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.