Transcript Chemical Bonding, Carbon style

Chemical Bonding, Carbon style
Discover
On the index card in your box, shade in a
circle as dark as you can with your pencil.
Take a piece of paper and rub across this
shading.
What did you notice?
The Carbon Atom and Its
 The atomic
number of carbon
Bonds
is 6
 There are 6 protons in the
nucleus and 6 electrons
surrounding the nucleus.
 4 of these electrons are
valance meaning they are
ready for bonding.
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Chemical bonds are the force that hold two atoms
together.
A chemical bond between two atoms is made up
of the atom’s valance electrons.
Atoms of all elements (except noble gases) form
chemical bonds.
But few elements have the ability of Carbon to
bond with both itself and other elements in so many
different ways.
 It
is possible for carbon to arrange the same
number of atoms in different ways.
 They can form straight chains, branched chains,
and rings.
 Sometimes even networks of two or more rings of
carbon atoms are joined together.
Forms of Pure Carbon
 Because
of the ways
carbon forms bonds,
the pure element
can exist in different
ways.
 Diamond, graphite,
and fullerene are
three forms of the
element Carbon.
Diamond
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The hardest mineral – diamond –
forms deep within Earth.
At very high temperatures and
pressures, carbon atoms for
diamond crystals. Each carbon
atom is bonded strongly to 4
other carbon atoms.
The result is a solid that is
extremely hard and unreactive.
The melting point of diamond is
over 3,500 degrees Celsius.
They are formed in a crystalline
pattern.
Graphite
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Every time you write with pencil you leave a layer of
carbon on the paper.
“lead” in the pencil is actually graphite, another
form of the element carbon.
It does not contain any of the element lead.
Carbon atoms are bonded strongly together in flat
layers. But the bonds connecting the layers are very
weak, so the layers past by each other very easily.
Homework Questions
1.
2.
3.
List three different forms of pure carbon.
What happens to valence electrons
when a chemical bond forms between
atoms?
How can you use differences in carbon
bonds to explain why graphite and
diamonds have different properties?
Carbon
Compounds
Slide guide starts Here
Organic Compounds
 Carbon
Compounds are so numberous
that they are given a special name.
 With some exceptions, a compound that
contains carbon is called Organic
Compounds.
 Organic means “of living things”.
 Any items that is made of from once living
organisms is an Organic Compound.
 They can also be made artificially.
Hydrocarbons
 The
simplest organic compounds are the
hydrocarbons.
 A hydrocarbon is a compound that
contains only the elements carbon and
hydrogen.
Life with
Carbon
Nutrients from Food
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Nutrients are substances that provide the
energy and raw materials the body needs to
grow, repair worn parts, and function
properly.
Most of the nutrients in food are organic
compounds.
Many nutrients are large, chain like molecules
called polymers.
Each link in the chain is a small molecule
called a monomer.
 The
body can break apart the large molecules in
food into smaller molecules.
 The process of breaking polymers into monomers,
which involves chemical changes, has the familiar
named digestion.
 After food is digested, the body then breaks apart
some of the monomers, which releases energy.
 The body takes other monomers and reassembles
them into polymers that match specific body
chemistry
 The
four classes of polymers found in all
living things are carbohydrates, lipids,
proteins and nuclei acids.
carbohydrates
A
carbohydrate is an energy-rich organic
compound made of the elements carbon,
hydrogen, and oxygen.
 The word carbohydrate is made of two parts:
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Carbo and hydrate
Carbo means “Carbon” and hydrate means
“Combined with water”
If you remember that water is made up of the
elements hydrogen and oxygen, then you should be
able to remember the three elements in
carbohydrates.
Simple Carbohydrates
 The
simplest carbohydrates are sugars.
 You may be surprised to learn that there
are many different kinds of sugars.
 The sugar listed in baking recipes, which
you can buy in bags or boxes at the
grocery store, is only one kind. Other
sugars are found naturally in fruits, milk,
and some vegtables.
 One
of the most important sugars in your body is
glucose.
 Its molecular formula is C6H12O6.
 Glucose is sometimes called “blood sugar”
because the body circulates glucose to all body
parts through the blood.
 The name of the white sugar that sweetens cookies,
candies, and many soft drinks is sucrose. It is a more
complex molecule than glucose and has a
molecular formula of C12H22O11
Complex Carbohydrates
 When
you eat plants or food products made from
plants, you are often eating complex
carbohydrates.
 Each molecule of a simple carbohydrate, or sugar,
is relatively small compared to a molecule of
complex carbohydrates.
