Biology Chapter 2
peptide bond
is one that links the carboxyl group of one amino acid to amino group of another amino acid.
What elements are essential to life? What are their chemical symbols?
Oxygen (O) Carbon (C ) Hydrogen (H) Nitrogen (N) Calcium (Ca) Phosphorus (P) Potassium (K) Sulfur (S) Chlorine (Cl) Sodium (Na) Magnesium (Mg)
if a bottle of ammonia is spilled in the basement and you begin to smell it upstair, what process has occurred
dispersion
a atom has all the characteristics of and is the smallest unit of a/an
element
the first law of thermodynamics states that
energy can be neither created nor destroyed
Describe an atom. What is the significance of its electron configuration?
An atom is the smallest unit of an element that still exhibits the characteristic of that element. The significance of its electron configuration is it allow matter to be stable and stay together.
List and compare the characteristics of a chemical change and a physical change.
Chemical Change - take place in definite portions, new compounds are formed and there is a release of elements, energy is involved Physical Change - changes it appearance, change state of something
according to the heat energy involved, what are the two basic types of chemical reactions
Endothermic and Exothermic
Name. describe and give example of two basic forms of energy
Kinetic which is energy of motion and potential is stored energy. Example: falling is kinetic and potential is a rock sitting on the top of a cliff.
Chemistry
The science of matter, its properties, and its interactions
permeable
a barrier that allows passage of all molecules
sucrose
a common disaccharide, table sugar; a substance made of one glucose molecule and one fructose molecule
glucose
a common six-carbon simple sugar
Molecular formula
a description of molecule that indicates the number and kinds of atoms in the molecule
buffer
a dissolved substance that makes a solution resistance to a change in its pH (the concentration of hydrogen ions).
hydrolysis
a reaction whereby a substance is split apart by the addition of a molecule of water
monosaccharide
a simple sugar
concentration
a solution ratio of the solute in the solvent
Compound
a substance composed of two or more elements combined in definite proportions
catalyst
a substance that affects the rate of reaction but is not changed in the reaction
base
a substance that releases hydroxyl ions when dissolved in water; neutralizes an acid
disaccharide
a sugar compound of two monosaccharides
ph
a symbol that is used with numbered values from 1 to 14 to indicate the concentration of hydrogen ions in a solution
the amount of energy required to initiate a chemical reaction is called
activation energy
Ion
an atom or group of atoms that has a positive or negative charge as a result of losing or gaining electrons
Structural formula
an expanded drawing that shows the arrangement of atoms and bonds with the molecule
acid
any substance that yields hydrogen ions when dissolved in water; a substance that neutralizes a base
hydrophilic
attracted to or having an affinity of water
an aqueous solution that has an excess of hydrogen ions would
be an acid
cellulose
chains of glucose molecules; found in plant cell walls
polypepride chain
consists of smaller subunits or amino acids that are linked together.
a chemical bond characterized by sharing electrons is called a _______ bond
covalent
catalysts affect the rate of a reaction by
decreasing the amount of activation energy needed
osmosis
diffusion of water molecules through a semipermeable membrance
chemical reaction that release heat are called _____ reaction
exothermic
sterol
have a carbon backbone of 4 different carbon rings plus a side chain of carbons
hydrogen bond
involves the hydrogen of one molecule attracted to the negative region of another water molecule
Define the two components of the physical world
matter and energy
the nucleus of an atom is made up of
neutrons and protons
Neutron
no charge
a chemical change is demonstrated by: A. Boiling of water B. Mixing sugar and water C. Chilling gelatin D. All of the above E. None of the above
none of the above
hydrophobic
not having an affinity for water
Carbohydrate
organic compound that contains only carbon, hydrogen and oxygen
lipid
organic compound that is insoluble in water but soluble in certain organic solvents
when only water diffuses through a semipermeable membrane, the process is termed
osmosis
list four characteristics of water that contribute to its unique biological importances
polarity of the molecule, Shape of the molecule, specific heat, the hydrogen bonds between the molecules
Protons
positive charge
list the three normal states of matter in order of increasing kinetic energy
solid, liquid and gas
Electron
that part of the atom that has a negative charge and that moves in a shell-like orbit around the nucleus
suspension
that state of a substance of a substance when its particles are mixed but not dissolved
energy
the ability to do work
amino acid
the basic "building block" of a protein molecule
concentration gradient
the difference between the number of molecules in one area as opposed to the number of the same molecules in an area nearby
activation energy
the initial energy necessary to start a reaction
diffusion pressure
the pressure for diffusion that is produced by the concentration gradient
Molecule
the smallest possible unit of a substance that consists of two or more atoms
Atom
the smallest unit of an element that can exist either alone or in combination
fatty acid
unbranched carbon chain with hydrophobic and hydeophilic ends
when mixed together, an acid and a base neutralized each other, forming
water and salt
equilibrium
when there are no longer places of higher or lower concentrations
Name and describe the two primary types of chemical bonding?
