Studied by 0 people
Looks like no one added any tags here yet for you.
Hierarchy of Life
biosphere>ecosystem>community>population>organism>organ system>organ>tissue>cell>organelle>molecule>atom
Emergent Properties
New properties that emerge as a result of interactions of components at lower levels
Structure-Function Relationship
The idea that the structure of a biological component determines its function
Prokaryotic Cells
Cells that lack a nucleus and membrane-bound organelles
Eukaryotic Cells
Cells that have a nucleus and membrane-bound organelles
Genetic Information
Information encoded in the nucleotide sequence of DNA (genes)
Gene Expression
The process by which genes program a cell's protein production
Energy Flow
The movement of energy through an ecosystem
Organism-Environment Interaction
The continuous interaction between organisms and physical factors in their environment
Evolution
The process that accounts for the unity and diversity of life
Domains of Life
Bacteria, Archaea, and Eukarya
Similarities in Life
Despite being diverse, all forms of life have similarities
Natural Selection
The mechanism for the evolutionary adaptation of populations to their environments
Interconnectedness of Life
All life is connected to each other through evolutionary history
Scientific Method
Scientists form and test hypotheses by collecting data
Elements
Substances that cannot be chemically broken down into other substances
Compound
A substance that contains two or more elements in a fixed ratio
Major Elements in Living Matter
Oxygen, carbon, hydrogen, and nitrogen
Atom
The smallest unit of an element
Atomic Number
The number of protons in an atom
Isotope
An atomic form of an element with a different number of neutrons
Electron Shells
The regions of an atom where electrons occupy
Reactive Atom
An atom with an incomplete outer shell (valence shell)
Chemical Bonds
Form when atoms interact and complete their valence shells
Covalent Bonds
Formed when electron pairs are shared between atoms
Single Bond
The sharing of a pair of valence electrons by two atoms
Double Bond
The sharing of two pairs of valence electrons by two atoms
Molecule
Consists of two or more covalently bonded atoms
Electronegativity
The attraction of an atom for the electrons of a covalent bond
Polar Covalent Bond
A covalent bond between atoms that differ in electronegativity
Ion
A charged atom
Ionic Bond
A chemical bond resulting from the attraction of oppositely charged ions
Hydrogen Bond
An attraction between a hydrogen atom carrying a partial positive charge and an electronegative atom
Van der Waals Interactions
Interactions that occur between transiently positive and negative regions of molecules
Chemical Reactions
Processes that change reactants into products while conserving matter
Chemical Equilibrium
The state reached when the forward and reverse reaction rates are equal
Hydrogen Bonds in Water
Form when the partial negative charge of oxygen is attracted to the partial positive hydrogen of a nearby water molecule
Cohesion of Water
Water molecules are kept close together by hydrogen bonds
Surface Tension
The result of hydrogen bonding between water molecules
High Specific Heat of Water
Water can absorb a large amount of heat before its temperature changes
Heat of Vaporization
The amount of heat required to convert a liquid into a gas
Density of Ice
Ice floats because it is less dense than liquid water
Versatility of Water as a Solvent
Water's polar molecules are attracted to ions and polar substances that can form hydrogen bonds
Hydrophilic Substances
Substances that have an affinity for water
Hydrophobic Substances
Substances that do not have an affinity for water
Hydronium Ion
Formed when water transfers a hydrogen ion
pH
A measure of the concentration of H+ ions in a solution
Carbon
Can bond to various other atoms and forms the backbone of organic compounds
Carbon Skeletons
Formed when carbon atoms bond to other carbon atoms
Hydrocarbons
Consist of carbon and hydrogen
Isomers
Compounds that have the same number of atoms of the same elements but different structures and properties
Functional Groups
Chemical groups attached to carbon skeletons that participate in chemical reactions
ATP
Adenosine triphosphate, a molecule that releases energy when its phosphate bonds are hydrolyzed
Carbohydrates
Polymers made up of monosaccharides that function as fuel and carbon sources
Proteins
Polymers made up of amino acids that have various functions in the cell
Nucleic Acids
Polymers made up of nucleotides that store and transmit genetic information
Monosaccharides
Simple sugars that can be converted to other molecules or combined into polymers
Disaccharides
Two monosaccharides joined by a glycosidic linkage
Polysaccharides
Long chains of monosaccharides that have various functions
Strengthens Plant Cell Walls
Cellulose in plants
Stores Glucose for Energy
Starch in plants
Strengthens Exoskeletons and Fungal Cell Walls
Chitin in animals and fungi
Important Energy Source
Triacylglycerols (fats or oils)
Lipid Bilayers of Membranes
Phospholipids
Component of Cell Membranes
Steroids
Catalyze Chemical Reactions
Enzymes
Provide Structural Support
Structural proteins
Store Amino Acids
Storage proteins
Transport Substances
Transport proteins
Coordinate Organismal Responses
Hormones
Receive Signals from Outside Cell
Receptor proteins
Function in Cell Movement
Motor proteins
Protect Against Disease
Defensive proteins
DNA
Stores hereditary information and is usually double-stranded
RNA
Performs various functions in gene expression and is usually single-stranded
DNA Similarity
The more closely two species are related evolutionarily, the more similar their DNA will be
Light Microscope
An optical instrument that uses lenses to magnify images of specimens
Electron Microscope
A microscope that uses magnets to focus an electron beam on or through a specimen
Cell Fractionation
The disruption of a cell and separation of its parts by centrifugation
Plasma Membrane
The boundary of a cell, consisting of a phospholipid bilayer
Prokaryotic Cells
Cells that lack membrane-bound organelles and nuclei
Eukaryotic Cells
Cells that have membrane-bound organelles and nuclei
Surface Area to Volume Ratio
The ratio of the surface area of an object to its volume
Endoplasmic Reticulum
A network of membranous tubules and sacs involved in protein synthesis and lipid metabolism
Ribosome
A cellular structure involved in protein synthesis
Golgi Apparatus
A stack of membranous sacs involved in the modification, sorting, and secretion of proteins
Lysosome
A membranous sac of hydrolytic enzymes involved in intracellular digestion
Vacuole
A large membrane-bounded vesicle involved in various cellular processes
Mitochondrion
An organelle involved in cellular respiration
Chloroplast
An organelle involved in photosynthesis
Peroxisome
A specialized metabolic compartment involved in various metabolic processes
Cytoskeleton
A network of protein fibers that provides structural support and facilitates cell movement
Microtubules
Protein fibers that shape the cell, guide organelle movement, and separate chromosomes
Cilia and Flagella
Motile appendages containing microtubules
Microfilaments
Thin rods that function in contraction, movement, and support
Intermediate Filaments
Protein fibers that support cell shape and fix organelles in place
Cell Walls in Plants
Made of cellulose fibers embedded in other polysaccharides and proteins
Extracellular Matrix
A complex network of glycoproteins and proteoglycans that functions in support, adhesion, movement, and regulation
Cell Junctions
Structures that connect neighboring cells
Plasmodesmata
Channels that connect the cytoplasm of adjacent plant cells
