Basic Conceptsof Biochemistry, Atom,.ppt

Basics of Biochemistry for Nurses

1. Basic Concepts
of Biochemistry
BScNGeneric
Dr. KalimUllah
PhD (Pharmacology), M. Phil., Pharm. D, R.Ph, GPP (Taiwan)
Associate Professor, Department of Nursing, Superior University
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2. CHEMISTRY OF LIFE
•Elements: simplest form of a
substance -cannot be broken down
any further without changing what it is
•Atom: the actual basic unit -
composed of protons, neutrons, and
electrons
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3. THE ATOM
•Just like cells are the basic unit of life, the
ATOMis the basic unit of matter.
•They are very small. If placed side by side
one million would stretch a distance of 1cm.
•The atom is made up of 3particles.
Particle Charge
PROTON +
NEUTRON NEUTRAL
ELECTRON -
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4. •Electrons are not present within the atom,
instead THEY REVOLVE AROUND THE
NUCELUS OF THE ATOM & FORM THE
ELECTRON CLOUD
•Draw a helium atom. Indicate where the
protons, neutrons and electrons are.
++
-
-
PROTONS
NEUTRONS
ELECTRONS
ATOMIC # = 2 (PROTONS)
ATOMIC MASS = 4
(PROTONS &
NEUTRONS)
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5. ISOTOPES
•atoms of the same element that HAVE A
DIFFERENT NUMBER OF NEUTRONS
•Some isotopes are radioactive. This means
that their nuclei is unstable and will break
down at a CONSTANT RATEover time.
•There are several practical uses for
radioactive isotopes:
1.CARBON DATING
2.TRACERS
3.KILL BACTERIA / CANCER CELLS
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6. COMPOUNDS
•a substance formed by the chemical
combination of 2 or more elementsin definite
proportions
–Ex: water, salt, glucose, carbon dioxide
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7. •The cell is a COMPLEX CHEMICAL
FACTORYcontaining some of the same
elements found in the non living
environment.
•carbon (C), hydrogen (H), oxygen (O), and
nitrogen (N) are present in the greatest
percentages
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8. TWO TYPES OF COMPOUNDS
•Organic -Contain C, H, and O in some
ratio (usually referred to as chemicals of
life)
–Carbohydrates, Proteins, Lipids, Nucleic Acids
•Inorganic -usually "support" life -no
specific ratio of C, H, and O
–Water (H2O), Carbon Dioxide (CO2)
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9. MIXTURES
•Water is not always pure. It is often found as
part of a mixture.
•A mixture is a material composed of TWO OR
MORE ELEMENTS OR COMPOUNDS THAT
ARE PHYSICALLY MIXED
–Ex: salt & pepper mixed, sugar and sand –can be
easily separated
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10. SOLUTION
Two parts:
•SOLUTE –SUBSTANCE THAT IS BEING
DISSOLVED (SUGAR / SALT)
•SOLVENT-the substance in which the solute
dissolves
•Materials that do not dissolve are known as
SUSPENSIONS.
–Blood is the most common example of a
suspension.
–Cells & other particles remain in suspension.
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11. FORMULA
•The chemical symbols and numbers that
compose a compound ("recipe")
•Structural Formula–Line drawings of the
compound that shows the elements in
proportion and how they are bonded
•Molecular Formula–the ACTUAL
formula for a compound
C2H6O
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12. ACIDS & BASES
•Acids: always (almost) begin with "H" because
of the excess of H+ ions (hydrogen)
–Ex: lemon juice (6), stomach acid (1.5), acid rain
(4.5), normal rain (6)
Facts about Acids
•Acids turn litmus paper BLUEand usually
taste SOUR.
•You eat acids daily (coffee, vinegar, soda,
spicy foods, etc…)
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13. ACIDS & BASES
•Bases: always (almost) end with -OH because
of the excess of hydroxide ions (Oxygen &
Hydrogen)
–EX: oven cleaner, bleach, ammonia, sea water,
blood, pure water
Facts about Bases
•Bases turn litmus BLUE.
•Bases usually feel SLIPPERYto touch and taste
BITTER.
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14. Neutralization Reactions
•When an acid reacts with a base to produce a
salt and water.
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15. pH SCALE
•measures degree of
substance alkalinity or
acidity
•Ranges from 0 to 14
•0 –5 strong acid
•6-7 neutral
•8-14 strong base
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16. •The goal of the body is to maintain
HOMEOSTASIS (neutrality)–to do this when
pH is concerned, we add weak acids & bases to
prevent sharp changes in pH.
•These are called BUFFERS
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17. 17

18. FUNCTIONAL GROUPS
•A group of atoms responsible for the characteristic
reactions of a particular compound.
•There are certain groups of atoms that are frequently
attached to the organic molecules and dominates in
characteristics of compound with which it is attached is
called functional groups.
•These are things like hydroxyl groupswhich form
alcohols, carbonyl groupswhich form aldehydesor
ketones, carboxyl groupswhich form carboxylic acids,
and amino groupswhich form amines.
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19. 19

