Macromolecules
A very large organic molecule composed of many smaller molecules
CHNOPS
elements essential for life
Covalent Bond
A chemical bond that involves sharing a pair of electrons between atoms in a molecule
Polar
Molecule with partial charges. Mixes with water.
Nonpolar
No partial charges. Do not mix with water.
Ionic Bond
Formed when one or more electrons are transferred from one atom to another
Hydrogen Bond
A type of weak chemical bond formed when the slightly positive hydrogen atom of a polar covalent bond in one molecule is attracted to the slightly negative atom of a polar covalent bond in another molecule.
Electronegative
the ability of an atom of an element to attract electrons when the atoms is in a compound
Cohesion
Attraction between molecules of the same substance
Adhesion
An attraction between molecules of different substances
Capillarity
The rise of a liquid in a fine, hollow tube or in a narrow space.
Specific Heat
The amount of energy required to raise the temperature of 1 gram of a substance by 1 degree Celsius
Evaporation
The change of a substance from a liquid to a gas
Solvent
the substance in which the solute dissolves
pH
hydrogen ion concentration
Acid
A substance that increases the hydrogen ion concentration of a solution.
Base
A substance that decreases the hydrogen ion concentration in a solution.
Neutral
Not favoring either side (pH of 7)
Hydronium
H3O+
Hydroxide
OH-
Buffer
A solution that minimizes changes in pH when extraneous acids or bases are added to the solution.
Carbohydrate
compound made up of carbon, hydrogen, and oxygen atoms; major source of energy for the human body
Monosaccharide
A single sugar molecule such as glucose or fructose, the simplest type of sugar.
Protein
An organic compound that is made of one or more chains of amino acids and that is a principal component of all cells
Amino Acid
Building blocks of protein; has an amino group, carboxyl group and a variable group
Lipid
Energy-rich organic compounds, such as fats, oils, and waxes, that are made of carbon, hydrogen, and oxygen.
Fatty Acid
hydrocarbon chain often bonded to glycerol in a lipid
Glycerol
A three-carbon alcohol to which fatty acids are covalently bonded to make fats and oils.
Phospholipid
a lipid that contains phosphorus and that is a structural component in cell membranes
Triglyceride
a lipid made of three fatty acid molecules and one glycerol molecule
Wax
lipid made of a long-chain fatty acid that is esterified to a long-chain alcohol; serves as a protective coating on some feathers, aquatic mammal fur, and leaves
Nucleic Acid
macromolecule containing hydrogen, oxygen, nitrogen, carbon, and phosphorus
Nucleotide
monomer of nucleic acids made up of a 5-carbon sugar, a phosphate group, and a nitrogenous base
Polymer
large compound formed from combinations of many monomers
Monomer
A simple compound whose molecules can join together to form polymers
Isomer
Compounds with the same formula but different structures.
Hydrocarbon
An organic compound that contains only carbon and hydrogen
Functional Group
A specific configuration of atoms commonly attached to the carbon skeletons of organic molecules and involved in chemical reactions.
Dehydration Synthesis
A chemical reaction in which two molecules covalently bond to each other with the removal of a H from one molecule and an OH from the other molecule
Hydrolysis
Breaking down complex molecules by the chemical addition of water
Glycosidic Linkage
A covalent bond formed between two monosaccharides by a dehydration reaction.
Saturated Fat
A lipid made from fatty acids that have no double bonds between carbon atoms
Unsaturated Fat
A lipid made from fatty acids that have at least one double bond between carbon atoms.
Hydrophobic
Water fearing
Hydrophilic
water loving
Polypeptide
long chain of amino acids that makes proteins
Peptide Bond
The chemical bond that forms between the carboxyl group of one amino acid and the amino group of another amino acid
Amino Group
A functional group that consists of a nitrogen atom bonded to two hydrogen atoms
R-Group
used to represent one of 20 possible side chains found in amino acids of living systems
Carboxyl Group
A functional group present in organic acids and consisting of a single carbon atom double-bonded to an oxygen atom and also bonded to a hydroxyl group.
Primary Structure
The first level of protein structure; the specific sequence of amino acids making up a polypeptide chain.
Secondary Structure
The second level of protein structure; the regular local patterns of coils or folds of a polypeptide chain.
