chemistry 112 overview of chapters 5, 8, 16, & 9
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Chemistry 112Chemistry 112
Overview of Chapters 5, 8, 16,
& 9
Overview of Chapters 5, 8, 16,
& 9
Chapter 5 HighlightsChapter 5 Highlights
Chemical reactions involve energy. There are two types of energy:
potential (stored) and kinetic (energy of motion).
The first law of thermodynamics states that energy is conserved during chemical reactions, but it may be transformed from one type to another.
Chemical reactions involve energy. There are two types of energy:
potential (stored) and kinetic (energy of motion).
The first law of thermodynamics states that energy is conserved during chemical reactions, but it may be transformed from one type to another.
Chapter 5 Highlights(cont)Chapter 5 Highlights(cont)
Reactions can be exothermic (releasing heat) or endothermic (absorbing heat).
Chemical reactions are spontaneous if the products are energetically downhill with respect to the reactants.
The second law of thermodynamics states that increasing molecular disorder (entropy) is favored.
Reactions can be exothermic (releasing heat) or endothermic (absorbing heat).
Chemical reactions are spontaneous if the products are energetically downhill with respect to the reactants.
The second law of thermodynamics states that increasing molecular disorder (entropy) is favored.
Chapter 5 Highlights(cont)Chapter 5 Highlights(cont)
The size of the energy barrier between reactants and products (the activation energy) dictates the rate of a chemical reaction (the kinetics).
A catalyst lowers the activation energy, thereby speeding up the rate of a chemical reaction.
Collision theory predicts that increasing concentration of reactants or temperature leads to increased reaction rates.
The size of the energy barrier between reactants and products (the activation energy) dictates the rate of a chemical reaction (the kinetics).
A catalyst lowers the activation energy, thereby speeding up the rate of a chemical reaction.
Collision theory predicts that increasing concentration of reactants or temperature leads to increased reaction rates.
Energy Measuring Energy
The two general types of energy are potential(stored energy) and kinetic (energy of motion).
Energy is most often measured in either joulesor calories.
Energy Measuring Energy
The two general types of energy are potential(stored energy) and kinetic (energy of motion).
Energy is most often measured in either joulesor calories.
Types of EnergyTypes of Energy
Energy (cont) Energy and Temperature
Materials at higher temperatures contain more energy than the same amount of material at a lower temperature.
Energy (cont) Energy and Temperature
Materials at higher temperatures contain more energy than the same amount of material at a lower temperature.
Thermal EnergyThermal Energy
Energy (cont) Energy and Chemical Reactions
In chemistry, having low energy means increased stability, which is favored.
Atoms and molecules undergo reactions to decrease their overall energies.
Energy (cont) Energy and Chemical Reactions
In chemistry, having low energy means increased stability, which is favored.
Atoms and molecules undergo reactions to decrease their overall energies.
Reactions Go Energetically Downhill
Reactions Go Energetically Downhill
Energy Changes During Reactions Energy Diagrams
Depict the relative energies of the reactants and products, as well as the energy barrier to reaction.
Energy Changes During Reactions Energy Diagrams
Depict the relative energies of the reactants and products, as well as the energy barrier to reaction.
Energy Diagrams Energy Diagrams
The First Law of Thermodynamics Energy is conserved during chemical reactions. Heat of Reaction
Heat transferred during a chemical reaction Endothermic vs. Exothermic
In endothermic reactions, heat can be considered to be one of the reactants. Endothermic reactions often feel cold and are energetically uphill.
In exothermic reactions, heat can be considered to be one of the products. Exothermic reactions often feel warm and are energetically downhill.
The First Law of Thermodynamics Energy is conserved during chemical reactions. Heat of Reaction
Heat transferred during a chemical reaction Endothermic vs. Exothermic
In endothermic reactions, heat can be considered to be one of the reactants. Endothermic reactions often feel cold and are energetically uphill.
In exothermic reactions, heat can be considered to be one of the products. Exothermic reactions often feel warm and are energetically downhill.
