1. Biomolecules

3. Overview Energy and matter Atoms, molecules, and chemical bonds
Importance of organic and inorganic nutrients and metabolites
Structure and function of carbohydrates, lipids, proteins, and nucleic acids
Enzymes and ATP help run the metabolic reactions of the body

4. Energy The capacity to do work (put matter into motion)
Types of energy
Kinetic – energy in action
Potential – energy of position; stored (inactive) energy
Energy is easily converted from one form to another
During conversion, some energy is “lost” as heat

5. Why is chemistry important to anatomy and physiology?
Chemistry is the science that deals with matter
Matter is anything that takes up space and has mass
Smallest stable units of mass are atoms

6. Elements vs. Molecules
Elements are atoms of one particular type (from the periodic table)
Molecules are groups of atoms that contain more than one element

7. Elements found in the body
13 principal elements
Oxygen (O)
Carbon (C)
Hydrogen (H)
Nitrogen (N)
Calcium (Ca), phosphorus (P), potassium (K), sulfur (S), sodium (Na), chlorine (Cl), magnesium (Mg), iodine (I), and iron (Fe)
13 trace elements
(e.g. zinc, manganese)

8. Elements with unfilled electron shells are reactive
To become stable they form chemical bonds.
Three main types of chemical bonds
Intramolecular:
Ionic bonds (charged atoms resulting from the gain or loss of electrons)
Covalent bonds (electrons are shared)
Intermolecular
Hydrogen bonds

9. Ionic and covalent bonds
Molecules: atoms held together by covalent bonds
Salts: molecules held together by ionic bonds
Q: What are the strongest type of bonds?

10. Importance of water
The body is mostly water (~2/3rds of total body weight) so all chemical reactions in the body occur in water
Covalent bonds are much stronger than ionic bonds in water

11. Water properties
Water can dissolve organic and inorganic molecules making a solution
Water is needed for chemical reactions
Water can absorb and retain heat
Water is an effective lubricant

12. Water properties
Water has all these amazing properties due to their ability to form hydrogen bonds

13. Hydrogen bonds: weak bonds between molecules

14. Mixtures and Solutions
Mixtures – two or more components physically intermixed (not chemically bonded)
Solutions – homogeneous mixtures of components
Colloids (emulsions) – heterogeneous mixtures whose solutes do not settle out
Suspensions – heterogeneous mixtures with visible solutes that tend to settle out

15. Essential Molecules Nutrients: Metabolites:
essential molecules obtained from food (you have to eat them to get them)
Metabolites:
molecules made or broken down in the body

16. Organic vs. inorganic Organic molecules:
Always contain carbon with hydrogen, and sometimes oxygen
Often soluble in water
Inorganic: Electrolytes, minerals, and compounds that do not contain carbon with hydrogen.
Important examples: oxygen, carbon dioxide, water, inorganic acids and bases, salts

17. Vitamins and Minerals
Vitamins and minerals are essential nutrients that are required in very small amounts for healthy growth and development.
Examples?
They cannot be synthesized by the body and are essential components of the diet.

18. Vitamins Organic substances necessary for metabolism
There are 13 known vitamins (e.g. A, B1, D, K)
Some are fat soluble while others are water soluble
Are Coenzymes that help carry out the reactions of metabolism

19. Minerals
Inorganic compound (often salts or elements) necessary for proper body function
Can be bulk or trace minerals
Are Cofactors in metabolic reactions

20. Electrolytes
Inorganic ions (usually minerals) that conduct electricity in solution
Electrolyte balance is maintained in all body fluids; imbalance seriously disturbs vital body functions

21. Electrolytes

22. Biological Macromolecules
Life depends on four types of organic macromolecules:
1. Carbohydrates
2. Lipids
3. Proteins
4. Nucleic acids
Can you think of an example of each?

23. 1. Carbohydrates
Contain carbon, hydrogen and oxygen in a ratio of 1:2:1
Account for less that 1% of body weight
Used as energy source
Called saccharides

24. Glucose is a monosaccharide

25. Disaccharides
Sucrose
Lactose

26. Polysaccharides Starch Glycogen Cellulose
All are long strings of glucose molecules
Difference lies in how they are bonded together

27. Polysaccharides
Polysaccharides or polymers of simple sugars

28. Polymers
A polymer is any molecule made up of several repeating units. Starch is a polymer of glucose.

29. 2. Lipids
Contain carbon, hydrogen, and oxygen but the ratio of C:H is 1:2 (much less O)
May also contain other elements, phosphorous, nitrogen, and sulfur
Form essential structures in cells
Are important energy stores

30. Lipids: Triglycerides (Fats and Oils)
Consist of 3 fatty acids and glycerol
Insulation
Energy
protection
Q: What ‘s the difference between saturated and unsaturated?