Tertiary Structure
The third level of protein structure; the overall, three-dimensional shape of a polypeptide due to interactions of the R groups of the amino acids making up the chain.
Quaternary Structure
The fourth level of protein structure; the shape resulting from the association of two or more polypeptide subunits.
Enzyme
A type of protein that speeds up a chemical reaction in a living thing
Catalyst
substance that speeds up the rate of a chemical reaction
DNA
deoxyribonucleic acid, a self-replicating material present in nearly all living organisms as the main constituent of chromosomes. It is the carrier of genetic information.
Cell
The basic unit of structure and function in living things
Homeostasis
A tendency to maintain a balanced or constant internal state; the regulation of any aspect of body chemistry, such as blood glucose, around a particular level
Responsiveness
Reaction to a change inside or outside the body
Reproduction
Ability to generate offspring
Prokaryote
A unicellular organism that lacks a nucleus and membrane bound organelles
Unicellular
Made of a single cell
Multicellular
Made up of more than one cell.
Cell Wall
A rigid layer of nonliving material that surrounds the cells of plants and some other organisms.
Flagella
whiplike tails found in one-celled organisms to aid in movement
Eukaryote
A cell that contains a nucleus and membrane bound organelles
Nucleus
A part of the cell containing DNA and RNA and responsible for growth and reproduction
Organelle
specialized structure that performs important cellular functions within a eukaryotic cell
Cytoskeleton
A network of fibers that holds the cell together, helps the cell to keep its shape, and aids in movement
Endosymbiosis
A theorized process in which early eukaryotic cells were formed from simpler prokaryotes.
Mitochondrion
Cell organelle that converts the chemical energy stored in food into compounds that are more convenient for the cell to use
Chloroplast
An organelle found in plant and algae cells where photosynthesis occurs
Cytoplasm
A jellylike fluid inside the cell in which the organelles are suspended
Cell Membrane
thin, flexible barrier around a cell; regulates what enters and leaves the cell
Chromatin
granular material visible within the nucleus; consists of DNA tightly coiled around proteins
Nuclear Envelope
layer of two membranes that surrounds the nucleus of a cell
Nucleolus
Found inside the nucleus and produces ribosomes
Ribosome
Cytoplasmic organelles at which proteins are synthesized.
Endomembrane System
A network of membranes inside and around a eukaryotic cell, related either through direct physical contact or by the transfer of membranous vesicles.
Endoplasmic Reticulum
A cell structure that forms a maze of passageways in which proteins and other materials are carried from one part of the cell to another.
Smooth ER
That portion of the endoplasmic reticulum that is free of ribosomes.
Rough ER
ER that is dotted with ribosomes
Golgi Apparatus
A system of membranes that modifies and packages proteins for export by the cell
Lysosome
A small, round cell structure containing chemicals that break down large food particles into smaller ones.
Vesicle
Small membrane-bound sac that functions in moving products into, out of, and within a cell.
Vacuole
Cell organelle that stores materials such as water, salts, proteins, and carbohydrates
Hydrolytic Enzyme
enzyme that catalyzes a reaction in which the substrate is broken down by the addition of water
Contractile Vacuole
saclike organelles that expand to collect excess water and contract to squeeze the water out of the cell
Central Vacuole
in a mature plant cell, a large membranous sac with diverse roles in growth, storage, and sequestration of toxic substances
Peroxisome
organelle with various specialized metabolic functions; produces hydrogen peroxide as a by-product, then converts it to water
Microtubules
Spiral strands of protein molecules that form a tubelike structure
Microfilaments
a small rodlike structure, about 4-7 nanometers in diameter, present in numbers in the cytoplasm of many eukaryotic cells.
Extracellular Matrix
a collection of extracellular molecules secreted by cells that provides structural and biochemical support to the surrounding cells.
Plasmodesmata
An open channel in the cell wall of plants through which strands of cytosol connect from adjacent cells
Tight Junction
a firm seal between two adjacent animal cells created by protein adherence
Desmosome
a type of intercellular junction in animal cells that functions as a rivet, fastening cells together
Gap Junction
A type of intercellular junction in animals that allows the passage of materials between cells.
Lipid Bilayer
flexible double-layered sheet that makes up the cell membrane and forms a barrier between the cell and its surroundings
ATP
(adenosine triphosphate) main energy source that cells use for most of their work