20. CHEMICAL REACTIONS
•a process that changesone set of chemicals into
another set of chemicals
•REACTANTS–elements or compounds that
enter into a chemical reaction
•PRODUCTS–elements or compounds that are
produced in a chemical reaction
•Chemical reactions always involve the breaking of
bonds in reactantsand the formation of new
bonds in products.
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21. •In a reaction, energy is either TAKEN IN
(ENDOTHERMIC) or GIVEN OFF
(EXOTHERMIC)
•Can you think of an everyday example of
each type of reaction?
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22. A molecule is
formed when two
or more atoms
join together
chemically.
The smallest bit
of each of these
substances.
Diatomic molecules
are made of two
atoms of the same
element.
Examples
•Hydrogen –H
2
•Oxygen –O
2
•Water-H
2O

23. Intermolecular forces are the attractive forces
between molecules, between ions, or between
ions and molecules.
Question: What is the difference between
Intramolecular and Intermolecular Forces?
Intramolecular
Force that hold atoms
together in a
molecule
Intermolecular
are attractive
forces between
molecules

24. •Electrical forces exerted on the electrons of one
particle by the nucleus (or nuclei) of the other.
Electronegativity
•-the ability of an atom to attract (pull)
electrons to itself.
•Electrostatic force depends on the charge on
the ions.
Aggregation of atoms,
oppositely charged ions and
molecules is a consequence of

25. O
+

-
H
H
Intermolecular Forces

26. •Three types
1.Ionic
2.Covalent
3.Coordinate Covalent Bond
Intramolecular Forces

27. IONIC BONDS
•The bond which is formed when one or
more electrons are TRANSFERRED from
one atom to another.
•The atom loses electron gains POSITIVE
charge.
•While the atom accepts electron gains
NEGATIVEcharge.
•These newly charged atoms are now
called IONS
–Example: NaCl(SALT)
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28. 28

29. •Electrostatic force of attraction between ions of
opposite charge
•Ions are formed from atoms as a result of
electron transfer from one atom to another
•Formed as a result of a large difference in
electronegativity of atoms
•Formed between metals and non-metals
Ionic or Electrovalent Bond

30. •Crystalline solids-rigidity and strength
•High melting and boiling points
•Conduct electricity in molten and aqueous state
•They are hard
•They are brittle
•Soluble in polar solvents such as water (solute-
solvent interactions)
Properties

31. COVALENT BONDS
•“The bond which is formed by mutual sharing of
electrons”
•These new structures that result from covalent
bonds are called MOLECULES
•** In general, the more chemical bonds a
molecule has the more energy it contains
SHARING IS CARING!
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32. •Formed between atoms with a small difference in
electronegativity
•Formed by the overlapping of atomic orbital.
•Molecular orbital result
•Electrons are shared between nuclei of the two atoms
•The attraction between the shared electrons and the nuclei
that holds the molecule together
Covalent Bonds

33. •Liquids and gases at room temperature
•Relatively low boiling point.
•Do not conduct electricity
•Insoluble in polar solvent
•Soluble in non-polar solvent
Properties of Covalent
Compounds

34. •One atom donates both electrons to form a
covalent bond
•Recall-in a normal covalent bond each atom
donates an electron to be shared.
•The atom donating the electrons must have at
least one lone pair of the electrons.
Coordinate covalent Bond

35. •The other atom must have an available empty
orbital to accommodate this electron pair

36. has no separation of
charge, so no positive or negative poles are
formed.

37. Attractive forces betweenpolar
molecules.
Polar molecules have permanent dipoles that interact with
the permanent dipoles of neighboring molecules. The
positive end of one permanent dipole is attracted to the
negative end of another permanent dipole.
Polar molecules have a higher melting and boilingpoints
than nonpolar molecules of similar molarmass.

38. Orientation of Polar Molecules in aSolid

40. Hydrogen bonding is a special case of dipole -
dipole forces between (hydrogen bonded) F, N,
or O of one molecule andHydrogen atom of an
other similar molecule.

41. H-bonding is especially strong in biological
systems —such as DNA.
DNA—helicalchainsofphosphategroupsand
sugarmolecules.Chainsarehelicalbecauseof
tetrahedralgeometryofP,C,andO.
Chains bind to one another by specific
hydrogen bonding between pairs of Lewis
bases.
—adenine with thymine
—guanine with cytosine

43. Attractive forces between an ionand
a polarmolecule.
•a negative ion attracts the positive dipole ofanother
molecule
•a positive ion attracts the negative dipole ofanother
molecule

44. Ion-DipoleInteraction

45. Hydration
Of
Sodium ions

46. Hydration
of
Chloride Ions

47. •Thestrongestforceistheion-ionforce
andisconsideredlaterinthesectionon
ionicsolids.
•Theseforces(ion-ion)increaseasthesize
oftheiondecreasesandasthemagnitude
ofthechargeincreases.
•Remember that anions are larger than the
atoms they are derived from and cations
are smaller than the atoms they are derived
from.

48. Na
+—Cl
-in salt.
These are the
strongest forces.
Lead to solids
with high melting
temperatures.
NaCl, mp = 800
oC

49. •Also known as the DispersionForces.
•Interactions involving InducedDipoles.
Nonpolar molecules have no permanent dipole
moment, but transient dipoles exist due to the random
motion of the electrons about the positive charge
center.
Induced dipole forces result when an ion or a dipole
induces a dipole in an atom or a molecule with no
dipole. These are weak forces.

51. Thankuuuuuuu!
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