translates into Water/splitting
• Addition of a water to a polymer causes (lysis)
  of the covalent bond joining the 2 monomers.
• Reestablishes the hydroxyl groups in both
  monomers
• All digestion reactions consists of hydrolysis
  reactions

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Monomers/Polymers

• Carbohydrates
• Monosaccharides
  Polysaccharides
• Fats (lipids)
• Glycerol 3 fatty Acids
  Triglycerides
• Protein
• Amino acids
  Polypeptide
• Nucleic Acids
• nucleotides DNA, RNA
• Dehydration Synthesis
• Hydrolysis

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Carbohydrates

• Hydrophilic organic molecule that contain
  carbon, hydrogen, and oxygen 121 atomic ratio(
  carbo/carbonhydrate/H2O)
• i.e. glucose C6H12O6
• Names of carbohydrates
• word root sacchar- or the suffix -ose often used
• Glucose is a monosaccharide which functions as a
  major fuel source for the cells.

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Carbohydrates

• Dehydration synthesis reactions allow the cell
  store excess carbohydrates in the form of
  glycogen.
• Hydrolysis reactions allow the cell to break the
  bonds holding the polysaccharide together
  allowing it to release more simple sugars.

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Disaccharides

• Major disaccharides
• sucrose table sugar
• glucose fructose
• Lactose sugar in milk
• glucose galactose
• Maltose grain products
• glucose glucose
• All digested carbohydrates converted to glucose
  broken down in ATP (Cellular fuel).

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Glycogen

• Glycogen is an energy storage polysaccharide
  produced by animals. 2 storage sites
• Liver cell synthesize glycogen after a meal
  which can be broken down later to maintains blood
  glucose levels.
• Muscle cells Store glycogen within the muscle at
  is only used by the muscle cell.

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Starch and Cellulose

• Starch is the storage form of sugar produced by
  plants. We produce an enzyme that breaks the
  bonds between the sugars allowing digestion to
  occur. i.e. potatoes and grains
• Cellulose provides structure to plants but
  contains a different type of bond. The ß form is
  insoluble because we dont produce the enzyme
  .i.e. dietary fiber

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Lipids

• Hydrophobic organic molecule
• Composed of carbon, hydrogen and oxygen
• Better fuel source since it contains many more
  carbon and hydrogen molecules.
• There is an unlimited supply.
• Chain of 4 to 24 carbon atoms
• carboxyl (acid) group on one end, methyl group on
  the other and hydrogen bonded along the sides
• Classified
• saturated - carbon atoms saturated with hydrogen
• unsaturated - contains CC bonds without hydrogen

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Lipids Found in the Body

• Neutral fats found in subcutaneous tissue and
  around organs.
• Phospholipids chief component of cell membranes
• Steroids cholesterol, bile salts, vitamin D,
  sex hormones, and adrenal cortical hormones
• Eicosanoids prostaglandins, leukotrienes, and
  thromboxanes
• These play a role in various reactions in the
  body such as inflammation and immunity.
• Lipoproteins transport fatty acids and
  cholesterol in the bloodstream
• Fat-soluble vitamins A,D, E, and K

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Triglycerides

• Functions
• energy storage in adipose (fat) tissue
• Fats contain 9 kcal per gram where as
  carbohydrates and proteins contain 4 kcal per
  gram.
• They contain more energy rich hydrogen.
• insulation
• Prevent heat loss from the body
• protection
• Adipose tissue cushions the organs.

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Triglycerides (Neutral Fats)

• Contain C, H, and O, but the proportion of oxygen
  in lipids is less than in carbohydrates 3
• Fatty acids are bonded to a glycerol molecule
  during dehydration synthesis.
• At room temperature Contain double bonds.
• when liquid called oils
• often mono and polyunsaturated fats from plants
• when solid called fat
• saturated fats from animals.
• No double bonds.
• Function - energy storage, insulation and shock
  absorption

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Neutral Fats (Triglycerides)

• Composed of three fatty acids bonded to a
  glycerol molecule

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Phospholipids

• Modified triglycerides with two fatty acid groups
  and a phosphorus group

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Protein Functions

• Catalysts
• proteins which are enzymes significantly increase
  the rate of a chemical reaction i.e. Salivary
  Amylase increases the rate of hydrolysis of
  starch.
• Structural
• hold the parts of the body together i.e.
  collagen, elastin and keratin
• Communication
• act as chemical messengers between body areas
  .i.e. hormones such as insulin.
• Transport
• allow substances to enter/exit cells
• Carry things in the blood i.e. hemoglobin,
  lipoproteins,

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Protein Functions

• Movement
• Actin and myosin function in muscle contraction
• Defense
• Antibodies( immunoglobulins) recognize and
  inactivate foreign invaders( bacteria, toxins,
  and some viruses)
• Metabolism
• Help regulate metabolic activities, growth and
  development
• Regulation of pH
• Plasma proteins such as albumin can function both
  as an acid or a base. Therefore have an important
  role as a buffer

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Amino Acids Structure

• Building blocks of protein
• Amino and carboxyl group groups are common in all
  Amino acids.
• R-group (radical group) 20 amino acids are
  different both structurally and from a functional
  level.

