1. 2.1 Basic Chemistry
Matter is anything that takes up space and has mass.
The three states of matter are solid, liquid, and gas.
All matter, living or nonliving, is made up of elements.
Elements are substances that cannot be broken down into simpler substances by ordinary chemical means.

2. © Tom Mareschal/Alamy RF
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Earth’s crust
organisms 40
Percent by Weight 20 Fe Ca K S P Si Al Mg Na O N C H
Element
© Tom Mareschal/Alamy RF
92 naturally-occurring elements serve as building blocks of all matter.
Other elements have been “human-made” and are not biologically important.

3. Elements That Make up 95% of Organisms (by weight)
C Carbon
H Hydrogen
N Nitrogen
O Oxygen
P Phosphorus
S Sulfur

4. 2.4 Organic Molecules Organic molecules always include:
carbon (C) and hydrogen (H)
Those with only (H) and (C) are called hydrocarbons
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. H H H H H H H H H C C C C C C C C H H H H H H H H H

5. 2.4 Organic Molecules
The chemistry of carbon accounts for the formation of great variety of organic molecules.
Carbon atoms contain four valence electrons.
A carbon atom may share electrons with another carbon atom or other atoms in order to achieve eight electrons.
Satisfying the octet rule

6. 2.4 Organic Molecules
Functional groups are a specific combination of bonded atoms that always react in the same way.
The more common functional groups are listed in Table 2.1.

8. 2.4 Organic Molecules
Macromolecules contain many molecules joined together.
Monomers: Simple organic molecules that exist individually
Polymers: Large organic molecules form by combining monomers

9. 2.4 Organic Molecules Polymers in cells and their monomers Polymer
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Polymer
Monomer
carbohydrate (e.g., starch)
monosaccharide
protein
amino acid
nucleic acid
nucleotide

10. 2.4 Organic Molecules Cells use common reactions to join monomers.
In a dehydration reaction an -OH and -H are removed as a water molecule.
In a hydrolysis reaction, components of water are added.

11. Figure 2.13 monomer OH H monomer dehydration reaction H2O monomer
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monomer OH H
monomer
dehydration
reaction
H2O
monomer
monomer a.
monomer
monomer
hydrolysis
reaction
H2O
monomer OH H
monomer
Figure 2.13 b.

12. 2.5 Carbohydrates
Carbohydrates function for quick fuel and short-term energy storage in organisms.
Play a structural role in woody plants, bacteria and insects
On cell surfaces, involved in cell-to-cell recognition

13. Simple Carbohydrates
Monosaccharides are sugars with carbon atoms.
Pentose refers to a 5-carbon sugar
Hexose refers to a 6-carbon sugar
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CH2OH
CH2OH 6 5 C O O O H H H H H C C 4 1 OH H OH H HO OH HO OH C C 3 2 H OH H OH
C6H12O6
Figure 2.14

14. Simple Carbohydrates
Disaccharides contain two monosaccharides joined by the dehydration reaction.
Examples – maltose, sucrose, lactose
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CH2OH
CH2OH
CH2OH
CH2OH O O O O H H
dehydration reaction + + O
H2O
hydrolysis reaction OH HO
glucose C6H12O6
glucose C6H12O6
maltose C12H22O11
water + +
monosaccharide
monosaccharide
disaccharide
water
Figure 2.15

15. Polysaccharides
Polysaccharides such as starch, glycogen, and cellulose are long polymers that contain many glucose subunits.

16. Starch and Glycogen Starch is the storage form of glucose in plants.
May contain up to 4,000 glucose units
Fewer side branches than glycogen
Glycogen is the storage form of glucose in animals.
Liver stores glucose as glycogen
In between meals, the liver releases glucose stored in glycogen

17. © Jeremy Burgess/SPL/Photo Researchers, Inc.
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
CH2OH
CH2OH
CH2OH
CH2OH H O H H O H H O H H O H H H H H OH H OH H OH H OH H O O O O O H OH H OH H OH H OH
branched
nonbranched
starch
granule
cell wall
potato cells
Figure 2.16
© Jeremy Burgess/SPL/Photo Researchers, Inc.

18. © Don W. Fawcett/Photo Researchers, Inc.
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
CH2OH
CH2OH
CH2OH
CH2OH O O O O H H H H H H H H H H H H OH H OH H OH H OH H O O O O O H OH H OH H OH H OH
glycogen
granule
Figure 2.17
liver cells
© Don W. Fawcett/Photo Researchers, Inc.

