Unit 1 - Weebly
Transcript of Unit 1 - Weebly
Biochemistry and Digestion
Unit 1
Topic 1The Nature of Matter
● 80% Water!● 20% Organic compounds
● Carbon● Hydrogen● Oxygen● Nitrogen● Phosphorus● Sulfur
● Trace Elements● Iron, iodine, fluoride, etc
What are your cells made of?
SPONCH
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Figure 2.2A
Goiter in a Burmese woman
Bohr Model and Structural Formulas
Chlorine – Bohr model
Alanine - structural formula
Glucose – structural formula
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Chemical Formula:C6H12O6
Key things for Exercise B and C● Bond types:
● Ionic● Polar Covalent● Nonpolar Covalent● Hydrogen (more like an attraction)
● O2 = Oxygen molecule CO2 ≠ Oxygen molecule
● Graphs:● Remember exothermic, endothermic??● The lines represent the starting and ending materials…
Topic 2Bonding and Properties of Water
● Ionic Bonds(don’t need to know for bio…)
● Covalent Bonds
● Electronegativity
Bonding
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Properties of Water● Why is water polar?
● Uneven distribution of electrons● Due to large differences in electronegativity between
the atoms● Greater chance of finding
electrons at one end of the molecule
● ENOxygen = 3.5● ENHydrogen = 2.1● Difference = 1.4
(strong polar covalent)
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Why do hydrogen bonds form?● Molecule acts like a magnet with positive and
negative poles● Allows them to form hydrogen bonds with each other,
giving special properties● Involved in as many as 4 H-bonds
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● Chart on the Board!
Properties of Water
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Objective 8: Explain the following properties of water (including how these are biologically relevant): high surface tension, high specific heat, solid water is less dense than liquid water, water as the “universal solvent,” and capillary action. Along the way, be sure to address cohesion and adhesion (2.11-2.14).
Objective 9: Define and relate the terms solution, solvent, and solute (2.14).
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● Atomic properties
● Intramolecular property
● Intermolecular properties● H-bonds – attraction between polar molecules● Cohesion – attraction of water to other water● Adhesion – attraction of water to other substances
Properties of water
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Cohesion● Attraction between molecules of the same substance● Cause molecules on surface to be drawn inward,
forming a bead
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Surface tension● Film on top of water● Water molecules “hold hands”● Allows insects and spiders to
walk on surface● Spread their weight over a large area
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Basilisk lizard!● Surface tension and rapid movement
● See video (also seen on The Animal Planet’s “Most Extreme: Speed”)
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Capillary Action● Causes water to rise in a narrow tube against force of
gravity● Adhesion on the sides of the tube; cohesion pulls
other molecules up● Try it out!
Water conducting cells
100 µmFigure 3.3
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Animation: Water TransportRight click on animation / Click play
High Specific Heat/Heat of Vaporization● Specific heat – heat to
change the temperature● Heat of vaporization –
heat to evaporate● Water absorbs a lot of
heat to change temperature or state
● Keeps coastal climates moderate
● Helps keep your body cool
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● Solution - mixture with one substance dissolving into the other
● Solute – substance being dissolved● Solvent – substance that does the dissolving● Ex. – sugar (solute) in water (solvent)
● Different regions of water interact with ionic compounds called solutes to dissolve them
● See NaCl video
“Universal Solvent”
“Universal Solvent”Negative
oxygen regions
of polar water molecules are
attracted to sodium cations (Na+).+
+
+
+Cl –
–
–
–
–
Na+
Positive hydrogen regions
of water molecules cling to chloride anions (Cl–).
+
+
+
+
–
–
–
–
–
–Na+
Cl–
“Universal Solvent”● Solvent = dissolving
agent● Solute = dissolved
substance● Solution = mixture of the
two
Ice!● Ice is less dense than liquid water● It floats!
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Why does ice float?● Hydrogen bonds in ice allow it to float● http://www.visionlearning.com/library/module_viewe
r.php?mid=57&l=&c3=
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Why does ice float?
Liquid waterHydrogen bonds
constantly break and re-form
IceHydrogen bonds are stable
Hydrogen bond
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● Chart on the Board!
Properties of Water
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Objective 8: Explain the following properties of water (including how these are biologically relevant): high surface tension, high specific heat, solid water is less dense than liquid water, water as the “universal solvent,” and capillary action. Along the way, be sure to address cohesion and adhesion (2.11-2.14).
Objective 9: Define and relate the terms solution, solvent, and solute (2.14).
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Topic 3Basic Chemistry
Acids and Bases – Activity D● Acids – contribute H+● Bases – contribue OH-● pH scale● Human blood = ??
