N.S. Lecture 3 – Biochemistry is broken
up into 3 parts - this is part 3b
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Hemoglobin carries
oxygen
Antibodies fight
disease
PROTEINS
PROVIDE STRUCTURE
AND FUNCTION TO LIFE
Fibers clot blood
Fibers gives cell’s shape
Some foods high in protein
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Proteins are polymers
made-up of monomers
called amino acids.
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Protein (polymer)
= all blue circles linked together
Amino acid (monomer)
= each individual blue circle
Proteins
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Amino Acids
Dipeptide
Polypeptide
or Protein
SOME CHARACTERISTICS OF AMINO ACIDS
-20 different amino acids
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-Each amino acid has a different structure
-Each amino acid is like a letter in the alphabet
-Each letter (amino acid) can be linked with any other letter,
in any order, for any length, to make an infinite number of
words (proteins)
-In English only certain combinations of letters (amino acids)
form words (proteins) with meaning.
-In living things the proteins (words) determine everything
about structure and function of life (language).
-Only certain combinations of amino acids produce proteins
that have meaning in a specific living thing.
Alphabet (26 letters):
A
B
C
D
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E
F …………..…………….Z
Amino Acids (20 different one):
AA1 AA2 AA3 AA4 AA5 AA6………………………….AA20
Words (sentence with 35 letters):
“I hope that you get an A grade in Natural Science 100”
Proteins (hemoglobin with 400 amino acids):
AA3-AA2-AA4-AA6-AA1-AA1-……-AA400 amino acids (some
used more than once)
Amino Acids
ABCDEFGHIJKLMNOPQRSTUVWXYZ
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These 26 letters can be put together in any order for
any length to form an infinite number of words.
Only a finite number of the possible words have
meaning in the English language JXTRETZ
Letters of alphabet assembled
for Spanish text have no
meaning in English
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Human
DNA
20 different
Amino Acids
Human DNA assembles
human proteins
Dog DNA assembles
dog proteins
Dog
DNA
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These 20 different
amino acids are
analogous to an
alphabet with 20
letters
Each letter can be
put together in
any order, for any
length to form an
infinite number of
proteins (words)
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Hemoglobin is a
protein (like a word)
composed of almost
400 amino acids (like
letters)
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How do amino acids link to each other?
Any car can be linked to any other car in any order for any length
Dipeptide (dimer) formation
Amino acid A
(Monomer A)
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Amino Acid B
(Monomer B)
OH
HO
HOH
(Monomer
A)
Monomer A
Dehydration
(removal of water)
synthesis (uniting)
(Monomer B)
O
Dipeptide (dimer = two monomers)
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Amino acids (like letters)
Green part varies in each amino acid
Building more complex R groups is like adding additional
parts to the letter I to form the letters L, P, B, D, or T.
L
P
I
B
T
D
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Elephant
x
Letters spell word (protein)
that means Elephant
Changing “e” for “x” does
not spell a word that means
Elephant (or anything else)
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Two amino
acids are
replaced;
protein
structure
and
function
changes
Normal structure =
normal function
Abnormal structure =
abnormal function
Hemoglobin is polypeptide made
of almost 400 amino acids.
Normal RBC
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Amino acid
substitutions that
have been found
Sickle RBC
Amino acid
substitutions that
result in a disease
Amino acid
substitutions
Amino
acid substitution
resulting
sickle
(mutation)
in hemoglobin
anemia
results cell
in sickle
cell anemia
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HIV
HIV
Protein–Protein
match up during
infection
HIV (red dots) attacking
white blood cell
White blood cell
Mad Cow Disease –
a infectious protein
called a prion
destroys the brain
tissue of cows.
Cows dead from mad cow in 1997
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Cows are
destroyed because
prion is known to
jump species from
cows to humans
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Neurological changes in brain
tissue caused by prions
Normal brain tissue (solid)
Prion brain tissue (holes)
Plants
Make all amino
acids
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no essential
amino acids
Animals
make some amino
acids
cannot make some
amino acids
– called essential
amino acids
Green plants
Photosynthesis
All amino acids
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Animals must eat plants or other animals to
acquire specific essential amino acids
Muscles and brains allow
animals to acquire food
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Biologically Important Organic Molecules
Hydrocarbons – Carbon (C), Hydrogen (H)
Carbohydrates – C, H, Oxygen (O)
Proteins – C, H, O, Nitrogen (N), Sulfur(S)
Lipids – C, H, O
Nucleic Acids – C, H, O, N, Phosphorous (P)
Lipids
Fat storage cells
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Fatty acid
glycerol
Lipids (fats) =
polymers made
of monomers
called fatty acids
and glycerol
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1
2
3
A triglyceride
3 fatty acids
1 glycerol
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Unsaturated
carbon=carbon
bond
Saturated
carbon-carbon
bond
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saturated
unsaturated
Be able to recognize saturated vs.
unsaturated fatty acids
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