Chemistry Basics

Element- made of only one kind of atom.
The number of protons determines what the
element is called. In an atom, the number of
protons and electrons are equal.
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The same element will always have a set
number of protons.
The number of neutrons may vary. These are
called isotopes.
Electrons may also vary. These are called ions.
Chemistry Basics

The ion is determined by the
number of electrons in the
outer shell or orbit. These
are called valence
electrons.
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If an atom gains electrons,
it becomes negatively
charged.
If an atom loses electrons,
it becomes positively
charged.
Chemistry Basics
Bonds- joining two or more atoms together
Ionic bond- formed by joining two ions together
Example: NaCl
Covalent bond-formed by the sharing of electrons
Example: C6H12O6
Ionic Bond
Covalent Bond
Carbohydrates
Carbohydrates:
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Made of carbon, hydrogen, oxygen (CHO)
Covalent bonds
For every 1 oxygen atom, there are 2
hydrogen atoms
4 types of Carbohydrates:
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Sugar
Starch/Glycogen
Cellulose
Chitin
Carbohydrates: Sugar
Sugar
Monosaccharides
Mono = one
saccharide = sugar
Disaccharide
Di = two
Polysaccharide
Poly = many
Carbohydrates: Sugars
• Sugar
• 1) Monosaccharides: simple sugars that
may contain 5 or 6 carbon atoms.
Examples: Glucose, Fructose, Galactose
• These simple sugars are made in plant
cells. They have the same empirical or
molecular formula: C6 H12 O6.
• Their structural formulas are different.
Monosaccharide: Examples
Monosaccharides
Glucose
Fructose
Galactose
Monosaccharides
Structural formulas allow you to visualize the molecule.
Notice, even though these molecules all have the same number
of each atom, they look different.
pentagon
Holt, Modern Biology
Sugar: Type 2) Disaccharides
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Disaccharides
Di = two saccharide =sugar
Two simple sugars form one molecule of a
double sugar. One molecule of water is given off.
This is called a dehydration synthesis reaction or
a condensation reaction.
De = take away hydro = water (from mono’s)
for synthesis = putting together (building or
making something)
Condensation: the formation of water
Sugar: Disaccharides
Disaccharides
Maltose
Sucrose
Lactose
Disaccharides
Glucose + glucose
C6H12O6 + C6H12O6
maltose + water
C12H22O11 + H2O
Maltose is found in germinating seeds like barley.
Dehydration synthesis- take away water to put a molecule together
Holt, Modern Biology
Disaccharides
Glucose + fructose
sucrose + water
C6H12O6 + C6H12O6
C12H22O11 + H2O
Sucrose is common table sugar. It is found in sugar cane and
sugar beets.
Dehydration synthesis- take away water to put a molecule together
Dehydration Synthesis (Condensation)
Prentice Hall, Biology
Sugar: Disaccharides
Glucose + galactose
C6H12O6 + C6H12O6
lactose + water
C12H22O11 + H2O
Lactose is milk sugar, found in the milk of mammals.
Dehydration synthesis- take away water to put a molecule together
Nutrition: Digestion
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When we eat carbohydrates, the molecules
are broken apart to form simple sugars.
Where does the digestion of carb’s begin?
What is the name of the enzyme?
In addition to enzymes, what else is needed
for this process to occur?
The process is called hydrolysis:
hydro=water, lysis=break down or apart
Hydrolysis of Maltose
Prentice Hall, Biology
Hydrolysis of Sucrose
Prentice Hall, Biology
Polysaccharides
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Polysaccharides are large molecules
formed by joining monosaccharides.
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Poly = many
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Starch/Glycogen
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Cellulose
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Chiten
How to Make a Polysaccharide
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Slap together three or more mono’s
/ Dehydration Synthesis
Polysaccharide: Starch
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Starch is a polysaccharide made up of
glucose connected in branched chains.
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Each time a glucose molecule is added, one water
molecule is removed (dehydration synthesis).
There may be 500 to many thousands of glucose
molecules joined to form a starch molecule.
Examples: potatoes,corn, rice, wheat, and other
grains.
Polysaccharide: Glycogen
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Glycogen is animal starch.
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It is made of highly branched chains of
glucose molecules.
It is made in the liver and stored in
the liver and muscles.
When extra energy is needed, the liver
converts glycogen into glucose.
Polysaccharide: Glycogen
(From an animal)
Polysaccharide: Cellulose
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Cellulose is a large polysaccharide
made of chains of glucose molecules.
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It may contain as many as 3,000 glucose
molecules.
Cellulose forms a strong fibrous structure
in plant cell walls. It gives the walls
support.
Polysaccharide: Cellulose
Polysaccharide: Cellulose
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We do not break down cellulose. For us,
it is fiber.
Cows use intestinal bacteria to break it
down for them. This is an example of a
mutualistic relationship.
Polysaccharide: Chitin
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Chitin is a polysaccharide found in
the exoskeleton (outer skeleton) of
insects, crabs, shrimps, and lobsters
and in the internal structures of other
invertebrates and in the cell walls of
fungi. It has a nitrogen group added
to the glucose.
REVIEW
Lipids
Carbohydrates
Macromolecules
Proteins
Nucleic Acids
Network Tree
N
Starch
Cellulose
N
Carbohydrates
(C,H,O)
Glycogen
1
Sugar
Monosaccharide
Glucose
Chitin
3+
Polysaccharide
Galactose
Fructose
2
Disaccharide
Lactose
Maltose
Sucrose
Monosaccharides
Structural formulas allow you to visualize the molecule.
Notice, even though these molecules all have the same number
of each atom, they look different.
Holt, Modern Biology
Disaccharides: How are they put together?
Dehydration synthesis- take away water to put a molecule together
Glucose + glucose
maltose + water
Glucose + fructose
Glucose + galactose
C6H12O6 + C6H12O6
sucrose + water
lactose + water
C12H22O11 + H2O
Dehydration Synthesis:
What does it look like?
Prentice Hall, Biology
Disaccharides:
How do we digest them?
Hydrolysis. Water is added to maltose in order to break it down
into two glucose molecules. Of course, enzymes would control
this process.
Holt, Modern Biology
Review
Compare and Contrast
Starch
Plants
Glycogen
Stored for later,
converted into
glucose for
respiration..
Branched chains
of glucose
Big
Animals
Compare and Contrast
Starch
Branched chains
Stored for later,
converted into
glucose for
respiration.
Cellulose
Carbohydrates
Polysaccharides
glucose
Big
Straight Chains
Found in plant
cell walls
Used for support