AP Biology Big Idea #4
Biological systems interact, and these interactions possess complex properties.
Terms in this set (74)
Active site- The region on the surface of an enzyme or ribozyme where the substrate
binds, and where catalysis occurs.
the tubular passage that extends from mouth to anus, functions in
digestion and absorption of food and elimination of residual waste, and includes the mouth,
pharynx, esophagus, stomach, small intestine, and large intestine
the regulation of an enzyme or other protein by binding
an effector molecule at the protein's allosteric site (that is, a site other than the
protein's active site). Effectors that enhance the protein's activity are referred
to as allosteric activators, whereas those that decrease the protein's activity are
called allosteric inhibitors.
a small, baglike cavity, especially the blind sacs of the lung.
An organic compound containing both NH2 and COOH groups. Proteins are
polymers of amino acids.
The smallest unit of a chemical element. Consists of a nucleus and one or more
same as atomic weight
the number of protons in the nucleus of an atom; also equals the number
of electrons around the neutral atom. Determines the chemical properties of the atom.
the average of the mass umbers of a representative sample of atoms of an
element, with all the isotopes in their normally occurring proportions.
an internal chamber. In the hearts of vertebrates, the thin-walled chamber(s)
entered by blood on its way to the ventricle(s). Also, the outer ear.
Organic compounds containing carbon, hydrogen, and oxygen in the ratio
1:2:1 (i.e., with the general formula CnH2nOn.) Common examples are sugars, starch, and cellulose
A relatively rigid structure that encloses cells of plants, fungi, many protists,
and most prokaryotes, and which gives these cells their shape and limits their expansion in
A paired organelle that helps organize the microtubules in animal and protest
cells during nuclear division
an organic molecule. It is asterol (or modified steroid),
essential structural component of animalcell membranes that is required to establish
proper membrane permeabilityand fluidity. Cholesterol is thus considered within the class
of lipid molecules. In addition to its importance within cells, cholesterol also serves as a
precursor for the biosynthesis of steroid hormones, bile acids, and vitamin D.
is the principal sterol synthesized by animals, all cells; invertebrates the liver typically
produces greater amounts than other cells
an organelle bounded by a double membrane containing the enzymes and
pigments that perform photosynthesis. Chloroplasts occur only in eukaryotes.
a nonprotein organic molecule that plays a role in catalysis by an enzyme.
An inorganic ion that is weakly bound to an enzyme and required for its activity
chemical bond based on the sharing of electrons between two atoms
the fundamental hereditary material of all living organisms.
In eukaryotes, stored primarily in the cell nucleus. A nucleic acid using deoxyribose rather than ribose
a carbohydrate made up of two monosaccharides(simple sugars)
a subatomic particle outside the nucleus carrying a negative charge and very little mass
a mechanism for regulating a metabolic pathway in which the
end product of the pathway can bind to and inhibit the enzyme that catalyzes the first
committed step in the pathway. Also called end-product inhibition.
a molecule made up of a long nonpolar hydrocarbon chain and a polar carboxyl
group. Found in many lipids.
a lipid to which sugars are attached.
A system of concentrically folded membranes found
in the cytoplasm of eukaryotic cells; functions in secretion from the cell by exocytosis.
in diploid organisms, having different alleles of a given gene on the pair of
homologs carrying that gene
Homozygous- in diploid organisms, having identical alleles of a given gene on both
homologous chromosomes. An individual may be a homozygote with respect to one gene
and a heterozygote with respect to another.
a chemical signal produced in minute amounts at one site in a multicellular
organism and transported to another site where it acts on target cells
a weak electrostatic bond which arises from the attraction between the
slight positive charge on a hydrogen atom and a slight negative charge on a nearby oxygen or nitrogen atom
having an affinity for water
having no affinity for water. Uncharged and nonpolar groups of atoms are hydrophobic
an exotic species that reproduces widely, and has negative effects on the
native species of the region to which it has been introduced
Ionic bond- an electrostatic attraction between positively and negatively charged ions
isotopes of a given chemical element have the same number of protons in their
nuclei(and thus are in the same position on the periodic table), but differ in the number of
species that has a disproportionately large effect on its
environment relative to its abundance.
critical role in maintaining the structure of an ecological community, affecting many
other organisms in an ecosystem and helping to determine the types and numbers of
various other species in the community.
Such species are described as playing a
bean shaped organs that serve several essential regulatory roles
in vertebrate animals. They are essential in the urinary system and also
serve homeostatic functions such as the regulation of electrolytes, maintenance of acid-
base balance, and regulation of blood pressure (via maintaining salt and water balance).
