Lec 1.1 & 1.2 - org of life, subatomic particles
Upcoming SlideShare
Loading in...5
×
 

Lec 1.1 & 1.2 - org of life, subatomic particles

on

  • 1,215 views

 

Statistics

Views

Total Views
1,215
Views on SlideShare
1,215
Embed Views
0

Actions

Likes
0
Downloads
7
Comments
0

0 Embeds 0

No embeds

Accessibility

Categories

Upload Details

Uploaded via as Adobe PDF

Usage Rights

© All Rights Reserved

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Processing…
Post Comment
Edit your comment

Lec 1.1 & 1.2 - org of life, subatomic particles Lec 1.1 & 1.2 - org of life, subatomic particles Document Transcript

  • LCC Biol 121, Kitty O'Neil, Instructor 1/8/2010 Course details • Office Hours – Tu 2:30 – 3:00, Tu & Th 6:00 – 6:40PM – in the LSARC (AS455) Biology 121 – Biological – Plus additional time as needed, before & after class • 2 Textbooks – Foundations for Physiology – Essentials of Biology, 2nd ed., Sylvia Mader Instructor: – Lab manual, Wagner • LCC Angel website - http://angel.lcc.edu Kitty O’Neil • Attendance – doesn’t count for anything, or does it? oneil17@lcc.edu • Grades, exams, quizzes, homeworks • Additional learning resources Date Part Lecture Title 1/14/2010 1 Basic chemistry 1.1 Organization of Life / Atoms Course details 1/14/2010 1/21/2010 1/21/2010 1 1 1 1.2 1.3 1.4 Subatomic Particles / Ionic bonds Covalent Bonds and Polarity Water and pH 1/28/2010 1 1.5 pH and Buffers 1/28/2010 2 Basic organic chemistry 2.1 Organic Compounds 2/4/2010 Exam 1 • Office Hours – Tu 2:30 – 3:00, Tu & Th 6:00 – 6:40PM 2/4/2010 2 2.2 Functional Groups and Reactions 2/11/2010 2 2.3 Carbohydrates – in the LSARC (AS455) 2/11/2010 2/18/2010 2 2 2.4 2.5 Lipids Proteins and Nucleic Acids – Plus additional time as needed, before & after class 2/18/2010 2/25/2010 3 Cells and organelles 3.1 Cells and Organelles Exam 2 • 2 Textbooks – 2/25/2010 3/4/2010 3 3 3.2 3.3 Cytoskeleton Membranes and Transport – Essentials of Biology, 2nd ed., Sylvia Mader 3/4/2010 3/18/2010 3 3.4 Osmosis and Capillary Dynamics Exam 3 3/18/2010 4 Cellular energy metabolism 4.1 Reduction and Oxidation – Lab manual, Wagner 3/25/2010 4 4.2 Glycolysis and the Kreb’s Cycle 3/25/2010 4 4.3 Electron Transport Chain • LCC Angel website - http://angel.lcc.edu 4/1/2010 4/1/2010 4 5 Genetic Information 4.4 5.1 Other Energy Sources, Energy Wrap Up DNA & Replication • Attendance – doesn’t count for anything, or does it? 4/8/2010 4/8/2010 5 5.2 Exam 4 RNA, Transcription • Grades, exams, quizzes, homeworks 4/15/2010 4/15/2010 5 5 5.3 5.4 Proteins, Translation Regulation of Gene Expression 4/22/2010 5 5.5 Mendelian Genetics • Additional learning resources 4/22/2010 4/29/2010 5 5 5.6 5.7 Beyond Mendel Part I Beyond Mendel Part II Cell Division · Meiosis in Humans · Chromosomal 4/29/2010 5 5.8 Abnormalities Exam 5 1
  • LCC Biol 121, Kitty O'Neil, Instructor 1/8/2010 Course details LCC Withdrawal Policy • In-class participation is encouraged • Schedule – approximate • Periodic Table – – KEEP THIS IN YOUR NOTEBOOK! We’ll need to refer to it in class during Part 1 of the course. Biology 121 ? Lecture 1.1 Biology Defined Organization of Life Q of the Day :: Define “Life” -- what characteristics typify a living creature??  Defining Life is a question you might address in a philosophy class  In biology, we can satisfy ourselves by describing common characteristics of life.  What those important characteristics are depends on………who you ask. 2
