Your SlideShare is downloading. ×
0
Introduction to biomolecules
Introduction to biomolecules
Introduction to biomolecules
Introduction to biomolecules
Introduction to biomolecules
Introduction to biomolecules
Introduction to biomolecules
Introduction to biomolecules
Introduction to biomolecules
Introduction to biomolecules
Introduction to biomolecules
Introduction to biomolecules
Introduction to biomolecules
Introduction to biomolecules
Introduction to biomolecules
Introduction to biomolecules
Introduction to biomolecules
Introduction to biomolecules
Introduction to biomolecules
Introduction to biomolecules
Introduction to biomolecules
Introduction to biomolecules
Introduction to biomolecules
Introduction to biomolecules
Introduction to biomolecules
Introduction to biomolecules
Introduction to biomolecules
Introduction to biomolecules
Introduction to biomolecules
Introduction to biomolecules
Introduction to biomolecules
Introduction to biomolecules
Introduction to biomolecules
Introduction to biomolecules
Introduction to biomolecules
Introduction to biomolecules
Introduction to biomolecules
Upcoming SlideShare
Loading in...5
×

Thanks for flagging this SlideShare!

Oops! An error has occurred.

×
Saving this for later? Get the SlideShare app to save on your phone or tablet. Read anywhere, anytime – even offline.
Text the download link to your phone
Standard text messaging rates apply

Introduction to biomolecules

1,105

Published on

Lecture discuss about: …

Lecture discuss about:
1. Definition of biochemistry
2. Structure of water
3. Properties of water
4. Acid base reaction
5. Buffer system

Published in: Technology, Business
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total Views
1,105
On Slideshare
0
From Embeds
0
Number of Embeds
0
Actions
Shares
0
Downloads
22
Comments
0
Likes
0
Embeds 0
No embeds

Report content
Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
No notes for slide