31. Lipids: Steroids and Cholesterol
All consist of a complex ring structure

32. Lipids: Phospholipids
Amphipathic

33. 3. Proteins
Consist of chains of amino acids liked together by peptide bonds
Enzymes are proteins

35. Protein Chemistry

36. Proteins
are very important biological molecules that play crucial roles in virtually all biological processes

37. BIOLOGICAL FUNCTIONS OF PROTEINS
1. Catalytic function:
Nearly all chemical reactions in biological systems are catalyzed by specific enzymes.
2. Transport and storage:
For example;
Hemoglobin transports oxygen in erythrocytes
Myoglobin carries & stores oxygen in muscle.
Albumin transports free fatty acids in blood.
Transferrin transports iron in blood.
3. Coordinated motion:Actin and myosin are contractile proteins in muscle.

38. BIOLOGICAL FUNCTIONS OF PROTEINS (cont.)
4. Structural and Mechanical support:
For Example; collagen, a fibrous protein in skin and bone.
5. Defense function:
For Example Clotting factors prevent loss of blood.
Immunoglobulins protects against infections.
6. Generation and transmission of nerve impulses:
For example, rhodopsin is the photoreceptor protein in retinal rod cells.
7. Control of growth and differentiation:
For Example
growth factor proteins.
hormones such as insulin and thyroid-stimulating hormone.

39. General structure of protein
All biologically known protein are polymers of a set of twenty known amino acids.
All biologically known amino acids are α L amino acids.
They are composed of carboxylic end COOH and amino end NH2 and α carbon attached to both of them and special side chain (R) attached to this α carbon .
This side chain is characteristic of every amino acid.

40. are the basic building blocks of
AMINO ACIDS
are the basic building blocks of
PROTEINS

41. a specific side chain (R group)
Each AMINO ACID
has
An amino group,
A carboxyl group,
A hydrogen atom and
a specific side chain (R group)
Bonded to
the α-carbon atom

43. Classification of amino acids
Side chain reaction classification
Biological classification
Metabolic classification

44. Side chain classification
1- Hydrophobic (non-polar) R-group)
2- Hydrophilic (polar) R-group
Glycine (Gly-G) Alanine (Ala-A) Valine (Val-V) Leucine (Leu-L) Isoleucine (Ile– I) Methionine (Met– M) Proline (Pro– P) Phenylalanine (Phe– F) Tryptophan (Trp–W)
Uncharged
Aspargine (Asn – N) Glutamine (Gln – Q ) Serine
(Ser – S) Threonine (Thr – T ) Tyrosine
(Tyr – Y) Cysteine (Cys – C )
Positively charged
Lysine
(Lys – K )
Arginine
(Arg – R)
Histidine
(His – H )
Negatively charged
Aspartic acid
(Asp – D)
Glutamic acid (Glu – E )

45. Non polar (hydrophobic) amino acids
Side chains of non polar (hydrophobic) a.a. can not participate in hydrogen or ionic bonds, but they form hydrophobic interactions.
In aqueous environment, non polar a.a. tend to be present in the interior of proteins.
They include:
Amino acids with aliphatic R group (glycine, alanine,
Amino acids with aliphatic branched R group (valine, leucine and isoleucine).
Amino acids with aromatic R group (phenylalanine, tryptophan)
Amino acids with sulfur group (methionine) and
Imino acid (proine).

46. Polar (hydrophilic) amino acids
Side chains of polar (hydrophilic) a.a. can participate in hydrogen or ionic bonds.
Therefore, in aqueous environment polar a.a. tend to be present on the surface of proteins.
Polar (hydrophilic) amino acids are classified into:
- Polar charged amino acids include
acidic (Negatively charged): (aspartic and glutamic a.) and
basic (Positively charged group): (arginine, lysine, histidine) amino acids.
Polar non charged amino acids include:
Amino acids with OH group (serine, threonine, tyrosine)
Amino acids with SH group (cysteine)
Amino acids with amide group (glutamine, asparagines)

48. Biological classification
1- Non essential amino acids: These are Glycine, Alanine, Serine, Tyrosine, Cysteine, Arginine, Asparagine, Aspartic, Glutamic acid , Glutamine and Proline.
2- Essential amino acids:
They include Valine, Leucine, Isoleucine, Threonine, Methionine,, Lysine, Histidine, Phenylalanine and Tryptophan.

