Transcript Slide 2.1 - Cloudfront.net

Essentials of Human Anatomy & Physiology
Seventh Edition
Elaine N. Marieb
Chapter 2
Basic Chemistry
A Refresher
Lecture Slides in PowerPoint by Jerry L. Cook
Modified by Marcia Sloan
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Energy
• The ability to do work; to act on matter
• Kinetic vs Potential
• Types
• Chemical
• Electrical
• Mechanical
• Radiant
• Energy Conversion
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Slide 2.1
Matter
• Occupies space (volume) and
has mass (weight)
• Three states
• Gas
• Liquid
• Solid
Composition of Matter
• Elements
• Fundamental units of matter
• 96% of the body is made from four elements
• Carbon (C)
• Oxygen (O)
• Hydrogen (H)
• Nitrogen (N)
• Atoms
• Building blocks of elements
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Slide 2.2
Atomic Structure
• Nucleus
• Protons (p+)
• Neutrons (n0)
• Outside of
nucleus
• Electrons (e-)
Figure 2.1
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Slide 2.3
Identifying Elements
• Atomic number
• Equal to the number of protons that the
atoms contain
• Atomic mass number
• Sum of the protons and neutrons
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Slide 2.4
Isotopes
• Have the same number of protons
• Vary in number of neutrons
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Slide 2.5
Atomic Weight
• Atomic weight
• Close to mass number of most abundant
isotope
• Atomic weight reflects natural isotope
variation
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Slide 2.5
Radioactivity
• Radioisotope
• Heavy isotope
• Tends to be unstable
• Decomposes to more stable isotope
• Radioactivity
• Process of spontaneous atomic decay
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Slide 2.6
Molecules and Compounds
• Molecule – two or more atoms
combined covalently
• Compound – two or more different
atoms combined chemically
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Slide 2.7
Mixtures
• Definition – substance composed of 2
or more substances NOT chemically
bonded together.
• No properties of original substances
are lost
• Can be separated by physical means
• Evaporation, filtration, distillation,
centrifugation, etc.
Types of Mixtures
• Solutions
• Solvent + Solute
• Usually transparent
• Examples
• IV solutions
• Koolaid, tea, salt water
Types of Mixtures
• Colloids
• Solute particles are huge, but they form
a mesh that does not settle out
• Tindel effect
• Sols (liquidy) and Gels (solidy)
• Examples
• Jello, cytoplasm
Types of Mixtures
• Suspensions
• Will settle out because solute has much
larger particles than solvent
• Examples
• Sand in water, blood
Chemical Reactions
• The creation and/or destruction of
molecules
• The making and/or breaking of chemical
bonds forming new combinations of the
same atoms
• Metabolism
• All the chemical reactions in the body
• Anabolism – builds larger molecules
• Catabolism – breaks down molecules
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Slide 2.8
Chemical Reactions
Metabolism
• All the chemical reactions in the body
• Anabolism
• Builds larger molecules
• Ex: Combining many amino acids to form protein
• Catabolism
• Breaks down molecules
• Ex: Digesting starches into sugars
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Slide 2.8
Electrons and Bonding
• Electrons occupy energy levels called
electron shells
• Electrons closest to the nucleus are
most strongly attracted
• Each shell has distinct properties
• Number of electrons has an upper limit
• Shells closest to nucleus fill first
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Slide 2.9
Electrons and Bonding
• Bonding involves interactions between
electrons in the outer shell (valence
shell)
• Full valence shells do not form bonds
• Noble Gases
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Slide
2.10
Inert Elements
• Have complete valence shells and are
stable
• Rule of 8s
• Shell 1 has 2
electrons
• Shell 2 has 8
electrons
• Shell 3 has 8
electrons
Figure 2.4a
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Slide
2.11
Reactive Elements
• Valence shells are
not full and are
unstable
• Tend to gain, lose,
or share electrons
• Allows for bond
formation, which
produces stable
valence
Figure 2.4b
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Slide
2.12
Chemical Bonds
• Covalent Bonds
• Atoms become stable through shared electrons
• Single covalent bonds share one electron
• Double covalent bonds share two electrons
Figure 2.6c
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Slide
2.14
Examples of Covalent Bonds
Figure 2.6a, b
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Slide
2.15
Chemical Bonds
• Ionic Bonds
• Form when electrons are completely
transferred from one atom to another
• Ions
• Charged atoms
• Anions are negative
• Cations are positive
• Either donate or accept electrons
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Slide
2.13
Chemical Bonds
Ionic Bond Formation
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Slide
2.13
Polarity
• Covalently bonded
molecules
• Some are
non-polar
• e- are shared equally
• Some are
polar
• e- are NOT shared
equally
• Have a positive and
negative side
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Figure 2.7
Slide
2.16
Chemical Bonds
• Hydrogen bonds
• Weak chemical bonds
• Hydrogen is attracted to negative portion of
polar molecule
• Provides attraction between molecules
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Slide
2.17
Patterns of Chemical Reactions
• Synthesis reaction (A+BAB)
• Atoms or molecules combine
• Energy is absorbed for bond formation
• Anabolism
• Examples
• Combining amino acids to make proteins
• Combining glucose to make glycogen when
blood sugar levels are too high
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Slide
2.18
Patterns of Chemical Reactions
Decomposition reaction (ABA+B)
• Molecule is broken down
• Chemical energy is released
• Catabolism
• Examples
• Digestion of foods
• Breaking down glycogen to restore blood sugar
levels
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Slide
2.18
Synthesis and Decomposition
Reactions
Figure 2.9a, b
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Slide
2.19
Patterns of Chemical Reactions
• Exchange reaction (AB + C  AC + B)
• Involves both synthesis and decomposition
reactions
• Switch is made between molecule parts
and different molecules are made
• Example
• The terminal phosphate on ATP is exchanged
for a hydroxyl group (OH) on glucose
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Slide
2.20
Equilibrium
• All reactions are potentially reversible
• A + B ↔ AB
• Synthesis and decomposition
occurring at the same rate
Factors Affecting Reaction Rates
•
•
•
•
Temperature
Surface area/particle size
Concentration
Catalysts
• Speed reactions without being used up
• Enzymes at Discovery Video Streaming
• Enzymes from Campbell’s