Introductory Biochemistry II

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Biochemistry The Chemistry of the Human Body

• Part IV - Macromolecules

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Macromolecules

• Many of the common macromolecules are synthesized
  from monomers.

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Carbohydrates

1. Monosaccharides
2. Disaccharides
3. Polysaccharides

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Carbohydrates

• Compounds which provide energy to living cells.
• Made up of carbon, hydrogen and oxygen with a
  ratio of two hydrogens for every oxygen atom.
• The name carbohydrate means "watered carbon" or
  carbon with attached water molecules.
• Are used directly to supply energy to living
  organisms.

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Carbohydrates

• Many carbohydrates have empirical formuli which
  would imply about equal numbers of carbon and
  water molecules.
• The general formula for carbohydrates is (CH2O)n.
• The names of most sugars end with the letters
  -ose.
• The pentose sugars ribose and deoxyribose are
  important in the structure of nucleic acids like
  DNA and RNA.

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Carbohydrates

• Three key classification schemes for sugars are
• Monosaccharides
• Disaccharides
• Polysaccharides

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Monosaccharides

• Simple sugars, having 3 to 7 carbon atoms.
• Are linear molecules but in aqueous solution they
  form a ring form structure.
• In aqueous solution, monosaccharides with five or
  more C atoms form cyclic ring structures.
• These 6-membered ring compounds are called
  pyranoses.
• These rings form due to a general reaction that
  occurs between alcohols and aldehydes or ketones
  to form derivatives called hemiacetals or
  hemiketals.

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Monosaccharides
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Monosaccharides

• May form several types of stereoisomers since
  they share the same molecular formula.
• Four Classes of Stereoisomers
• Diastereomers
• Enantiomers
• Epimers
• Anomers

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Monosaccharides Isomers
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Monosaccharides Diastereomers

• Stereoisomers that are not mirror images of each
  other.
• Diastereomers for the molecular formula C5H10O5

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Monosaccharides Diastereomers

• Diastereomers for the molecular formula C6H12O6

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Monosaccharides Enantiomers

• Stereoisomers that are mirror images of each
  other.
• Two types D or L

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Monosaccharides Epimers

• Two diastereomers that differ around one chiral
  center.

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Monosaccharides Anomers

• Stereoisomers that differ in the configuration
  around the anomeric carbon.
• Two types of anomers are a or ß.
• In hemiacetals, the anomeric carbon is at
  position 1.

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Monosaccharides Anomers
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Monosaccharides Anomers

• In hemiketals, the anomeric carbon is at position
  2.

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Disaccharides

• Glycosides
• Formed from two monosaccharides.
• The -OH of one monosaccharide condenses with the
  intramolecular hemiacetal of another
  monosaccharide, forming a glycosidic bond.
• Glycosidic bonds can be a or ß.

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Disaccharides
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Disaccharides

• Common disaccharides are
• Sucrose
• Lactose
• Maltose
• Trehalose

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Disaccharides
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Sucrose

• Prevalent in sugar cane and sugar beets

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Sucrose
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Lactose

• Found exclusively in milk.

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Lactose
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Maltose

• Major degradation product of starch.

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Maltose
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Trehalose

• Found in bacteria, yeast, invertebrates,
  mushrooms and seaweed.
• Glycosidic Linkages
• Protects organisms from extreme temperatures and
  drying out.

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Trehalose

• Is used
• As a preservative for foods and to minimize harsh
  flavors and odors.
• As a moisturizer in cosmetics.
• As an natural sweetener for diabetics.
• Antioxidant to stabilize proteins and lipids in
  neurodegenerative diseases like Alzheimer's and
  Huntington's Disease.
• To protect organs for transplants.

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Trehalose

• Is
• Involved in the regulation of developmental and
  metabolic processes in plants.
• The major transport sugar in shrimp, insects and
  plants.
• The major carbohydrate energy storage molecule
  used by insects for flight.

