Definitions Flashcards
Cell
The basic unit of structure and function for all living organisms
Tissue
Multicellular organisms, similar cells, combine to form a tissue.
Organ
A group of tissues combine to form organs for a specific function
Organ system
A group of organs working together as a whole for a specific function
Organism
A complete living thing
Population
Organisms of the same species in a particular area
Community
Interacting populations in a particular area
Ecosystem
A community plus the physical environment
Biosphere
Regions of the earth’s crust, waters, and atmosphere inhabited by living things. The entire world!
Hypothesis
An educated guess
Theory
Concepts that join together well-supported and related hypotheses
Proton
Positive particle:: In the nucleus of an atom
Electron
Negatively charge particle:: In the nucleus of an atom
Neutron
Uncharged particle :: move in orbitals AROUND the nucleus in an electron shell.
Molecule
Electrically neutral group of two or more atoms held together by chemical bonds
Compound
Pure chemical substance consisting of two or more chemical substances that can be combined into smaller substances to create chemical bonds
Atomic number
Number of protons in an atom
Mass number
The sum of protons and neutrons in the nucleus
Acid
releasing hydrogen (H+) ions
Bases
take up hydrogen ions
Polymer
Largest of the biomolecules
Monomers
Subunits of polymer
Examples: amino acids (monomers) are linked to form a protein (polymer);
Example: many nucleotides (monomers) are linked to form a nucleic acid (polymer).
Peptide bond
synthesized when the carboxyl group of one amino acid molecule reacts with the amino group of the other amino acid molecule, causing the release of a molecule of water (H2O), hence the process is a dehydration synthesis reaction
Cytoskeleton
a network of fibers composed of proteins contained within a cell’s cytoplasm.
Ex: actin filaments, intermediate filaments, and microtubules
Turgor pressure
Swelling of a plant cell in hypotonic solution
Helps plant maintain erect position.
Crenation
Red blood cells that have shrunk
Plasmolysis
Shrinking of the cytoplasm due to osmosis
Active site
a small port in an enzyme where substrate molecules bind and undergo a chemical reaction.
Induced fit model
only the proper substrate is capable of inducing the proper alignment of the active site that will enable the enzyme to perform its catalytic function