Welcome%20to%20Biology%20(SBI4U)%20University%20Preparation

1
Welcome to Biology (SBI4U) University Preparation

• Teacher Ms. Karellas
• Email georgia.karellas_at_yrdsb.ca
• Website karellas.weebly.com

2
Course Outline

• Unit 1 - Biochemistry
• Students will analyse the technological
  applications used in the food, pharmaceutical,
  and medical industries that affect biological
  processes and cellular functions. They will
  investigate how molecules and their chemical
  properties affect cellular processes and
  biochemical reactions. Students will demonstrate
  an understanding of the important structural and
  functional roles compounds play in the cells of
  all living organisms.
• Unit 2 - Metabolic Processes
• Students will investigate the chemical changes
  and energy conversions that occur in metabolic
  processes. They will demonstrate the ways in
  which an understanding of metabolic processes
  enables people to make informed choices with
  respect to a range of personal, societal, and
  environmental issues.
• Unit 3 - Molecular Genetics
• Students will demonstrate an understanding that
  DNA contains all the genetic information for any
  living organism. They will investigate how
  proteins control a wide variety of cellular
  processes. Students will assess the social,
  legal, and ethical implications of genetic
  research and biotechnology.
• Unit 4 - Homeostasis
• Students will demonstrate an understanding of the
  strict limits on the internal conditions that
  organisms can tolerate. The will investigate the
  ways in which organ systems that maintain
  homeostasis rely on feedback mechanisms. Student
  will explore the environmental factors that
  affect homeostasis.
• Unit 5 - Population Dynamics
• Students will demonstrate an understanding of how
  population growth follows predictable patterns.
  They will investigate how increased consumption
  of resources and production of waste is
  associated with population growth and results in
  specific stresses that affect Earth's
  sustainability. Students will assess
  technological developments that can contribute to
  or help offset the ecological footprint
  associated with population growth and the
  consumption of natural resources.

3
Unit 1 Biochemistry

• Introduction to Biochemistry
• https//www.youtube.com/watch?vtpBAmzQ_pUE

4

• Prior understanding
• Elements are pure substances that cannot be
  broken down through chemical or physical methods,
  elements consist of only one type of atom, an
  atom is the smallest component of an element that
  retains the properties of that element
• A compound is a pure substance composed of two or
  more elements chemically combined, there is a
  specific ratio of types of atoms
• Atoms contain a nucleus with protons and
  neutrons, protons are positively charged and
  neutrons have no charge
• The number of protons defines the element i.e.
  Carbon has 6 protons
• Negatively charged electrons travel in orbits
  (energy levels) around the nucleus, loss or gain
  of an electron causes the formation of a charged
  ion, electrons in the outer orbits are referred
  to as valence electrons, negatively charged ions
  are anions, positively charged ions are cations
• The number of electrons in an uncharged atom is
  the same as the number of protons
• The number of protons and neutrons determines the
  mass number of the element i.e. Carbon 12 has 6
  protons and 6 neutrons

5
Complete the Diagnostic
6
Lesson 1Chemistry in Living Systems

• What is biochemistry?
• BRAINSTORM

• Biochemistry the branch of science dealing with
  the chemical and physiochemical processes that
  occur within living organisms.

7
Organic Chemistry

• What is the difference between organic and
  inorganic molecules?
• Organic molecules
• usually contain CARBON and HYDROGEN
• Inorganic molecules
• usually do not contain CARBON

8
Isotopes

• elements that contain atoms with the same number
  of protons but different numbers of neutrons
• the atomic number remains the same, the mass
  number changes
• C-12 has a mass 12, 6 protons and 6 neutrons
• C-13 has a mass 13, 6 protons and 7 neutrons
• C-14 has a mass 14, 6 protons and 8 neutrons

9

• C-12 makes up 99 of the carbon in nature, C-14
  is a radioisotope that breaks down to release
  N-14, subatomic particles and energy
• Radioisotopes decay in a predictable manner
  called the half-life (time taken for one half of
  the nuclei to decay)

10
(No Transcript)
11

• Organisms take in radioactive carbon dioxide from
  the environment until the day they die but over
  time the radioactive carbon will decay but
  non-radioactive carbon will remain the same so
  the ratio of radioactive carbon to
  non-radioactive carbon can be used to date a
  specimen

12
Organic Elements and Bonding

• electrons occupy volumes of space around the
  nucleus called orbitals or energy levels
• 2 electrons occupy the first energy level (1s
  orbital), 8 electrons occupy the second
  energy level (2 in a 2s orbital, 6 in a 2p
  orbital)
• the outermost s and p orbitals are valence
  orbitals, and the electrons in them are called
  valence electrons
• the chemical behavior of elements is determined
  by these valence electrons

13
Organic Elements and Bonding

• Atoms combine to make molecules.
• The bonds between atoms of the same molecule
  (i.e. within the molecule) are intramolecular
  bonds.
• DEMO ?

