Chapter 2 Chemistry Flashcards
Matter
anything that occupies space and has mass
Element
a substance that cannot be broken down into simpler substances by chemical reactions
Atom
the smallest unit of an element that can exist either alone or in combination
Neutron
the non-charged particle in the atoms nucleus
Proton
positively charged ions
Electron
negatively charged ions
Isotope
atoms with the same number of protons and different numbers of neutrons
Ion
an atom or group of atoms that has a + or - charge as a result of losing or gaining electrons
Ionic Bond
the formation of a chemical bond between ions of opposite charge
Covalent Bond
a bond formed between atoms as a result of sharing a pair of electrons
Hydrogen Bond
the weak intermolecular attraction between a hydrogen atom of one molecular and a nitrogen, oxygen, or fluorine atom of another molecule; especially significant in affecting the characteristics of water.
Molecule
the smallest possible unit of a substance that consists of 2 or more atoms
Compound
a substance composed of 2 or more elements chemically combined in definite proportions
Chemical Change
a change in which a substance loses its characteristics and changes into one or more new substances
Physical Change
alternating a substance in its state of matter and appearance without changing it into a new substance
Mixture
a material that contains 2 or more substances
energy
the ability to do work
kinetic energy
the energy of motion; may take the form of heat , light, electricity, etc.
potential energy
the energy that is stored until being released
entropy
a measure of unusable energy that escapes when energy is being converted from one form to another; an increase in disorder and degression
reactant
the starting substance of a chemical reaction
product
the physical result of a chemical reaction
activation energy
the initial energy necessary to start a chemical reaction
catalyst
a substance that affects the rate of a reaction but is not changed in the reaction
enzyme
a protein molecule that is produced by living cells to catalyze specific reactions
active site
the portion of an enzyme’s surface that is believed to band to a particular substrate during the action of an enzyme
substrate
the chemical or chemicals an enzyme will affect
solution
the uniform dissolving of one substance into another substance
solute
the dissolved substance in a solution
solvent
the substance (often a liquid) into which a solute is dissolved
concentration
an expression of the proportions of solute to solvent in a solution
diffusion
the random movement of atoms, ions, or molecules from an area of higher concentration to an area of lower concentration
equilibrium
a state of balance as is seen when diffusion has progressed to the point where there are no longer regions of higher and lower concentration
polar molecule
a molecule with charged poles (not balanced by symmetry)
cohesion
the force that holds molecules of the same substance together; characteristics that cause water to move up plant stem
adhesion
the force that holds molecules of different substances together
concentration gradient
the difference between the numbers of molecules in one area and the number of the same molecules in an area nearby
semipermeable membrane
a membrane that is permeable to certain molecules or ions but not to others
acid
any substance that yields hydrogen ions when dissolved in water; a substance that neutralizes a base
base
a substance that releases hydroxyl ions when dissolved in water; neutralizes an acid
pH
the measure of the concentration of hydrogen ions in a solution using values from 0 to 14
buffer
a dissolved substance that makes a solution resistant to a change in its pH (the concentration of hydrogen ions)
osmosis
diffusion of water molecules through a semipermeable membrane
organic compound
those that contain carbon
carbohydrate
an organic compound that contains only carbon, hydrogen, and oxygen
monosaccharide
a simple sugar
glucose
a common six-carbon simple sugar
disaccharide
a sugar composed of two monosaccharide
polysaccharide
a large, complex carbohydrate composed of many monosaccharides
starch
a polysaccharide; often used for energy storage by plants
glycogen
a polysaccharide; animal starch; branching chains of glucose molecules
cellulose
chains of glucose molecules; found in plant cell walls
lipid
an organic compound that is insoluble in water but soluble in certain organic solvent
fatty acid
a common lipid composed of a chain of 14-18 carbon atoms with a carboxyl group on the end
hydrophilic molecule
a molecule attracted to or having an affinity for water
hydrophobic molecule
a molecule not having an affinity for water
triglyceride
the body’s most abundant type of lipid; formed by combining three fatty acid molecules to a molecule of glycerol (glycerin), a 3-carbon alcohol
saturated
describing a fatty acid molecule with only single bonds between carbon atoms
unsaturated
a fatty-acid molecule in which some of the carbon atoms are double-bonded to each other
steroid
a lipid composed of a carbon backbone of four carbon rings and a side chain of carbon atoms; many functions as hormones
monomer
one of the repeating units within a polymer or macromolecule
polymer
a macromolecule made up of a chain of a chain of monomers, sometimes identical
protein
an organic compound that is composed of amino acids
amino acid
the basic “building blocks” of a protein molecule
polypeptide
a chain formed by many peptide bonds, as in formation of a protein by many amino acids being bonded by peptide bonds
nucleic acid
an organic compound in living cells that is responsible for passing on hereditary information; DNA and RNA
DNA
deoxyribonucleic acid; the nucleic acid that is located primarily in the nucleus; carrier of genetic information
double helix
the shape of a DNA molecule, characterized by two parallel, spiral strands
nucleotide
the basic components of a DNA or RNA molecule; each is made up of sugar, a phosphate, and a base
replication
the process whereby a DNA molecule duplicates itself and forms a new DNA molecule
RNA
ribonucleic acid; the type of nucleic acid that forms from DNA and functions with ribosomes to form proteins molecules
RNA polymerase
an enzyme that separates the DNA double helix to initiate transcription
What is a carb made up of and how does it function?
organic compounds that contain carbon, hydrogen, and oxygen
Primary function of carbs
Examples of monosaccharides
examples of disaccharides
sucrose
examples of polysaccharides
what substances make up lipids
Lipids are an essential component of the cell membrane. The structure is typically made of a glycerol backbone, 2 fatty acid tails (hydrophobic), and a phosphate group (hydrophilic)
what characteristics do lipids have
what are the physical characteristics of unsaturated fats
what are the physical characteristics of saturated fats
solid at room temp
list several lipids
What is the relationship b/w proteins and nucleic acids?
What is the realationship b/w amino acids and proteins?
An amino acid is the fundamental molecule that serves as the building block for proteins. There are 20 different amino acids. A protein consists of one or more chains of amino acids (called polypeptides) whose sequence is encoded in a gene.
What are the primary nucleic acids?
DNA and RNA
Describe the structure of the DNA model?
it is a double helix
What is unique about replication of a DNA molecule?
This is why DNA replication is described as semi-conservative, half of the chain is part of the original DNA molecule, half is brand new.
What is the structural difference b/w DNA and RNA?
DNA has a double helix and RNA is just a single strand