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Trehalose

• In plants, synthesis is carried out by trehalose
  phosphate synthase and trehalose phosphatase 

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Trehalose
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Trehalose

• Degradation

Trehalase
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Polyssacharides

• Ten or more monosaccharides bonded together to
  form long chains.
• The chains are typically contain hundreds of
  monosaccharaides.
• Can have one, two or many different types of
  monosaccharides.
• Homopolysaccharides
• Heteropolysaccharides

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Polyssacharides
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Polyssacharides

• Are classified as
• Cellulose
• Chitin
• Glycogen
• Starches

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Cellulose Chitin

• Are polysaccharides with 1500 glucose rings chain
  together.
• Function is support and protection.
• The monomers of cellulose and chitin are bonded
  together in such a way that the molecule is
  straight and unbranched.
• The molecule remains straight because every other
  glucose is twisted to an upside-down position
  compared to the two monomers on each side.

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Cellulose Chitin

• Humans and most animals do not have the necessary
  enzymes needed to break the linkages of cellulose
  or chitin.
• Some bacteria and some fungi produce enzymes that
  digest cellulose.
• Some animals have microorganisms in their gut
  that digest cellulose for them.
• Fiber is cellulose, an important component of the
  human diet.

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Cellulose

• Is composed of beta-glucose monomers.
• Cellulose fibers are composed of long parallel
  chains of these molecules.
• The chains are attached to each other by hydrogen
  bonds between the hydroxyl groups of adjacent
  molecules.
• The cell walls of plants are composed of
  cellulose.

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Cellulose
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Chitin

• The cell walls of fungi and the exoskeleton of
  arthropods are composed of chitin.
• The glucose monomers of chitin have a side chain
  containing nitrogen.

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Chitin
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Glycogen

• Animals and some bacteria store extra
  carbohydrates as glycogen.
• In animals, glycogen is stored in the liver and
  muscle cells.
• Between meals, the liver breaks down glycogen to
  glucose in order to keep the concentration of
  glucoses in the blood stable.
• After meals, as glucose levels in the blood rise,
  glucose is removed from the blood and stored as
  glycogen.

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Glycogen
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Glycogen

• Homopolymer of glucose.
• Two types of glycosidic linkage
• a(1, 4) for straight chains
• a(1, 6) for branched chains, occurring every
  8-10 residues.

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Glycogen

• Glycogen is a very compact structure that results
  from the coiling of the polymer chains.
• This compactness allows large amounts of carbon
  energy to be stored in a small volume, with
  little effect on cellular osmolarity.

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Starches

• Starch and glycogen are composed of 300 1000
  alpha-glucose units join together.
• It is a polysaccharide which plants use to store
  energy for later use.
• Starches are smaller than cellulose units, and
  can be more readily used for energy.

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Starches

• Foods such as potatoes, rice, corn and wheat
  contain starch granules which are important
  energy sources for humans.
• The human digestive process breaks down the
  starches into glucose units with the aid of
  enzymes, and those glucose molecules can
  circulate in the blood stream as an energy
  source.

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Starches

• Amylopectin is
• A form of starch that is very similar to
  glycogen.
• Branched but have less branches than glycogen.
• Amylose is
• A form of starch that is unbranched.

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Starches
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Starches Glycogen

• The bond orientation between the glucose subunits
  of starch and glycogen allows the polymers to
  form compact spirals.

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Summary of Carbohydrates

• CHO
• Monosaccharides simple sugars
• Functional group(s)
• Carboxyl
• Hydroxyl
• Disaccharides
• Polysaccharides

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Summary of Carbohydrates
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Summary of Carbohydrates
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Summary of Carbohydrates
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Proteins
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Definitions

• Peptide - a short chain of amino acids bonded
  together.
• Oligopeptide- a short chain of at least 2 amino
  acids and up to 20 amino acids long.
• Polypeptide - a longer chain of many amino acids,
  typically 50 or more. 
• Proteins - consist of one or more polypeptides,
  subunits, chains or domains.

