UNIT 0: Controlled Experiments
Independent variable: Factor that scientist is manipulating/investigating, is added/applied to
experimental set up
Dependent variable: Data collected throughout experiment, responds to IV
Null hypothesis: Predicted outcome will not differ from the observed outcome, any difference is due to
chance
Alternative hypothesis: Predicted outcome will differ observed outcome and difference is due to the
independent variable
Control groups do NOT receive the independent variable, experimental groups do.
Constants are components in the experimental setup that remain identical in every group.
→ Ensure results are due to IV alone
Positive control groups: Show an effect of the known standards
→ Establish baseline
Negative control groups: Nothing is applied
Mean: Avg. of data set
Standard deviation: How much values in a data set differ from the mean
→ Lower SD means data set is close to mean
Standard error of the mean: Reflects precision of mean value
● Standard error + error bars display overall confidence
● 95% confidence uses +/- 2SEM
● Means = end of bar, Error bars = thin line
○ Error bars overlap = difference in means is NOT
significant
○ Error bars do NOT overlap = difference in means IS
significant
Bar graphs are used for categorical data and comparative stats.
Scatterplots or line graphs are used to display association or for data
collected over a continual independent variable (ex. time)
Chi-Square value is used to evaluate the null hypothesis.
If the chi-square is higher than the critical value, the difference between
observed and expected values is great enough to reject the null hypothesis.
If the chi-square is higher than the critical value, the
difference between observed and expected values is
great enough to reject the null hypothesis
,UNIT 1: CHEMISTRY OF LIFE
Carbon, hydrogen, oxygen, and nitrogen are the most abundant.
● Isotope: element w/different # of neutrons than most abundant type of element
○ ex. O-18 (tracers for photosynthesis), C-14 (dating), I-131 (thyroid tissue label), P-32
(label nucleic acid, only macromolecule containing P), S-35 (label protein)
Bonding:
1. Ionic bonds: 1 atoms —electron→ other atom
a. Water is usually the solvent
2. Covalent bonds: 1 or more pairs of valence electrons shared btwn 2 atoms
a. Nonpolar: 2 atoms have equal electronegativity + electrons equally shared
i. Even dist. of charge
b. Polar: 2 atoms have unequal electronegativity, more electronegative atom holds electrons
more closely
i. Unequal dist. of charge
3. Hydrogen bonds: Intermolecular force (btwn 2 or more
molecules) in which polar molecules bond with each other
a. Dipole-dipole attraction
b. Attractive force between hydrogen atom covalently
bonded to N, O, or F and another electronegative atom
Properties of Water (due to H-bonds):
1. Cohesion: ability to stick to other molecules of water
a. Surface tension: amount of force needed to break liquid's surface
i. Water has high ST, lets certain animals walk on it
b. Adhesion: stick to other polar molecules
i. Sticks to phloem to travel up xylem in plants
c. Transpirational pull: water's evaporation out of the stomata of leaves creates a
tension/pulling force through length of xylem - adhesion and cohesion creates continuous
column of water pulled upwards
2. High specific heat: requires more energy to raise temperature by 1 deg. Celcius
a. Moderation of temperature: Areas of land that border water warmed as water cools,
leading to more moderate temperatures
b. Evaporative cooling: Evaporation of water from a surface leaves surface at cooler
temperature, water molecules w/highest kinetic energy are those that evaporate, leaving
behind cooler molecules
i. Sweating
3. Ice floats
a. At lower temperatures, H-bonds expand, lowering density of ice compared to liquid
water
b. Floating ice insulates liquid water, allowing life to persist in low temps
4. Almost all biological reactions occur in water
Hydrophobic: water-fearing, includes nonpolar molecules
Hydrophilic: water-loving, includes polar molecules
, Acidity is measured by pH: concentration of hydrogen ions
● pH dec, H+ ion concentration inc
Buffers: maintain pH by acting as an acid in certain conditions, as base in others
BAAD - Bases accept H+, acids donate H+
Carbon's Molecular Diversity:
● Organic compounds possess carbon (and H)
● Carbon is versatile
○ 4 valence electrons, can make 4 covalent bonds to