  • LCC Biol 121, Kitty O'Neil, Instructor 1/8/2010 Life is cellular Life uses energy • Life is not defined by its • How do living things survive? size • All living things process • From a unicellular amoeba energy – to a brontosaurus… – Eat, or ingest nutrients • All life is composed of – Excrete waste individual units called cells – Harvest energy in a useable form • The cell is the smallest unit of a living organism • Collectively, these processes are called “metabolism” Life can sense its environment, respond Life reproduces itself Life can maintain homeostasis • All life forms can sense and • How does life continue? respond to stimuli in their environments • All life forms duplicate – See plants respond to themselves, through light sexual or asexual http://www.ncsu.edu/project/agron auts/mission4_6.htm means, by duplicating • Living organisms can their genetic material maintain homeostasis – (DNA) internal conditions different from surrounding environment Life is highly complex, but highly organized Summing it all Up… • There is a large array and variety 1. life is cellular (the cell is the of living organisms…. smallest unit considered “alive” ) – Single cell organisms – Multicellular organisms 2. life takes in and uses energy – Microorganisms 3. life responds to the – Plants and animals environment • ….but all are composed of the 4. life maintains homeostasis same essential elements 5. life reproduces itself • organization is hierarchal 6. life is highly complex and organized 3
  • LCC Biol 121, Kitty O'Neil, Instructor 1/8/2010 More about the Hierarchal Can you organize these units, from Organization of Life smallest to largest? Here are the answers. Let’s go through each level individually. “Cell and tissue, shell and bone, leaf and flower, are so many portions of matter, and it is in obedience to the laws of physics that their particles have been moved, moulded, and conformed.” 7: organism 1: atom 4: cell 5: organ -D’Arcy Thompson, 1917 from On Growth and Form 3: organelle 2: molecules and compounds 6: organ system Molecule -- when two or more atoms Atom – the smallest unit of matter interact, they form a molecule • Although this is the smallest in the series you • Molecules are formed had to choose from, we’ll when individual atoms see later that each atom or bond together. This “element” is actually molecule is called ATP composed of smaller (adenosine subunits, called subatomic triphosphate), and is particles, named protons, the energy currency for neutrons and electrons. most cells. • The atom is the smallest • A compound unit of an element 4
  • LCC Biol 121, Kitty O'Neil, Instructor 1/8/2010 Organelle -- many molecules working together to perform a single function Cell – the smallest unit of life for the cell • Organelles work • This is a photograph of a mitochondria, one of together within a the organelles present living cell in eukaryotic organisms. • Cells parcel out their workload to various organelles, or “little organs”. • Mitochondria are the organelles responsible for making ATP. Tissue -- two or more cells working Organ -- two or more tissues performing together to perform a function a function • Not a choice in your series! But you will learn a great deal • This picture of the about tissues in lungs also has other Biology 201, Human organs included -- Anatomy. This Areolar connective you can see the hierarchal level and tissue trachea and the the remaining levels bronchi. are specific to Bone -- the multicellular strongest connective tissue organisms. Adipose – storing fat Organ System -- two or more organs Organism -- All 11 organ systems working performing a function for the organism cooperatively to form one individual • This is an example of • There are 11 organ a multicellular systems in the organism human body. You’ll • Plants, animals, fungi cover them progressively in Biol … 201 and 202 5
  • LCC Biol 121, Kitty O'Neil, Instructor 1/8/2010 Population - Community • A group of the same • All populations in type of organism one particular located together in location one area • Plant community in a prairie • Microorganism community in our GI tract Ecosystem Biosphere • A community + the physical • All the ecosystems environment in which it exists making up the earth and interacts • Earth, water, atmosphere and organisms Learning Goal: Be able to rank order Biol 121 is concerned with Levels 1-5 levels of organization 1. Subatomic particles 1. Subatomic particles 2. Atoms 2. Atoms 3. Molecules 4. Organelles 3. Molecules 5. Cells 4. Organelles 6. Tissues 5. Cells 7. Organs 6. Tissues 8. Organ systems 7. Organs 9. Multicellular Organism 8. Organ systems 10.Population -- a group of the same kind of organisms occupying the 9. Organism same area 10.Population -- a group of the same kind of organisms occupying the 11.Community -- Populations of different species occupying the same area same area 11.Community -- Populations of different species occupying the same 12.Ecosystem -- The community AND the physical environment area 13.Biosphere -- all regions sustaining life 12.Ecosystem -- The community AND the physical environment 13.Biosphere -- all regions sustaining life 6