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Proteins

• Are the building materials for living cells,
  appearing in the structures inside the cell and
  within the cell membrane. About 75 of the dry
  weight of our bodies.
• They contain carbon, hydrogen, oxygen, nitrogen,
  sulfur and phosphorus.
• Protein molecules are often very large and are
  made up of hundreds to thousands of amino acid
  units.

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Proteins

• Functions
• Transport oxygen (Hb)
• Build tissue (Muscle)
• Copy DNA for cell replication
• Support the body as structural proteins
• Components of cell membranes (receptors, membrane
  transport, antigens)
• Control metabolic reactions as regulatory
  proteins called enzymes

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Proteins

• Functions
• Hormones
• Storage (egg whites of birds, reptiles seeds)
• Protection (antibodies)
• Toxins (botulism, diphtheria)
• Some proteins are in solution in the blood and
  other body fluids.
• Others are solids that make up the framework of
  tissue, bone and hair.

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Proteins

• Proteins can be characterized as extremely
  long-chain polyamides. The amides contain
  nitrogen, and nitrogen composes about 16 of the
  protein atomic content.
• In the cell, the DNA directs or provides the
  master blueprint for creating proteins, using
  transcription of information to mRNA and then
  translation to actually create proteins.

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Proteins

• Proteins are synthesized via condensation of
  amino acids under the influence of enzyme
  catalysts.
• The 20 amino acids are combined in different ways
  to make up the 100,000 or so different proteins
  in the human body.
• The amino acid units in a protein molecule are
  held together by peptide bonds, and form chains
  called polypeptide chains.

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Proteins
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Proteins

• During translation, the protein goes through
  several different structural stages
• Primary
• Secondary
• Tertiary
• Quaternary
• Final structures may undergo post-translational
  modifications based on their determined function.

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Proteins
Subunit or domain
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Proteins Primary Structure

• The sequence of amino acids in the polypeptide
  chain.
• The sequence of the R groups determines the
  folding of the protein.
• A change of a single amino acid can alter the
  function of the protein.
• Sickle cell anemia - caused by a change of one
  amino acid from glutamine to valine.

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Proteins Primary Structure
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Proteins Secondary Structure

• Folding and coiling due to H bond formation
  between carboxyl and amino groups of non-adjacent
  amino acid.
• R groups are NOT involved.
• This bonding produces two common kinds of shapes
  seen in protein molecules- coils, called alpha
  helices, and beta sheets.
• A single polypeptide may contain many of these
  helices and sheets.

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Proteins Secondary Structures
Alpha
Beta
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Proteins Tertiary Structure

• The overall 3-dimensional shape of the
  polypeptide chain.  
• Hydrophobic interactions with water molecules are
  important in creating and stabilizing the
  structure of proteins. 
• Hydrophobic (nonpolar) amino acids aggregate to
  produce areas of the protein that are out of
  contact with water molecules.

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Proteins Tertiary Structure

• Hydrophilic (polar and ionized) amino acids form
  hydrogen bonds with water molecules.
• Hydrogen bonds and ionic bonds form between R
  groups to help shape the polypeptide chain.
• Disulfide bonds are covalent bonds between sulfur
  atoms in the R groups of two different amino
  acids.  These bonds are very important in
  maintaining the tertiary structure of some
  proteins.

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Proteins Tertiary Structure
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Proteins Tertiary Structure

• The shape of a protein is typically described as
  being globular or fibrous. 
• Globular proteins contain both coils and sheets.
• Fibrous proteins are elongated molecules in which
  either a-helices or ß-pleated sheets are the
  dominant structures. 