Transcript

  • 1. MASTERSKILL UNIVERSITY COLLEGE OF HEALTH SCIENCES THE LEADER In Nursing & Allied Health Education in MalaysiaBCH 1023 S1 PREMIER o RECOGNISED o TRUSTED JAN 2012
  • 2. BACHELOR IN BIOMEDICAL SCIENCE (HONS) BCH 1023 BIOCHEMISTRY SEM 2 Chapter 1 INTRODUCTION TO BIOMOLECULESBCH 1023 S2 PREMIER o RECOGNISED o TRUSTED JAN 2012
  • 3. LEARNING OUTCOMES At the end of the lesson students should be able to: 1. Define study of biochemistry. 2. Describe the structure of water. 3. Describe the properties of water. 4. Describe acid-base reaction and buffer systemBCH 1023 S3 PREMIER o RECOGNISED o TRUSTED JAN 2012
  • 4. INTRODUCTION  Cell is the basic unit and building block of biology.  Biochemistry is the science concerned with the various molecules that occur in living cells.  Cell biochemistry is the study of chemical substances and vital processes in living organism.  Modern cell biology involves the combination of three area of studies: 1. Cytology – concerned with cellular structure. 2. Biochemistry – understanding of cellular functions. 3. Genetics and molecular biology.BCH 1023 S4 PREMIER o RECOGNISED o TRUSTED JAN 2012
  • 5. 1)WATER  In human tissues the percentage of water ranges from 20% in bones to 85% in brain cells.  Water made up 70% of human body weight.  Water is important as solvent for most biological reactions and a product or reactant for many chemical reactions.  Water’s unique combination of physical and chemical properties is considered to have been essential to the origin of life, continuing survivality and evolution of life on Earth.BCH 1023 S5 PREMIER o RECOGNISED o TRUSTED JAN 2012
  • 6. CHEMISTRY OF WATER  Molecular structure: Water is composed of one oxygen atom and two hydrogen atoms.  Each hydrogen atom is covalently bonded to the oxygen through a shared pair of electrons.  Oxygen atom consist of two unshared pairs of electrons/lone pair of electrons.  Water is a tri-atomic molecule, H2O  The arrangement of hydrogen and oxygen atoms in water molecule is nonlinear with an H-O-H  Bond angle of water 104.5oCBCH 1023 S6 PREMIER o RECOGNISED o TRUSTED JAN 2012
  • 7. WATER MOLECULES HYDROGEN BONDING  Hydrogen bonding is of electrostatic origin and can be considered as a special case of dipole-dipole interaction.  Hydrogen bonding of water molecules results from the O-H bond of one water molecule (positive end, δ+) points towards one of electron pairs of another water molecule(negative end, δ-)  Each water molecule is involved in four hydrogen bond – two hydrogen-bond donor and two hydrogen-bond acceptor.  The ability to form strong hydrogen bonding contribute to the high melting point and boiling point of water.BCH 1023 S7 PREMIER o RECOGNISED o TRUSTED JAN 2012
  • 8. - +H + - + H + Hydrogen bonding of water moleculesBCH 1023 S8 PREMIER o RECOGNISED o TRUSTED JAN 2012
  • 9. PROPERTIES OF WATER 1)Physical states 2)Polarity of 3)Water as a of water water universal solvent 4)High specific 5)High surface 6)Solid heat tension expansionBCH 1023 S9 PREMIER o RECOGNISED o TRUSTED JAN 2012
  • 10. 1)Physical states of water  The physical states of water are solid, liquid and gas.  Melting point is 0°C (32°F).  Boiling point is 100°C (212°F).  Pure water are colorless, tasteless and odorless.  Pure water is neutral (pH 7)  In pure water the content of OH- and H+ are balances at 25°C with the value of 1.0x10-7 moles/L.BCH 1023 S10 PREMIER o RECOGNISED o TRUSTED JAN 2012
  • 11. 2)Polarity of water  The bond form by atoms with differing electronegativity will cause unequal electron sharing.  In the O-H bonds in water, O is more electronegative than H.  The different electronegativity between O and H gives rise to the partial positive (δ+) and partial negative (δ-) of water molecule.  The O-H bonding of water molecule are polar bond.BCH 1023 S11 PREMIER o RECOGNISED o TRUSTED JAN 2012
  • 12. 3)Water as a universal solvent  Water is called universal solvent because it dissolves more substances than any other liquid.  The ability of ions and other molecules to dissolve in water is due to polarity of water.  Ionic compounds with full charges (e.g KCL, K+ and Cl- in solution) and polar compounds with partial charges or dipoles (e.g alcohol or acetone) tend to dissolves in water.  The physical principle is due to the electrostatic attraction between unlike/different charges.BCH 1023 S12 PREMIER o RECOGNISED o TRUSTED JAN 2012
  • 13. a) Ion – dipole interaction b) Dipole – dipole interaction Ion-dipole and dipole-dipole interactions help ionic and polar compound dissolve in water.BCH 1023 S13 PREMIER o RECOGNISED o TRUSTED JAN 2012
  • 14. 3)Water as a universal solvent  Hydrophilic or “water-loving” compound have the ability to dissolve in water because they have polar functional groups that form favorable attraction toward water molecules  Polar covalent compound, ionic compounds, sugars and amino acids hydrophilic in nature.  Hydrophobic or “water-hating” compounds are is not water soluble because they have no charge or non-polar functional groups.  Non-polar covalent compound (hydrocarbon), fatty acids and cholestrol are hydrophobic compounds.BCH 1023 S14 PREMIER o RECOGNISED o TRUSTED JAN 2012
