1. The Chemical Building Blocks of Life
Chapter 3

2. Proteins
Protein functions:
enzyme catalysis
defense
transport
support
motion
regulation
storage

3. Protection/insulation

4. Transport -red blood cells (with Hemoglobin…a protein,
Carries Oxygen and
CO2)

5. Support

6. Protection

7. Check all this out! Very important function of proteins
that we will devote
a separate lesson
to it!

8. The smallest units of a protein are……..
Amino Acids
contain an amino group (-NH2), a carboxyl group (-COOH) and a hydrogen atom, all bonded to a central carbon atom
twenty common amino acids grouped into five classes based on side groups. ?
carboxyl
NH2 C
C=O
Amino H OH

9. Check out the many different side groups…..
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NONAROMATIC
AROMATIC
Nonpolar
CH3
CH3
CH3 NH
CH3
CH3 CH
CH2 C
CH3 CH
CH2 H C
CH3
CH2
CH2
H3N+ C C O–
H3N+ C C O–
H3N+ C C O–
H3N+ C C O–
H3N+ C C O–
H3N+ C C O– H O H O H O H O H O H O
Alanine
(Ala)
Valine
(Val)
Leucine
(Leu)
Isoleucine
(Ile)
Phenylalanine
(Phe)
Tryptophan
(Trp)
Polar uncharged O
NH2 OH O C
NH2 OH
CH3 C
CH2 H
CH2 H C OH
CH2
CH2
CH2
H3N+ C C O–
H3N+ C C O–
H3N+ C C O–
H3N+ C C O–
H3N+ C C O–
H3N+ C C O– H O H O H O H O H O H O
Glycine
(Gly)
Serine
(Ser)
Threonine
(Thr)
Asparagine
(Asn)
Glutamine
(Gln)
Tyrosine
(Tyr)
Charged
NH2 C
NH2+ O O–
CH2
NH3+ NH C O O– HC
NH+
CH2
CH2
CH2 CH C C N
CH2
CH2
CH2 H
CH2
CH2
CH2
CH2
H3N+ C C O–
H3N+ C C O–
H3N+ C C O–
H3N+ C C O–
H3N+ C C O– H O H O H O H O H O
Glutamic
acid (Glu)
Aspartic
acid (Asp
Histidine
(His)
Lysine
(Lys)
Arginine
(Arg)

10. Forming Proteins
A protein is composed of one or more long chains of amino acids linked by peptide bonds.
-One Amino acid loses an “H” another an “OH” to form water and the
polypeptide (Condensation)
-Peptide bond links two amino acids.
C - N

11. Peptide bond

12. Proteins function is determined by its shape.
Protein Structure
Proteins function is determined by its shape.
There are several “levels” of organization
primary - specific amino acid sequence chains….just a chain, like beads on a
string.

13. Fig. 3.8c(TE Art) Primary structure 1 R H H O R H H O R H H C C N C C
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Primary structure R H H O R H H O R H H C C N C C N C C N C C N C C N C H O H H O H H O R R R
= peptide bonds
How many peptide bonds are formed to
Connect 100 amino acids?

14. 2. Secondary - folding of amino
acid chains
* Helix: twisted chain (hair)
*Pleated sheet: Side by side
chains (silk)

15. -side by side chains that bond2
Secondary
structure
b pleated sheet
Pleated sheet= silk
-side by side chains that bond

16. Helix
-hair

17. Protein Structure
3. Tertiary – amino acid chain folds and twists, called “globular” proteins
( one chain)

18. Beta globin subunit of hemoglobin

19. 4. Quaternary - forms when two
or more polypeptide chains
associate to form a functional
protein, combination of primary,
secondary and tertiary structures.

21. Fig. 3.8b(TE Art) Tertiary structure Domains Quaternary structure 4 5
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Tertiary
structure 5
Domains
Domain 1 6
Quaternary
structure
Domain 2
Domain 3

22. How do proteins Fold?
Bonding patterns between specific groups of atoms within the chain of amino acids determine the folding pattern.

23. Fig. 3.7(TE Art) Amino acid chains R H O C C C N C C N 1 R O (CH2)4
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. R H O C C C N C C N 1 R O
(CH2)4
Hydrogen
bond 3
(NH3+) H
Ionic bond R C N O– C C O C O
CH2 O C N H H C N C C C S S C C O H H O O N C C N 2 C
CH3
CH3 C
Disulfide
bridge N C O 4
Van der Waals
attraction
CH3
Amino acid chains H
CH3 5 C
CH3
Hydrophobic
exclusion
CH3
CH3
CH2
CH3 C
CH3

24. Chaperone Proteins
Chaperone proteins are special proteins which help new proteins fold correctly.
Chaperone deficiencies may play a role in facilitating certain diseases.

25. Unfolding Proteins
Denaturation refers to the process of changing a protein’s shape due to breaking of bonds.
usually rendered biologically inactive
Changing pH
salt-curing and pickling used to preserve food ( chemical, too acidic, too basic)
Heating
Freeze/thaw

27. If a protein changes shape, it changes function.
Important!!!!!!
If a protein changes shape, it changes function.

28. Part 2:
Overview of Nucleic acids
(more to come in another unit)

29. Nucleic Acids Deoxyribonucleic Acid (DNA)
Encodes information used to assemble proteins that determine form and function
of living things
-codes are passed on: heredity/genetics
Ribonucleic Acid (RNA)
Reads DNA-encoded information to direct protein synthesis.

30. Nucleic Acid Structure
Nucleic acids are composed of long polymers of repeating subunits, nucleotides.
five-carbon sugar
Phosphate group
nitrogenous base
purines
adenine and guanine
pyrimidines
cytosine, thymine, and uracil

31. One nucleotide Fig. 3.18(TE Art) Nitrogenous base (adenine) NH2 N
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One nucleotide
Nitrogenous base
(adenine)
NH2 N
Triphosphate group N O O O –O P O P O P O
CH2 N N O– O– O– O O OH OH
5-carbon sugar

32. Nucleic Acid Structure
DNA exists as double-stranded molecules.
double helix
complementary base pairing
hydrogen bonding
RNA exists as a single stand.
contains ribose instead of deoxyribose
contains uracil in place of thymine

33. occurs between base-pairs
Structure of DNA
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DNA
Deoxyribose-
phosphate
backbone P P P P T T T G P A G A P P C P A P C G
Bases A P T C P P P
Hydrogen bonding
occurs between base-pairs P P

34. Sugar-phosphate "backbone"
Fig. 3.16(TE Art)
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Sugar-phosphate "backbone" O P O
Hydrogen bonds between
nitrogenous bases C G P O O C P P G O O P A P T O O P G P C O O T OH A P
Phosphodiester
bond O P

35. Fig. 3.17b(TE Art) Structure of RNA P P P Ribose-phosphate P backbone
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Structure of RNA P P P
Ribose-phosphate
backbone P C A G P U A
Bases U P P G

36. All of the Biomolecules: review

37. Review

38. Review