force tetrahedral shape
○ Can make single, double, triple bonds
○ Can make large molecules in chains, rings,
branches
● Isomers: same formula, different structure
Structural Isomers: different arrangement of atoms
Geometric/cis-trans isomers: Different arrangement around
carbon-carbon double bond
Cis: same side
Trans: opp. sides
Enantiomers: Mirror images
Chemical Hydroxyl Carbonyl Carboxyl Amino Sulfhydryl Phosphate Methyl
Group
Structure –OH =CO –COOH –OPO3 2-
–NH2 –SH
Name of Alcohols Ketones Carboxylic Amines Thiols Organic Methylated
Compoun within acids/organ phosphates compounds
d carbon ic acids
skeleton
Aldehydes if
at the end of
carbon
skeleton
,Example
Chemical ● Polar ● Present ● Acidic ● Basic (H+ ● Form ● Adds ● NP +
behavior ● Dissolves in (H+ acceptors) disulfide negative hydroph
in H2O ketose + donor) bridges → charge → obic
aldose forms free
sugars protein energy
structure increases
● Phosphor
ylation
Polymers: Large molecules made of monomers
→ Carbohydrates, proteins, nucleic acids
Monomer: subunit that composes larger molecules
Dehydration synthesis: Molecule of water removed to form covalent bond btwn 2 monomers or a
monomer and polymer
Hydrolysis: Add water to break covalent bond
,*Nitrogen is in nucleic acids and proteins, phosphorus is in nucleic acids and some lipids
*ATP = adenine, ribose, three phosphate groups, d=specify using deoxyribose
UNIT 2: CELL STRUCTURE/FUNCTION + WATER POTENTIAL
All cells have:
● Plasma membrane: lipid boundary for cell contents
○ Selectively permeable
■ Particle moves in if nonpolar and/or small
○ Phospholipids in bilayer
○ Contains transport proteins
■ Allows big and/or polar molecules to pass
● Amino acids
● Sometimes water
● Ions
○ Glycoproteins: Carb used for cellular identification
● Cytosol: Semifluid gel that fills cell + site of metabolic reactions
● Chromosomes: Lengths of DNA that contain genes (sections of DNA that codes for protein)
○ Prokaryotic - 1 looped chromosome
● Ribosomes
○ Responsible for protein synthesis based on mRNA sequence
○ Composed of rRNA and proteins
3 Domains of life:
● Archaea
● Bacteria
● Eukarya
○ Protists
○ Fungi
○ Plants
○ Animal
→ E+A=similar DNA
, → E+B=similar structure
→ Descended from LUCA
Surface Area/Volume
→ Greater SA/V ratio = more efficient
● Smaller cells = Great SA relative to volume
○ Smaller cells = more biochem. efficient
Ways to increase efficiency
1. Split up into many cells
a. Root hair cells on plant root tissue increase SA for
water absorption
2. Create ridges/folds
a. Mitochondria
Organelles
1. Rough ER = has ribosomes on surface, synthesizes proteins, compartmentalizes cell
2. Smooth ER = cellular detoxification + lipid/carb synthesis
3. Golgi complex = membranous, flattened sacs, modifies newly-made proteins + packages them
for redistribution
4. Mitochondrial = respiration function - creates ATP. Posses double membrane (outside = smooth,
inside = folded)
a. Folds = efficiency in cellular respiration: the process of making ATP w/glucose and O2
→ membranes put rxns into compartments
b. Cristae: highly convoluted membrane folds
c. Matrix: fluid within inner membrane
d. Intermembrane space: inner + outer membrane space
e. Prokaryotes "fake" mitochondria w/internal respiration membrane
5. Lysosome = membranous sacs containing hydrolytic enzymes for intracellular digestion. Facil.
cell death
a. Apoptosis: Programmed cell death
i. Get rid of old/damaged cells
ii. Triggered by intrinsic + extrinsic DNA damage that send death
signal
iii. Formation of blebs
6. Vacuoles = membrane-bound sacs used for storage of nutrients and
wastes
7. Chloroplasts = algae + plants, photosynthesis
a. Thylakoids: membranous sacs
b. Grana: stacks of thylakoids
i. Increase SA for photosystems
c. Stroma: liquid inside
Endosymbiont Theory: Theory that mito and chloro were prokaryotic organisms ingested by large
anaerobic bacteria → eukaryotes. Evidence –
● Have own DNA
Independent variable: Factor that scientist is manipulating/investigating, is added/applied to
experimental set up
Dependent variable: Data collected throughout experiment, responds to IV
Null hypothesis: Predicted outcome will not differ from the observed outcome, any difference is due to
chance
Alternative hypothesis: Predicted outcome will differ observed outcome and difference is due to the
independent variable
Control groups do NOT receive the independent variable, experimental groups do.