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Proteins Tertiary Structure
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Proteins Quaternary Structure

• Relationship among multiple polypeptide chains
  forming one protein structure.
• Contain two or more tertiary structures that
  associate to form a single protein. 
• The overall 3-D structure is due to interactions
  between polypeptide chains after synthesis
• Hydrophobic hydrophilic interactions
• H- bonds
• Ionic interactions
• Disulfide bonds

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Proteins Quaternary Structure
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Proteins Enzymes

• Some proteins are structural, but some are
  control proteins called enzymes.
• These enzymes can be used in the synthesis of
  proteins, including their own synthesis.
• Each protein, including enzymes, is made
  according to a pattern of nucleotides along a
  segment of the DNA called a "gene".
• A single living cell contains thousands of
  enzymes.

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Proteins Enzymes
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Proteins Enzymes

• Speed up the rate of chemical reactions.
• Proteins are able to function as enzymes due to
  their shape.
• Enzyme molecules are shaped like the reactants,
  allowing the reactants to bind closely with the
  enzyme.

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Proteins Enzymes

• Have a small a pocket located on the 3-D surface
  of the folded protein.
• This is the binding site, where the substrate
  binds and chemical reactions take place .

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Proteins Enzymes

• The binding site matches the shape of the
  substrate molecules.
• The enzyme is then able to hold the substrate
  molecules in the correct orientation for the
  chemical reaction to proceed.
• The enzyme itself does not participate in the
  reaction and is not changed by the reaction.

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Other Kinds of Proteins

• Simple proteins contain only amino acids.
• Conjugated proteins contain other kinds of
  molecules.
• Three key classes of conjugated proteins
• Glycoproteins (carbohydrates)
• Nucleoproteins (nucleic acids)
• Lipoproteins (lipids)

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Conjugated Proteins
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Conjugated Proteins
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Amino Acids

• Are organic compounds.
• Each has a carboxyl group and an amino group
  attached to the same carbon atom, called the
  alpha carbon.
• Amino acids have the general form

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Amino Acids

• There are 20 amino acids which make up the
  proteins, distinguished by the R-group.
• The structure of the R-group determines the
  chemical properties of the amino acid.
• Types of chemical properties
• Polar Charged
• Nonpolar
• Electrically Charged

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Amino Acids Polar Uncharged

• Are hydrophilic and can form hydrogen bonds.
• Serine
• Threonine
• Glutamine
• Asparagine
• Tyrosine
• Cysteine

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Amino Acids Nonpolar

• Are hydrophobic and are usually found in the
  center of the protein.
• Also found in proteins which are associated with
  cell membranes.

1. Glycine
2. Alanine
3. Valine
4. Leucine

1. Isoleucine
2. Methionine
3. Phenylalanine
4. Tryptophan
5. Proline

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Amino Acids Electrically Charged

• Have electrical charges that can change depending
  on the pH.
• Aspartic Acid
• Glutamic Acid
• Lysine
• Arginine
• Histidine

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Amino Acids Chemical Properties

• The simplest amino acid is glycine. It fits in
  tight spaces in the 3-D structure of proteins. It
  contain hydrogen as an R group.
• Cysteine can form covalent disulfide bonds in 3
  and 4 structures.
• Proline has a unique structure and causes kinks
  in the protein chains.

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Amino Acids

• Amino acids are the structural elements from
  which proteins are built.
• When amino acids bond to each other, it makes an
  amide bond.
• This bond is formed as a result of a condensation
  reaction between the amino group of one amino
  acid and the carboxyl group of another.

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Amino Acids

• Amino acids can have either left-handed or
  right-handed molecular symmetry.
• The most common are left-handed amino acids.
  These are the building blocks of proteins.

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Amino Acids

• The human body can synthesize all of the amino
  acids necessary to build proteins, except for the
  ten called the essential amino acids.
• An adequate diet must contain these essential
  amino acids.
• Typically, they are supplied by meat and dairy
  products, but if those are not consumed, some
  care must be applied to ensuring an adequate
  supply.

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Amino Acids Non-essential

• The 10 amino acids that we can produce are
  alanine, asparagine, aspartic acid, cysteine,
  glutamic acid, glutamine, glycine, proline,
  serine and tyrosine.
• Tyrosine is produced from phenylalanine, so if
  the diet is deficient in phenylalanine, tyrosine
  will be required as well.