● Biological fluids contain buffers to maintain this pH
7.4
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Figure 2.14_3
Acidicsolution
Neutralsolution
Basicsolution
Topic 4Organic Molecules
● Carbon-based● Functional groups
What is an organic molecule?
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● Macromolecule
● Polymer
● Monomer
● Dehydration synthesis
● Hydrolysis
Some basic definitions
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Four types of organic compounds● Carbohydrates (starch and sugar)
● Lipids (fats)
● Proteins
● Nucleic acids (DNA and RNA)
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What are carbohydrates?● Sugars and starches● Contain C, H, O● Always have 2 hydrogen
atoms for every 1 oxygen atom (2:1 ratio)
● Hydrophilic● Used for energy (short
and long term storage)● Monosaccharides,
disaccharides, and polysaccharides
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Types of carbohydrates● Monosaccharides –
glucose, fructose
● Disaccharides – sucrose, lactose, maltose
● Polysaccharides – starch, cellulose, glycogen
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Figure 3.7
Making polymers from monomers?
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Dehydration synthesis!
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Break down polymers into monomers?
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Degradation hydrolysis!
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© 2012 Pearson Education, Inc.
Animation: PolymersRight click on animation / Click play
● Glycogen and starch● Insulin lowers blood
glucose● Glucagon raises
blood glucose
● Homeostasis!!
How are carbohydrates stored?
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What are lipids?● Fats, oils, and waxes● Mainly hydrogen and
carbon atoms (some O)● Used for energy storage,
cushioning vital organs, insulating the body, and transmitting messages
● Hydrophobic ● Not true polymers…
(don’t have a monomer)
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Fatty Acid chains● Fatty Acids
● Unsaturated (one or more double bonds in hydrocarbon chain)
● Saturated (all single bonds in hydrocarbon chain)
Types of Lipids - Triglycerides● Energy storage● Made of:
● 1 Glycerol (glycerin)● 3 Fatty Acid chains
● Can be:● Unsaturated (one or
more double bonds in hydrocarbon chain)
● Saturated (all single bonds in hydrocarbon chain)
H
H
H
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© 2012 Pearson Education, Inc.
Animation: FatsRight click on animation / Click play
Lipids and Atherosclerosis
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Atherosclerosis
Types of Lipids - Steroids● All have rings of carbons● Examples:
● Cholesterol● Sex hormones
● How will you tell these apart from carbs?
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Types of Lipids - Phospholipids● Like a triglyceride:
● Glycerol ● Phosphate group● 2 Fatty acid chains
● Major components of cell membranes (barriers)
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What are proteins?● Contain C, H, O, N
(sometimes S)● Made of amino acids
(100s or 1000s of them)● Typically globular or
fibrous● Require a specific 3D
shape to function● Nearly all proteins
recognize and bind to another molecule
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Amino acids
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Figure 3.11B
Hydrophobic Hydrophilic
Aspartic acid (Asp)Serine (Ser)Leucine (Leu)
20 different amino acids
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● 2 amino acids = dipeptide● 3 - 50ish amino acids = polypeptide● 50ish – 100,000ish amino acids = protein
● The bond joining them is a peptide bond
Joining amino acids to make a dipeptide
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Joining amino acids to make a dipeptide
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● Hemoglobin● Cell structural proteins (cell surface, muscle fiber)● Body structural proteins (hair, fingernails, collagen) ● Contractile proteins (in muscle fibers)● Defensive proteins (antibodies)● Enzymes● Hormones (insulin, glucagon)● Growth factors (heals cuts, controls development)● Cell membrane component (transporters, receptors)● How can there be so many different proteins??
Types of proteins
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Protein folding
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© 2012 Pearson Education, Inc.
Animation: Protein Structure IntroductionRight click on animation / Click play
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Animation: Primary Protein StructureRight click on animation / Click play
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Animation: Secondary Protein StructureRight click on animation / Click play
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Animation: Tertiary Protein StructureRight click on animation / Click play
© 2012 Pearson Education, Inc.
