1 / 32

Chapter 2 - Biochemistry

Chapter 2 - Biochemistry. Wakefield 2010-2011. Nature of Matter (2.1). Life Depends on chemistry - The science of matter and the changes it undergoes. Nature of Matter (2.1). Matter - everything around you - anything made of atoms and molecules Atoms – the basic unit of matter

brock
Télécharger la présentation

Chapter 2 - Biochemistry

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Chapter 2 - Biochemistry Wakefield 2010-2011

  2. Nature of Matter (2.1) • Life Depends on chemistry - • The science of matter and the changes it undergoes

  3. Nature of Matter (2.1) • Matter - everything around you - anything made of atoms and molecules • Atoms – the basic unit of matter • Means unable to be cut • First referred to by the Greek philosopher, Democritus about 2500 years ago • Made up of sub-atomic particles

  4. Nature of Matter (2.1) • Atoms – the basic unit of matter • Made up of sub-atomic particles • Protons – located in the nucleus of the atom and have a (+) positive charge • Neutrons – located in the nucleus of the atom and have a (+/-) neutral charge • Electrons – located in orbit around the nucleus of the atom and have a (-) negative charge • Nucleus – the center of the atom

  5. Nature of Matter (2.1) • Atoms – the basic unit of matter • Atoms are usually neutral in charge because the # of positively charged protons and the # of negatively charged electrons are equal – giving the atom a neutral charge

  6. Nature of Matter (2.1) • Element - pure substance containing only one type of atom – indicated by a chemical symbol or abbreviation • More than 100 known elements • Only about 2 dozen commonly occurring elements

  7. Nature of Matter (2.1) • Element - pure substance containing only one type of atom • Atomic Number – indicates the # of protons present • Atomic Mass - indicates the sum of the protons and neutrons in the nucleus (Protons + Neutrons = Mass #) • Atomic Mass is also an average of the protons and neutrons as they naturally occur

  8. Nature of Matter (2.1) • Isotopes – occur when atoms of the same element have different numbers of neutrons – identified by their atomic mass number Nonradioactive carbon-12 Nonradioactive carbon-13 Radioactive carbon-14 6 electrons 6 protons 6 neutrons 6 electrons 6 protons 7 neutrons 6 electrons 6 protons 8 neutrons Carbon 12 Carbon 13 Carbon 14 See Figure 2-2 – page 36

  9. Nature of Matter (2.1) • Radioactive isotopes – occur because the nucleus of these atoms become unstable and start to break down over time Nonradioactive carbon-12 Nonradioactive carbon-13 Nonradioactive carbon-14 6 electrons 6 protons 6 neutrons 6 electrons 6 protons 7 neutrons 6 electrons 6 protons 8 neutrons (See Figure 2-2 – page 36)

  10. Nature of Matter (2.1) • Radioactive isotopes – • Unstable and break down over time • Give off radiation that can be dangerous • Can be practical and useful • Treat Cancer • Kill Bacteria • Used as labels & tracers to follow movement of substances within organisms

  11. Nature of Matter (2.1) Radiation Therapy

  12. Nature of Matter (2.1) • Compounds – a substance formed by the chemical combination of 2 or more elements in definite proportions • Indicated by a chemical formula • H2O, CO2 • Properties of a compound are usually very different from those of the elements from which it is formed • NaCl for example

  13. Nature of Matter (2.1) • Chemical Bonds – atoms in compounds are held together by chemical bonds • Involves the electrons that orbit the nucleus of the atoms involved in the bond

  14. Nature of Matter (2.1) • Chemical Bonds – atoms in compounds are held together by chemical bonds • Ionic Bonds – formed when one or more electrons are transferred from one atom to another Salt Na+Cl-

  15. Nature of Matter (2.1) • Chemical Bonds – atoms in compounds are held together by chemical bonds • Covalent Bonds – formed when electrons are shared between atoms • Single Covalent Bond - formed when only 2 electrons are shared in the bond • Double Covalent Bond – formed when 4 electrons are shared in the bond • Triple Covalent Bond – formed when 6 electrons are shared in the bond (rarely does this occur) 3-D molecular structure of H2O

  16. Nature of Matter (2.1) • Molecule – substance formed from bonding of elements and is the smallest part of a compound

  17. Nature of Matter (2.1) • van der Waals – intermolecular bonding

  18. Properties of Water (Section 2.2) Page 40

  19. Earth – “the blue planet”

  20. Properties of Water 2.2 • Water • Covers ¾ of the earth’s surface • One of the few compounds that is liquid in most of our environments • Expands when it freezes so it floats • Evaporates when it is heated

  21. Properties of Water 2.2 • Water • Molecule of water is neutral in charge • Water does have polarity • Occurs when there is an uneven distribution of electrons between the oxygen and the hydrogen atoms • Water molecule is bent in shape • Oend has a slightly negative (-) charge • H end has a slightly positive (+) charge

  22. Properties of Water • Cohesion – an attraction of like molecules

  23. Properties of Water • Adhesion – the attraction between molecules of different substances.

  24. Properties of Water Adhesion >>>>>> Capillary Action • Capillary Action – adhesion between water and another substance – will draw water up that substance • Ex. Water up the stem of a plant to the leaves

  25. Mixtures, Solutions & Suspensions • Mixture – a material composed of two or more elements or compounds that are physically mixed together but not chemically combined • Other • Types of Mixtures • Solutions • Suspensions

  26. Mixtures, Solutions & Suspensions • Solution – • Components are evenly distributed • Contains: • Solute - substance getting dissolved • Solvent – Substance which dissolves the solute Cl- Cl- Na+ Na+ Water Water

  27. Mixtures, Solutions & Suspensions • Suspension - occurs when solute breaks into tiny pieces - some so small they cannot be seen – they then stay suspended in the solvent . . . . . . . . But will eventually settle out of suspension.

  28. Acids, Bases & pH • Acid – any compound that forms H+ ions in solution • Base – a compound that produces hydroxide ions (OH- ions) in solution • pH – measurement to indicate the concentration of H+ ions in a solution • Buffer – weak acids or bases that can react with strong acids or bases to prevent sharp, sudden changes in pH

More Related