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Amino Acids Essential

• The essential amino acids are arginine (required
  for growing children), histidine, isoleucine,
  leucine, lysine, methionine, phenylalanine,
  threonine, tryptophan, and valine.
• Humans do not have all the enzymes required for
  the biosynthesis of essential amino acids.

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Amino Acids

• The failure to obtain enough of any of the 10
  essential amino acids has serious health
  implications and can result in degradation of the
  body's proteins.
• Muscle and other protein structures may be
  degraded to obtain the one amino acid that is
  needed.
• The human body does not store excess amino acids
  for later use. The amino acids must be obtained
  from food daily.

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Amino Acids
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Summary of Proteins Amino Acids

• Monomer amino acids
• 20 total, 9 or 10 essential
• Functional group(s)
• Carboxyl
• Amino
• Polymer
• Polypeptide
• Protein

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Summary of Amino Acids
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Nucleic Acids

• Control the processes of heredity
• Transcription
• Translation
• Cell Replication
• The key nucleic acids are
• DNA (deoxyribonucleic acid)
• RNA (ribonucleic acid)

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Nucleic Acids

• Nuclei acid consist of a long chain of units
  called nucleotides.
• Nucleotides are the basic structural units of
  nucleic acids
• The nucleotides are made up of a phosphate group,
  a pentose sugar, and a nitrogen base.

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Nucleic Acids
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Nucleic Acids

• The sugar ribose is characteristic of RNA.
• The sugar deoxyribose is characteristic of DNA.

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Nucleic Acids

• For RNA, the bases are adenine, guanine, cytosine
  and uracil.
• For DNA, the bases may be adenine, guanine,
  cytosine or thymine.

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Nucleic Acids
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Nucleic Acids

• The larger bases adenine and guanine are purines
  which differ in the kinds of atoms that are
  attached to their double ring.
• The other bases (cytosine, uracil, and thymine)
  are pyrimidines, which differ in the atoms
  attached to their single ring.
• The resulting DNA (deoxyribonucleic acid)
  contains no uracil, and RNA(ribonucleic acid)
  does not contain any thymine.

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DNA

• Stores information regarding the sequence of
  amino acids in each of the bodys proteins.
• Is the master blueprint for the production of
  proteins and cell replication.
• In protein synthesis, serves as a pattern for
  mRNA synthesis, in a process called
  transcription.
• mRNA contains all the DNA information to
  manufacture a protein, in a process called
  translation.

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DNA Structure

• Is a double helix.
• The bases may be attached in any order. This
  gives the vast number of possibilities of
  arrangements, making the genetic code diverse.
• The bases are only attached by hydrogen bonds to
  their complementary base. This arrangement makes
  possible the separation of the strands and the
  replication of the DNA double helix.

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DNA Structure
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DNA Structure

• Antiparallel
• The end of a single strand that has the phosphate
  group is called the 5 end. The other end is the
  3 end.
• The two strands of a DNA molecule run in opposite
  directions.

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DNA Structure
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DNA Structure

• Complimentary base pairing
• A-T
• G-C
• Two hydrogen bonds hold adenine to thymine.
• Three hydrogen bonds hold cytosine to guanine.

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DNA Base Pairing
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RNA

• Is directly involved in the synthesis of proteins
  in a process called "translation".
• mRNA itself is directed synthesized from DNA in a
  process called transcription.
• mRNA is the template for the synthesis of all
  proteins.
• RNA has many forms, but the three most important
  are messenger RNA (mRNA), transfer RNA (tRNA) and
  ribosomal RNA (rRNA).

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RNA Structure
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RNA Base Pairing
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mRNA

• The anti-sense strand is used as a template to
  produce a single strand of mRNA.
• The sequence of bases on a segment of DNA called
  a gene is copied to a strand of mRNA with the
  assistance of RNA polymerase.
• The bases in the mRNA strand are complimentary to
  the bases in DNA.

