Studied by 10 peopleArchaea
Domain of unicellular prokaryotes that have cell walls that do not contain peptidoglycan
Bacteria
single-celled organisms that lack a nucleus; prokaryotes
dependent variable
a variable whose value depends upon independent variable
eukaryotic cell
A type of cell that has a membrane-enclosed nucleus and other membrane-enclosed organelles. All organisms except bacteria and archaea are composed of eukaryotic cells.
eukarya
Domain of all organisms whose cells have nuclei, including protists, plants, fungi, and animals. Includes all eukaryotic organisms
homeostasis
A state of balance among all the body systems needed for the body to survive and function correctly.
hypothesis
a testable explanation for a set of observations based on the available data
independent variable
a variable that stands alone and isn't changed by the other variables you are trying to measure.
organelle
A membrane-enclosed structure with a specialized function within a cell.
prokaryotic cell
A type of cell lacking a membrane-enclosed nucleus and other membrane-enclosed organelles; found only in the domains Bacteria and Archaea.
theory
widely accepted idea that is broader in scope than a hypothesis, generates new hypothesis and is supported by a large body of evidence
adhesion
attraction between different kinds of molecules
cohesion
the sticking together of molecules of the same kind, often by hydrogen bonds
covalent bond
type of strong chemical bond in which 2 atoms share 1 or more pairs of valence electrons
polar covalent bond
covalent bond between atoms that differ in electronegativity. the shared electrons are pulled closer to the more electronegative atom, making it slightly negative and the other atom slightly positive
unequal sharing of electrons
nonpolar covalent bond
type of covalent bond in which electrons are shared equally between 2 atoms of similar electronegativity
electronegativity
attraction of a given atom for the electrons of a covalent bond
evaporative cooling
process in which the surface of an object becomes cooler during evaporation, a result of the molecules with the greatest energy changing from the liquid to gaseous state.
hydrogen bond
type of weak chemical bond formed when the slightly positive hydrogen atom of a polar covalent bond in 1 molecule is attracted to the slightly negative atom of a polar covalent bond in another molecule
ionic bond
chemical bond resulting from the attraction between oppositely charged ions
surface tension
measure of how difficult it is to stretch/break the surface of a liquid. Water has a high surface tension because of the hydrogen bonding of surface molecules
dehydration synthesis
the creation of larger molecules from smaller monomers where a water molecule is released
denaturation
in which a protein unravels, losing its specific structure and hence function -- can be caused by changes in pH/salt concentration/high temperature
enzymes
macromolecule, usually a protein that serves as a biological catalyst, changing the rate of a chemical reaction without being consumed by the reaction
hydrolysis
chemical reaction that breaks bonds between 2 molecules by the addition of water; process by which polymers are broken down and an essential part of digestion
hydrophilic
“water-loving” pertaining to polar/charged molecules (or parts of molecules) that are soluble in water
hydrophobic
“water-fearing” pertaining to nonpolar molecules (or parts of molecules) that do not dissolve in water
monomer
the subunit that serves as a building block of a polymer
phospholipids
liquid made up of glycerol joined to 2 fatty acids and a phosphate group, giving the molecule 2 nonpolar hydrophobic tails and a polar hydrophilic head
peptide bond
the covalent bond between two amino acid units in a polypeptide, formed by a dehydration reaction
polymer
large molecule consisting of many identical/similar monomers linked together by covalent bonds
central vacuole
in a plant cell, a large membranous sac with diverse roles in growth and the storage of chemicals and wastes
chloroplast
organelle found in plants and algae that absorb sunlight and uses it to drive the synthesis of organic compounds (sugars) from carbon dioxide and water
cytoskeleton
network of protein fibers in the cytoplasm of a eukaryotic cell, includes microfilaments, intermediate filaments and microtubules
endoplasmic reticulum (ER)
extensive membranous network in a eukaryotic cell, continuous with the outer nuclear membrane and composed of ribosome-studded (rough) and ribosom-free (smooth) regions
golgi apparatus
organelle in eukaryotic cells consisting of stacks of membranous sacs that modify, store, and ship products of the endoplasmic reticulum
lysosomes
digestive organelle in eukaryotic cells; contain hydrolytic enzymes that digest engulfed food/damaged organelles
mitochondrion
organelle in eukaryotic cells where cellular respiration occurs. Enclosed by two membranes, where most of the cells ATP is made
nucleus
the atoms central core, containing proteins and neutrons.
the organelle of a eukaryotic cell that contains the genetic material in the form of chromosomes, made of chromatin
ribosomes
cell structure consisting of RNA and protein organized into two subunits and functioning as the site of protein synthesis in the cytoplasm.
vesicles
sac made of membranes in the cytoplasm of a eukaryotic cell
activation energy
amount of energy that reactants must absorb before a chem reaction will start
active site
part of an enzyme where a substrate molecule attatches, typically, a pocket or groove on the enzymes surface
aquaporin
transport protein in the plasma membrane of an animal, plant, or microorganism cell that facilitates the diffusion of water across the membrane (osmosis)
induced fit
change in shape of the active site of an enzyme, caused by entry of the substrate so that it binds the substrate snugly.
osmosis
diffusion of free water across a selectively permeable membrane
osmoregulation
homeostatic maintenance of solute concentrations and water balance by a cell organism
selective permeability
property of biological membranes that allows them to regulate the passage of substances across them
substrate
a specific substance (reactant) on which an enzyme acts. each enzyme recognizes only its specific substrate/substrates of the reaction it catalyzes
controlled experiment
An experiment in which an experimental group is compared with a control group that varies only in the factor being tested. -- only one variable is changed
x axis
which axis is the independent variable on?
y axis
which axis is the dependent variable on?
school of fish, ant colony, heart pumping blood, flock of starlings, human consciousness
what are some biological examples of emergent properties?
surface tension of water, structure of diamond, hurricane
what are some non-biological examples of emergent properties?