Endothermic vs. Exothermic
Endothermic vs. Exothermic
The Second Law of Thermodynamics No energy transformation can be absolutely
efficient. Entropy
Time’s arrow, molecular disorder Examples of favorable entropy
Solids or liquids are converted to gases More molecules of products than of
reactants A solid dissolves
The Second Law of Thermodynamics No energy transformation can be absolutely
efficient. Entropy
Time’s arrow, molecular disorder Examples of favorable entropy
Solids or liquids are converted to gases More molecules of products than of
reactants A solid dissolves
Dissolving Solids Increases Entropy
Dissolving Solids Increases Entropy
Kinetics Activation Energy
The size of the energy barrier on the pathway from reactants to products determines how fast a reaction proceeds.
Slow reactions have relatively large energy barriers, while fast reactions have relatively small energy barriers.
Kinetics Activation Energy
The size of the energy barrier on the pathway from reactants to products determines how fast a reaction proceeds.
Slow reactions have relatively large energy barriers, while fast reactions have relatively small energy barriers.
Kinetics (cont) Collision Theory
Two chemical species must come together in the right orientation with sufficient energy to undergo reaction.
Kinetics (cont) Collision Theory
Two chemical species must come together in the right orientation with sufficient energy to undergo reaction.
Collision TheoryCollision Theory
Kinetics (cont) Factors that Affect Reaction Rates
Concentration of ReactantsTemperature Catalysts
Kinetics (cont) Factors that Affect Reaction Rates
Concentration of ReactantsTemperature Catalysts
Effect of TemperatureEffect of Temperature
Effect of CatalystsEffect of Catalysts
Chapter 8 HighlightsChapter 8 Highlights
The classes of molecules that form the basis of all living organisms are lipids (fats), carbohydrates (sugars), proteins, and nucleic acids.
Lipids are nonpolar compounds that serve as the scaffolding for cell membranes, function in energy storage, and play a role in signaling.
The classes of molecules that form the basis of all living organisms are lipids (fats), carbohydrates (sugars), proteins, and nucleic acids.
Lipids are nonpolar compounds that serve as the scaffolding for cell membranes, function in energy storage, and play a role in signaling.
Chapter 8 Highlights(cont)Chapter 8 Highlights(cont)
Carbohydrates, composed of monosaccharide building blocks, function in energy storage and cellular recognition.
Proteins, composed of amino acids, act as catalysts, as structural components in hair, muscle, and other tissue, and as antibodies in the immune response.
Nucleic acids, composed of nucleotides, are the molecules of inheritance.
Carbohydrates, composed of monosaccharide building blocks, function in energy storage and cellular recognition.
Proteins, composed of amino acids, act as catalysts, as structural components in hair, muscle, and other tissue, and as antibodies in the immune response.
Nucleic acids, composed of nucleotides, are the molecules of inheritance.
Lipids Overview
Lipids are hydrophobic molecules that act as energy stores, as the structural units of membranes, and as cellular signals.
Energy-Storage Lipids: TriglyceridesThree fatty acids linked to glycerolThe fatty acids can be saturated or
unsaturated, depending on the source.
Lipids Overview
Lipids are hydrophobic molecules that act as energy stores, as the structural units of membranes, and as cellular signals.
Energy-Storage Lipids: TriglyceridesThree fatty acids linked to glycerolThe fatty acids can be saturated or
unsaturated, depending on the source.
Triglycerides Triglycerides
Lipids (cont) Membrane Lipids: Phospholipids
Amphiphilic molecules composed of glycerol linked to two fatty acids and a charged phosphorus-containing group
Phospholipids form a membrane bilayer in water.
Lipids (cont) Membrane Lipids: Phospholipids
Amphiphilic molecules composed of glycerol linked to two fatty acids and a charged phosphorus-containing group
Phospholipids form a membrane bilayer in water.
Phospholipids Phospholipids
Lipids (cont) Rigid Lipids: Steroids
Steroids are based on cholesterol.Some steroids are hormones, which send
messages between cells. Examples include the sex hormones estradiol and testosterone.