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mRNA

• The mRNA contains three-letter codes, called a
  codon. It is the code for one amino acid.
• The sequence of codes in DNA therefore determines
  the sequence of amino acids in the protein.

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mRNA

• The mRNA has regions called introns and exons.
• Introns are not a part of the pattern for the
  protein to be synthesized, so those segments are
  excised from the mRNA.
• Exons are the only segments present before the
  mRNA's are released from the nucleus.
• These pattern for protein synthesis is then read
  and translated into the language of amino acids
  for protein synthesis with the help of tRNA.

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mRNA
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tRNA

• Is directly involved in the translation of the
  sequence of nucleotides in mRNA with rRNA.
• The synthesis of tRNA itself is directed by the
  DNA in the cell that provides a pattern for the
  production of mRNA by "transcription".
• When mRNA reaches rRNA to be translated, tRNA
  molecules with all the required amino acids must
  be present for the process to proceed.
• Since most proteins use all twenty amino acids,
  all must be available, attached to appropriate
  tRNA molecules.

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tRNA

• Is commonly called a cloverleaf form.
• Binds an amino acid at one end opposite to the
  anticodon on the other end.
• This anticodon will bind to a codon consisting of
  three nitrogenous bases which specify an amino
  acid according to the genetic code.

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tRNA

• The many types of tRNA have roughly the same size
  and shape, varying from about 73 to 93
  nucleotides.
• Besides the usual bases A, U, G, and C, all have
  a significant number of modified bases, which are
  formed by modification after the transcription.

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tRNA
Letter Code Modified Bases
I Inocine
mI methylinosine
mG methylguanosine
m2G dimethylguanosine
Psi Pseudouridine
D Dihydrouridine
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tRNA

• All tRNAs have sequences of nucleotides that are
  complementary to other parts of the molecule and
  base-pair to form the five arms of the tRNA.
• Four of the arms are fairly consistent, but the
  variable arm can range from 4 to 21 nucleotides.

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tRNA
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rRNA

• Associates with a set of proteins to form
  ribosomes.
• Physically moves an mRNA molecule and catalyze
  the assembly of amino acids into protein chains.
• Binds tRNAs and various accessory molecules
  necessary for protein synthesis.
• Ribosomes are composed of a large and small
  subunit, each of which contains its own rRNA
  molecule or molecules.

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rRNA
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Translation

• Translation is the whole process by which the
  base sequence of an mRNA is used to bring and
  join amino acids in a polypeptide.
• The three types of RNA participate in this
  essential protein-synthesizing pathway in all
  cells.

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Translation
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ATP

• Adenosine triphosphate is a nucleotide that is
  used in energetic reactions for temporary energy
  storage.
• Energy is stored in the phosphate bonds of ATP.
• The cells use the energy stored in ATP by
  breaking one of the phosphate bonds, producing
  ADP.

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ATP
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ATP
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ATP
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Summary of Nucleic Acids

• Monomer nucleotide
• A, T (or U), C, G
• Functional group(s)
• Phosphate
• Amino
• Hydroxyl
• Polymer
• DNA and RNA

Basic Nucleotide Structure
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Summary of Nucleic Acids
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Lipids

• Fats, oils, waxes, and sterols are collectively
  known as lipids.
• Fats contain only carbon, hydrogen, and oxygen.

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Lipids

• Are insoluble in water but soluble in nonpolar
  solvents. 
• Are also an important component of cell
  membranes.
• Used for long-term energy storage.
• One gram of fat stores more than twice as much
  energy as one gram of carbohydrate.

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Lipids

• Important classes of lipids
• Phospholipids
• Steroids
• Glycerides
• Waxes

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Phospholipids

• Contain
• Phosphate group on third -OH group of glycerol.
• Two fatty acids.
• Have a polar head, which increases hydrophilicity.