14
Organic Elements and Bonding

• The three types of intramolecular bonds are
• Non-Polar Covalent Bonds
• Polar Covalent Bonds
• Ionic Bonds

15

• 1. Non-Polar Covalent Bonds
• Bond formed by sharing a pair
• of valence electrons between
• two atoms.

16

• 2. Polar Covalent Bonds
• Bond formed by unequal sharing of a pair
• of valence electrons between two
• atoms.
• One atom is slightly negative one is
• slightly positive (dipole)

17

• 3. Ionic Bonds
• Bond formed by transfer of electrons
• from atom to atom.
• This results in the formation of positive
• cation, and negative anion. Ions are held
• together by electrostatic attraction.

18

• Ions are important in living systems
• H ions are important in cellular respiration
• Na ions are part of transport mechanisms that
  enable molecules to enter cells
• Ca ions are involved in nerve transmission

19
The Role of Electronegativity

• Electronegativity is a measure of an atoms
  ability to attract a shared electron pair in a
  covalent bond
• Each element in the periodic table has an
  assigned electronegativity number (EN) - the
  larger the number, the greater the greater the
  pull on the electron pair
• The element with the greater EN has a partial
  (d-) charge, the element with the smaller EN has
  a partial (d) charge

20

• ?En is the difference between the
  electronegativity number between two atoms
  participating in a covalent bond
• Electronegativity values can be found on a
  periodic table.

21

• Electronegativity difference
• determines the BOND TYPE
• ?En 0 is when atoms share electrons equally,
  nonpolar covalent
•  ?En gt 0 lt 1.7 one atom attracts the
  electrons more than the other, polar covalent
  bond 
• ?En gt 1.7 or 1.7 electrons are gained by one
  atom, lost by the other, (anions and cations),
  ionic bond

22
?En ?En
?En 0 ---0.5--------------gt 1.7
---------------gt 4.2 Non-polar polar
covalent ionic
23

• EXAMPLE
• Bonds in Water (H2O)
• Oxygen electronegativity 3.44
• Hydrogen electronegativity 2.2
• Difference 3.44 2.2 1.24
• Bond Type ? Polar covalent
• In a water molecule the oxygen is slightly
  negatively charged because it has a higher
  electronegativity

24
Learning Check!

• Determine the type of bond
• KCl
• CH4
• H2

25
Learning Check!

• Determine the type of bond
• a) KCl
• K 0.9 Cl 2.9
• 2.9 0.9 2.0 ionic bond
• b) CH4
• C 2.5 H 2.1
• 2.5 2.1 0.4 non-polar covalent
• c) H2
• H 2.1
• 2.1 2.1 0 nonpolar covalent

26
Organic Elements and Bonding

• The bonds between molecule intermolecular bonds.
  
• Weaker than intramolecular bonds
• DEMO ?
• Two types of intermolecular interactions are
  particularly important for biological system
  hydrogen bonding and hydrophobic interactions

27

• Hydrogen bonding
• water is a polar molecule, attractions between
  () ends and (-) ends are called hydrogen bonds
  (see role of water)
• FON

28

• Hydrophobic interactions non-polar molecules
  such as cooking oil and motor oil do not form
  hydrogen bonds, but in the presence of polar
  molecules such as water, they tend to clump
  together, extruding water.
• These are referred to as hydrophobic (water
  fearing)
• Polar molecules that form hydrogen bonds with
  water are said to be hydrophilic (water loving)
• DEMO ?

29
Why is WATER a special molecule?

• Greater than 2/3 of body mass is water, lungs 90
  water, bones 20 water, fat is 25 water
• Controls body temperature, lubricates joints,
  shock absorber in brain and spinal cord and
  moisturizes surfaces
• Polar covalent bonds and asymmetrical structure
  creates a highly polar molecule
  
• Polarity of water allows it to form chemical
  bonds with other molecules (adhesion), itself
  (cohesion) and ions

30
?En ?En
?En 0 ---0.5--------------gt 1.7
---------------gt 4.2 Non-polar polar
covalent ionic
31
Learning Check!