Lipids (cont) Rigid Lipids: Steroids
Steroids are based on cholesterol.Some steroids are hormones, which send
messages between cells. Examples include the sex hormones estradiol and testosterone.
Carbohydrates (Sugars) Overview
Polar molecules with the general formula CxH2Oy that have roles in energy storage, structure, and cell recognition.
Building Blocks: Monosaccharides Examples include glucose (blood sugar)
and fructose (fruit sugar).
Carbohydrates (Sugars) Overview
Polar molecules with the general formula CxH2Oy that have roles in energy storage, structure, and cell recognition.
Building Blocks: Monosaccharides Examples include glucose (blood sugar)
and fructose (fruit sugar).
Monosaccharides Monosaccharides
Carbohydrates (cont) Carbohydrate Polymers:
PolysaccharidesExamples include cellulose and starch.
Carbohydrates for RecognitionExamples include blood-type
carbohydrates.
Carbohydrates (cont) Carbohydrate Polymers:
PolysaccharidesExamples include cellulose and starch.
Carbohydrates for RecognitionExamples include blood-type
carbohydrates.
Blood-Group CarbohydratesBlood-Group
Carbohydrates
Proteins Amino Acids and Peptides
Twenty different amino acid building blocks comprise proteins.
Linking two or more amino acids leads to a peptide.
Long peptide chains (polypeptides) fold up to form proteins.
Proteins Amino Acids and Peptides
Twenty different amino acid building blocks comprise proteins.
Linking two or more amino acids leads to a peptide.
Long peptide chains (polypeptides) fold up to form proteins.
Polypeptide FoldingPolypeptide Folding
Protein Principles Structure Determines Function Enzymes are Protein Catalysts Abnormal Protein Structures Can Lead
to Disease
Protein Principles Structure Determines Function Enzymes are Protein Catalysts Abnormal Protein Structures Can Lead
to Disease
Nucleic Acids (DNA and RNA) Building Blocks: Nucleotides
Contain a phosphate group, a sugar ring, and a nitrogen-containing base (A, G, C, T/U).
Structure DNA is a two-chained helix with the chains
running in opposite directions. Strands interact through specific hydrogen-
bonding interactions (A with T and G with C). Function
Stretches of DNA called genes code for proteins.
Nucleic Acids (DNA and RNA) Building Blocks: Nucleotides
Contain a phosphate group, a sugar ring, and a nitrogen-containing base (A, G, C, T/U).
Structure DNA is a two-chained helix with the chains
running in opposite directions. Strands interact through specific hydrogen-
bonding interactions (A with T and G with C). Function
Stretches of DNA called genes code for proteins.
DNA StructureDNA Structure
Chapter 16 HighlightsChapter 16 Highlights
Every contact leaves its trace. Physical evidence is any material
related to a crime, including fingerprints, weapons, and bodily fluids.
Crime scene investigators document and collect physical evidence for analysis at a crime laboratory.
Every contact leaves its trace. Physical evidence is any material
related to a crime, including fingerprints, weapons, and bodily fluids.
Crime scene investigators document and collect physical evidence for analysis at a crime laboratory.
Chapter 16 Highlights(cont)
Chapter 16 Highlights(cont)
A variety of techniques are used to characterize physical evidence, including mass spectrometry, which provides a unique fingerprint
of a compound spectroscopy, which uses interactions with
electromagnetic radiation to characterize compounds microscopy, which reveals features of fingerprints,
bullets, and fibers invisible to the naked eye DNA analysis, which can be used to uniquely identify
the source of a biological sample even years later
A variety of techniques are used to characterize physical evidence, including mass spectrometry, which provides a unique fingerprint
of a compound spectroscopy, which uses interactions with
electromagnetic radiation to characterize compounds microscopy, which reveals features of fingerprints,
bullets, and fibers invisible to the naked eye DNA analysis, which can be used to uniquely identify
the source of a biological sample even years later
Evidence Collection Preserve and Protect
First responders must isolate the crime scene so that physical evidence is not disturbed
Physical EvidenceAnything that can link a suspect to a
crime
Evidence Collection Preserve and Protect
First responders must isolate the crime scene so that physical evidence is not disturbed
Physical EvidenceAnything that can link a suspect to a
crime
Evidence Analysis Organization of the Crime Lab
Specialized branches handle specific types of evidence; e.g., latent prints
What is it? Identification at the molecular level
(e.g., is the white powder cocaine?) Comparison to a reference sample
(e.g., is the blood from the suspect?)