19. Cellulose Cellulose is found in the cell walls of plants.
Some polysaccharides function as structural components of cells.
Cellulose is found in the cell walls of plants.
Accounts for the strong nature of the cell walls
Has different chemical linkage than starch or glycogen
Prevents us from digesting foods with cellulose
Chiton, found in the exoskeleton of crabs, is another structural polysaccharide.

20. © Science Source/J.D. Litvay/Visuals Unlimited
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plant
cell wall
cellulose
fiber
cellulose fibers
microfibrils
CH2OH H OH
CH2OH H OH H O H H O H O OH H H O OH H O OH H H O OH H H O H H H H O O H OH
CH2OH H OH
CH2OH
CH2OH H OH
CH2OH H OH H O H H O H O OH H H O OH H O OH H H O OH H H O H H O H H O H OH
CH2OH H OH
CH2OH
glucose
molecules
CH2OH H OH
CH2OH H OH H O H H O H O OH H H O OH H O OH H H O OH H H O H H H H O O H OH
CH2OH H OH
CH2OH
Figure 2.18
© Science Source/J.D. Litvay/Visuals Unlimited

21. 2.6 Lipids
Lipids contain more energy per gram than other biological molecules.
Types
Fats and oils used for energy storage
Phospholipds from membranes
Steroids include sex hormones

22. 2.6 Lipids Lipids are diverse in structure and function.
Lipids have one common characteristic – they do not dissolve in water (hydrophobic).

23. Fats and Oils Fats Oils Usually of animal origin
Solid at room temperature
Store energy, insulate against heat loss, form protective cushion
Oils
Usually of plant origin
Liquid at room temperature

24. Fats and Oils
A fat molecule is also known as a triglyceride or neutral fat.
A triglyceride consists of
One glycerol backbone
Three fatty acids

25. Fats and Oils Figure 2.19 + + H H H H H H O H H H H O C C C C C H H C
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. H H H H H H O H H H H O C C C C C H H C O C C C C C H H C OH HO H H H H H H H H H H H H H H
dehydration reaction O H H H H H H O + C C C C C C C H H C O C C C C C C C H + H C OH 3
H2O HO
hydrolysis reaction H H H H H H H H H H H H H H H H H O H H H H H O C C C C C C H H C O C C C C C C H H C OH HO H H H H H H H H
glycerol
3 fatty acids
fat molecule
3 water
molecules
Figure 2.19

26. Emulsification Fat droplets disperse in water.
Emulsifiers contain molecules with a polar and nonpolar end.

27. Saturated, Unsaturated, and Trans-Fatty Acids
A fatty acid is a hydrocarbon chain that ends with the acidic group —COOH.
Saturated fatty acids have no double bonds between carbon atoms.
Unsaturated fatty acids have one or more double bonds between carbon atoms.

28. Comparison of Saturated, Unsaturated and Trans-Fats
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. H H H H H C C C C C C H H H
Unsaturated cis fats
(oils)
Saturated
(butter)
Unsaturated trans-fats
(hydrogenated oils)

29. Phospholipids
Phospholipids are comprised of two fatty acids and a phosphate group
The phosphate group is polar so the molecules are not electrically neutral.
The phosphate group forms a polar head (hydrophilic) while the rest of the molecule is a nonpolar (hydrophobic) tail.

30. Phsopholipids
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Polar Head R – O – O –
phosphate – P O O –
1CH2
2CH
3CH2
Spontaneously form a bilayer in which the hydrophilic heads face outward toward watery solutions and the tails form the hydrophobic interior
glycerol – – O O C O O C
CH2
CH2
CH2
CH2
Fatty acids
CH2
CH2
inside cell
CH2
CH2
CH2
CH2
CH2
CH2
CH2
CH2 CH CH CH CH
CH2
outside cell
CH2
CH2
CH2
a. Plasma membrane of a cell
CH2
CH2
CH2
CH2
CH2
Nonpolar Tails
CH2
CH2
CH2
CH2
CH2
CH2
CH3
CH2
Figure 2.21
CH3
b. Phospholipid structure

