Cellular organization
all livings things are made from one or more cells
Ordered complexity
living systems are made more than the sum of their parts (all living things are complex and made up of many different things with different molecular structures)
Sensitivity and Responsivness
organisms respond to stimuli from their environment
Growth, development, and reproduction
all living things increase in size (or mass) and pass on characteristics (via DNA)
Homeostasis
all living things have mechanisms to maintain a steady, stable internal state
Evolutionary adaptation
Organisms change over time to become better suited to changing environments
Negative feedback
reduces the gap between the set point (homeostasis) and the environmental conditions
Development
the process an organisms undergoes to move from a simpler form to a more complex form (immature to mature state)
Growth
the process an organism undergoes to get bigger and to increase their number of cells over time (by dividing)
Deductive reasoning
hypothesis that starts with general observations to predict something specific
Inductive reasoning
hypothesis that starts with specific observations (or experimental findings) to make a general conclusion
Statistical Purpose
helps scientists understand their results and if there is a correlation between things/groups
Standard Deviation
the amount of variability in the data
Mode
the most frequently occurring data in a data set
p-value > 0.05
high probability that the samples are from the same population (accept null hypothesis and is likely not statistically significant)
P-value < 0.05
low probability that the samples are from the same population (rejects the null hypothesis and data is statistically significant) (likely that samples are from different populations)q
Nominal scales of neasurement
word or numbers that are used to classify, label, or categorize observations (Ex: color : blue, green, yellow…)
Ordinal scales of measurement
classifying the order of something (putting results in order/ ranking)
Interval/ratio scale of measurement
quantities (measurements) or differences (interval between measurements can be calculated) (Ex: ages of dogs: 1-3yrs, 4-5 yrs…)
Orbital
The region surrounding the nucleus of an atom where the probability is high of finding a particular electron (balloon of space where an electron is likely to be) can only contain 2 e- max
Energy
the capacity to do work or to cause a change
Isotopes
atoms that have the same amount of protons, but vary in the amount of neutrons
Radioisotopes
unstable isotopes (emit radiation as they decay)
Trace elements
elements in a living thing that are found in very small quantities (still important to the living things)
When are atoms most stable?
when their outer shells are fully or half filled with electrons
molecular formula
tells us the number of elements and what elements make up a molecule or compound
Covalent bonds
when atoms share a pair of electrons
Double bond
covalent bond where two pairs (4 total) of electrons are shared
Structural formula
when covalent bonds are shown with a line (usually lewis dot structures)
Electronegativity
an atom’s ability (measured) to attract electrons (to create a bond)
High electronegativity
attraction between elements is strong
low electronegativity
weak attraction to another atom’s electrons
Non-polar covalent bonds
when electronegativity differ by less than 0.4
Ionic bonds
when electronegativity differs by more than 1.8 (cation+anion)
polar covalent bonds
electrons shared unequally (when electronegativity differs by 0.4-1.8)
Cation
atom or molecule with a net positive charge
Anion
atom or molecule that has a net negative charge
van de waals dispersion forces
attractive forces between molecules in close proximity to each other (because of electron density)
Free radical
a molecule containing an atom with a singular, unpaired electron in the outer shell
Solutes
substances that are dissolved in a liquid
Solvents
the liquids that dissolve something
Hydrophilic
loves water (attracted to water) (tend to be polar molecules)
Hydrophobic
hates water (repelled by water) (tend to be non-polar molecules)
Amphipathic
molecules that both love an hate water (some regions polar, some regions non-polar)
Micelles
formed by amphipathic molecules (polar heads face towards water, non-polar tails face away from water) creates little bubble looking things
Solute concentration
the amount of a solute dissolved in a certain volume of a solution
Molarity (M)
how many moles of a substance are in 1L of a solution
Heat of vaporization