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Phospholipids

• Arrange themselves into double-layered membranes
  with the water-soluble phosphate ends on the
  outside and the fatty acid facing the inside.
• Cell membranes are not rigid or stiff since
  phospholipids are in constant motion as they move
  with the surrounding water molecules and slide
  past one another.

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Phospholipids

• They also form spheroid structures called
  micelles.

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Steroids

• Have no fatty acid component.
• Contains a backbone of 4 carbon rings in 6-6/6-5
  arrangement.
• Examples
• Hormones
• Cholesterol
• Cell membrane components

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Steroids
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Steroids Cholesterol

• Cholesterol is a vital component of the cell
  membranes and used by cells to synthesize other
  steroids.
• High cholesterol levels are associated with heart
  disease and the formation of plaques which
  obstruct blood vessels.
• High blood levels of cholesterol bound to a
  carrier molecule called a low-density lipoprotein
  (LDL) are associated with the formation of the
  plaques in arteries.

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Steroids Cholesterol
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Steroids Cholesterol

• Cholesterol bound to high-density lipoproteins
  tends to be metabolized or excreted and is often
  referred to as "good cholesterol".

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Glycerides

• Fats and oils are composed of fatty acids and
  glycerol.
• Fatty acids have a long hydrocarbon chain with a
  carboxyl group.
• The chains of fatty acids usually contain 16 to
  18 carbons.
• Fats are nonpolar and therefore they do not
  dissolve in water.

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Glycerides

• Fats are generally classified as esters of fatty
  acids and glycerol.
• There can be one to three ester linkages of fatty
  acid chains to the glycerol, leading to the
  classification as
• Monoglycerides
• Diglycerides
• Triglycerides

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Glycerides Nomenclature
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Fatty Acids

• Structure
• Two classes
• Saturated
• Unsaturated

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Saturated Fatty Acids

• Have no double bonds between the carbons in its
  fatty acid chains.
• Animal fats are more highly saturated than
  vegetable fats.
• Highly saturated fats are usually solid at room
  temperature.

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Unsaturated Fatty Acids

• Also called polyunsaturated fat.
• Contain at least one to several double bonds
  between the carbons in its fatty acid chains.
• Each double bonds produces a "bend" in the
  molecule.
• Molecules with many bends cannot be packed as
  closely together, so these fats are less dense.

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Unsaturated Fatty Acids

• Usually these fatty acid are oils.
• Most oils are of vegetable origin.
• Triglycerides composed of unsaturated fatty acids
  melt at lower temperatures than those with
  saturated fatty acids.

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Unsaturated Fatty Acids

• Trans fat is the common name for a type of
  unsaturated fat with trans-isomer fatty acids.
• Most trans fats consumed today are created
  industrially by partial hydrogenation of plant
  oils.
• The goal of partial hydrogenation is to add
  hydrogen atoms to cis-unsaturated fats, making
  them more saturated.

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Unsaturated Fatty Acids

• These saturated fats have a higher melting point,
  which makes them attractive for baking and
  extends their shelf-life.
• Trans fats are not essential in the diet and have
  been linked with rises in levels of "bad" LDL
  cholesterol and lowering levels of "good" HDL
  cholesterol.

158
Saturated Unsaturated Fatty Acids
159
Triglycerides

• Are made up of a glycerol molecule with three
  fatty acid molecules attached to it.
• Glycerol contains 3 carbons and 3 hydroxyl
  groups.
• It reacts with 3 fatty acids to form a
  triglyceride or fat molecule.
• The naturally occurring fatty acids always have
  an even number of carbon atoms.

160
Triglycerides
161
Waxes

• Are composed of a long-chain fatty acid bonded to
  a long-chain alcohol
• They form protective coverings for plants and
  animals (plant surface, animal ears).

162
Summary of Lipids

• Monomer Fatty acid
• Functional group(s)
• Carboxyl
• Cholesterol Fused Rings
• Ester
• Polymers many depending on the type of lipid
• Phospholipid, Steroid, Triglycerides, Waxes

163
Summary of Lipids
164
Summary of Biochemistry