Iconic bond - a chemical bond between ions of opposite charge Covalent bond - a chemical bond formed between atoms as a result of sharing a pair of electrons
Chemical Change
a change in which a substance loses its characteristics and changes into one or more new substances.
phospholipid
a molecule consisting of two fatty acid molecules and a phosphate group attached to a glycerol molecule.
starch
a polusaccharide; often used for energy storage by plants
glycogen
a polysaccharide; animal starch; branching chains of glucose molecules
Physical Change
alternation of a substance in its state of matter and appearance without it being changed into a new substance.
potential energy
is stored energy, like the energy found in rocks sitting at the top of a cliff, in a log waiting to be burned, or in a battery ready to be connected to a light bulb
kinetic energy
is the energy of motion, such as falling, heat, light and electricity
in a solution of seawater, is water the solute or the solvent
solvent
nucleotide
the basic component of a DNA or RNA molecule; each is made up of a sugar, a phosphate and a base
solute
the dissolved substance in a solution
saturated
what the fatty acid is called if each of the carbon atoms in a fatty acid molecule (except the end ones) has 2 hydrogen atoms attached
unsaturated
what the fatty acid is called if one or more of the carbon atoms are double bonded resulting in fewer hydrogen atoms attached to the carbon backbone.
neutralize
when an acid and base are put together
polysaccharide
a large complex carbohydrate composed of many monosaccharides
entropy
a measure of the unusable energy that escapes when energy is being converted from one form to another; an increases in disorder and degeneration
semipermeable membrane
a membrane that is permeable to certain molecules or ions but not to others
colloid
a mixture of fine particles, often including proteins molecules; these particles do not settle out
polar
a molecule with charged poles
dehydration synthesis
the process where by two molecules combine and a water molecule is released
diffusion
the random movement of atoms, ions or molecules from an area of higher concentration of an area of lower concentration
solvent
the substance (often a liquid) into which a solute is dissolved
solutions
the uniform dissolving of one substance into another
what are the first and second laws of thermodynamics
1st Law states - that in any process, energy is neither created nor destroyed 2nd Law state - states that whatever energy is used (changed from one form to the other) some of it is rendered usable (though not destroyed or lost).
Element
A substance that cannot be broken down into simpler substances by chemical reactions
Define and compare the following: An atom, an ion, a molecule, a compound, a mixture
An atom - the smallest unit of an element that can exist either alone or in combination An Ion - an atom or group of atoms that has a positive or negative charge as a result of losing or gaining electrons A Molecule - a substance composed of two or more elements combined in definite proportions, smallest unit of a compound that is still in nature state A compound - a substance composed of two or more elements combined in definite proportions Mixture - when two substance are combined without chemical bonding.
Matter
Anything that occupies space and has mass
Why is an understanding of chemistry important for an understanding of Biology?
Because changes of matter take place and therefore in order to understand Biology you must first understand chemistry.
DNA
The nucleic acid that is located primarily in the nucleus; carrier of genetic information
Ionic Bond
a chemical bond between ions of opposite charge
Covalent Bond
a chemical bond formed between atoms as a result of sharing a pair of electrons
chitin
a chemical component in the exoskeletons if arthropods and in the cell walls of fungi
What things can a scientist determine (a) by studying a molecular formula of a compound and (b) by studying a structural formula of a compound?
by studying a molecular formula - they can discover the number of type of atoms in a compound By studying a structural formula - they can discover where the atoms are atoms are located and the arrangement of chemical bonds.