 A complex carbohydrate is made of a long chain
of simple carbohydrates bonded to each other.
Just one molecule of a complex carbohydrate
may have hundreds of carbon atoms.
 Two
of the complex carbohydrates assembled from
glucose molecules are starch and cellulose.
 Starch and cellulose are both built from glucose
monomers, but the monomers are arranged
differently in each case.
 So starch and cellulose are different compounds.
They serve different functions in the plants that form
them.
 They body uses starch from foods very differently
from the way it uses cellulose
Starch
 Plants
store energy in the form of the complex
carbohydrate starch.
 You can find starches in food products made from
wheat grains, such as bread, cereal, and pasta.
 Starches are also found in rice, potatoes and other
vegetables.
 The body digests the large starch molecules from
these foods into individual glucose molecules. Then
the body breaks apart the glucose and releases
energy.
Cellulose
 Plants
build strong stems and roots with the complex
carbohydrate cellulose and other polymers. If you
imagine yourself crunching on a stick of celery, you
will be able to imagine what cellulose is like.
 Most fruits, vegetables, and nuts are high in
cellulose. So are food products made from whole
grains.
 Even though the body can break down starch, the
body cannot break down cellulose into individual
glucose molecules.
 Therefore
the body cannot use cellulose
as a source of energy. In fact, when you
eat foods with cellulose, the molecules
pass right through you undigested.
 However, this undigested cellulose helps
keep your digestive track active and
healthy. Cellulose is sometimes called
fiber.
Proteins
 If
the proteins in your body suddenly
disappeared you would not have much
of a body left.
 Your muscles, hair, skin, and fingernails are
all made of proteins. A bird’s feathers, a
spider’s web, a fish’s scales, and the horns
of a rhinoceros are also made of proteins.
Chains of Amino Acids
 The
polymers called proteins are made of
organic compounds called amino acids.
 That means that amino acids are the
monomers in a protein molecule.
 Unlike the sugars in complex
carbohydrates, the monomers in a protein
are not exactly alike.
 In fact, there are 20 different kinds of
amino acids.
Food Proteins Become Your Proteins
 Some
of the best sources of protein include meat,
fish, eggs and milk or milk products.
 Some plant products such as beans are good
sources of protein as well.
 The body uses proteins from food to build and
repair body parts. But the body must first break
apart the protein polymers into monomers.
Remember that starch in digested into individual
glucose molecules.
 In the same way, proteins are digested into
individual amino acids. The body reassembles those
amino acids into thousands of protein
Lipids
 The
third class of organic compounds in living things
is lipids.
 Like carbohydrates, lipids are energy-rich polymers
made of carbon, oxygen, and hydrogen. Lipids
include fats, oils, waxes, and cholesterol.
 Gram for gram, lipids store more than twice as
much energy as do carbohydrates. Lipids behave
somewhat like hydrocarbons- the compounds of
carbon and hydrogen.
 Lipids mix poorly with water.
Fats and Oils
 Fats
are found in foods such as meat, butter, and
cheese.
 Oils in foods include those such as corn oil,
sunflower oil, peanut oil, and olive oil.
 Fats and oils have the same basic structure. Each
fat or oil polymer is made of three fatty acid
monomers and one alcohol monomer named
glycerol. There is on main difference between fats
and oils.
 Fats are usually solid at room temperature where as
oils are liquid
Saturated and Unsaturated
 You
may hear fats and oils described as
saturated or unsaturated. Like saturated
hydrocarbons, the fatty acids of saturated
fats have no double bonds between
carbon atoms. Unsaturated fatty acids are
found in oils.
 Monounsaturated oils have fatty acids with
one double bond. Polyunsaturated oils
have fatty acids with many double bonds.
 Saturated fats end to have higher melting
points that unsaturated.
Cholesterol
 Another
important lipid is cholesterol, a waxy
substance found in all animal cells. The body builds
cell structures from cholesterol and uses it to form
compounds that serve as chemical messengers.
 The body produces the cholesterol it needs from
other nutrients. But foods that come from animalscheese, eggs, and meat-also provide cholesterol.
Foods from plant sources, such as vegetable oils,
never contain cholesterol.
 Vitamins:
organic compounds that serve as helper
molecules in a variety of chemical reactions in your
body.
 Vitamin C or ascorbic acid, is important for keeping
your skin and gums healthy. Vitamin D develops
your bones and teeth and keep them strong.
 Minerals: elements needed by your body. Unlike
other nutrients, minerals are not organic
compounds.
 Common minerals are sodium, calcium, iorn, iodine,
and potassium