Transcript File - FHS Mrs. Uy`s Science Class

Essentials of Anatomy & Physiology, 4th Edition
Martini / Bartholomew
2
The Chemical Level
of Organization
PowerPoint® Lecture Outlines
prepared by Alan Magid, Duke University
Slides 1 to 74
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Matter: Atoms and Molecules
Atoms
• Smallest unit of
an element
• Subatomic
particles
• Protons: (+)
charge
• Neutrons:
neutral
• Electrons: (-)
charge
Figure 2-1
Matter: Atoms and Molecules
Structure of an atom
• Nucleus
• Protons
• Neutrons
• Electron Shell
Figure 2-2(b)
Matter: Atoms and Molecules
Structure of atom
• Atomic number
• Equals number of protons
• Atomic mass
• Equals protons + neutrons
• Isotopes of element
• Reflects number of neutrons
• Atomic weight
• Averages isotope abundance
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Matter: Atoms and Molecules
Structure of atom
• Electrons surround nucleus
• Electrons organized in shells
• The outer shell determines
chemical properties
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Matter: Atoms and Molecules
Atoms and Electron Shells
Figure 2-3
Matter: Atoms and Molecules
Key Note
All matter is composed of atoms
in various combinations. Their
interactions establish the
foundations of physiology at the
cellular level.
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Matter: Atoms and Molecules
Chemical Bonds and Compounds
•
•
•
•
Atoms bond in chemical reactions
Reactions transfer electrons
Electrons are gained, lost, or shared
Molecules or compounds result
• Compounds contain several
elements
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Matter: Atoms and Molecules
Ionic Bonds
• Atoms gain or lose electrons
• Charged atoms are ions
• Ions bear (+) or (-) charge
• Cations have (+) charge
• Anions have (-) charge
• Cations and anions attract
• Ions form bonds
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Matter: Atoms and Molecules
Ionic Bonding
Figure 2-4(a)
Matter: Atoms and Molecules
Sodium chloride crystal
Figure 2-4(b)
Matter: Atoms and Molecules
Table 2-2
Matter: Atoms and Molecules
Covalent bonds
• Some atoms share electrons
• Shared electrons complete outer shell
• Sharing atoms bond covalently
• Single covalent bond
• One shared electron
• Double covalent bond
• Two shared electrons
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Matter: Atoms and Molecules
Covalent Bonds
Figure 2-5
Matter: Atoms and Molecules
Nonpolar and Polar Covalent Bonds
• Equal electron sharing
• Nonpolar covalent bonds
• Example: carbon-carbon bonds
• Non-equal electron sharing
• Polar covalent bonds
• Example: oxygen-hydrogen bonds
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Matter: Atoms and Molecules
Hydrogen bonds
• Weak attractive force
• Between 2 neighboring atoms
• A polar-bonded hydrogen, and
• A polar-bonded oxygen or
nitrogen
• For example, between water
molecules
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Matter: Atoms and Molecules
Hydrogen Bonds
Figure 2-6
Chemical Notation
A chemical “shorthand”
• Simplified descriptions of:
• Compounds
• Structures
• Reactions
• Ions
• Abbreviations of elements
• Abbreviations of molecules
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Chemical Reactions
Metabolism
All the chemical reactions in
the body
• Consumes reactants
• Produces products
• Breaks or makes chemical
bonds between atoms
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Chemical Reactions
Basic Energy Concepts
• Work—movement or change in
matter’s physical structure
• E.g., running, synthesis
• Energy—ability to do work
• Kinetic energy
• Potential energy
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Chemical Reactions
Basic Energy Concepts (continued)
• Potential energy—stored energy
• E.g., leopard lurks in a tree
• Kinetic energy—energy of movement
• E.g., leopard pounces on prey
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Chemical Reactions
3 types of reactions
• Decomposition—breaks
molecule into smaller pieces
• Synthesis—assembles smaller
pieces into larger one
• Exchange—shuffles pieces
between molecules
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Chemical Reactions
Decomposition Reactions
• In chemical notation:
• AB
A+B
• Releases covalent bond energy
• Hydrolysis—Decomposition
reaction with H•OH
• E.g., food digestion
• Catabolism—Sum of all the
body’s decomposition reactions
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Chemical Reactions
Synthesis Reactions
• In chemical notation:
•A+B
AB
• Absorbs energy
• Formation of new bonds
• Dehydration synthesis
• Removal of H•OH between molecules
• Anabolism—Sum of the body’s
synthesis reactions
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Chemical Reactions
Exchange Reaction
• In chemical notation:
• AB + CD
AC + BD
• Decomposition and synthesis
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Chemical Reactions
Reversible Reactions
• A+B
AB
• Equilibrium—Condition when
the forward and reverse
reactions occur at the same
rate
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Chemical Reactions
Key Note
When energy is exchanged,
heat is produced. Heat raises
local temperatures, but cells
cannot capture it or use it to
perform work.
