Transcript Chapter 2.3: Chemistry of Cells

Chapter 2.3:
Chemistry of Cells
Biochemistry
Organic Compounds
Organic molecules are molecules that
contain Carbon atoms bonded usually to
Hydrogen, Oxygen or other Carbon atoms.
 The four most important organic
compounds found in living things are:
- Carbohydrates
- Lipids
- Proteins
- Nucleic Acids
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Carbohydrates
(The dreaded carb!)
Made of Carbon, Hydrogen and Oxygen.
 For every Carbon atom there is an Oxygen
and two Hydrogens. 1 : 2 : 1
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Carbohydrates are a huge source of energy.
 Carbs are made of single sugar molecules
called monosaccharides.
 An example of a monosaccharide is glucose
C6H12O6 Notice the ratio!
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Carbohydrates cont.
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Does this look familiar?
This is a monosaccharide
called glucose.
A single sugar molecule
can easily be pieced
together with another sugar
to make a disaccharide.
When this is done 1
molecule of water is
released.
Forming a disaccharide
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Notice that when you remove a water molecule the two
molecules bond together to form a much larger
molecule.
What do you think will happen if you throw in a water
molecule?
Forming a carbohydrate
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If you take more than
two glucose
molecules and bond
them together you
form a
polysaccharide.
Each one of the little
blue hexagons = a
glucose molecule
Examples of Carbohydrates
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What is the carbohydrate that is
stored in plants?
Hint:
Starch
The carbohydrate that is found in
animals is called glycogen.
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These polysacharides store a lot
of energy in the form of sugar.
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Sugar turns into fat.
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Hence the carb diet
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When you break down a
polysaccharide not only do you
lose water you release energy.
Lipids
A Lipid is a non-polar organic molecule
that is one of the principal structural
materials of living cells.
 A lipid is not soluble in water… Why?
 Lipids are oily or greasy in texture.
 Examples of lipids are fats, phospholipids,
steroids and wax.
 Some lipids can be pieced together to
form larger molecules.
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Phospholipids
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Phospholipids, like
fat, and cholesterol
are made of two
distinct parts.
- Glycerol
(Polar Head)
- Fatty Acid tails
(Non-polar tail)
Phospholipids Cont.
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If you take a bunch of phospholipids and put
them in water what do you think might happen?
Because of the properties of phospholipids,
when in the presence of water a group of them
will form what is called a phospholipid bi-layer.
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This is what makes up the cell membrane.
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FAT
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Fat – a lipid in an
organism that stores
ENERGY.
Fat is also made of
glycerol and fatty acids.
Glycerol is an alcohol
Fatty acids are a bunch
of Carbons bonded to
Hydrogens
Do you notice any similarity
between a fat and a
phospholipid?
Different types of fat
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1.
2.
There are two different types of fat that
store energy in the body.
Saturated fat – The Carbons in the fatty
acid are all bonded to two Hydrogens,
except for the last which is bonded to
three. This forms a straight molecule.
Unsaturated fat – Some Carbons are
only bonded to one Hydrogen, making a
double bond and causing a kink in the
chain.
Saturated and Unsaturated Fat
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Which fat is the “bad” fat? Why?
Protein
Proteins are made of a chain of amino
acids linked together.
 Great! What’s an amino acid?
 Amino Acid – The building blocks of a
protein. There are 20 different amino
acids, each with a different chemical
structure.
 All amino acids are made of Carbon,
Hydrogen, Oxygen and Nitrogen.
 Some of the 20 amino acids are made of
sulfur.
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Proteins cont.
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Each amino acid has a similar chemical
structure but different functional groups.
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Another type of functional group is the “R”
group. This is what gives us our 20 different
amino acids
Proteins cont.
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Some amino acids are polar
Some amino acids are electrically charged.
These give proteins a very distinct shape.
Nucleic Acids… an intro
Nucleic Acid – a long chain of nucleotides.
 Once again… Great! What’s a nucleotide?
 Nucleotide – part of a nucleic acid that has
three parts.
1. Sugar
2. Nitrogen base
3. Phosphate group
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Nucleotides
Nucleotides are put together to make a Nucleic
Acid like so…
Nucleic Acid
Nucleic Acids cont.
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There are two types
of nucleic Acids
- Deoxyribonucleic Acid
(DNA)
Double stranded
- Ribonucleic Acid
(RNA)
Single stranded
ATP
ATP – Adenosine tri-phosphate
(ENERGY)
 A single nucleotide with two extra
phosphates.
 Main energy resource for cells.
 Energy from carbs and fat are stored
temporarily as ATP.
 When ATP is broken down it turns into
ADP and releases energy.
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ATP
When one of the phosphate groups are broken off Energy is released
ATP cycle