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Different R- groups
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Protein

• Macromolecules composed of combinations of 20
  types of amino acids bound together with peptide
  bonds
• Animal ,dairy and right combination of beans and
  rice are good sources of protein.
• Enzymes are specific types to proteins that
  enable reactions.

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Protein Structure

• Primary structure
• amino acid linked together by peptide bonds. The
  order of the amino acids critical for both form
  and function. No hydrogen bonds formed.
• Secondary structure The primary structure will
  now form hydrogen bonds and take one of 2 forms
• a helix (coiled), ß-pleated sheet (folded)
• Tertiary structure
• more hydrogen bonds form and increased
  interaction between R groups in surrounding water
  results in protein taking a globular 3
  dimensional shape.
• Quaternary structure
• two or more separate polypeptide chains conjugate
  and form a functional protein
• Hemoglobin.

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Structural Levels of Proteins

• Primary amino acid sequence
• Secondary alpha helices or beta pleated sheets

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Structural Levels of Proteins

• Tertiary superimposed folding of secondary
  structures
• Most enzymes are in this form.
• Quaternary polypeptide chains linked together
  in a specific manner

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Functional Proteins (Enzymes)

• Enzymes are chemically specific. They fit a
  specific substrate like a lock and key.
• Enzyme names usually end in ase
• for example Lactase will be specific for the
  substrate lactose ( Glucose Galactose)
• Gycosidic bond
• Frequently named for the type of reaction they
  catalyze i.e. hydrolases add water during
  hydrolysis reactions.
• lipase/lipids, protease/ proteins,
• Act as biological catalysts which lower
  activation energy allowing reactions to occur at
  faster rates.

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Activation Energy

• Activation energy refers to the extra energy
  required to break an existing chemical bonds and
  initiate a chemical reaction.
• Activation energy determines rate of reaction
  (higher activation energy slower reaction)
• catalyst - substance that lowers the activation
  energy by influencing (stressing) chemical bonds

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Characteristics of Enzymes
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Enzymatic Reaction Steps
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Enzyme Substrate Complex

• Enzymes need their 3 dimensional structure
• created by both Hydrogen and disulfide bonds
  which is specific to a certain substrate.
• Proper conditions are needed to keep these
  enzymes functioning.
• pH
• Temperature

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Protein Denuaturation

• Hydrogen bonds are broken and tertiary level
  protein reverts back to primary structure.
  Peptide bonds are still intact.

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Protein Denuaturation

• Proteins will become denatured if
• ? pH
• ? temperature
• Hydrogen bonds are broken from complex tertiary
  level proteins to basic primary structure.
• Peptide bonds are still intact.
• Visible changes you see when frying an egg

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Nucleic Acids

• Two major classes DNA and RNA
• Composed of carbon, oxygen, hydrogen, nitrogen,
  and phosphorus
• Five nitrogen bases contribute to nucleotide
  structure
• Adenine (A) Thymine (T)
• Guanine (G) Cytosine (C)
• Uracil (U) replaces Thymine in RNA

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Nucleotides

• The structural unit of the a nucleotide is
  composed of
• N-containing base A,T,C,G and U in RNA
• Pentose sugar Ribose, and deoxyribose
• Phosphate group

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Deoxyribonucleic Acid (DNA)

• Double-stranded helical molecule confined in the
  nucleus of the cell
• Helical shape is a result of H-bonds between a
  purine on one strand and a pyramidine on the
  other strand
• A only pairs with T
• G only pairs with C
• Replicates itself before the cell divides,
  ensuring genetic continuity
• Provides instructions for protein synthesis

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Structure of DNA
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Structure of DNA
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Ribonucleic Acid (RNA)

• Single-stranded molecule
• Made from the nucleotides that complimentary pair
  
• A U G C
• Three varieties of RNA
• messenger RNA transcribe DNA and carry it out of
  nucleus.
• transfer RNA Bring amino acids to site of
  protein synthesis (ribosome).
• ribosomal RNA building blocks of ribosomes ,made
  in the nucleolus

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Adenosine Triphosphate (ATP)

• Adenine-containing RNA nucleotide with three
  phosphate groups
• Second and third phosphate groups are attached by
  high energy covalent bonds
• The 3rd high energy phosphate bond of ATP is
  hydrolyzed producing ADP P energy
• The cell can recycle the ADP and P back into ATP
  using the energy harvested from dietary foods
  primarily carbohydrates and lipids.
• Source of immediately usable energy for the cell.
• It is the currency that all cellular reactions
  accept.

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Adenosine Triphosphate (ATP)
Figure 2.22
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How ATP Drives Cellular Work
Figure 2.23