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Enzymes and Reactions
Activation Energy
Quantity of energy needed
to start a chemical reaction
• Catalysts reduce activation
energy to speed reaction
• Enzymes catalyze cellular
reactions
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Enzymes and Reactions
Enzymes and Activation Energy
Figure 2-7
Enzymes and Reactions
Exergonic—Reactions that
release energy
• E.g., decomposition reactions
Endergonic—Reactions that
consume energy
• E.g., synthesis reactions
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Bell work
08/29/11
Please answer the bell work question of
the day. Thank you!
1. Explain why water is a very important
inorganic compound?
Inorganic Compounds
Nutrients
Essential elements and molecules obtained
from the diet
Metabolites
Molecules synthesized or broken down by
chemical reactions inside the body
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Two broad categories of nutrients and
metabolites
( chemical substances)
Inorganic compounds
 rarely contains carbon ( C)
 usually smaller molecules than organic
compounds
 usually dissociate in water ( separates)
•
electrolytes – formed ions
example: Na + and Cl water
 Oxygen
 Carbon dioxide
 Inorganic Salts
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Organic Compounds
 compounds that contain carbon and hydrogen
 typically larger molecules, due to carbons
bonding capability
 some dissolves in water
• nonelectrolytes ( no ions formed)
 most dissolved in organic liquids ( ether)
 Carbohydrates
Protein
 Lipids
 Nucleic acids
Inorganic Compounds
Water and its properties
• Most abundant compound in the living material
• Makes up about 2/3 ( 70%) of the weight of an
adult human
• Makes metabolic processes possible- excellent
solvent
 due to dissolving ability- polarity
• Responsible for transporting chemicals – gases,
nutrients
• Absorbs heat – high heat capacity
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Inorganic Compounds
Water Dissociates Ionic Bonds
Figure 2-8
Inorganic Compounds
Key Note
Water accounts for most of your body
weight. Proteins, key components of cells,
and nucleic acids, which control cells,
work only in solution.