Evidence Analysis Organization of the Crime Lab
Specialized branches handle specific types of evidence; e.g., latent prints
What is it? Identification at the molecular level
(e.g., is the white powder cocaine?) Comparison to a reference sample
(e.g., is the blood from the suspect?)
Evidence Analysis (cont) Qualitative vs. Quantitative
Analysis Qualitative analysis determines the
identity of a sample (what is it?). Quantitative analysis measures how
much of a substance is present.
Evidence Analysis (cont) Qualitative vs. Quantitative
Analysis Qualitative analysis determines the
identity of a sample (what is it?). Quantitative analysis measures how
much of a substance is present.
Techniques for Evidence Analysis Separating and Identifying
Chromatography separates the components of a mixture based on polarity.
Spectroscopy identifies molecules based on differential interactions with electromagnetic radiation.
Techniques for Evidence Analysis Separating and Identifying
Chromatography separates the components of a mixture based on polarity.
Spectroscopy identifies molecules based on differential interactions with electromagnetic radiation.
Chromatography Chromatography
Spectroscopy Spectroscopy
Analysis of Evidence Arson
Accelerants are used during arson to make fires burn faster.
Accelerants are volatile compounds that easily enter the gas phase.
Gas chromatography coupled with mass spectrometry (GC-MS) is used to separate and identify the components of a suspected accelerant.
Analysis of Evidence Arson
Accelerants are used during arson to make fires burn faster.
Accelerants are volatile compounds that easily enter the gas phase.
Gas chromatography coupled with mass spectrometry (GC-MS) is used to separate and identify the components of a suspected accelerant.
Mass Spectrum of Dodecane
Mass Spectrum of Dodecane
Analysis of Evidence (cont) Drugs
Forensic toxicologists identify alcohol, drugs, and poisons in biological samples.
Liquid chromatography coupled with mass spectrometry (LC-MS) is commonly used to analyze liquid mixtures such as blood.
Analysis of Evidence (cont) Drugs
Forensic toxicologists identify alcohol, drugs, and poisons in biological samples.
Liquid chromatography coupled with mass spectrometry (LC-MS) is commonly used to analyze liquid mixtures such as blood.
Analysis of Evidence (cont) Microscopic Analysis
Tiny features of a sample invisible to the naked eye can be detected with a microscope.
Types of evidence examined by microscopy include fingerprints, bullets and shell casings, and fibers.
Analysis of Evidence (cont) Microscopic Analysis
Tiny features of a sample invisible to the naked eye can be detected with a microscope.
Types of evidence examined by microscopy include fingerprints, bullets and shell casings, and fibers.
Microscopic View of FibersMicroscopic View of Fibers
DNA Analysis Nuclear DNA Analysis
Unique among individuals (except identical twins).
Detects differences between individuals at highly variable, noncoding regions.
In restriction fragment length polymorphism (RFLP) analysis, DNA is cut to yield fragments that vary in length between individuals.
In PCR-STR analysis, DNA is amplified via the polymerase chain reaction to yield products that vary in length between individuals.
DNA Analysis Nuclear DNA Analysis
Unique among individuals (except identical twins).
Detects differences between individuals at highly variable, noncoding regions.
In restriction fragment length polymorphism (RFLP) analysis, DNA is cut to yield fragments that vary in length between individuals.
In PCR-STR analysis, DNA is amplified via the polymerase chain reaction to yield products that vary in length between individuals.
RFLP AnalysisRFLP Analysis
PCR-STR AnalysisPCR-STR Analysis
DNA Analysis (cont) Mitochondrial DNA Analysis
Identical among those related on a maternal line.