the heat required to vaporize 1 mol of any substance (boiling point)
heat of fusion
amount of heat/energy that is required to melt a solid substance into a liquid
Specific heat
the amount of heat/energy required to raise the temp of 1g of a substance by 1ºC
Heat capacity
the amount of heat required to raise the temp of an entire object/ a particular amount of a substance
Colligative properties
properties that depend strictly on the total number of dissolved solute particles
Hydrolysis reaction
reaction which breaks apart water (ex: H20 → H+ and OH-)
Cohesion
when molecules of the same type attract to each other (ex: h20 + h20 attraction)
Adhesion
ability of unlike particles to be attracted to each other (ex: h20 to glass attraction)
Surface tension
the attraction between molecule at the surface of a liquid
Acids
substances that release H+ ions (more H+ ions, lower pH)
Bases
substances that release OH- ions (increases OH- concentration → higher pH)
pH
a measure of H+ concentrations in a solution (pH=-log[H+])
Buffers
a pair of substances that minimize pH fluctuations (usually and acid and its related base)
Macromolecules
carbohydrates, proteins, lipids, and nucleic acids
organic molecules
molecules containing carbon
Inorganic molecules
molecules that are not found in living organisms
Hydrocarbons
molecules with a high proportion of hydrogen and carbon atoms bonded
Functional groups
groups of atoms with characteristic chemical structures and properties
Isomers
2 or more molecules with the same chemical formulas, but different structures
sterioisomers
identical building relationships, but spacial positioning of atoms differ
cis isomer
when the two hydrogen atoms are on the same side of the carbon double bonds
trans isomer
when the two hydrogen atoms are on different sides of the carbon double bonds
enantiomer
one pair of molecules that are mirror images of each other
Enzyme
molecules that catalyze rates of chemical reactions (lowers the activation energy of a reaction)
monomers
one part of a polymer
polymer
many monomers
Condensation/dehydration reaction
when 2 molecules combine to produce a larger molecule and RELEASES a water molecule
Hydrolysis reaction
when a polymer is broken down into monomers (requires water)
Carbohydrates
organic molecules made of C,H, and O atoms
monosaccharides
the monomer of carbohydrates (the simplest
Disaccharides
2 monosaccharides that are linked together by a dehydration reaction (glycosidic bond)
Glycosidic bond
bond formed between 2 sugars (dehydration reaction) (the bond that holds polysaccharides together)
polysaccharides
many monosaccharides linked together by glycosidic bonds (forms long polymers)
Cellulose
a polymer of monosaccharides with a linear arrangement of carbon-carbon bonds (NO branching)
Lipids
hydrophobic molecules composed of hydrogen and carbon atoms, with some oxygen atoms. (non-polar, insoluble, includes fats, phospholipids, steroids, and waxes)
Triglycerides
fats that are formed when glycerol bonds to 3 fatty acids
Ester bond
the bond that is formed between the fatty acids and the glycerol in a triglyceride
Saturated fatty acids
formed when all the carbons are linked by single covalent bonds (can’t wiggle and are packed tightly together)
unsaturated fatty acids
fatty acids that contain 1 or more carbon double bond (which create “kinks” in the chain)
cis fats
unsaturated fats that exist in nature
trans fats
unsaturated fats that do NOT exist in nature
phospholipids
similar in structure to triglycerides, but one hydroxyl group of glycerol is linked to phosphate group instead of a fatty acid
Steroids
four fused carbon atoms rings that typically have 1 or more polar hydroxyl groups attached to the ring structure
Waxes
Complex lipids which contain 1 or more hydrocarbons and long structures (that resemble a fatty acid) are attached to its carboxyl group to another long hydrocarbon chain (very non-polar)
Amino Acids
monomers of proteins (only 20 amino acids)
polypeptide
a linear sequence of animo acids joined together by peptide bonds
Peptide bonds
the covalent bonds formed between a carboxyl group and an amino acid
protein
A FUNCTIONAL unit composed of 1 or more polypeptides
N-terminus
the amino group on a protein (NH3) connected to the alpha carbon
C-terminus
the carboxyl group on a protein connected to the alpha carbon
peptide backbone
the amino group, the alpha carbon, and the carboxyl group
primary structure
the amino acid sequence of polypeptides (single chain)
secondary structure
the helix (alpha helix) or pleated (beta pleated) sheet structure that is stabilized by hydrogen bonds