Download Lecture 1001

Class Business
 Tomorrow is lab day. Come prepared.
 Next week Tuesday(10/6) we will have our first quiz
 October 21th (Wednesday) we will have our first Exam.
 By next week; form groups of four for your poster project.
Themes for poster project
1. DNA and inheritance
2. Gene therapy
3. Vaccines
4. Biology of Cancer
5. Biology and Forensics
6. Ecosystem
7. Evolution
Chemical Bonds
 Two or more elements can combine to form molecules. They are
held together by chemical bonds.
Outer shell
has 1 electron
Na
Sodium atom
The outer electron is stripped
from sodium and completes
the chlorine atom’s outer shell
Outer shell
has 7 electrons
Cl
Chlorine atom
Complete
outer shells
Na
Sodium ion
Cl
Chlorine ion
The attraction
between the
ions—an ionic
bond—holds
them together
Sodium chloride (NaCl)
1
Chemical Bonds
Outer shell
has 1 electron
The outer electron is stripped
from sodium and completes
the chlorine atom’s outer shell
Na
Sodium atom
Outer shell
has 7 electrons
Cl
Chlorine atom
Complete
outer shells
Na
Sodium ion
Cl
Chlorine ion
The attraction
between the
ions—an ionic
bond—holds
them together
Sodium chloride (NaCl)
Ionic Bonds : a chemical bond between charged elements
Covalent Bonds: a chemical bond between atoms sharing electrons
Hydrogen Bonds: is an attraction between two polar molecuels
Covalent Bonds
 A covalent bond forms when two atoms share one or more pairs of outer-shell
electrons.
Oxygen O
Atomic number = 8
Hydrogen H
Atomic number = 1
Water
 Atoms held together by covalent bonds form a molecule.
 The number of covalent bonds an atom can form is equal to the number of
additional electrons needed to fill its outer shell.
2
Covalent Bonds
single bonds: = bond between
atoms share one pair of e-
 double bonds= bonds between
atoms sharing two pairs of e-
 triple covalent bond: bonds
between atoms sharing three
pairs of e-.
In covalent bonds, electrons are not
always shared equally
Non-Polar molecule
Polar molecule
slightly 
slightly 
H
H
O
CH4 (methane)
slightly –
H2O (water)
3
Polar molecules form Hydrogen Bond
Water is a compound in which the electrons in its
covalent bonds are shared unequally.
Hydrogen bond
What makes water uniquely important for
life?
 The polarity of water molecules and the hydrogen bonding
that results explain most of water’s life-supporting properties.
Water molecules stick together.
Water molecules stick to other polar molecules
Water has a strong resistance to change in
temperature.
Frozen water floats.
Water is a common solvent for life.
4
Properties of Water
 Cohesion: is the attraction between
molecules of water.
 Adhesion is the attraction of water to the
molecules of the container or tube it is in.
 High specific heat capacity is the
capacity to hold energy
Properties of Water
 Ice Floating.
 When cold, water molecules move
apart, forming ICE.
 If ice did not float, ponds, lakes, and
even the oceans would freeze solid.
Per unit volume, liquid
water holds more
molecules than ICE
 Water is the universal solvent.
The dissolving agent is the solvent.
The dissolved substance is the solute.
When a solute is dissolved with water it is
called Aqueous Solution
5
Work in groups
For the following atoms:
1.
Draw the planetary atomic representation
3.
Form compounds by combining elements
2.
4.
Indicate valence electrons
Discuss the type of bond
Hydrogen, Helium, Sodium,
Carbon, Nitrogen, Oxygen
Lithium, Florine, Chlorine,
Magnesium
Solution pH, Acids and Bases
In biology, solution pH play important role
 Acidic solutions release H+ to solution. The compound is an
acid.
 Basic solutions accept H+. The compound is a base.
 Solutions that resist changes in hydrogen concentration are
called Buffers.
Buffers
Accept H+ ions when they are in excess
Donate H+ ions when they are depleted
 Increases in global CO2 concentrations may lead to the
acidification of the oceans.
 To describe the acidity of a solution, chemists use the pH scale.
6
The pH Scale
 The pH scale is used to measure the
solution acidic or basic property
 The pH scale range from 0-14 with 7
being neutral.
 pH is the concentration of
Hydrogen ions in logarithmic scale.
 pH of water is 7 (neutral) Why?