• Determine the type of bond
• a) KCl
• K 0.9 Cl 2.9
• 2.9 0.9 2.0 ionic bond
• b) CH4
• C 2.5 H 2.1
• 2.5 2.1 0.4 non-polar covalent
• c) H2
• H 2.1
• 2.1 2.1 0 nonpolar covalent

32
POLAR vs. NON-POLAR BONDS

• RECALL Intramolecular vs. Intermolecular bonds
• Electronegativity
• Elements have varying electronegativity (EN)
• i.e. how strongly an atom can attract electrons
• Non-Polar Covalent Bonds the atoms involved have
  similar electro negativities, so the electrons
  are equally shared.
• (ex. H-H, O-O, C-H)
• Polar Covalent Bonds the atoms involved have
  different electro negativities, so there is
  unequal sharing of electrons. This results in a
  separation of charge.
• (ex. O-H)

33
?En ?En
?En 0 ---0.5--------------gt 1.7
---------------gt 4.2 Non-polar polar
covalent ionic
34
POLAR vs. NON-POLAR MOLECULES

• Polar bonds ? Polar molecule
• Non-polar bonds ? Non-polar molecule
• Polar Molecules
• If the molecule is asymmetrical and has polar
  covalent bonds, the molecule will also be polar
  (e.g. glucose)
• These molecules are hydrophilic (water loving)
• Non-Polar Molecules
• Non polar molecules occur when a molecule has
  non-polar covalent bonds (e.g. C-H backbone) OR
• the polar covalent bonds are in a symmetrical
  arrangement (e.g. CCl4)
• These molecules are hydrophobic (water hating)

35
Practice Questions

• 1.Do the following groups contain polar or
  non-polar bonds?
• -OH
• -COOH
• -NH2
• -PO4
• -CH2
• 2. Are the above groups hydrophobic or
  hydrophilic?
• 3. Are the following molecules polar or
  non-polar?
• 4. Why is this important for biology?
• (e.g. glucose, phospholipids)

36
Practice Questions

• Do the following groups contain polar or
  non-polar bonds?
• -OH (polar) (hydrophilic)
• -COOH (polar) (hydrophilic)
• -NH2 (polar) (hydrophilic)
• -PO4 (polar) (hydrophilic)
• -CH2 (non-polar) (hydrophobic)
• Are the above functional groups hydrophobic or
  hydrophilic?
• Are the following molecules polar or non-polar?
• (polar) (non-polar)
• Why is this important for biology?
• (e.g. glucose, phospholipids)

37
Functional Groups (aka reactive clusters)

• What are functional groups and why are they
  important?
• All the biological molecules we will be studying
  have important functional groups which determine
  their function and interactions in cells

38

• With the exception of a few molecules (i.e.
  carbon dioxide) compounds containing carbon are
  referred to as organic compounds. The organic
  molecules of importance to living organisms can
  be classified into groups carbohydrates,
  lipids, proteins and nucleic acids.

39

• Carbon
• 4 valence electrons can form 4 covalent bonds
  with other elements

40

• attach to each other to form linear or branched
  or ring structures and therefore are the backbone
  of biological molecules
• molecules with only carbon and hydrogen are
  hydrocarbons, non-polar due to the symmetrical
  arrangement of their bonds

41

• other elements such as hydrogen, oxygen, sulfur,
  nitrogen and phosphorus may also attach to the
  carbon backbone to form functional groups

42
Functional Groups
Group Chemical Formula Structural Formula
Hydroxyl -OH
Carboxyl -COOH
Amino -NH2
Sulfhydryl -SH
Phosphate -PO4
Carbonyl -COH or -CO-
Create Study Cards for each functional group to
REVIEW and ASSESS your learning of todays
lesson.
43
Macromolecules of Life
44
MINDS-ON Macromolecule Sorting Activity!

• Get into groups of 4
• Go to a station set up around the lab benches
• Using your understanding of functional groups,
  sort the following molecules into the four
  categories of macromolecules (carbohydrates,
  lipids, proteins, and nucleic acids) paste them
  on the sheet
• First group to finish (correctly) gets a prize! ?
  

