Download Proteins

BioMolecules
Lipids
Mia Brownell
EXTRA CREDIT
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One page HANDWRITTEN. You MUST use 1
book (for ex. your textbook)
At the end, write REFERENCES
Author/s, Title, Year, pages that you
consulted. If you use a Website, site the page.
What does it happen to the sugar when you eat a candy
bar? How is sugar regulated? What are the normal
glucose levels in blood?
What does your body do when it does not have any
carbohydrates left to use as fuel. Explain in detail
Clues: Insulin, Glucagon. Hormone regulation
What Are Lipids?
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They are grouped together because they do not
mix with water.
They comprise Oils, Fats, Waxes, Phospholipids
and Steroids.
Contain Only Carbon, Hydrogen, and Oxygen
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Lipids are classified into two groups
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1. Lipids with fatty acids: Triglycerides
Phospholipids
2. Lipids without fatty acids: Steroids.
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What is a fatty acid?
A fatty acid consists of a carboxyl group attached to a
long carbon skeleton, often 16 to 18 carbons long.
Carboxyl or Acid Group
If the carbon chain is single bonded: Saturated. Saturated fatty
acids are solid at room temperature and are found mainly in
animals.
If the carbon chain has one or more double or triple bonds, then
the fatty acid is unsaturated. Unsaturated fatty acids are liquid
at room temperature and are more commonly found in plants.
Triglycerides
„ Commonly
known
as fats oils and
waxes.
„ They are formed
by dehydration
synthesis
„ How? By adding
three fatty acids
and one molecule
of glycerol.
glycerol
fatty acids
triglyceride
3 water
molecules
The functions of triglycerides
include:
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Storage of energy
Insulation
Cushioning
Help to prevent
dehydration
Help to maintain the
internal temperature.
Plenty of storage and
cushioning here!
Phospholipids
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Consist of a polar head, a glycerol and two fatty
acids. These are the main components of the
cell membrane.
glycerol
backbone
(hydrophilic)
polar head
fatty acid tails
(hydrophobic)
Steroids
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Steroids Consist of Four Carbon Rings Fused
Together
Steroids functions include:
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Structural molecules: Steroids are part of the cell
membrane. For example in animal cells we find
cholesterol (never found in plants).
Some hormones (regulators) are chemically
steroids. For example Estrogen, Progesterone
and Testosterone.
Vitamin D is a steroid.
Synthetic (man made) steroids
include:
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Cortisones : antinflamatories
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Birth control pills: usually synthetic variants of
estrogen.
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Anabolic steroids. Anabolic steroids are usually
synthetic variants of testosterone
Proteins
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What Are Proteins?
Proteins are biomolecules that are made of C, O,
H, N and S.
The building blocks of proteins are amino acids.
What are amino acids?
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An amino acid is a molecule that has an carboxyl
group and an amino group. R represents the
radical or rest of the molecule.
Variable group
amino
group
carboxylic
acid group
hydrogen
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There are 20 different amino acids. Out of the
20, 8 are called essential.
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Essential amino acids are amino acids that the
human body cannot make (we do not have the
enzymes to produce them, thus we have to
ingest them as part of our food). Why? Because
we need them to make our own proteins.
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Cells link amino acids together by dehydration
synthesis
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The bonds between amino acid monomers are
called peptide bonds
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The bond between an amino group of one
amino acid and the carboxyl group of another
amino acid makes a peptide bond.
What is missing in this equation? Fill in the
missing factors.
Amino Acid
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Amino Acid
Peptide Bond
Many amino acids are group together in a long
amino acid chain, this is called a polypeptide
chain.
ƒThe primary structure of a
protein is its unique
sequence of amino acids.
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secondary structure of a protein is the
folding pattern of the polypeptide chain.
„ Two typical shapes of secondary structure are
coils (an alpha helix) or folds (beta pleated
sheets).
Amino acid
Primary
structure
chain
Secondary
structure
Alpha helix
Pleated sheet
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The tertiary structure of a protein is its
“packing pattern”. This is the active form of the
protein.
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The quaternary structure of a protein is a
complex association of several polypeptide
chains. Each of these polypeptide chains have a
primary, secondary and tertiary structure.
Collagen (gives your skin its strength) is formed
by several chain making like a rope.
Hemoglobin
(transports
oxygen) is another
example of
quaternary
structure
protein.
Primary
structure
Amino
acid
Secondary
structure
Hydrogen
bond
Alpha
helix
Pleated
sheet
Tertiary
structure
Polypeptide
(single subunit
of transthyretin)
Quaternary
structure
Transthyretin, with four
identical polypeptide subunits
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Denaturing is breaking the weak bonds that
keep the tertiary structure together. Heat, Ph
and high salt are factors that may denature
proteins.
Denaturing inactivates the protein.
Denaturing can be reversible.
Functions
„ Proteins are involved in
„ enzymes
„ cellular structure
„ movement
„ defense
„ transport
„ Communication
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Regulation.
Structure
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15% of your cell membranes are made of
proteins.
Mammals hair and nails is made of protein
Spider webs are made of protein.
Movement
Muscle cells
involved in the
formation of
muscles are made
of pure protein:
actin and
myosin. Muscles
are responsible
for movement.
Defense
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All antibodies produced by your
white blood cells are proteins!
Venom produced by poisonous
snakes and other poisonous
animals are made
of proteins.
Transport
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Hemoglobin in your
red blood cells transports
oxygen and carbon
dioxide.
Regulators
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Some hormones, such as insulin and glucagon
that regulate the glucose levels in the blood
stream are proteins.
The human growth hormone that regulates
growth is a protein.