Chapter Summary
 An element is a substance that cannot be broken down into smaller
substances
 Elements are arranged in a periodic table
 Living things are made of four main elements
 Trace elements are important for physiology
 Atoms are the smallest unit of an element
 Atomic substructures are protons, neutrons, and electrons
 Some elements exist in different forms called isotopes
 Chemical Bonds 1. Ionic Bonds, 2. Covalent Bonds, 3. Hydrogen Bonds
 Compounds could be acidic, neutral or basic pH
 pH is the logarithmic concentration of H-ions. The pH scale ranges
from 0-14
 Water is neutral pH
7
Isotopes
 Elements with differing neutrons and protons are called isotopes
Few examples of Nitrogen and Carbon isotopes
Element
Isotope
Neutrons
Protons
Nitrogen (N2)
15N
8
7
Nitrogen (N2)*
Carbon (C)*
12C
Carbon (C)
14C
Carbon (C)
*=
14N
13C
7
6
7
8
most abundant isotope form of the element
7
6
6
6
http://www.radiolab.org/story/elements/
Home work
Isotope forms of elements are important in science and medicine
 Look for application of isotope form of an element used in
science and medicine
 Describe the kind of application
 Determine the number of electrons, protons, and neutrons
 Draw a planetary description of the isotopic element
8
 Macro = large
 Mono = one
 Di = two
 Tri = three
 Poly = many
 Saccharide = Sugar
 Hydro = water
 Lysis = break
 Hydrogenation = adding hydrogen
 Hydration = Adding water
 Dehydration = removing water
 Phobic = fearing
 Philic = loving
9
 Macromolecule:
 Hydrophilic
 Polymer
 Protein
 Peptide bond
 Amino acids
 Fold
 Primary Structure
 Secondary structure
 Tertiary structure
 Amino Acid sequence
 Monomer
 Hydrolysis
 Dehydration
 Hydrogenation
 Chemical reaction
 Bond
 Ionic
 Covalent
 Hydrogen
 Single
 Double
 Triple
 Carbohydrates
 Monosaccharide
 Disaccharide
 Polysaccharides
 Lipids
 Triglycerides
 Saturated fat
 Unsaturated fat
 Steroids
 Phospholipids
 Hydrophobic
 Nucleic acids
 DNA (deoxyribonucleic acid)
 RNA (ribonucleic acid).
 Thymine
 Adenine
 Guanosine
 Cytosine
 Uracil
 DNA or RNA sequence
 Deoxyribose
 Ribose
 Functional group
 Hydroxyl
 Carboxyl
 Amino
Do weight loss pills work???
What are carbs, fats and proteins?
Are all body fat types bad?
10
Do weight loss pills work???
What are carbs, fat and proteins?
Are all body fat types bad?
 If there was a magic pill obesity would not be at
epidemic proportions in the US.
 Our body needs essential nutrients for growth,
health and overall wellbeing.
 Understanding the various nutrient required for
our body should be the bases in the fight against
obesity
 A cell is mostly water.
 The rest of the cell consists mainly of carbon-based molecules.
 Carbon forms large, complex, and diverse molecules necessary
for life’s functions.
 Organic compounds are carbon-based molecules.
11
 Carbon can share electrons with other atoms in four covalent
bonds.
 This enables constructing an endless diversity of carbon
skeletons varying in
 size and
 branching pattern.
Structural formula
Ball-and-stick model
Space-filling model
12
Macromolecules = -large molecule.
-are organic molecules
-are made up of elements Carbon, Hydrogen,
Oxygen, Nitrogen, Phosphorus and Sulfur
-are essential nutrients for the body.
13
Macromolecules = -large molecule.
-are organic molecules
-are made up of elements Carbon, Hydrogen,
Oxygen, Nitrogen, Phosphorus and Sulfur
-are essential nutrients for the body.
The four main types of macromolecules?
1.
Carbohydrates (sugars)
3.
Proteins
2.
4.
Lipids
Nucleic Acids (DNA and RNA)
 Macromolecules are polymers.
 Polymers are made by stringing together many smaller
molecules called monomers.
 A dehydration reaction Vs Hydrolysis
 links two monomers together Vs breaks a molecule.
 removes a molecule of water Vs Adds ionic elements of water (H+ and OH-)
© 2016 Pearson Education, Inc.
14
Carbohydrates (Sugars)
 Organic compounds composed of Carbon, Hydrogen and Oxygen.
 Carbohydrates include sugars and polymers of sugar.
 small sugar molecules in soft drinks and
 long starch molecules in spaghetti and bread.
 Monosaccharides (simple sugars)
example = C6H12O6 glucose,
 Disaccharides (double sugars)
example = sucrose and lactose
 Polysaccharides (complex sugars)
example = starch, cellulose, and glycogen
Simple sugars: monosaccharides
are the monomers of carbohydrates and cannot be broken down
into smaller sugars.