  • 15. Homework /Tutorial  What is ion-dipole and dipole-dipole interaction?  Sodium chloride in its crystalline form is dissolve in water. Explain how does this happened.  Explain why oil and water when mixed together separate into layers?BCH 1023 S15 PREMIER o RECOGNISED o TRUSTED JAN 2012
  • 16. 4)HIGH SPECIFIC HEAT  Water has high specific heat which means that water can absorb a lot of heat before it begins to get hot.  Heat is used to break down the hydrogen bonding of water molecules but it does not increase the kinetic energy of the water molecules.  Water releases heat energy slowly causing cooling effect.  This properties explain why: 1. Water is used as coolant. 2. Large change in temperature does not takes place when heat is produced by chemical reactions in the cells. 3. Body temperature can be regulates effectively.BCH 1023 S16 PREMIER o RECOGNISED o TRUSTED JAN 2012
  • 17. 5)HIGH SURFACE TENSION  Water molecules at the liquid surface are pulled laterally and towards the bulk by the remaining stronger hydrogen bonds and resulting the high surface tension of water.  Thus water tends to clump together in drops rather than spread out in a thin film.  Surface tension along with adhesion is responsible for capillary action.  Capillary action is the tendency of water to move in narrow tubes against the force of gravity.  Capillary action allows water (and its dissolved substances) to move through the roots of plants and through tiny blood vessels.BCH 1023 S17 PREMIER o RECOGNISED o TRUSTED JAN 2012
  • 18. Surface tension of water enable water striders to walk on the surface of the water. Capillary action shows that the colored water move through plant stem to leaves.BCH 1023 S18 PREMIER o RECOGNISED o TRUSTED JAN 2012
  • 19. 5)HIGH SURFACE TENSION  Hydrogen bonding of water molecules makes water cohesive and adhesive. 1. Cohesive  tendency to stick to each other 2. Adhesive  adhesive forces explain how water makes things wet.  Cohesive and adhesive forces accounts for the phenomenon of capillary action.  Cohesiveness of water molecules contribute to the high degree of surface tension.BCH 1023 S19 PREMIER o RECOGNISED o TRUSTED JAN 2012
  • 20. 6)SOLID EXPANSION  Ice has lower density than liquid water because the fully hydrogen bonded array in an ice crystal is less densely packed that the liquid water.  Liquid water is less extensively hydrogen- bonded and thus is denser than ice.  This explain why ice cubes and iceberg floats.  Most substances contract when freeze but the opposite occur to water.BCH 1023 S20 PREMIER o RECOGNISED o TRUSTED JAN 2012
  • 21. a) Picture of ice cubes float in b) Ice form on the lake surface. water.BCH 1023 S21 PREMIER o RECOGNISED o TRUSTED JAN 2012
  • 22. OSMOSIS AND DIFFUSION  Osmosis is the movement of solvent from a region of high concentration to a low concentration.  Diffusion is the transport of molecules through their random movement.  Osmotic pressure is the pressure that must be applied to the solution to prevent the inward flow of water.  In 1M solution, the osmotic pressure is 22.4atm.BCH 1023 S22 PREMIER o RECOGNISED o TRUSTED JAN 2012
  • 23. IONIZATION OF WATER  Water is a neutral molecule with very slight tendency to ionize. Pure water ionizes slightly can act as an acid (proton donor) or base (proton acceptor). 2H2O H3O+ + OH- but usually written as H2O H+ + OH- This generate the hydronium ion (H3O+) and hydroxide ion (OH-)  Equilibrium of water: Keq= [H+][OH-] = 1.8 x 10-16 M at 25oC [H2O]BCH 1023 S23 PREMIER o RECOGNISED o TRUSTED JAN 2012
  • 24. Equilibrium Constant  Keq represent equilibrium constant for the reaction and the brackets for each chemical entity indicate concentration units in moles per liter (M). Keq = [H+] [OH-] / [H2O]  Calculation of Keq of pure water from experimental measurements enable calculation of quantity for [H+] and [OH-].  Thus enable estimation of the extent of pure water self dissociation.  Keq for pure water at 25°C is 1.8 x 10-16 MBCH 1023 S24 PREMIER o RECOGNISED o TRUSTED JAN 2012
  • 25. Equilibrium constant  The value of [H2O] can be estimated by: [H2O] = Weight of water in 1L / Molecular weight of water = 1000g / 18 = 55.5 M  Thus, [H+] [OH-] = Keq [H2O] [H+] [OH-] = (1.8 x 10-16 M) (55.5 M) [H+] [OH-] = 1.0 x 10-14 M2 [H+] = [OH-] = √ (1.0 x 10-14 M2) = 1.0 x 10-7 MBCH 1023 S25 PREMIER o RECOGNISED o TRUSTED JAN 2012
  • 26. pH  Hydrogen ion concentration expressed in exponential form are difficult to utilize.  Thus, negative logarithm of [H+] or pH is used. pH = -log 10 [H+]  A different of 1 pH unit indicates a tenfold different in ion concentration, [H+].  For example, a solution at pH 7 have 10x greater [H+] than a solution at pH 8.BCH 1023 S26 PREMIER o RECOGNISED o TRUSTED JAN 2012