Constants are components in the experimental setup that remain identical in every group.
→ Ensure results are due to IV alone
Positive control groups: Show an effect of the known standards
→ Establish baseline
Negative control groups: Nothing is applied
Mean: Avg. of data set
Standard deviation: How much values in a data set differ from the mean
→ Lower SD means data set is close to mean
Standard error of the mean: Reflects precision of mean value
● Standard error + error bars display overall confidence
● 95% confidence uses +/- 2SEM
● Means = end of bar, Error bars = thin line
○ Error bars overlap = difference in means is NOT
significant
○ Error bars do NOT overlap = difference in means IS
significant
Bar graphs are used for categorical data and comparative stats.
Scatterplots or line graphs are used to display association or for data
collected over a continual independent variable (ex. time)
Chi-Square value is used to evaluate the null hypothesis.
If the chi-square is higher than the critical value, the difference between
observed and expected values is great enough to reject the null hypothesis.
If the chi-square is higher than the critical value, the
difference between observed and expected values is
great enough to reject the null hypothesis
,UNIT 1: CHEMISTRY OF LIFE
Carbon, hydrogen, oxygen, and nitrogen are the most abundant.
● Isotope: element w/different # of neutrons than most abundant type of element
○ ex. O-18 (tracers for photosynthesis), C-14 (dating), I-131 (thyroid tissue label), P-32
(label nucleic acid, only macromolecule containing P), S-35 (label protein)
Bonding:
1. Ionic bonds: 1 atoms —electron→ other atom
a. Water is usually the solvent
2. Covalent bonds: 1 or more pairs of valence electrons shared btwn 2 atoms
a. Nonpolar: 2 atoms have equal electronegativity + electrons equally shared
i. Even dist. of charge
b. Polar: 2 atoms have unequal electronegativity, more electronegative atom holds electrons
more closely
i. Unequal dist. of charge
3. Hydrogen bonds: Intermolecular force (btwn 2 or more
molecules) in which polar molecules bond with each other
a. Dipole-dipole attraction
b. Attractive force between hydrogen atom covalently
bonded to N, O, or F and another electronegative atom
Properties of Water (due to H-bonds):
1. Cohesion: ability to stick to other molecules of water
a. Surface tension: amount of force needed to break liquid's surface
i. Water has high ST, lets certain animals walk on it
b. Adhesion: stick to other polar molecules
i. Sticks to phloem to travel up xylem in plants
c. Transpirational pull: water's evaporation out of the stomata of leaves creates a
tension/pulling force through length of xylem - adhesion and cohesion creates continuous
column of water pulled upwards
2. High specific heat: requires more energy to raise temperature by 1 deg. Celcius
a. Moderation of temperature: Areas of land that border water warmed as water cools,
leading to more moderate temperatures
b. Evaporative cooling: Evaporation of water from a surface leaves surface at cooler
temperature, water molecules w/highest kinetic energy are those that evaporate, leaving
behind cooler molecules
i. Sweating
3. Ice floats
a. At lower temperatures, H-bonds expand, lowering density of ice compared to liquid
water
b. Floating ice insulates liquid water, allowing life to persist in low temps
4. Almost all biological reactions occur in water
Hydrophobic: water-fearing, includes nonpolar molecules
Hydrophilic: water-loving, includes polar molecules
, Acidity is measured by pH: concentration of hydrogen ions
● pH dec, H+ ion concentration inc
Buffers: maintain pH by acting as an acid in certain conditions, as base in others
BAAD - Bases accept H+, acids donate H+
Carbon's Molecular Diversity:
● Organic compounds possess carbon (and H)
● Carbon is versatile
○ 4 valence electrons, can make 4 covalent bonds to
force tetrahedral shape