Present in multiple copies per cell. Most useful for badly damaged remains. Hypervariable DNA region is amplified
via the polymerase chain reaction and then sequenced.
DNA Analysis (cont) Mitochondrial DNA Analysis
Identical among those related on a maternal line.
Present in multiple copies per cell. Most useful for badly damaged remains. Hypervariable DNA region is amplified
via the polymerase chain reaction and then sequenced.
Nuclear vs. mitochondrial DNANuclear vs. mitochondrial DNA
Chapter 9 HighlightsChapter 9 Highlights
The macronutrients are carbohydrates (sugars and starches), lipids (fats and oils), and proteins.
The micronutrients are vitamins, minerals, and phytochemicals.
Dietary carbohydrates are broken down to glucose or its derivatives and oxidized for energy.
The macronutrients are carbohydrates (sugars and starches), lipids (fats and oils), and proteins.
The micronutrients are vitamins, minerals, and phytochemicals.
Dietary carbohydrates are broken down to glucose or its derivatives and oxidized for energy.
Chapter 9 Highlights (cont)Chapter 9 Highlights (cont) “Good” carbohydrates, such as the
complex carbohydrates, tend to raise blood sugar slowly.
Proteins are broken down into their component amino acids, which are generally used to assemble new proteins rather than being oxidized.
Lipids are oxidized for energy. “Good” lipids are polyunsaturated fats
such as omega-3 and omega-6 fatty acids.
“Good” carbohydrates, such as the complex carbohydrates, tend to raise blood sugar slowly.
Proteins are broken down into their component amino acids, which are generally used to assemble new proteins rather than being oxidized.
Lipids are oxidized for energy. “Good” lipids are polyunsaturated fats
such as omega-3 and omega-6 fatty acids.
Chapter 9 Highlights(cont)Chapter 9 Highlights(cont) “Bad” lipids are cholesterol, saturated fats,
and trans fats. Dieting alone is not effective for weight
control because the body responds by decreasing the amount of energy expended to maintain essential life processes.
Vitamins are essential carbon-based compounds used as chemical reactants.
Minerals are essential inorganic elements. Phytochemicals are disease-fighting
molecules found in plant products. Processed food contains food additives.
“Bad” lipids are cholesterol, saturated fats, and trans fats.
Dieting alone is not effective for weight control because the body responds by decreasing the amount of energy expended to maintain essential life processes.
Vitamins are essential carbon-based compounds used as chemical reactants.
Minerals are essential inorganic elements. Phytochemicals are disease-fighting
molecules found in plant products. Processed food contains food additives.
Food Guide Pyramids USDA’s Original Pyramid
Grains form the base of the pyramid; fats, oils, and sweets form the tip; fruit, vegetable, dairy, and protein groups are in the middle.
MyPyramid Importance of exercise is stressed.
Healthy Eating Pyramid Distinguishes between “good” and “bad” carbs
and fats.
Food Guide Pyramids USDA’s Original Pyramid
Grains form the base of the pyramid; fats, oils, and sweets form the tip; fruit, vegetable, dairy, and protein groups are in the middle.
MyPyramid Importance of exercise is stressed.
Healthy Eating Pyramid Distinguishes between “good” and “bad” carbs
and fats.
Dietary Carbohydrates Simple Sugars (Monosaccharides) Complex Carbohydrates
(Polysaccharides) Glycemic Index
A measure of how fast dietary carbohydrates are broken down to raise blood sugar
Diets rich in foods with high GI values have been linked to increased risk of certain chronic diseases such as diabetes.
Dietary Carbohydrates Simple Sugars (Monosaccharides) Complex Carbohydrates
(Polysaccharides) Glycemic Index
A measure of how fast dietary carbohydrates are broken down to raise blood sugar
Diets rich in foods with high GI values have been linked to increased risk of certain chronic diseases such as diabetes.
Overview of Carbohydrates
Overview of Carbohydrates
Dietary Proteins Essential Amino Acids
Adult humans cannot make 9 of the 20 amino acids and must obtain these in the diet on a regular basis.