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Inorganic Compounds
Oxygen (O2)
• Vital molecule
• Critical for body’s energy support
 cellular respiration
•Atmospheric gas consumed by cells
in order to produce energy
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Inorganic Compounds
Carbon Dioxide (CO2)
• Contains carbon- but still inorganic
• Waste product from metabolic
reactions
• In blood, not typically in CO2 form
• Gas produced by cellular metabolism
and released into the atmosphere via
the lungs
Inorganic Compounds
Inorganic Acids and Bases
• Acid—Releases hydrogen ions (H+) into
solution
•E.g., HCl
H+ + Cl•Produce in stomach to help assist the
breakdown of food
• Base—Removes hydrogen ions from
solution to liberate hydroxide ion
•E.g., NaOH + H+
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Na+ + H•0H
Inorganic Compounds
Hydrogen Ions and pH
 hydrogen ions are extremely
reactive, can break chemical
bonds, change the shape of a
molecules, disrupt cell and tissue
functions
Concentration must be regulated
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Inorganic Compounds
pH- a measure of hydrogen ion
concentration in a solution
• Neutral solution—pH = 7
( hydrogen ions = hydroxide ions)
• Acidic solution—pH below 7
( more hydrogen ions)
• Basic or alkaline solution—pH above 7
( more hydroxide ions)
Inorganic Compounds
pH and Hydrogen Ion
Concentration
Figure 2-9
Inorganic Compounds
Buffers
• Maintain pH within normal limits
(pH 7.35 to pH 7.45)
• Release hydrogen ions if body fluid is
too basic
• Absorb hydrogen ions if body fluid is
too acidic
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Inorganic Compounds
Salts
•
source of important ions for metabolism
• an ionic compound not containing H+ or OH•Salts are electrolytes
•Electrolytes dissociate in water
• E.g., NaCl
Na+ + Cl-
•Electrolytes carry electrical currents in the body
•Constantly lost, but must be replaced
•Important in homeostasis
 electrolyte balance- maintaining specific ion
concentrations inside and outside the cell
 Other example: K+ and Ca2+
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Bell work
08/30/11
Please answer the bell work question
of the day. Thank you!
1. Why is water considered a very
important inorganic compound in
our body?
2. What are the different types of
organic compounds?
Organic Compounds
Organic Compounds
• Contain carbon, hydrogen, and usually
oxygen
• Important classes of organic compounds
include:
•Carbohydrates
•Lipids
•Proteins
•Nucleic acids
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Organic Compounds
Carbohydrates
• composed of sugars
• Contain carbon, hydrogen, and oxygen
• C6H12O6- glucose
• Most important energy source for
metabolism
• Water soluble
• Three major types
• Monosaccharides (E.g., glucose)
• Disaccharides (E.g., sucrose)
• Polysaccharides (E.g., glycogen)
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Organic Compounds
Monosaccharide
 simple sugars/simple carbs
Contain 3-7 carbon atoms
Structure can be chain or ring
Examples:
 glucose
 fructose
 Galactose
 Ribose
 deoxyribose
Organic Compounds
Glucose- monosaccharides
Figure 2-10
Organic Compounds
Disaccharides
• consists of two monosaccharide
combined
• formed by dehydration synthesis
( removal of water molecule)
• examples:
 sucrose- glucose + fructose
 lactose- glucose + galactose
 maltose – glucose + glucose
Organic Compounds
Formation and Breakdown of Complex Sugars
Figure 2-11 (a), (b)
Organic Compounds
Polysaccharides
• complex carbohydrates
•Built of many simple sugars
•Examples:
 cellulose- plant ( can’t be digested,
source of dietary fibers)
 starch- plant ( can be digested)
 glycogen- animals
( stored polysaccharides)
Organic Compounds
Formation of Glycogen
Figure 2-11(c)
Organic Compounds
Table 2-4
Organic Compounds
Lipids
• made of glycerol and fatty acids
• Composed of C, H, O and often P
• Water-insoluble
• Formed by dehydration synthesis
• Four important classes
•Fatty acids
•Fats
•Steroids
•Phospholipids
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Organic compounds
Saturated:
 solid at room temperature
 eating a lot can increase the risk of heart
disease
 butter, lard, bacon grease
Unsaturated:
 liquid at room temperature
 should be used as substitute to saturated
fats
 olive oil, vegetable oil
