Exactly what does Chemistry have to do with Biology?

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Exactly what does Chemistry have to do with
Biology?

• Biochemistry is the branch of science concerned
  with the chemical processes that occur within
  living organisms.
• But, why
• Living things consist of atoms of different
  elements.
• Elements are the fundamentals of chemistry.

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What do a frog, a skyscraper, a car and your body
have in common?
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Atoms!

• Every physical thing, whether living or not, is
  made up of atoms.
• An atom is the smallest basic unit of matter.

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Atoms consist of three smaller particles.

1. Protons
2. Neutrons
3. Electrons

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Living things consist of atoms of different
elements.

• An element is one particular type of atom. It
  can NOT be broken down into a simpler substance
  by ordinary chemical means.

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What distinguishes one element from another?

• Different elements have different atomic numbers.
• The atomic number is the number of protons.

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Only about 25 elements are found in organisms.

• 4 particular elements make up 96 of the human
  body
• Oxygen (O)
• Carbon (C)
• Hydrogen (H)
• Nitrogen (N)

• The other 4 is made up of Calcium (Ca),
  Potassium (K), Phosphorus (P), Sulfur (S), and
  Sodium (Na) and other trace elements.
• Trace elements are found in very small amounts
  but are still important for bodily functions.

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Compounds

• Atoms of elements found in organisms are often
  linked, or bonded, to other atoms.
• A compound is a substance made of atoms of
  different elements bonded together.

Water bond between hydrogen and oxygen
Carbon Dioxide bond between carbon and oxygen
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Certain compounds are found in living things.

• Organic Compounds

• Inorganic Compounds

• Compounds formed with Carbon
• Compounds found in all living things

• Compounds that do NOT contain carbon
• Many are essential to life water, nitrate and
  phosphate but are NOT organic
• Carbon Dioxide and Carbon Monoxide are NOT
  organic (though they contain Carbon only
  exception!

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Ions form when atoms gain or lose electrons.

• An ion is an atom that has gained or lost one or
  more electrons.
• positive ions - lost electrons
• negative ions - gained electrons
• Ionic bonds form between oppositely charged ions.

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Atoms share pairs of electrons in covalent bonds.

• A covalent bond forms when atoms share a pair of
  electrons.

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Molecules

• A molecule is two or more atoms held together by
  covalent bonds.
• Some elements occur naturally in the form of
  diatomic (two-atom) molecules.
• For example, a molecule of O2 consists of two
  oxygen atoms that share two pairs of electrons.
• Almost all substances that make up organisms are
  molecules held together by covalent bonds.

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Celebration of Learning Moment!

1. Why is it important to study biochemistry?
2. What distinguishes one element from another?
3. What is the difference between an ionic bond and
   a covalent bond?
4. How does a molecule differ from an atom?

Because all living things are made of atoms. It
is important to understand the make-up of atoms,
compounds, and molecules to understand organisms.
The number of protons or atomic number.
Ionic bonds form when electrons are lost or
gained. Covalent bonds form when electrons are
shared.
An atom is the smallest unit of matter.
Molecules are two or more atoms covalently bonded
together.
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Water

• Water covers 75 of the Earths surface.
• It is the single most abundant compound in living
  organisms.

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Physical Properties of Water

1. Water is a liquid at the temperature of the
   Earths surface.
2. Water expands when it freezes.
3. Water is less dense in the solid form (ice) than
   the liquid form.

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The Water Molecule

• Overall, water is a neutral molecule.
• It has the same number of protons as electrons
• The electrons are unequally distributed.
• The oxygen atom has 8 positively charged protons
  and has a strong pull on the negative electrons.
• Because of this, it is more likely to find
  electrons near the oxygen atom than the hydrogen
  atom.
• This gives the oxygen end of the water molecule a
  slightly negative charge and the hydrogen end of
  the water molecule a slightly positive charge.

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Polarity

• The unequal distribution of charges on a molecule
  results in polarity.
• Polarity is when a molecule has a positive pole
  (end) and a negative pole.
• Water molecules positive and negative charges
  cause opposite ends of water molecules to attract
  each other like tiny magnets.
• Opposites attract!!

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If a water bug can walk across the water, why
cant a frog?

• The Nature of Water video

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Opposite charges of polar molecules can interact
to form hydrogen bonds.

