bio part 1

main charactertistics of life order, evolutionary adaptation, response to the environment, regulation, energy processing, reproduction, growth & development

taxonomy from most inclusive to least inclusive:

domain → kingdom → phylum → class → order → family → genus → species

levels of organization from most inclusive to least inclusive:

biosphere → ecosystem → community → population → organism → organs/organ systems → tissues → cells → organelles → molecule

central dogma DNA transcripts into RNA, which translates to proteins

adaptation an inherited trait that enhances individual’s ability to survive and reproduce in a particular environment OR a change occurring in a population in response to a changing environment

natural selection the survival of certain organisms with traits necessary for survival

conditions necessary: variation, overproduction, and heritability

theory a potential reason for a hypothesis

prediction testable statement that could support the hypothesis (if/then format)

control group a group of the experiment held to every condition but the testable variable

experimental group a group of the experiment held to every condition including the testable variable

independent variable manipulated/changed by the experimenter

dependent variable measured during the experiment; the result of the independent variable

controlled variables variables held constant throughout the experiment

placebo a variable with no real effect designed to look like the actual variable being tested

inductive reasoning used to come up with a general hypothesis

deductive reasoning used to come up with a specific prediction

elements pure substance that cannot be broken down into other types of substances. the most important ones for life are carbon, hydrogen, oxygen, nitrogen, phosphorous, and sulfur

atom smallest unit of matter that retains properties of a given element

protons a subatomic particle with a positive charge

electrons a subatomic particle with a negative charge

neutrons a subatomic particle with neutral charge

valence the bonding capacity of an atom. the number of electrons required to complete the atom’s outermost shell

ionic bond an electrical attraction between ions (cation and anion)

ex: NaCl

must be with a metal and a nonmetal.

covalent bond involves the sharing of electrons. strength INCREASES from a single to a double bond, double to triple, etc.

this is the strongest bond

non-polar covalent bond involves the equal sharing of electrons

ex: O2, N2, CH4

polar covalent bond involves the unequal sharing of electrons

ex: H2O

hydrogen bond interaction between a Hydrogen atom that has a covalent link with an electronegative atom (F, N, or O) and another electronegative atom

ex: bond between a H2O molecule and a NH3 molecule

intermolecular force a force that exists between different molecules

intramolecular force a force that holds atoms together within a molecule

universal solvent a property of water: dissolving more substances than any other liquid

adhesion a property of water: sticking to and interacting with other surfaces

cohesion a property of water: interacting with itself, this property allows for surface tension

high specific heat a property of water: maintaining temperature

pH a measure of hydrogen ion concentration in a solution

pH equations pH = -log[H+]

[H+]*[OH-] = 10^-14

increases if a pH of solution decreases, the H+ concentration of the solution ___

tetravalent carbon is chemically versatile because it is ___ (meaning it can form up to 4 covalent bonds)

functional groups, 3D shape the function of a biological molecule is determined by its ___ and its overall ___

isotope a variant of an atom of a chemical element that has the same # of protons but a different number of neutrons, resulting in a different atomic mass

hydroxyl general molecular composition: -OH

compound name: alcohols

carbonyl general molecular composition: >C=O

compound name: ketones/aldehydes

ketones a carbonyl group that is in the middle/inside of a molecule

aldehydes a carbonyl group that is on the end of a molecule

carboxyl general molecular composition: -COOH

compound name: organic acids

amino general molecular composition: -NH2

compound name: amines

sulfhydryl general molecular composition: -SH

compound name: thiols

phosphate general molecular composition: -OPO3^-2

compound name: organic phosphates

methyl general molecular composition: -CH3

compound name: methylated compounds

isomers have the same molecular formula but different structures and properties

structural isomers differ in covalent arrangements of the atoms and/or location of double bonds

cis-trans isomers same covalent partners but differ in spatial arrangement about a double bond

cis isomers the covalent partners are on the same side of the molecule (such as both being at the top)

trans isomers the covalent partners are on different sides of the molecule (diagonal from each other)

enantiomers mirror images of each other, differ in spatial arrangement around an asymmetric carbon

monomer a single repeating subunit

polymer a long molecule consisting of many similar or identical subunits (monomers)

dehydration synthesis water molecule is lost when a covalent bond forms between two monomers

hydrolysis water is added, covalent bond is broken, and hydrogen and oxygen atoms from water are added to the monomers

polysaccharide a true polymer of carbohydrates, includes starch, glycogen, cellulose, and chitin

monomer of carbohydrates contains a hydroxyl group (OH) and a carboxyl group (-COOH)

examples include: glucose, fructose, galactose

glycosidic linkage the bond between carbohydrate monomers

maltose a disaccharide: forms with glucose + glucose

sucrose a disaccharide: forms with glucose + fructose

lactose a disaccharide: forms with glucose + galactose

starch a polysaccharide that functions as storage in plants. an alpha polymer of glucose