Animation: Quaternary Protein StructureRight click on animation / Click play
Nucleic Acids● DNA and RNA● Monomer - nucleotide
● Five-carbon sugar (deoxyribose or ribose)● Phosphate group● Nitrogenous base
● Adenine● Guanine● Cytosine● Thymine (DNA only) ● Uracil (RNA only)
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Topic 5Chemical reactions and enzymes
● Anabolism – building up● Catabolism – breaking down (CATastrophic…)
● Exergonic● Releases energy● Energy-rich reactants → Energy-poor products
● Endergonic● Absorbs/requires energy● Energy-poor reactants → Energy-rich products
Metabolism
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Enzyme shape
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Induced fit model of enzyme function
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Animation: How Enzymes WorkRight click on animation / Click play
Endergonic vs. Exergonic reactions
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Reading an energy graph
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Topic 7The Methods of Science
1. Observe and state a problem2. Form a hypothesis
• Testable• Falsifiable• If (the independent variable affect the dependent variable),
then (this is my specific prediction).3. Test the hypothesis4. Record and analyze data
● Qualitative vs. Quantitative● Observation vs. Inference● “The grass on the front lawn is wet”● “Reaction B produced twice as many bubbles as Reaction
A”
Scientific Method
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1. Observe and state a problem2. Form a hypothesis
• Testable• Falsifiable• If (the independent variable affect the dependent
variable), then (this is my specific prediction).3. Test the hypothesis4. Record and analyze data5. Form a conclusion6. Repeat the experiment (or publish so others can)
Scientific Method
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Experiment Vocab● Experiment: test of hypothesis to see if two
variables have a cause and effect relationship● Independent variable: the changes an
experimenter purposefully makes (the believed “cause” in the experiment)
● Dependent variable: the response to the experimenter’s purposeful change (the “effect” in the experiment)
Experiment Vocab● Controlled variable: variable that is kept from
changing during the experiment (usually based off of possible confounding factors)
● Confounding factors: a hidden variable whose presence affects the variables being studied so the results you get do not reflect the actual relationship between the IV and DV
Experiment Vocab● Experimental Group:
● A setup that is testing the effects of your IV on your DV
● You may have a hypothesis, but the results are unknown
● Positive Control Group: ● A setup where you know there will be an effect● Used to prove the test’s ability to show the desired
effect
Experiment Vocab● Negative Control Group:
● A setup where you know there will be no effect● Makes sure no confounding variables are acting on
your experiment● If you get a positive result, there is some other
variable that you need to take into account for ALL treatments (or redesign the experiment)
Experiment Vocab● Treatment: the different measures of the
independent variable● Trial: Each test of a treatment● Sample Size: number of trials you do for each
treatment
Food Testing Lab: VariablesSuccessfully Controlled● Amount of food● Temperature of
environment● Plastic trays for every
group● Concentration of the
indicator
Needs to be controlled● Cleanliness of tray● How well we mixed the
sample with indicator● Amount of each sample
(take a mass of each)● How long we wait to read
results● How much (and if) we stir
samples
● Independent Variable – changed by scientist● Dependent Variable – observed/measured by scientist● Controlled Variables● Experimental Group● Control Group – used as a baseline to compare to
experimental group● Positive Control Group● Negative Control Group
● Confounding Variables – outside factors that may correlate with both independent and dependent variables (affects results)
Controlled Experiments
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1.9 Scientists form and test hypotheses and share their results
● Observations and generalizations:● poisonous animals are brightly colored and● imposters resemble poisonous species but are actually
harmless.● Prediction: Mimics benefit because predators confuse
them with the harmful species.● Hypothesis: If _______________ affects _____________,
then ___________________________________
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1.9 Scientists form and test hypotheses and share their results
● The scientists conducted a controlled experiment, comparing● an experimental group (artificial king snakes) and● a control group (artificial brown snakes).● The groups differed only by one factor, the coloration of
the artificial snakes.● The data fit the key prediction of the mimicry
hypothesis.
© 2012 Pearson Education, Inc.
Figure 1.9B
Figure 1.9C
Figure 1.9D
Figure 1.9E
Coral snakespresent
Artificialking snakes
Artificialbrown snakes
84%
0
20
40
60
80
100
Coral snakesabsent
17%
16%
Perc
ent o
f tot
al a
ttack
son
art
ifici
al s
nake
s
83%
Enzymes
What affects an enzyme's effectiveness?
pH Temp
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Protein denaturation
What about enzyme concentration?
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Substrate Concentration?
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Substrate surface area?
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● Are usually proteins● Speed up reactions● Work by lowering activation energy● Are not used up during the reaction● Are specific to one reaction● Have a precisely shaped active site
Enzymes…
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The End(Topics 1-6)
● Radioisotopes can be used for…● Research
● Diagnosis
Isotopes and RadioisotopesOBJ 11
● Have you seen any commercials making certain claims that you’d be interested in testing??
● Let’s design a controlled experiment to test them…
Designing a controlled experiment
Reduces bad breath!
Make your hair shinier!Twice as much pain relief!
Better for your car!
Be a smart consumer!