  • LCC Biol 121, Kitty O'Neil, Instructor 1/8/2010 Biol 201 and 202 are concerned with You would learn about Levels 9-13 in an organismal/environmental biology course like Levels 5-9 128 or 120 1. Subatomic particles 1. Subatomic particles 2. Atoms 2. Atoms 3. Molecules 3. Molecules 4. Organelles 4. Organelles 5. Cells 5. Cells 6. Tissues 6. Tissues 7. Organs 7. Organs 8. Organ systems 8. Organ systems 9. Organism 9. Organism 10. Population -- a group of the same kind of organisms 10.Population -- a group of the same kind of organisms occupying the occupying the same area same area 11. Community -- Populations of different species 11.Community -- Populations of different species occupying the same area occupying the same area 12.Ecosystem -- The community AND the physical environment 12. Ecosystem -- The community AND the physical 13.Biosphere -- all regions sustaining life environment 13. Biosphere -- all regions sustaining life Biology 121 Lecture 1.2 Basic Chemistry Electron Shells Elements Atom • Fundamental forms of matter • Smallest particles that retain properties of an element • Can’t be broken apart by normal means is an ATOM • 92 occur naturally on Earth • Positively charged nucleus surrounded by cloud of negatively charged electrons • Most common elements in living organisms: • Made up of subatomic particles: – Oxygen (O) – Protons (+) – Hydrogen (H) – Electrons (-) – Carbon (C) – Neutrons (no charge) – Nitrogen (N) • Has mass (we can think of mass as weight) • Occupies space 7
  • LCC Biol 121, Kitty O'Neil, Instructor 1/8/2010 Representing the Hydrogen Atom How Much Do You Know About Atoms? • Atoms are composed of 3 subatomic particles, called protons, neutrons and electrons. • Each has a characteristics charge and mass associated with it: Particle Charge Mass Location Proton + 1 amu* nucleus Neutron 0 1 amu nucleus Electron - 0 amu shells Fig. 2-2, p.20 * 1 Amu is a unit of mass (atomic mass unit), like a pound or gram, but much, much, smaller. Atomic particles arranged in pattern Atomic Mass • The MASS of the atom is concentrated in its • It’s time to mention another important concept nucleus. regarding atomic weights…….. – Determined by numbers of protons and neutrons – Positively charged protons and uncharged neutrons are tightly packed in the nucleus • The VOLUME of the atom is determined by the negatively charged electrons – Electrons orbit the nucleus in a series of concentric 6.02 x 10 23 ‘shells’ What Does It Mean?? Why is it handy? • A dozen is………..12 • Avogadro’s Number is a convenient amount of very small things to count out, like 6.02 X 1023 protons • A gross is…………..144 • 6.02 X 1023 protons weigh exactly 1.00 grams. • A triple is……………..3 • 6.02 X 1023 H atoms weigh exactly 1.00 grams. • A century is…………….100 • 6.02 X 1023 amu weigh exactly 1.00 grams. • And Avogadro’s Number is…….6.02 X 1023 • Avogadro’s number relates the mass of a proton, which is unimaginably and immeasurably small, to something more tangible-- the gram • In other words……it’s a predetermined, • 6.02 X 1023 molecules = 1 mole. arbitrary number chosen for matters of • More information about Avogadro and his number ‘handiness.’ later 8