45
Learning Goals

• Understand the structure and function of
  carbohydrates
• Understand that monosaccharides are the smallest
  structural unit of carbohydrates
• List and describe the 4 types of carbohydrates
  monosaccharides, disaccharides, oligosaccharides,
  polysaccharides
• Demonstrate condensation and hydrolysis reactions
  for carbohydrates

46

• Macromolecules of Life
• What is a macromolecule?
• Macromolecules
• A large molecule (polymer) made of many smaller
  structural units (monomers) linked together
• 1)Carbohydrates
• 2)Lipids
• 3)Proteins
• 4)Nucleic Acids

47

• Macromolecules are assembled and disassembled in
  the same way
• Monomers ? Polymer
• (Condensation/Dehydration Synthesis Reaction)
• anabolic reaction - large molecules are built
  from small subunits
• energy is required
• Water is released

48

• Macromolecules are assembled and disassembled in
  the same way
• Polymer ? Monomer
• (Hydrolysis Reaction) hydro -water lysis
  -broken
• catabolic reaction - large molecules are broken
  down into small subunits
• energy is released
• Water is used

49
Carbohydrates (CHO)
50
Carbohydrates (CHO)

• What is the function of carbohydrates?
• Used as sources of energy
• -Glucose primary source of energy
• -Sucrose/Lactose dietary sugars
• Building materials
• Cell surface markers for cell-to-cell
  communication

51
Carbohydrates

• Contain C, H, O in a 121 ratio
• Formula (CH2O)n (n of Carbons)
• Sugar names end in ose
• Simple Carbohydrates
• - Monosaccharide and Disaccharide
• Complex Carbohydrates
• -Polysaccharide and Oligosaccharide

52
Simple Carbohydrates

• Monosaccharides the smallest structural unit
  (monomer) of a carbohydrate
• E.g. C6H12O6 Glucose, Fructose, Galactose

53
(No Transcript)
54
Numbering the Carbons

• monosaccharides with the same chemical formula
  but different arrangement of atoms are called
  isomers
• i.e. C6H12O6 is glucose, galactose and fructose

55
a-Glucose vs. ß-Glucose
When a glucose molecule forms a six-carbon ring
50 chance the -OH will be below the plane
(alpha) 50 chance the -OH will be above the
plane (beta)
56
Simple Carbohydrates

• Disaccharides composed of two monosaccharides
  (monomers) joined through a condensation
  reaction, forming a glycosidic linkage (covalent
  bonds)
• Glucose Glucose Maltose
• Ex. Infant formula, Beer
• Glucose Fructose Sucrose
• Ex. Sugar cane, Table Sugar
• Glucose Galactose Lactose
• Ex. Milk

57
(No Transcript)
58

• Disaccharides/Polysaccharides can be broken down
  through a hydrolysis reaction

59
Complex Carbohydrates

• Oligosaccharides
• 3-10 monosaccharides linked
• glucose galactose fructose Raffinose
• Found in beans, peas, lentils, broccoli,
• asparagus
• Humans lack enzymes to digest oligosaccharides
  (causes bloating, cramps, gas)

60
Complex Carbohydrates

• Polysaccharides
• - gt 10 monosaccharides linked
• - Most are made up of hundreds of monosaccharides
  bonded together
• - Types
• 1. Starch glucose storage in plants
• 2. Glycogen glucose storage in animals
• 3. Dietary Fiber not used for energy
• -Cellulose structural support in plants
• -Chitin structural support in organisms

61
Starch

• A starch molecule contains hundreds of glucose
  molecules in either
• branched chains Amylopectin or
• unbranched (coiled) chains Amylose
• Sources
• grains, dried beans, pasta, bread, potato

62
(No Transcript)
63
Glycosidic bonds in Starch
Coiled Branched
64
Glycogen

• Found in liver and skeletal muscles
• Many branch points allows for rapid break down
  for glucose to be released and used for energy

65
Dietary Fiber

• Group of plant polysaccharides that are not
  digested or absorbed in the human intestine
  structural
• Fibers Cellulose, Chitin

66
Cellulose

• Structural support in plant cell walls
• Also used by humans in
• wood for lumber and paper, cotton and linen
  for clothing
• Straight chain polymer of ß 1-4 glycosidic
  linkages

67
Chitin

• Structure support - exoskeleton of insects,
  crabs, lobsters, fungi cell wall
• Also used in medicine contact lenses, surgical
  thread

68
Homework

• Carbohydrates Worksheet
• Have a great weekend! ?