They serve the body as a natural filter of the blood, and remove water soluble wastes,
which are diverted to the urinary bladder. In producing urine, the kidneys excrete
wastes such as urea andammonium, and they are also responsible for the reabsorption
of water,glucose, and amino acids.
A membrane enclosed organelle originating from the Golgi apparatus and
containing hydrolytic enzymes
A type of protonephridium found in insects
an organelle in eukaryotic cells that contains the enzymes of the citric
acid cycle, the respiratory chain, and oxidative phosphorylation
a simple sugar. Oligosaccharides and polysaccharides are made up of monosaccharides
an invertebrate organ which occurs in pairs and performs a function similar to
the vertebrate kidney. Nephridia remove metabolic wastes from an animal's body.
a substance produced in and released by a neuron( the presynaptic
cell) that diffuses across a synapse and excites or inhibits another cell(the postsynaptic cell
A nervous system cell that can generate and conduct action potentials along an
axon to a synapse with another cell
The set of physical and biological conditions a species requires to survive, grow, and reproduce
nonpolar covalent bond
A polymer made up of nucleotides, specialized for the storage, transmission,
and expression of genetic information
a small, generally spherical body found within the nucleus of eukaryotic cells.
The site of synthesis of ribosomal RNA.
a basic chemical unit in nucleic acids, consisting of a pentose sugar, a
phosphate group, and a nitrogen-containing base.
(1) in cells, the centrally located compartment of eukaryotic cells that is bounded
by a double membrane and contains the chromosomes. (2) In the brain, an identifiable
group of neurons that share common characteristic s or functions
a body part, such as the heart, liver, brain, root, or leaf. Organs are composed of
different tissues integrated to perform a distinct function. Organs, in turn, are integrated
into organ systems.
any of the membrane-enclosed structures within a eukaryotic cell. Examples
include the nucleus, endoplasmic reticulum, and mitochondria.
a covalent chemical bond formed between two molecules when
the carboxyl group of one molecule reacts with the amino group of the other molecule,
causing the release of a molecule of water (H2O), hence the process is a dehydration
synthesis reaction (also known as a condensation reaction), and usually occurs
between amino acids. The resulting C(O)NH bond is called a peptide bond, and the
resulting molecule is an amide. The four-atom functional group -C(=O)NH- is called
a peptide link. Polypeptides and proteins are chains of amino acids held together by
peptide bonds, as is the backbone of PNA.
a lipid containing a phosphate group; an important constituent of cellular membrane
the membrane that surrounds the cell, regulating the entry and exit of
molecules and ions. Every cell has a plasma membrane.
polar covalent bond
a macromolecule composed on many monosaccharides(simple sugars)
Common examples are cellulose and starch.
In regulatory systems, information that amplifies a regulatory
response, increasing the deviation of the system from the set point
(1) A subatomic particle with a single positive charge. The number of protons in
the nucleus of an atom determine its element. (2) A hydrogen ion, H+
Purine- One of the two types of nitrogenous bases in nucleic acids. Each of the purines—
adenine and guanine—pairs with a specific pyrimidine
One of the two types of nitrogenous bases in nucleic acids. Each of the
pyrimidines—cytosine, thymine, and uracil—pairs with a specific purine
An often single-stranded nuclei acid whose nucleotides use ribose
rather than deoxyribose and in which the base uracil replaces thymine found in DNA.
Serves as genome from some viruses.
any of several species of the same chemical element with
different masses whose nuclei are unstable and dissipate excess energy by spontaneously
emitting radiation in the form of alpha, beta, and gamma rays.
a small particle in the cell that is the site of protein synthesis
rough endoplasmic reticulum
the portion of the endoplasmic reticulum whose outer surface has attached ribosomes
smooth endoplasmic reticulum
portion of the endoplasmic reticulum that lacks ribosomes and has a tubular appearance
any of a family of lipids whose multiple rings share carbons. The steroid
cholesterol is an important constituent of membranes; other steroids function as hormones
(1) the molecule or molecules on which an enzyme exerts catalytic action. (2)
The base material on which a sessile(an immobile) organism lives
a simple lipid in which three fatty acids are combined with one molecule of glycerol
van der waal interaction
Weak attractions between atoms resulting from the
interaction of the electrons of one atom with the nucleus of another. This type of attraction
is about one-fourth as strong as a hydrogen bond.
a muscular heart chamber that pumps blood through the lungs or through the body