  • LCC Biol 121, Kitty O'Neil, Instructor 1/8/2010 Compare 1 atom to 1 mole Protons -- the identity of the element • Protons are positively charged subatomic particles that have a mass of 1 amu 1 egg 1 dozen eggs • They are located in the (0.14 lbs) (12 eggs, 1.5 lbs) nucleus. See the green “dot” at the right? It’s a proton. • This particular atom contains 1 proton and 1 electron. 1 atom of C 1 mole of C (12 amu) (6.02 · 1023 atoms , 7.22 · 1024 amu, 12 g) Hydrogen Elements have abbreviations  Hydrogen is the simplest atom. H contains one proton • Each atom has a one or two letter short hand abbreviation. The first letter is capitalized, the • If a second proton were added to the nucleus, it wouldn’t be H any longer. It’d be Helium. In fact, second is small case. They are derived from every atom has its own characteristic number of the name of the atom: protons. Each atom has an atomic number, which reflects its proton total. H Hydrogen He Helium • For each proton in the nucleus, there must be a C Carbon corresponding electron in the shell to balance the charges. The atomic number also reflects the Co Cobalt number of electrons in a particular atom. • The Periodic Chart of the elements contains all of Name that element! Don’t use your the atoms, listed in atomic number order, reading in rows from left to right. In most periodic charts, the periodic chart atomic number is on the top. • H = Hydrogen • He = ??? • Ne = ??? • C = ??? • Si = ?? • P = ?? • Na = ??? • Know the symbols for elements 1 through 20 9
  • LCC Biol 121, Kitty O'Neil, Instructor 1/8/2010 Name that element! Name that Atom! • Based on the number of protons (dark blue circles), which • H = hydrogen atom is represented by each picture? For this, you DO • He = Helium need to use your periodic chart. • Ne = Neon • C = Carbon proton • Si = Silicon neutron • P = Phosphorus • Na = Sodium (from the Latin, Natrium) Name that Atom! Neutrons -- add mass but no charge Here are the answers! • Neutrons are subatomic particles that weigh 1 amu (same as a proton), 1 proton = Hydrogen (H) • but they are neutral, 6 protons = Carbon (C) which means they have no associated charge (unlike a proton). 2 protons = Helium (He) 12 protons = Magnesium (Mg) Atomic Mass (Weight) Calculate the atomic mass for these atoms • Since both protons and neutrons (but not electrons…) contribute mass (weight) to an atom, each atom has a characteristic atomic weight, the total of all its protons and neutrons • On most periodic charts, that number is written beneath the atom’s symbol Hydrogen (H) Carbon (C) Helium (He) Magnesium (Mg) 10
  • LCC Biol 121, Kitty O'Neil, Instructor 1/8/2010 Atomic Mass In Summary… • The atomic number is a whole number, and is equal to the number of protons in the nucleus of that atom. Since protons and electrons are equal to neutralize charges, it also tells you how many electrons are in Hydrogen (H) has 0 neutrons Carbon (C) has 6 neutrons the shells. and 1 proton and 6 protons – Atomic number = number of protons or electrons Atomic Weight = 1 amu Atomic weight = 12 amu • The atomic weight is a decimal number, and is the sum of the protons and the neutrons. You know the number of protons from the atomic number, the number of neutrons is the difference between atomic number and atomic weight. Helium (He) has 2 neutrons Magnesium (Mg) has 12 neutrons – Atomic wt – atomic number = number of neutrons and 2 protons Atomic weight = 4 amu and 12 protons – Atomic wt = no. of protons + no. of neutrons Atomic weight = 24 amu Problems Problems • How many neutrons are in one atom of the • How many neutrons are in one atom of the following elements? following elements? • Need to know 3 things… • Need to know 3 things… Element N Li B F Element N Li B F Atomic Wt Atomic Wt 14 7 11 19 No. Protons No. Protons 7 3 5 9 No. Neutrons No. Neutrons 14-7 = 7 7-3 = 4 11–5 = 6 19-9 = 10 Practice Problems Practice Problems - Answers Atom: C Be Atom: C Be Si Na O He Atomic number: 6 14 Atomic number: 6 4 14 11 8 2 Atomic weight: 12 22.99 Atomic weight: 12 9.012 28.09 22.99 16.00 4.003 No. Protons 6 8 No. Protons 6 4 14 11 8 2 No. Neutrons 6 2 No. Neutrons 6 5 14 12 8 2 No. Electrons 6 No. Electrons 6 4 14 11 8 2 Know how to calculate these parameters for elements 1 through 20. 11