Organic Compounds
Fatty Acids
• long chains of carbon atoms with
attached hydrogen atoms
that end in a carboxylic acid group
• lauric acid,
 a saturated fatty acid ( four single
covalent bond of carbon )
 unsaturated fatty acid ( carbon to
carbon bonds formed double bonds)
Organic Compounds
Fatty Acids
Figure 2-12
Organic Compounds
Fats
• can supply more energy than carbs ( but mostly stored)
• composed of C, H, O, but much less O
• composed of glycerol and 3 fatty acids ( triglyceride)
• can be saturated or unsaturated
Saturated:
 full , when fatty acid and carbon are linked by single
bond
Unsaturated:
 not full, when fatty acid and carbon have one or more
double bonds
Organic Compounds
Triglycerides—
Formed by three
fatty acid molecules
bonding to a
glycerol molecule
Figure 2-13
Organic Compounds
Steroids
• Significantly more complex than other lipids
•Composed of carbon rings
•Examples:
Cholesterol
 hormones- chemical messengers
( testosterone and estrogen)
Organic Compounds
Cholesterol
• Building block for steroid hormones
• Component of cell membranes
Figure 2-14
Organic Compounds
Phospholipids
•
•
•
•
Most abundant membrane lipid
Contain glycerol and 2 fatty acids
3rd bonding site is for phosphate group
Diglyceride
•Two fatty acids + glycerol
• Water-soluble and water-insoluble parts
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Organic Compounds
A Phospholipid
Molecule
Figure 2-15
Organic Compounds
Table 2-5
Organic Compounds
Proteins
 composed of chains of amino acids
 contains C, H, O and N and bit of S
 most abundant organic component
in human body
 about 100,000 different proteins
 have a wide ranges of functions
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Organic Compounds
Proteins play vital roles
Support ( structural proteins)
Movement ( Contractile proteins)
Transport ( Transport proteins)
Buffering
Metabolic Regulation ( enzymes)
Defense ( antibodies and clotting
proteins)
• Coordination, Communication and
control ( hormones)
•
•
•
•
•
•
Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings
Organic Compounds
Proteins are
built from
amino acids
Figure 2-16(a)
Organic Compounds
Peptide bonds join
amino acids into
long strings
Figure 2-16(b)
Organic Compounds
Protein Structure
Figure 2-17
Organic Compounds
Nucleic Acids
• Large molecules
• Composed of chains of nucleotides such as
sugar, phosphate group and nitrogenous
base ( P, S ,B)
• Composed of C, H, O, N and P
• Store and process molecular information
• Carry instruction for cellular activity
• Two classes of nucleic acid
•DNA (deoxyribonucleic acid)
•RNA (ribonucleic acid)
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Organic Compounds
The Structure of
Nucleic Acids
Figure 2-19ab
Organic Compounds
The Structure of Nucleic Acids
Figure 2-19cd
Differences between DNA and RNA
DNA:
• deoxyribonucleic acid
• double stranded helix
• stores genetic information
•Sugar- deoxyribose
•Nitrogenous base
 adenine
Thymine
Guanine
cytosine
RNA
 ribonucleic acid
Single stranded
Used in protein synthesis
Sugar- ribose
Nitrogen base
• adenine
•Uracil
•Guanine
•cytosine
Organic Compounds
Structure of Nucleic Acids
• Nucleotides contain a sugar, a
phosphate, and a base
• Sugar-phosphate bonds link
nucleotides in long strands
• Hydrogen bonds hold two DNA
strands in a double helix
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ATP ( adenosine triphosphate)
• single
molecule- 1 single nucleotide
•Cellular energy
•Sugar – ribose
•Phosphate – always 3
•Nitrogenous base- adenine
•ATP is the most important highenergy compound in cells
•ATP keeps cells alive!
High-Energy Compounds
Structure of ATP
Figure 2-20
ATP
Energy
from
cellular
catabolism
Energy
released
for cellular
activities
ADP
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Figure 2-21
1 of 5
ATP
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Figure 2-21
2 of 5
ATP
Energy
released
for cellular
activities
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Figure 2-21
3 of 5
ATP
Energy
released
for cellular
activities
ADP
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Figure 2-21
4 of 5
ATP
Energy
from
cellular
catabolism
Energy
released
for cellular
activities
ADP
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Figure 2-21
5 of 5
Summary of Body Chemistry
Organic Chemical Building Blocks
Figure 2-22