Order - All living things are highly organized, all made up of cells
Reproduction - Living things can reproduce themselves to create new organisms
Growth and Development - Organisms grow based off of their DNA
Energy Processing - Some organisms eat, others capture energy from the sun. Energy is required for organisms' metabolic activities
Regulation - Organisms maintain internal conditions through homeostasis, despite environmental changes
Response to Environment - Organisms can respond to changes in their environment. (Plants turn towards sun, people pull their hand away from a flame)
Evolutionary Adaptation - Natural selection - genetic makeup of population changes over time. Traits that provide benefit to species as a whole will develop over time.
what are the 7 characteristics of life?
cohesion
the sticking together of molecules of the same kind, often by hydrogen bonds
adhesion
attraction between different kinds of molecules
water is less dense as a solid than liquid because of hydrogen bonding
when water freezes, each molecule forms a stable hydrogen bond with its neighbors
how does ice float?
thermal energy in transfer from a warmer to a cooler body of matter (heat)
thermal energy is the energy associated with the random movement of atoms and molecules
how does water moderate temperature?
it is capable of dissolving more substances than any other liquid.
how is water the solvent of life?
carbohydrates
member of the class of biological molecules consisting of single-monomer sugars (monosaccharides), 2 monomer sugars (disaccharides), and polymers (polysaccharides)
lipids
organic compound consisting mainly of carbon and hydrogen atoms linked by nonpolar covalent bonds, making the compound mostly hydrophobic
proteins
functional biological molecule consisting of one or more polypeptides folded into a specific 3 dimensional surface
nucleic acid
polymer consisting of many nucleotide monomers; serves as a blueprint for proteins and through the actions of proteins, for all cellular structures and activities, the 2 types of nucleic acids are DNA and RNA
Primary - Sequence of amino acids
1st Level of a Protein Structure
Secondary - Interactions of backbone
Second level of Protein structure
Tertiary - Due to side chain interactions (3d shape)
Third level of protein structure
Quaternary - Arrangement of multiple polypeptide chains
Fourth level of protein structure
Plasma Membrane
Cytoplasm
Ribosomes
DNA (one or more chromosomes)
what are the requirements to be a cell?
Chloroplast
Cell wall (cellulose)
Central vacuole
Plasmodesmata
Which structures do plant cells have that animal cells do not?
Carry out genetic control.
Manufacture, distribute, and breakdown molecules.
Energy processing.
Movement, structural support, and communication between cells.
what are the four functional categories of eukaryotic organelles?
transport proteins
regulate movement of molecules in/out of cells
glycoproteins (cell ID proteins)
cell recognition
enzymes
catalyze biochemical reactions
receptor proteins
bind to external signals/relay messages
attachment protein
support membrane/coordinate external & internal
junction protein
\n intercellular connection
active transport
movement of a substance across a biological membrane against its concentration gradient, aided by specific transport proteins and requiring an input of energy. (often as ATP)
passive transport
diffusion of a substance across a biological membrane, with no expenditure of energy
diffusion (passive transport)
random movement of particles that results in the net movement of a substance down the concentration gradient from a region where it is more concentrated to less concentrated
osmosis (passive transport)
diffusion of free water across a selectively permeable membrane
facilitated diffusion
\n passage of a substance through a specific transport protein across a biological membrane down its concentration gradient
endocytosis (active transport/bulk transport)
cellular uptake of molecules/particles via formation of new vesicles from the plasma membrane
exocytosis (active transport/bulk transport)
movement of materials out of a cell by the fusion of vesicles with the plasma membrane
isotonic
\n referring to a solution that, when surrounding a cell, causes no net movement of water into/out of a cell
hypertonic
a solution that causes the cell to lose water
hypotonic
a solution that causes the cell to take in water
tonicity
ability of a solution surrounding a cell to cause that cell to gain or lose water
to obtain the potential energy stored in the bonds of organic molecules and bank this energy in ATP molecules
whats the basic purpose of cellular respiration?
Hydrolysis vs. Dehydration Synthesis
Dehydration Synthesis - Water is released to form larger molecules
Hydrolysis - Water is added to break apart larger molecules
Types of Microscopes
SEM - Surface electron microscope. Light doesn't pass through object, but it shows a 3D picture of the surface
TEM - Transmission electron microscope. Light passes through a thin layer of object
Light - Light passes through thin layer of object (shows color).
Three Tenets of Cell Theory
All organisms are composed of cells (unicellular, multicellular)
The cell is the structural functional unit of life
All cells arise from preexisting cells
Note
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