  • LCC Biol 121, Kitty O'Neil, Instructor 1/8/2010 Atomic Mass Atomic Mass • Although atomic numbers are reported as whole • Atoms can exist in multiple forms in nature, with digits, atomic weights are generally reported as differing numbers of neutrons. These forms are decimals called isotopes (same atom, different form) • C weighs 12.01 amu • Isotopes vary in number of neutrons; protons and • Al weights 26.98 amu electrons remain the same. • H weighs 1.008 amu • If protons and neutrons each weigh 1.00 amu, where does the extra “weight” of the atom come from? Atomic Mass -- Part II Atomic Mass -- Part II • Hydrogen typically has 1 proton and 0 neutrons, • Isotopes are indicated by writing the atomic symbol, with the weighing a total of 1 amu. specific weight of that isotope in the upper left hand corner • But alternate, isotopic forms of H exist; – Deuterim, 1 proton and 1 neutron, 2 amu, stable – 1H is hydrogen – Tritium, 1 proton and 2 neutrons, 3 amu, unstable or – 2H is deuterium radioactive – 3H is tritium Hydrogen = 1H Deuterium = 2H Tritium = 3H Stable Stable Radioactive Atomic Mass Radioisotopes • Have an unstable nucleus that emits • The atomic mass indicated on energy and particles as it ‘decays’ the periodic chart represents our knowledge about the • Radioactive decay transforms average mass, distributed radioisotope into a different element among all the known isotopes • Decay occurs at a fixed, predictable of each atom, that exist in the rate universe. • Emissions from the radioactive isotope can be detected with special instruments Isotope Rel. Abund. Half-life 12C 98.9% C is stable with 6 neutrons • Following movement of radioactivity 13C 1.1% C is stable with 7 neutrons is useful in many areas of biology 14C and health care trace 5730 y 12
  • LCC Biol 121, Kitty O'Neil, Instructor 1/8/2010 Radioactive Isotopes and Health Care Isotopes • Radioactive isotopes have two very special places in the health care industry – Diagnostics – Therapeutics How many protons? • Nuclear Energy Institute’s What element is it? Informational Website to How many neutrons? learn more about Nuclear What’s the atomic mass? Medicine What is the isotope? – http://www.nei.org/ Isotopes Biology 121 Lecture 1.2 How many protons? 1 1 1 6 6 What element is it? H H H C C Basic Chemistry How many neutrons? 0 1 2 6 8 What’s the atomic mass? 1 2 3 12 14 Electron Shells What is the isotope? 1H 2H 3H 12C 14C hydrogen deuterium tritium Electrons -- the Bonding Story Electron Shells • Electrons are the negatively charged subatomic • Electrons spin and rotate particles without mass that make up the volume around the nucleus of an of the atom atom, but are constrained • Electrons are SOCIAL -- they prefer: to particular paths. They – Being paired live in shells – Living in full shells • Electrons repel each other • Similar to layers of an onion, or floors of a hotel. • Electrons are attracted to protons in the nucleus • Electrons determine how atoms interact with or bond with each other. 13
  • LCC Biol 121, Kitty O'Neil, Instructor 1/8/2010 What keeps electrons constrained to What keeps electrons constrained to their shells? their shells? • Answer, part 1 • Answer, part 2  But, they don’t fly off into space…  Opposite charges attract Negatively charged electrons are attracted to the positive charges on the protons Electron shells • There are specific places (distances) around the nucleus where the opposing centrifugal forces (away) and charge forces (toward) exactly balance one another. • These are the “shells” where electrons reside • Shells closest to nucleus are lower energy and are filled first. Electron shells Electron shells • The first shell, • The second shell, a closest to the bit farther from the nucleus, is quite ► nucleus, is a bit small, only large larger, and can ► enough for 2 accommodate 8 electrons electrons 14