glycogen a polysaccharide that functions as storage in animals. an alpha polymer of glucose

cellulose a polysaccharide that functions as structure in plants. a beta polymer of glucose

chitin a polysaccharide that functions as structure in animals. a beta polymer of glucose

lipids the only group of large biological molecules that is not a true polymer

components of lipids contains glycerol and fatty acids

triacylglycerol a lipid that contains one glycerol and 3 fatty acids

saturated fatty acids these are fatty acids that do not contain double bonds

unsaturated fatty acids these are fatty acids that do contain double bonds

phospholipids a lipid that contains 1 glycerol, 2 fatty acids, and a phosphate group

steroids a lipid with 4 fused carbon rings with chemical groups attached

cholesterol a component of membranes and precursor for steroid hormones

ester linkage the bond connecting glycerol to fatty acid

polypeptides the polymer of proteins

components of proteins contains an amino group, a carboxyl group, and an R side chain

nonpolar side chain these are hydrophobic and are made up of mostly carbon and hydrogen atoms.

polar side chain these are hydrophilic and contain electronegative atoms such as OH, NH2, or SH

acidic side chain these are side chains with negatively charged atoms

basic side chains these are side chains with positively charged atoms

primary structure the sequence of amino acids

secondary structure alpha helices and beta sheets due to hydrogen bonding in backbone

tertiary structure the overall 3D structure of a protein

quaternary structure proteins consisting of two or more polypeptide chains

peptide bond the bond between protein monomers

nucleotides the monomer of nucleic acids

components of nucleic acids contains a nitrogenous base, a phosphate group, and a pentose sugar

deoxyribose the sugar of DNA

DNA contains deoxyribose sugar. the nitrogenous base is C, G, A, T.

usually double-stranded

stores hereditary info

ribose sugar of RNA

RNA contains ribose sugar, nitrogenous base is C, G, A, U

usually single-stranded

needed for gene expression, including carrying instructions from DNA to ribosomes

light microscopy uses light to view specimen. can view live cells

electron microscopy uses beams of electrons to view specimen. cannot view live cells

scanning electron microscopy (SEM) shows the surface (3D) of specimen

transmission electron microscopy shows the internal structure of specimen

nitrogenous bases cytosine, adanine, thymine, guanine

phosphodiester bond the bond between monomers for nucleic acids

prokaryotes contains a nucleoid region, is usually smaller, and is bacteria. also has a cell wall, plasma membrane, DNA, ribosomes, and cytosol

eukaryotes contains membrane-bound organelles, a nucleus, cell wall, plasma membrane, DNA, ribosomes, and cytosol

animal cells contains lysosomes and a centrosome. also has a cell membrane, nucleus, rough and smooth ER, Golgi apparatus, ribosome, mitochondrion, and a vacuole

plant cells contains cell wall, chloroplast, and a central vacuole. also has a cell membrane, nucleus, rough and smooth ER, Golgi apparatus, ribosome, mitochondrion, and a vacuole

plasma membrane selectively permeable membrane, encloses the cell, protects cell

nucleus storage sites of genetic material, headquarters of the cell

ribosome an organelle that synthesizes protein

rough ER produces protein, studded with ribosomes hence “rough”

smooth ER produces and processes lipids, detoxification, calcium storage

Golgi apparatus packages and transports proteins, synthesizes, packages, sorting and modifies cells

peroxisome decomposes hydrogen peroxide into water and oxidizes fatty acids

mitochondria powerhouse of the cell; energy production and cellular respiration

central vacuole stores nutrients, water disposal, storage, plant cell growth

chloroplasts photosynthesis, converting CO2 and H2O to glucose and oxygen

lysosomes recycles and breaks down waste in cells

cytoskeleton contains microtubules, microfilaments, and intermediate filaments

microtubules consists of tubulin.

movement and motility, cell division

ex: flagella and mitotic spindle

flagella sperm tail (a microtubule)

mitotic spindle carries out mitosis and meiosis (a microtubule)

microfilaments consists of actin.

muscle contraction, cell division, amoeboid movement

ex: cleavage furrow, flexing muscles

intermediate filaments consists of keratin, family proteins

anchors cells, nuclear lamina, formation

plasmodesmata only in plants. forms connections for small molecules to pass through channels

tight junctions in animals. creates an impenetrable barrier that prevents leakage

gap junctions in animals. forms connections for small molecules to pass through channels

desmosomes in animals. forms anchoring connections supporting cells under stress

endosymbiotic theory mitochondria and chloroplasts evolved from free-living prokaryotic cells

double both chloroplasts and mitochondria have a ___ membrane, circular DNA, cell membranes, and reproduce independently

membrane enfolding hypothesis proposes that the internal membrane systems found in eukaryotic cells originated from the plasma membrane of an ancestral prokaryotic cell folding inwards

lynn margulis proposed the endosymbiotic theory