Week 1 Flashcards
Definition of science
Knowledge or a system of knowledge covering general truths or the operation of general laws, especially as obtained and tested through scientific method
Natural Science
Such knowledge or such a system of knowledge concerned with the physical world and its phenomena
Hypothesis
A statement of what might be true
Fact
Confirmed to such a degree that it would be reverse to withhold provisional consent
Theory
A comprehensive explanation of some aspect of nature that is supported by a vast body of evidence
Element
A substance that cannot be broken down into other kinds of substances by ordinary chemical means
Atom
The smallest unit of an element that retains all of the elements properties, the number of protons in an atom determines the elements
Proton
Mass is 1 unit, electric charge is +1 unit
Neutron
Mass is 1 unit, electric charge is 0 units
Electron
Mass is 0 units, electric charge is -1 unit
The number of protons in an atom determines ____
The element
Isotopes
Atoms with the same number of protons (the same element) but different numbers of neutrons
Valence Shell
The outermost shell that contains one or more electrons
Covalent bond
A chemical bond in which two atoms share one pair of valence electrons
Molecule
Two or more atoms held together by chemical bonding
Compound
Molecule with two or more elements
Emergent properties
The properties of a compound are not simply a combination of the properties of its elements
Polar Molecule
A molecule with an uneven distribution of electric charge
Hydrogen bond
Weak attraction between polar molecules
Ion
Atom or molecule with a net electric charge
Ionic bond
A chemical bond resulting from the attraction between oppositely charged ions
Homogeneous mixture
Components cannot be distinguished with a light microscope
Heterogeneous mixture
Components can be distinguished visually
Chemical reaction
The making and breaking of chemical bonds
Enzyme
Makes a chemical reaction take place more easily
Diffusion
The net movement of a substance from an area of high concentration to an area of low concentration
Osmosis
The diffusion of water across a semipermeable membrane
Acidity
The concentration of the hydrogen ions
Acid (H+)
Substance that in water increases the concentration of hydrogen ions
Base (OH-)
Substance that in water increases the concentration of hydroxide ions
Acids and bases tend to ___
Neutralize each other
Lipids (ex: fat, oil, wax)
Non polar, high in chemical energy
Carbohydrates (ex: sugars, starch and cellulose)
Polar high in chemical energy, monosaccharides single sugar unit, disaccharides two sugar units and polysaccharides many sugar units
Nucleic acids (ex: DNA and RNA)
Genes and polymer of nucleotides
Proteins (ex: enzymes, hormones, structural proteins)
Folded chain of amino acids, polymer of amino acids
Prokaryotic cells
Have no true nucleus
Eukaryotic cells
Have a true nucleus
Unicellular
Each cell carries out all life processes
Bacterial cells
No true nucleus, no endoplasmic reticulum, no Golgi apparatus, no mitochondria, no chloroplasts, no vesicles or vacuoles, no centrosome
Animal cells
No cell wall, no plasmodesmata, no chloroplasts, no central vacuole
Plant cells have a cell wall called
Cellulose
Fungal cells are
Eukaryotic and have a cell wall named chitin