49. Metabolic classification
Glucogenic amino acids: These amino acids could give intermediates which finally can give glucose.
Purely ketogenic amino acids: They include Leucine & Lysine. They give ketone bodies after its degradation in the body, but no glucose.
Mixed amino acids: These are amino acids that can give both ketone bodies and glucose intermediates. These are Phenylalanine, Tyrosine, Tryptophan, Isoleucine and Lysine.
* The rest of amino acids are all purely glucogenic.

51. Ionic properties of amino acids
Amino acids have amphoteric properties .
They contain acidic (COOH) and Basic (NH2) groups.
The amino acids are usually ionized at physiological pH .
In acidic medium ; amino acid is positively charged ( behave as a base : proton acceptor )
In alkaline medium ; the amino acid is negatively charged ( behave as an acid: Proton donor)

53. Isoelectric point or “pI”
At certain pH “ specific for each amino acid “ the amino acid can exist in the dipolar from : fully ionized but with no net electric charge .
The characteristic pH at which the net electric charge is zero is called the Isoelectric point or “pI”.
The amino acid at the isoelectric pI is called
“ Zwitter Ion “ and is electrically neutral not migrating in an electric field
“Zwitter in German means hybrid or hermaphrodite”.

54. Isoelectric point or “pI”
At certain pH “specific for each amino acid” the amino acid can exist in the dipolar from : fully ionized but with no net electric charge.
The characteristic pH at which the net electric charge is zero is called the Isoelectric point or “pI”.
The amino acid at the isoelectric pI is called “Zwitter Ion” and is electrically neutral not migrating in an electric field.
Zwitter ion

55. Primary structure: the exact sequence of the different α-amino acids
along the protein chain.
Second and tertiary structure: the folding of the polyamide chain
which give rise to higher levels of
complexity.
Although hydrolysis of natural occurring proteins may yield as many
as 22 different amino acids, the amino acids have an important
structural feature in common.

58. Protein Structure
Proteins are the most abundant and important organic molecules
Basic elements:
carbon (C), hydrogen (H), oxygen (O), and nitrogen (N)
Basic building blocks:
20 amino acids

59. Protein Structure – 4 levels
Primary: amino acid sequence Secondary: Hydrogen bonds form spirals or pleats Tertiary: Secondary structure folds into a unique shape Quaternary: several tertiary structures together

60. Protein structure

61. Shape and Function Protein function is based on shape
Shape is based on sequence of amino acids
Denaturation:
loss of shape and function (due to heat, pH change or other factors)

62. Protein Functions buffering: regulation of pH metabolic regulation:
enzymes
coordination and control:
hormones
defense:
antibodies
support:
structural proteins
movement:
contractile proteins
transport:
transport proteins

63. Proteins: Enzymes Enzymes are catalysts:
proteins that lower the activation energy of a chemical reaction
are not changed or used up in the reaction
Other factors that speed up reactions:
Increased temperatures
Smaller particles
Higher concentrations

64. Activation Energy
Chemical reactions in cells cannot start without help
Activation energy gets a reaction started

65. Characteristics of Enzymes

66. Energy In, Energy Out Exergonic reactions: Endergonic reactions:
produce more energy than they use
Endergonic reactions:
use more energy than they produce

67. KEY CONCEPT
Most chemical reactions that sustain life cannot occur unless the right enzymes are present

68. How Enzymes Work Substrates: Active site:
reactants in enzymatic reactions
Active site:
a location on an enzyme that fits a particular substrate

69. How Enzymes Work + Active site Amino acids Enzyme (E) Enzyme-substrate
complex (E-S)
Internal rearrangements
leading to catalysis
Dipeptide product (P)
Free enzyme (E)
Substrates (S)
Peptide bond
H2O +
How Enzymes Work

70. 4. Nucleic acids Contain C, H, O, N, and P
DNA and RNA are nucleic acids
Nucleotide consists of
Sugar
Phosphate group
Nitrogenous base

71. Structure of DNA

72. A nucleotide: ATP Energy storage for cells Many enzymes use ATP
Provides a way to run reactions that are otherwise endergonic (require energy)

73. ATP is the energy currency of the cell
Solute
Solute transported
Contracted smooth
muscle cell
Product made
Relaxed smooth
Reactants
Membrane
protein P Pi
ATP X Y +
(a) Transport work
(b) Mechanical work
(c) Chemical work
ADP
ATP is the energy currency of the cell

74. Compounds Important to Physiology

75. Summary Energy and matter Atoms, molecules, and chemical bonds
Importance of organic and inorganic nutrients and metabolites
Structure and function of carbohydrates, lipids, proteins, and nucleic acids
Enzymes and ATP help run the metabolic reactions of the body