• A hydrogen bond is an attraction between a
  slightly positive hydrogen atom and a slightly
  negative atom.
• These bonds exist between water molecules but
  also other molecules.
• Hydrogen bonds are weaker than other bonds
  allowing them to be broken by other charges
  substances.

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Polarity of water molecules allows for several
unique chemical properties

1. Cohesion
2. Adhesion

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Cohesion

• Cohesion is the attraction of like molecules to
  each other.
• Ex water molecules attracting one another
• Cohesion causes surface tension which is when
  water molecules at the surface of a body of water
  cling tightly together
• Surface tension allows some insects to walk upon
  the surface.

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Adhesion

• Adhesion is the attraction of unlike molecules to
  one other
• Ex when water molecules are attracted to other
  types of molecules
• This allows water molecules to adhere to the
  insides of small tubes
• Ex those that carry water throughout plants and
  test tubes

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The forces of cohesion and adhesion work together
to produce capillary action.

• Capillary action is the force of water rising in
  a thin tube.
• This force makes it possible for water to travel
  up the thin tubes inside plants from roots to
  leaves.
• Adhesive forces cause the water molecules to be
  attracted to the insides of the tubes.
• Cohesive forces cause the water molecules to
  cling to each other.

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Note Break!

• You and your table mate will conduct an
  experiment using the following materials
• Two plastic cups
• One strip of paper towel
• Water
• Set up your experiment as follows
• One empty cup seated beside one cup of water.
  Using the paper towel strip, create a connection
  from your water cup to the empty cup.

• Answer the following questions.
• What is happening to the water?
• How is this happening?

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Water is often found in nature as a mixture.

• A mixture is a material that is composed of two
  or more substances.
• Ex dissolving sugar into hot tea to make sweet
  tea
• There are two types of mixtures that can be made
  with water.
• Solutions
• Suspensions

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Solutions

• A solution is a mixture where all substances are
  evenly distributed throughout
• Also called a Homogenous mixture
• A solution has two parts.
• The solvent is the substance that is present in
  the greater amount. This substance dissolves
  another substance.
• The solute is the substance that dissolves in a
  solvent.

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Suspensions

• A suspension is a mixture in which all of the
  components are NOT evenly mixed.
• Also called a heterogeneous mixture
• Suspensions occur when some materials do not
  dissolve in water but separate into small pieces
  that do not settle out.

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What is blood?

• Blood is an example of a biological fluid that is
  both a solution and suspension.
• There are some molecules that are evenly
  distributed throughout the plasma and others that
  are not evenly distributed.

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Water molecules can dissociate, or come apart,
into two ions.
Water hydroxide ion
hydrogen ion
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• The scale used to measure the concentration of
  hydrogen ions (H) and hydroxide ions (OH-) is
  called the pH scale. The pH scale ranges from 0
  to 14.
• When a solution has equal amounts of H and OH-,
  the solution has a neutral pH number 7 on the
  scale
• When a solution has a greater amount of H, it is
  said to be an acid or have an acidic pH numbers
  1-6 on the scale.
• When a solution has a greater amount of OH-, it
  is said to be a base or have a basic pH numbers
  8-14 on the scale.

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All living organisms have a set range of pH
levels that are optimal for their growth and
development.

• Sudden changes in pH levels can harm organisms.
• pH inside human cells must be kept close to
  neutral.
• If a chemical with an acidic or basic pH enters
  the cell, if could disrupt the cells homeostasis.
• To stay stable, cells contain weak acids and
  bases called buffers which work to neutralize
  substances inside cells that are too acidic or
  too basic.

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There are 4 classes of large molecules that make
up the majority of living things.

• These are called macromolecules. Macromolecules
  are made up of many smaller molecules and atoms.
• Also called polymers.
• A polymer is a large molecule made of many
  monomers bonded together.
• A monomer is a subunit in a complete molecule.

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The macromolecules of life are

• Carbohydrates
• Lipids
• Nucleic Acids
• Proteins

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Carbohydrates

• Macromolecules composed of carbon, hydrogen and
  oxygen in a ration of 121
• EX glucose, C6H12O6
• Carbohydrates are sugars
• Sugars can be simple monomers, such as glucose or
  fructose
• Or, complex polymers such as starch.