  • 27. BCH 1023 S27 PREMIER o RECOGNISED o TRUSTED JAN 2012
  • 28. ACID-BASE  A biological definition of acid and base are, acid is a molecule that acts as a proton (H+) donor and base is defined as proton (H+) acceptor.  The degree of acid losing proton or base gaining proton depends on the chemical nature of the compound.  Acid strength is the amount of H+ released when a given amount of acid is dissolved in water.  The numerical measurement of acid strength is expressed as acid dissociation constant, KaBCH 1023 S28 PREMIER o RECOGNISED o TRUSTED JAN 2012
  • 29. ACID-BASE  Ka can be written as HA for any acid. HA H+ + A- Ka = [H+] [A-] / [HA]  The greater the Ka value mean the stronger the acid.  Acid-base reaction is a proton-transfer reaction in which water acts as a base as well as the solvent.  The equation are, HA (aq) + H2O (l) H3O+ (aq) + A- (aq) (Acid) (Base) (Conjugate acid) (Conjugate base) to H2O to HABCH 1023 S29 PREMIER o RECOGNISED o TRUSTED JAN 2012
  • 30. BUFFERS  Buffers is something that able to resists change.  Buffer solutions tend to resist change in pH when a small to moderate amounts of a strong acid or strong base is added.  Buffer solution is a mixture of either a weak acid and its salt or a weak base and its salt.  Example of buffer solution: A mixture of acetic acid (CH3COOH) and sodium acetate (CH3COONa) dissolve in water. This buffer solution consist of high concentration of acidic (e.g CH3COOH) and basic (e.g CH3COO-) components.BCH 1023 S30 PREMIER o RECOGNISED o TRUSTED JAN 2012
  • 31. BUFFERS  When a small amount of strong acid e.g H3O+ is added, H3O+ will react with CH3COO- to produce CH3COOH and water. CH3COO- + H3O+ CH3COOH + H2O (Buffer component ) (Added strong acid)  The added H3O+ is removed from the solution thus, the pH hardly change.  When strong base e.g OH- is added the buffer solution reacts with CH3COOH forming CH3COO- ion and water CH3COOH + OH- CH3COO- + H2O (Buffer component ) (Added strong acid)  Added OH- are removed from the solution thus, thus the pH remain unchanged.BCH 1023 S31 PREMIER o RECOGNISED o TRUSTED JAN 2012
  • 32. Buffer system in living organism  The pH of various body fluids is maintained by buffers.  The H2PO4/HPO4- pair is the principle buffer in cell.  In blood the buffering system is based on the dissociation of carbonic acid (H2CO3)  The pH of human blood is 7.4.  Acidic condition of blood is signifies by pH less than 7.35 where the condition is known as acidemia  Alkaline condition of blood is signifies by the pH greater than 7.45 where the condition is known as alkalemia.  Death occurs when the pH of blood is more acidic than 6.8 or more basic than 7.8BCH 1023 S32 PREMIER o RECOGNISED o TRUSTED JAN 2012
  • 33. Buffer system in living organism  The process of respiration plays an important role in the buffering of blood.  An increase of [H+] can be dealt with raising the rate of respiration.  Hyperventilation (excessively deep and rapid breathing) removes CO2 from blood that it raises the pH of blood.  The increase of blood pH are dangerous as it bring weakness and fainting.  Athletes overcome hyperventilation by performing short burst of strenuous exercise to produce high levels of lactic acid in blood.  Lactic acid in blood results in anaerobic breakdown of glycogen.BCH 1023 S33 PREMIER o RECOGNISED o TRUSTED JAN 2012
  • 34. Buffer system in living organism  The presence of lactic acid tends to lower the pH of blood.  Exposure to high altitude has a similar effects as hyperventilation at sea level.  In response to the tenuous atmosphere, the rate of respiration will increase.  At high altitude more CO2 is expired from blood, lowering the H+ and raising the pH level of blood.  The rise of pH level occur at high altitude are temporary until they become acclimated.BCH 1023 S34 PREMIER o RECOGNISED o TRUSTED JAN 2012
  • 35. TUTORIAL 1. Ingestion of large dosage of aspirin can cause aspirin poisoning. Explain this condition toward the buffer system of the blood. 2. Lactic acid causes muscle pain and muscle fatigue. However in recent study, lactic acid actually has a positive effect on fatiguing muscle. Discuss. 3. A frequently recommended treatment for hiccups is to hold one’s breath. The resulting condition, hyperventilation causes buildup of CO2 in the lungs. Discuss about the effect of pH of blood.BCH 1023 S35 PREMIER o RECOGNISED o TRUSTED JAN 2012
  • 36. REFERENCES 1. M.K Campbell & S.O Farrell (2009). Biochemistry 6th Edition. Thomson Higher Education. USA. 2. D.Voet, JG Voet & CW Pratt (1999). Fundamentals of Biochemistry. John Wiley & Sons. Inc 3. M.Shahjahan (2006). Cell Biochemistry & Basic Genetics. PPSK,USM.BCH 1023 S36 PREMIER o RECOGNISED o TRUSTED JAN 2012
  • 37. End of Chapter 1 I run, they run, everybody run and we’re all just having fun, Sleigh ride, boat ride, piggy back and ride, I’m gonna tell them all how I can ride. ~Foster the People~BCH 1023 S37 PREMIER o RECOGNISED o TRUSTED JAN 2012

×