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What are the 6 steps of the scientific method?
- 1. observations
- 2. questions
- 3. hypothesis (statement of potential outcome)
- 4. data
- 5. conclusion
- 6. theory
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Broadest scientific generalization, based on many experiments over a broad range of conditions
Law, ex: law of gravity
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organization
growth
metabolism
adaptation
response to stimuli
reproduction
Living (vs. non-living)
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cells --> tissues --> organs --> organ systems --> organisms
Hierarchy
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All biochemical processes occurring within a cell
Metabolism
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Anabolism
synthesis (uses energy)
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Catabolism
"breakdown" of organic compounds to yield energy
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Growth- increase in mass OR increase in numbers requires:
energy
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changes in response to environment, requires two things:
1. ability to change, result of mutations
2. ability to detect changes in environment
Adaptation
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Ability to produce offspring
Reproduction
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Reproduction (explained)
- 1. offspring carry genetic material of parent
- 2. genetic material changes over time, leads to difference within individuals in population
- 3. cells contain heritable info:
- -deoxyribonucleic acid (DNA): ATGC- this sequence determines info carried, codes for proteins (and RNA)
- -inheritance is based on mechanism for copying DNA, and passing DNA from parent to offspring
- -**all forms of life use similar genetic code**
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ability of organism to interact with its environment, ex: heat, cold, pain, pressure, radiation, taste (includes other organisms and nonliving factors)
Response to stimuli
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cooling/heating of body
feedback mechanisms
chemical mediators
Regulation/homeostasis
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structure
gives clues about what something does
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function
gives clues about how something is constructed
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self replicating protein, ex: mad cow
prions
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self replicating RNA, no protection, very unusual, causes diseases in plants
viroids
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made up of proteins and nucleic acid, no cells, have some properties of life but not others
viruses
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property that emerges as a result of interactions between components
emergent properties
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.22 microns/micrometers
Light microscope
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person who 'named' cells in 1665
Robert Hooke
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Matthias Schleidan and Theodore Schwann
came up with cell theory: all living things are made of cells, and later on: all cells come from preexisting cells
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ability to observe more detail in cells using ______, became popular in 1954, greater resolution
Electron Microscope
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No membrane enclosed nucleus
No organelles
Smaller ribosomes
Cell wall made of unique molecules
Bacteria and Archaebacteria
70 S Ribosomes
Prokaryotic cells
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More complexity and organization
Membrane enclosed nucleus
Chromosomes
Larger ribosomes
Organelles
Protists, fungi, plants, animals
Eukaryotic cells
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new species arise from more ancient ones through "descent with modification"
Evolution
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mechanism of evolutionary change, acts on populations not individuals, accounts for unity and diversity, survival of the fittest
natural selection
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substance that cannot be changed into another substance by normal chemical reactions
elements
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1. proton: atomic mass of 1, positive charge
2. neutron: atomic mass of 1, no charge
3. electron: no atomic mass, negative charge
Atom
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Atomic number
Number of protons
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different number of neutrons
Isotopes (excessive number of neutrons make unstable isotopes and are said to be radioactive)
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_________ occupy orbitals around atoms
electrons
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each orbital corresponds to an _________ _________
energy level
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outer electrons are known as _________ electrons and contain most energy (outermost shell)
valence
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valence electrons are involved in _________ bonding
chemical
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-2 or more atoms form a molecule
-chemical formulas are used to describe atoms
Chemical reactions
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shared electrons, atoms with partially filled electron shells, shared electrons fill cells, polar or non-polar
Covalent bonds
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atoms lose or gain electrons and become charged, involve atoms with almost filled or almost empty electron shells, ionize (dissolve) in water
Ionic bonds, ex: NaCl (salt)
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hydrogen bonds, involved partially charged hydrogen atoms, individual bonds weak but collectively strong, very important in molecular structure and biological molecules and water
Chemical bonds
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Anything that is polar is ________
ex: H2O --> O (-)
/ \
H H (+)
oxygen is so much larger so it pulls hydrogen towards it
charged
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chemical reactions resulting in transfer of electrons from one atom to another
Redox Reactions
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looser of electrons
oxidation
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gainer of electrons
reduced
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essential to life, polar molecules, good solvent, cohesion and adhesion, helps maintain stable temperature: high specific heat, high heat of vaporization
Water
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water molecules being bound to each other
cohesion
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water molecules being bound to another molecule (other molecules)
adhesion
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prevent other molecules from stealing your electrons
antioxidants
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water slightly dissociates into OH- and H+, pure water has an H+ concentration of 1x10-7 moles per liter (0.0000001 moles)
Acids/Bases
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pH is a measure of _______, and of most living cells is about 7.0
acidity or basic
acidity
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the more H+ in the water, the ________ level of acidity in the water
higher or lower
higher
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solute + solvent = _________
solution
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used to "stabilize" pH, weak acids/bases
buffers
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acids and bases react to form _______
salts
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If water has a change from a pH of 3 to a pH of 5, how many log units is that? And is H+ going up or down in concentration?
100x less acid, and going down in H+ concentration
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Increase of acid = increase of __ concentration
H+
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4 valence electrons, can potentially form 4 bonds, bonds to CHNOPS
Carbon
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CHNOPS: 6 elements necessary for life
Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, Sulfur
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changing shape of molecule
conformation
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