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Three types of Carbohydrates

1. Polysaccharides
2. Disaccharides
3. Monosaccharides

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Polysaccharides

• Large sugar molecules composed of many smaller
  unites, linked together in complex arrangements
• Examples Starch, cellulose, glycogen
• Starches and glycogen are used to store energy
• Cellulose is the structural component of cell
  walls

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Disaccharides

• Sugar molecules with only two monomers
• Example Table sugar
• These types of sugars are generally used as a
  source of energy

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Monosaccharides

• Monomer units of carbohydrates
• Examples glucose, fructose, and galactose

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Lipids

• Macromolecules composed of mostly carbon and
  hydrogen chains
• NOT soluble in water
• Examples fats, waxes, oils, and steroids

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Fats and Oils

• Fats

• Oils

• Animal fats are found in food such as meat and
  butter
• Consists of glycerol bonded to fatty acids

• Plant fats as oils such as olive oil and peanut
  oil
• Consists of glycerol bonded to fatty acids

Fatty acids are chains of carbon atoms bonded to
hydrogen atoms.
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Fatty acids can be saturated or unsaturated

• Saturated Fatty Acids

• Unsaturated Fatty Acids

• Contain the maximum number of hydrogens
• These molecules are flat and tend to pack
  solidly like bricks
• Usually solid at room temperature
• Animal fat and butter are typical saturated fats

• Contain one of more double bonds
• Double bonds prevent these acids from holding the
  maximum number of hydrogens
• This causes the chain to bend into odd shapes so
  that they will not pack solidly
• Usually liquid at room temperature
• Vegetable oil is usually unsaturated

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Lipids have a lot of important jobs in living
things.

• They act as chemical messengers as steroids.
• They store energy as fats and oils.
• They form cell membranes as phospholipids.

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Celebration of Learning Moment!

• On a separate sheet of paper, answer the
  following questions
• What is the relationship between a polymer and a
  monomer?
• How are carbohydrates and lipids similar? How
  are they different?
• Why are lipids important to organisms?

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Nucleic Acids

• Macromolecules containing hydrogen, oxygen,
  nitrogen, carbon and phosphorus
• Associated with organisms genetic code
• Single units of nucleic acids are called
  nucleotides
• One nucleotide consists of a 5-carbon sugar, a
  phosphate group and a nitrogen base
• Examples DNA and RNA
• The function of nucleic acids is to store and
  transmit genetic information.

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Proteins

• Macromolecules containing carbon, hydrogen,
  oxygen, and nitrogen
• Building blocks of tissues
• Single units of proteins are called amino acids

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Proteins perform several critical jobs in cells.

• Control the rate of chemical reactions
• Regulate cell processes
• Form structural components of certain cells
• Transport substances into and out of cells
• Help to fight disease

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One of the most important types of proteins is
called an enzyme.

• Enzymes act as biological catalysts.
• A catalyst is a chemical that speeds up chemical
  reactions within a cell
• Enzymes are able to speed up the rate in which
  chemical reactions occur by reducing the energy
  needed to start a chemical reaction (activation
  energy).
• The specific reactants that an enzyme acts on are
  called substrates.

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How do enzymes work?
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Enzymes

• Can build up (synthetic)
• Can breakdown or digest (hydrolytic)
• Most end in ase.
• Examples Protease, Lipase, Maltase

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Water, water, everywhere!

• Water plays an important role in our world. The
  water we use on earth today is exactly the same
  water that existed billions of years ago. Water
  is a finite resource. There is no more and no
  less. Continually recycled and refreshed in its
  various forms as liquid, vapor, and ice, water is
  an incredible substance. Living things need water
  for life.
• .

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What If?

• In these questions we are going to play the "What
  If?" game. You will use your notes or a website
  you have found that describes the properties of
  water
• You will
• discuss one property of water by describing that
  property and
• explain how the world would be different if water
  did not have that property.
• You will do this in ATLEAST 5 complete sentences!

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Macromolecules Organized

• In this assignment, you will organize your
  information about the macromolecules in a form
  that will illustrate all the important facts in a
  neat and brief format. The following information
  must be included for carbohydrates, proteins, and
  lipids
• Name of the Macromolecule
• Elements in the molecule
• Name(s) of monomer
• Examples
• Functions of Uses