69
Lipids

• Triglycerides, Phospholipids, Sterols

70
Lipids

• Lipids
• -composed of carbon, hydrogen, and oxygen atoms
• -higher proportion of non-polar C-H (high energy)
  bonds makes lipids hydrophobic
• What is the function of lipids?
• Provides long-term energy storage, cushions
  organs, provides cell membrane structure,
  synthesis of hormones
• Four types
• 1) Triglycerides (fats)
• 2) Phospholipids
• 3) Steroids
• 4) Waxes

71
Fatty Acids

• The building block (monomer) of lipids
• Chain of carbon atoms
• Carboxyl group (-COOH) at alpha (a-) end
• Methyl group (-CH3) at omega (?-) end

a
?
72
How are fatty acids characterized?

• Based on
• Length of carbon chain
• Saturation
• Degree of Saturation
• Location of double bonds
• Hydrogenation
• Orientation of hydrogen around double bond

73
Length of Carbon Chain

• Length of carbon chain
• - Short-chain fatty acids (lt8 carbons)
• - Medium chain fatty acids (8-12 carbons)
• - Long chain fatty acids (gt12 carbons)

74
Saturation

• Saturated fatty acids
• have only single bonds between C atoms
• - contain maximum of H atoms possible
• Unsaturated fatty acids
• have one or more C-C double bonds
• - fewer than maximum of H atoms possible
• - formed by removing H atoms from molecule

75
Degree of Saturation

• Saturated fatty acid
• Single carbon-carbon atoms
• Solid at room temperature
• Examples?
• Monounsaturated fatty acid
• 1 double bond
• Thick liquid at room temperature
• Examples?
• Polyunsaturated fatty acid (must be obtained
  through diet)
• gt 2 double bonds
• Liquid at room temperature
• Examples?

76
Location of double bonds

• Omega number (where the 1st double bond is
  located relative to the methyl-end)
• Example Omega-3 and Omega-6 fatty acids

1 2 3 4 5 6
1 2 3
77
Hydrogenation

• Double bonds carry a slightly negative charge,
  and can accept positively charged hydrogen atoms
  to create a saturated fatty acid

Polyunsaturated fatty acid
H H H H
Hydrogenated (saturated) fatty acid
78
Orientation of Hydrogen around Double Bond

• Cis- double bond
• Hydrogen atoms are on the same side of
• the double bond
• Trans - double bond
• Hydrogen atoms are on opposite sides of double
  bond

79
Fatty acid deficiencies

• Irritated flaky skin
• Gastrointestinal problems
• Compromised immune system
• Slow growth in children
• Reproductive failure
• Neurological and visual problems

80
1)Triglycerides

• Made up of 1 Glycerol and 3 Fatty Acids

ESTER BOND
81
Triglyceride

Saturated fatty acid
Mono-unsaturated fatty acid
Poly-unsaturated fatty acid
82
2)Phospholipids
Head is polar (hydrophilic) glycerol,
phosphate, choline Tail is non-polar
(hydrophobic) fatty acids

• In FOOD
• Stabilizers in food
• Mayo and ice cream
• Phosphatidylcholine lecithin
• Soy products

1 Glycerol 2 fatty acids polar phosphate
group choline group
83
In water

• Phospholipids form micelles

• Roles
• Plasma membrane
• Emulsifiers

84
3)Sterols/Steroids

• Four fused carbon rings with many different
  functional groups

85

• Steroids can be synthesized in the body
• Steroids can be obtained through diet
• from plants and animals
• only animals have cholesterol
• (meat, eggs, fish, dairy products)
• NOT all sterols are cholesterol!

86

• Important Roles of Steroids
• Bile acids
• Precursor for the production of hormones
• Cholesterol found in cellular membranes
  (provides support and fluidity)
• In medicine used to reduce inflammation, skin
  ointments, found in inhalers to treat asthma
• Anabolic Steroids (synthetic) build muscle mass
  in people who have cancer or AIDS (misused by
  athletes!)

87
Important for us because we build our steroid
hormones out of cholesterol
88
4)Waxes

• Lipids that contain long-chain fatty-acids linked
  to alcohols or carbon rings solid at room
  temperature
• Produced in plants and animals
• Roles
• Cutin produced by plants to form a
  water-resistant coating of the surfaces of stems,
  leaves and fruit helps the plant conserve water
• Birds produce waxy material (to keep their
  feathers dry)
• Bees make beeswax to make honeycombs
• Humans earwax (protects the ear canal)

89
Negative Health Effects of Lipids

• Heart disease
• Cholesterol plaque deposits in the arteries of
  the heart (narrowed arteries)
• Cancer
• Breast cancer and Prostate cancer
• Association not as strong as between fat intake
  and heart disease
• Dietary fat may promote cancer once it has arisen
  (does not initiate it)
• Obesity
• - High fat food vs. high energy food (kcal from
  carbs)