Galactose
C6H12O6
15
Monosaccharides
are the monomers of carbohydrates and cannot be broken
down into smaller sugars.
Disaccharides
-Are double sugar constructed from two monosaccharides by a
dehydration reaction.
• Examples of disaccharides
maltose in beer, malted milk
shakes, and malted milk ball
candy, and sucrose in table sugar.
16
Polysaccharides
- are complex carbohydrates made of long chains of sugars—
polymers of monosaccharides.
Starch molecules
Starch, cellulose and glycogen are
formed from hundreds of glucose
molecules joined to form a long chain
Cellulose molecules in plants
Glycogen granules in muscle tissue
1. Quick energy foods. (glucose)
2. Energy Storage
Starch = Plants,
glycogen = Animals
3. Cellular structures (cellulose-Plants and Bacteria)
Almost all carbohydrates are hydrophilic (“water-loving”)
molecules that dissolve readily in water.
17
 The average American consumes about
45 kg of sugar (about 100 lb) per year,
mainly as sucrose and high-fructose
corn syrup.
 Sugar
 is a major cause of tooth decay and
overconsumption and
 increases the risk of developing type 2
diabetes and heart disease.
Lipids are fats and oils made up of mainly Carbon, Hydrogen and Oxygen
They are made up from glycerol and fatty acids (not made from monomers)
Glycerol
(head group)
fatty acids (tail group)
Lipids are hydrophobic (“water-fearing”) compounds composed of head
group and tail groups.
18
Triglyceride - 3 Fatty Acids bonded to a Glycerol
Steroids - The carbon skeleton has four fused rings.
Phospholipids – A phosphate moiety linked to the glycerol head group
Triglyceride – 3 Fatty Acids bonded to a Glycerol
Unsaturated: -One or more fatty acid
chains contain double bonded carbon chains
-Liquid at room temperature
-Found mostly in plants
Saturated: -All fatty acids contain no
double bond linked carbons
-Solid at room temperature
-Found mostly in animals.
 Hydrogenation: adds hydrogen,
 converts unsaturated fats to saturated fats,
 makes liquid fats solid at room temperature, and
 creates trans fats, a type of unsaturated fat that is particularly
bad for your health.
19
 Key importance in cell membrane
 High Energy food
 Protects vital organs
 Insulates the body
 Stores food for later use
 Cellular signaling
Not all fat is BAD
-Made up of mainly Carbon, Hydrogen, Oxygen, Nitrogen, and Sulphur
-Polymers of amino acid monomers,
-Essential to Life
-Build structure
-Movement:
Makes up muscle tissue
-Immunity:
Helps fight off foreign invaders
-Transport:
-Enzymes:
Carries oxygen in an organism
Speed up chemical reactions
(example, hemoglobin).
(example, antibodies).
(example, Dehydrogenase).
20
 All proteins are made by stringing together a common set of 20
kinds of amino acids.
 Every amino acid consists of a central carbon atom bonded to
four covalent partners.
Side chains = R groups (20
different R groups)
Hydrophobic side chain
© 2016 Pearson Education, Inc.
Leucine
Serine
Hydrophilic side chain
 Linking Amino acids form peptide
bonds.
 Linked amino Acids create long
chains of amino acids called
polypeptides.
 Peptide bonds are covalent
bonds.
21
 Primary
 Secondary
 Tertiary
 Quaternary
 Primary
 Secondary
 Tertiary
 Quaternary
 Proper protein folding and structure are important for function
 Sickle cell anemia
 Mad cow disease
22
 Nucleic acids are macromolecules that
 are polymers made from monomers called nucleotides,
 store information, and
 provide the instructions for building proteins.
 The monomer units are either:
1.
2.
DNA (deoxyribonucleic acid)
RNA (ribonucleic acid).
© 2016 Pearson Education, Inc.
 Monomeric DNA nucleotides
adenine (A),
guanine (G),
thymine (T), or
3.
4.
cytosine (C).
 to form a double helix.
1.
2.
 A only pairs with T and
Pyrimidines
 G can only pair with C.
Purines
Pyrimidines
© 2016 Pearson Education, Inc.
23
 There are many similarities between DNA and RNA.
 Both are polymers of nucleotides and
 both are made of nucleotides consisting of
 a sugar,
 a phosphate, and
 a base.
Thymine (T) Vs Uracil (U)
 DNA encode programmed instructions that must be translated
 from “nucleic acid language”
 to “protein language.”
© 2016 Pearson Education, Inc.
24