31. Steroids Steroids have a backbone of four fused carbon rings
Examples: Cholesterol, Testosterone, Estrogen
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. OH OH
CH3
CH3
CH3 O HO
Figure 2.22
a. Testosterone
b. Estrogen

32. 2.7 Proteins Proteins are polymers composed of amino acid monomers
Amino acids
Amino group (-NH2)
Acidic group (-COOH)
R group varies
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amino group
acidic group H H H R O OH H N C C N C C OH H O R H
Figure 2.24
amino acid
amino acid

33. Figure 2.23 H O H3N+ C C CH3 O– H O H3N+ C C O– CH H3C CH3 H O H3N+ C
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. H O
H3N+ C C
CH3 O– H O
H3N+ C C O– CH
H3C
CH3 H O
H3N+ C C
CH2 O– SH H O
H3N+ C C O–
CH2
Figure 2.23

34. 2.7 Proteins Proteins perform many functions
Structural proteins give support (keratin, collagen)
Enzymes speed up chemical reactions
Hormones are chemical messengers
Actin and myosin move cells and muscles
Some proteins transport molecules in blood
Antibodies protect cells
Channels allow substances to cross membranes

35. Peptides Peptides A polypeptide is a single chain of amino acids.
A peptide bond joins two amino acids.
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amino group
acidic group
peptide bond H H H H O O H R R OH OH
dehydration reaction H N C C N C C H N C C N C C
H2O OH H O O R H
hydrolysis reaction R H H
amino acid
amino acid
water
dipeptide
Figure 2.24

36. Figure 2.25 H3N+ amino acid peptide bond COO– C CH hydrogen bond C N R
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H3N+
amino acid
peptide bond
COO– C CH
hydrogen bond C N R CH C N
hydrogen bond CH R R C N CH C N CH R N R C CH C N CH R C N R CH
 (alpha) helix
(beta) pleated sheet
Figure 2.25

37. Figure 2.25  (alpha) helix (beta) pleated sheet disulfide bond
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 (alpha) helix
(beta) pleated sheet
disulfide bond
Figure 2.25

38. Copyright © The McGraw-Hill Companies, Inc
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H3N+
amino acid
peptide bond
COO– C CH C
hydrogen bond N CH R C N CH R
hydrogen bond R C N CH C N CH R N R C C CH CH N R C N R CH
 (alpha) helix
(beta) pleated sheet
disulfide bond
Figure 2.25

39. 2.8 Nucleic Acids The two types of nucleic acids are
DNA (deoxyribonucleic acid)
Stores genetic information in the cell and in the organism
DNA replicates to transmit its information when a cell divides or organism reproduces
RNA (ribonucleic acid)

40. Structure of DNA and RNA
Both DNA and RNA are polymers of nucleotides
Every nucleotide is a molecular complex of
Phosphate
Pentose sugar (ribose or deoxyribose)
Nitrogen-containing base
DNA contains: Adenine (A), Thymine (T), Guanine (G) and Cytosine (C)
In RNA, uracil (U) replaces thymine

41. O nitrogen- containing base phosphate C –O P O C O– 5' O 4' S 1' 3' 2'
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nitrogen-
containing
base
phosphate C –O P O C O– 5' O 4' S 1' 3' 2'
pentose sugar
Figure 2.26
Nucleotide structure

42. Structure of DNA and RNA
The nucleotides form a linear molecule called a strand.
DNA is a double helix of two strands.
The two strands are held together by hydrogen bonds.
Rungs of the ladder are formed by complementary paired bases.
Adenine (A) always pairs with thymine (T)
Cytosine (C) always pairs with guanine (G)

43. a: © Radius Images/Alamy RF
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. S S A T P P S C S G P P A G T T T A C S C
one nucleotide S A G P P C G S S P P S S A T P P a. b. c.
a: © Radius Images/Alamy RF

44. Structure of DNA and RNA
RNA is single-stranded.
Several types are involved in carrying information from DNA to make proteins.
ATP (Adenosine Triphosphate)
ATP is a high-energy molecule.
ATP undergoes hydrolysis and energy is released.
ATP is the energy “currency” of the cell.

45. Last two phosphate bonds are unstable and easily broken.
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H2O + + P P P P P P
energy
Last two phosphate bonds are unstable and easily broken.
Hydrolization forms ADP (adenosine diphosphate).
ATP can be rebuilt.
Add P to ADP to make ATP
Figure 2.28