N.S. Lecture 3 – Biochemistry is broken up into 3 parts - this is part 3b

Hemoglobin carries oxygen

Antibodies fight disease

Fibers gives cell’s shape

Fibers clot blood

PROTEINS PROVIDE STRUCTURE AND

FUNCTION TO LIFE

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Some foods high in protein 34

Proteins are polymers made-up of monomers called amino acids.

Protein (polymer) = all blue circles linked together

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Amino acid (monomer) = each individual blue circle

Amino Acids

Dipeptide

Polypeptide or Protein

Proteins 36

SOME CHARACTERISTICS OF AMINO ACIDS-20 different amino acids

-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.

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Alphabet (26 letters):

A B C D 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

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A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

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

Letters of alphabet assembled for Spanish text have no meaning in English

JXTRETZ

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20 different Amino Acids

Human DNA

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

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OH HO

O

Dehydration (removal of water) synthesis (uniting)

Monomer A

Dipeptide (dimer = two monomers)

HOH

(Monomer A) (Monomer B)

Amino Acid B (Monomer B)

Dipeptide (dimer) formation

Amino acid A (Monomer A)

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Amino acids (like letters) Green part varies in each amino acid

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I

P

B

L

TD

Building more complex R groups is like adding additional parts to the letter I to form the letters L, P, B, D, or T. 46

Elephant xLetters 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

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Amino acid substitutions that have been found

Amino acid substitutions that result in a disease

Amino acid substitutions resulting sickle cell anemia

Hemoglobin is polypeptide made of almost 400 amino acids. Normal RBC

Sickle RBC

Amino acid substitution (mutation) in hemoglobin

results in sickle cell anemia

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HIV

White blood cellHIV (red dots) attacking

white blood cell

Protein–Protein match up during

infection

HIV

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Mad Cow Disease – a infectious protein called a prion destroys the brain tissue of cows.

Cows are destroyed because prion is known to jump species from cows to humans

Cows dead from mad cow in 1997 51

Neurological changes in brain tissue caused by prions

Normal brain tissue (solid) Prion brain tissue (holes)

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Plants Make all amino acids

no essential amino acids

Animals make some amino acids

cannot make some amino acids

– called essential amino acids

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All amino acids

Photosynthesis

Green plants 54

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)

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Lipids

Fat storage cells

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Lipids (fats) = polymers made of monomers

called fatty acids and glycerol

glycerol

Fatty acid

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A triglyceride

3 fatty acids

1 glycerol

1

2

3

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Unsaturated carbon=carbon

bond

Saturated carbon-carbon

bond

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Be able to recognize saturated vs. unsaturated fatty acids

saturated

unsaturated

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