90
(No Transcript)
91
Positive Health Effects of Lipids

• Omega-3 Fats
• - Prevent blood clots
• - Protect against irregular heartbeats
• - Lowers blood pressure (especially for people
  with hypertension and atherosclerosis)

92
REVIEW CARBS and LIPIDS

• https//www.youtube.com/watch?vH8WJ2KENlK0
• Seatwork/Homework Lipids Worksheet

93
Proteins
https//www.youtube.com/watch?vH8WJ2KENlK0
94
Learning Goals

• Understand the function of proteins
• Identify and describe the structural units of
  proteins (amino acids)
• Describe and draw condensation and hydrolysis
  reactions
• Describe the four levels of protein structure
• Apply understanding of protein structure to
  explain the process of denaturation

95
Proteins

• What is the function of proteins?
• Speed up chemical reactions (catalysts),
  transport specific substances, provide structure,
  carry cellular messages, fight infectionand many
  more!

96
Proteins

• Amino acids the building blocks (monomers) of
  proteins
• The body uses 20 different types of amino acids
  to make proteins
• Consist of
• Central carbon bonded to hydrogen
• Amino group
• Carboxylic group
• R-group

The R group determines the FUNCTION of the
protein
97
Types of Amino Acids

• Polar prefer an aqueous (water) environment
  usually exposed on the surface of the protein
• Non-polar do not prefer aqueous environment
  usually make up the core of the protein
• Electrically Charged positively or negatively
  charged hydrophilic

98
(No Transcript)
99
Amino Acids

• Classification of Amino Acids in Nutrition
• 8 Essential a.a.
• - the body can NOT synthesize these
• - must be obtained through diet
• 12 Non-essential a.a.
• - The body can synthesize these from
• other sources
• TOTAL 20 a.a.

100
(No Transcript)
101
Proteins The peptide bond

• Proteins are formed when amino acid (monomers)
  are linked together by peptide bonds
• Proteins are broken down into amino acids by the
  addition of water to break peptide bonds

102
Proteins

• Dipeptide 2 amino acids linked by a peptide
  bond
• Tripeptide 3 amino acids linked by 2 peptide
  bonds

103
Levels of Protein Structure

• Primary
• Secondary
• Tertiary
• Quaternary

104
Primary (1)Structure - Polypeptide

• sequence of amino acids (aa) polypeptide chain
• Critical to final protein structure and function
• Determines the chemical and physical
  characteristics of the protein

• Sickle cell anemia single error in aa sequence
  ? affects folding ? rigid, sticky, sickle-shaped
  red blood cells

105
Secondary (2) Structure coils and folds

• As amino acids are added to the polypeptide
  chain, it starts to fold along its length and
  hydrogen bonds form between elements of the amino
  acid backbone
• Common patterns
• a- helix
• ß-folded sheets

106

• a-helix
• Ex. Fibrous proteins such as a-keratin in hair
• ß-sheet two parts of polypeptide lie parallel
  to one another
• Ex. Proteins in silk used
• by spiders to make webs

107
Tertiary (3) Structure

• Strong forces of attraction and repulsion between
  the polypeptide its environment force further
  folding into a tertiary structure
• Interactions involve the R-groups
• Hydrogen bonds polar side chains
• Ionic bonds charged side chains
• van der Waals forces non-polar R groups
• Proline natural kink (in a-helix or ß-sheet)
• Disulfide bridge covalent bond between sulfur
  containing R groups

108
Strong stabilizer
109
Quaternary (4) Structure the final shape

• Two or more folded polypeptide subunits come
  together to make a functional protein
• Physical and chemical environmental factors play
  a role (aq, pH, temp)
• Example Hemoglobin

110
Protein Folding

• http//www.youtube.com/watch?vPjt1Q2ZZVjA

111
Changes in 3D shape of protein

• Caused by changes in
• Temperature
• pH
• Ionic concentration

Protein Denaturation

• Useful Gastrin digestive enzyme works in stomach
  (low pH) and inactive in small intestine (high
  pH)
• Dangerous Prolonged fever above 39C can denature
  critical enzymes in brain ? death

112
(No Transcript)
113
The body burns

• Carbohydrates

Fat
Protein
Not exclusive. All burned at the same time but
in different amounts, in that order.
114

• Seatwork/Homework
• Macromolecule Chart
• (complete carbs, lipids, proteins)
• Quiz on TUES Carbs, Lipids, Proteins