○ Can make single, double, triple bonds
○ Can make large molecules in chains, rings,
branches
● Isomers: same formula, different structure
Structural Isomers: different arrangement of atoms
Geometric/cis-trans isomers: Different arrangement around
carbon-carbon double bond
Cis: same side
Trans: opp. sides
Enantiomers: Mirror images
Chemical Hydroxyl Carbonyl Carboxyl Amino Sulfhydryl Phosphate Methyl
Group
Structure –OH =CO –COOH –OPO3 2-
–NH2 –SH
Name of Alcohols Ketones Carboxylic Amines Thiols Organic Methylated
Compoun within acids/organ phosphates compounds
d carbon ic acids
skeleton
Aldehydes if
at the end of
carbon
skeleton
,Example
Chemical ● Polar ● Present ● Acidic ● Basic (H+ ● Form ● Adds ● NP +
behavior ● Dissolves in (H+ acceptors) disulfide negative hydroph
in H2O ketose + donor) bridges → charge → obic
aldose forms free
sugars protein energy
structure increases
● Phosphor
ylation
Polymers: Large molecules made of monomers
→ Carbohydrates, proteins, nucleic acids
Monomer: subunit that composes larger molecules
Dehydration synthesis: Molecule of water removed to form covalent bond btwn 2 monomers or a
monomer and polymer
Hydrolysis: Add water to break covalent bond
,*Nitrogen is in nucleic acids and proteins, phosphorus is in nucleic acids and some lipids
*ATP = adenine, ribose, three phosphate groups, d=specify using deoxyribose
UNIT 2: CELL STRUCTURE/FUNCTION + WATER POTENTIAL
All cells have:
● Plasma membrane: lipid boundary for cell contents
○ Selectively permeable
■ Particle moves in if nonpolar and/or small
○ Phospholipids in bilayer
○ Contains transport proteins
■ Allows big and/or polar molecules to pass
● Amino acids
● Sometimes water
● Ions
○ Glycoproteins: Carb used for cellular identification
● Cytosol: Semifluid gel that fills cell + site of metabolic reactions
● Chromosomes: Lengths of DNA that contain genes (sections of DNA that codes for protein)
○ Prokaryotic - 1 looped chromosome
● Ribosomes
○ Responsible for protein synthesis based on mRNA sequence
○ Composed of rRNA and proteins
3 Domains of life:
● Archaea
● Bacteria
● Eukarya
○ Protists
○ Fungi
○ Plants
○ Animal
→ E+A=similar DNA
, → E+B=similar structure
→ Descended from LUCA
Surface Area/Volume
→ Greater SA/V ratio = more efficient
● Smaller cells = Great SA relative to volume
○ Smaller cells = more biochem. efficient
Ways to increase efficiency
1. Split up into many cells
a. Root hair cells on plant root tissue increase SA for
water absorption
2. Create ridges/folds
a. Mitochondria
Organelles
1. Rough ER = has ribosomes on surface, synthesizes proteins, compartmentalizes cell
2. Smooth ER = cellular detoxification + lipid/carb synthesis
3. Golgi complex = membranous, flattened sacs, modifies newly-made proteins + packages them
for redistribution
4. Mitochondrial = respiration function - creates ATP. Posses double membrane (outside = smooth,
inside = folded)
a. Folds = efficiency in cellular respiration: the process of making ATP w/glucose and O2
→ membranes put rxns into compartments
b. Cristae: highly convoluted membrane folds
c. Matrix: fluid within inner membrane
d. Intermembrane space: inner + outer membrane space
e. Prokaryotes "fake" mitochondria w/internal respiration membrane
5. Lysosome = membranous sacs containing hydrolytic enzymes for intracellular digestion. Facil.
cell death
a. Apoptosis: Programmed cell death
i. Get rid of old/damaged cells
ii. Triggered by intrinsic + extrinsic DNA damage that send death
signal
iii. Formation of blebs
6. Vacuoles = membrane-bound sacs used for storage of nutrients and
wastes
7. Chloroplasts = algae + plants, photosynthesis
a. Thylakoids: membranous sacs
b. Grana: stacks of thylakoids
i. Increase SA for photosystems
c. Stroma: liquid inside
Endosymbiont Theory: Theory that mito and chloro were prokaryotic organisms ingested by large
anaerobic bacteria → eukaryotes. Evidence –
● Have own DNA