Complete Proteins Provide all the essential amino acids
Role of Dietary Proteins Provide the amino acids needed to make new
proteins
Dietary Proteins Essential Amino Acids
Adult humans cannot make 9 of the 20 amino acids and must obtain these in the diet on a regular basis.
Complete Proteins Provide all the essential amino acids
Role of Dietary Proteins Provide the amino acids needed to make new
proteins
Dietary Lipids
Cholesterol Cholesterol is carried through the bloodstream
in lipoprotein complexes. LDL is the “bad” form of cholesterol, while HDL
is the “good” form. Diets rich in saturated fats and cholesterol are
linked to increased risk of heart disease. Although the French have diets rich in animal
fats, they have a lower incidence of heart disease. This “French paradox” is attributed to protective compounds in red wine.
Dietary Lipids
Cholesterol Cholesterol is carried through the bloodstream
in lipoprotein complexes. LDL is the “bad” form of cholesterol, while HDL
is the “good” form. Diets rich in saturated fats and cholesterol are
linked to increased risk of heart disease. Although the French have diets rich in animal
fats, they have a lower incidence of heart disease. This “French paradox” is attributed to protective compounds in red wine.
Lipoprotein ComplexesLipoprotein Complexes
Dietary Lipids (cont) Triglycerides
Dietary triglycerides from animal sources tend to contain saturated fatty acids and are generally solids at room temperature
Dietary triglycerides from plant sources tend to contain unsaturated fatty acids and are generally liquids at room temperature.
Dietary Lipids (cont) Triglycerides
Dietary triglycerides from animal sources tend to contain saturated fatty acids and are generally solids at room temperature
Dietary triglycerides from plant sources tend to contain unsaturated fatty acids and are generally liquids at room temperature.
Dietary Fatty AcidsDietary Fatty Acids
Dietary Lipids (cont) The “Bad” Fats
Saturated fats: linked to increased risk of heart disease
Trans fats: made during hydrogenation of unsaturated fats
The “Good” Fats Polyunsaturated fats such as the essential fats
the omega-6 and omega-3 fatty acids
Dietary Lipids (cont) The “Bad” Fats
Saturated fats: linked to increased risk of heart disease
Trans fats: made during hydrogenation of unsaturated fats
The “Good” Fats Polyunsaturated fats such as the essential fats
the omega-6 and omega-3 fatty acids
Dieting Energy Balance
Energy is expended through basal metabolism, physical activity, and thermogenesis.
Dieting Affects Energy Expenditure The body adapts to less food by reducing its
energy expenditure. The hormone leptin also tells the brain to stop eating.
Low Fats vs. Low Carbs Diets low in carbohydrates lead to production of
ketone bodies from fat stores, which can lead to a dangerous drop in blood pH and stress on the liver and kidneys.
Dieting Energy Balance
Energy is expended through basal metabolism, physical activity, and thermogenesis.
Dieting Affects Energy Expenditure The body adapts to less food by reducing its
energy expenditure. The hormone leptin also tells the brain to stop eating.
Low Fats vs. Low Carbs Diets low in carbohydrates lead to production of
ketone bodies from fat stores, which can lead to a dangerous drop in blood pH and stress on the liver and kidneys.
Micronutrients Vitamins
Fat soluble (A, D, E, K) Water soluble (C and B family)
Minerals Macrominerals (e.g., calcium) Trace minerals (e.g., iron)
Phytochemicals Disease-preventing molecules found in plant
products
Micronutrients Vitamins
Fat soluble (A, D, E, K) Water soluble (C and B family)
Minerals Macrominerals (e.g., calcium) Trace minerals (e.g., iron)
Phytochemicals Disease-preventing molecules found in plant
products
PhytochemicalsPhytochemicals
Food Additives GRAS List
preservatives, coloring agents, flavoring agents, sweeteners, or nutrients
Incidental Additives
Food Additives GRAS List
preservatives, coloring agents, flavoring agents, sweeteners, or nutrients
Incidental Additives
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