  • LCC Biol 121, Kitty O'Neil, Instructor 1/8/2010 Electron shells Electron shells • The third shell, a bit • As we are only farther from the dealing with elements nucleus, is also a bit 1-20, and we can larger, but still only account for 18 accommodates 8 electrons with three electrons shells (2 + 8 + 8), only ► the last two elements (K and Ca) need to use the 4th shell. ► Electron shells Filling electron shells • Helium example: • As you might imagine, – Helium has atomic number 2, indicating it has 2 this ‘shell’ description protons and 2 electrons. is a slight – The two electrons will both fit in the first shell. oversimplification. • But that’s all we need for now. We won’t worry about how complicated shells can really be in Biol 121. – The last, outermost shell with an electron in it is the atom’s “valence” or outer shell. The first shell is the valence shell for He. Filling electron shells Filling electron shells • Lithium example: – Lithium has atomic number 3, indicating it has 3 • Draw the electron shells for the following atoms -- protons and 3 electrons. using your periodic chart. – The first two electrons will both fit in the first shell. The third electron goes into the second shell. H C O – The second shell is the valence shell for Li. Na Cl 15
  • LCC Biol 121, Kitty O'Neil, Instructor 1/8/2010 Electron Shells - Answers Noble Gases • Argon, like Helium, has a full valence shell • Some atoms have full valence shells. They’re called the Noble Hydrogen 1 e- Carbon 2 + 4 = 6 e- Oxygen 2 + 6 = 8 e- Gases -- they do not react or bond with other elements. You can find them in a nice neat column on the periodic chart, on the farthest to the right. Sodium 2 + 8 + 1 = 11 e- Chlorine 2 + 8 + 7 = 17 e- Let’s look at another column in the Oxygen and Sulfur are also in the same periodic chart…. column (16) of the periodic chart  Oxygen  Sulfur  8 e- = 2 in the first and  16e- = 2 in the first, 8 6 in the second in the second and 6 in (valence) shell the third (valence) shell And O and S have the same number of Periodic Table is organized electrons (6) in their valence shells • The periodic chart is not a random arrangement of atoms, they are all conveniently arranged for your viewing pleasure, • Elements in column (we call them groups or families of elements) having the same number  Oxygen  Sulfur of valence electrons.  8 e- = 2 in the first and  16e- = 2 in the first, 8 • Families of elements have similar bonding 6 in the second in the second and 6 in capabilities (valence) shell the third (valence) shell 16
  • LCC Biol 121, Kitty O'Neil, Instructor 1/8/2010 Is there a similar significance to the rows on the Noble Gases periodic chart? • Remember Helium and Argon, who both had full valence shells? They are the noble gases. • Noble gases end each row. The next atom is written in the next row (period) of the chart. • What is the significance of that? Oxygen and Sulfur have the same number of Oxygen is found in the second period (row), its electrons (6) in their valence shells, but they are second shell is occupied in different shells  Oxygen  Sulfur  Oxygen  Sulfur  8 e- = 2 in the first and  16e- = 2 in the first, 8  8 e- = 2 in the first and  16e- = 2 in the first, 8 6 in the second in the second and 6 in 6 in the second in the second and 6 in (valence) shell the third (valence) (valence) shell the third (valence) shell shell Sulfur is found in the third period (row), its third In Summary….Location, location, shell is occupied location  Oxygen  Sulfur  8 e- = 2 in the first and  16e- = 2 in the first, 8 6 in the second in the second and 6 in (valence) shell the third (valence) shell 17
  • LCC Biol 121, Kitty O'Neil, Instructor 1/8/2010 The period (row) represents which shell is the valence Lecture 1.1 and 1.2 Study Guide shell The group (column) represents how many electrons • Biology overview and Subatomic particles are in that valence shell – Name and describe the characteristics of life – Know the levels of organization of life from least to most complex – Know the name, charge, location, and mass of the subatomic particles – Know the names (spelled correctly!) and symbols for elements 1-20 – Know what a mole is, what Avogadro’s number is and how they are both used 18