Chapter 2: Chemistry Comes Alive

acidic solutions

pH less than 7

covalent bond is also called____?

peptide bond

two types of covalent bonds

polar and nonpolar

endergonic reaction

A non-spontaneous chemical reaction in which free energy is absorbed from the surroundings. (anabolic reactions)

Protons have a _______ charge.

positive charge

cushioning

protects certain organs from physical trauma

bases

proton acceptors

acids

proton donors

What is located in the nucleus?

protons and neutrons

Atoms are composed of three subatomic particles:

protons, neutrons, electrons

Decomposition

reactions involve breakdown of a molecule into smaller molecules or its constituent atoms (reverse of synthesis reactions) (catabolic reactions) AB --> A + B

atoms are _____ when they gain electrons and ______ when they lose electrons

reduced; oxidized

Buffers

resist abrupt and large swings in pH; convert strong acids or bases into weak ones

synthesis

(combination) reactions involve atoms or molecules combining to form larger, more complex molecule (anabolic) A + B --> AB

Structural levels of proteins

1. Primary 2. Secondary 3. Tertiary 4. Quaternary

exergonic reaction

A spontaneous chemical reaction that releases energy (catabolic and oxidative reactions)

Dissacharides

A sugar containing two monosaccharides (Sucrose, Lactose, Maltose)

steroids

A type of lipid characterized by a carbon skeleton consisting of four rings with various functional groups attached.

What is the primary energy-transferring molecule in cells?

ATP

Isotope

Atoms of the same number of protons but have a different numbers of neutrons

covalent bonds

Bonds created by sharing electrons with other atoms.

atomic weight

Average of the mass numbers of all isotopes

Polysaccharides

Carbohydrates that are made up of more than two monosaccharides

organic compounds

Compounds that contain carbon and hydrogen carbohydrates, fats, proteins, and nucleic acids

Polar solvent properties

Dissolves and dissociates ionic substances forms hydration (water) layers around large charged molecules

high heat of vaporization

Evaporation requires large amounts of heat Useful cooling mechanism

When an acid is added to a solution containing a weak base, the weak base will buffer the drop in pH by completely dissociating and accepting all of the hydrogen ions released from the acid.

False Buffers resist abrupt and large swings in the pH of body fluids by releasing hydrogen ions (acting as acids) when the pH begins to rise and by binding hydrogen ions (acting as bases) when the pH drops. Buffers can do this because they consist of a combination of a weak acid and a corresponding weak base. Weak acids and bases dissociate (ionize) partially and reversibly, whereas strong acids and bases dissociate completely and irreversibly.

What is the difference between kinetic and potential energy?

Kinetic energy is energy in action, while potential energy is stored energy. Energy can be transformed from potential -> kinetic.

Solvent

In a solution, the substance in which the solute dissolves. substance present in greatest amount

What explains the negative charge on the oxygen atom within the water molecule?

Oxygen atoms have a stronger pull on the electrons shared within a covalent bond formed between oxygen and hydrogen.

What is energy?

The ability to do work or put matter into motion

Which of the following statements regarding atoms is true? 1. The chemical reactivity of an atom is based on the overall number of electrons in the atom. 2. Atomic weight is determined by the number of electrons in an atom of a given element. 3. The reactivity of an atom is based on the number of electrons in its outer valance shell. 4. Atomic weight is determined by the number of protons in an atom of a given element.

The reactivity of an atom is based on the number of electrons in its outer valance shell.

Ture or False The major function of DNA is to provide the genetic instructions for protein synthesis.

True

high heat capacity

Water's ability to absorb and retain heat

inorganic compounds

Water, salts, and many acids and bases Do not contain carbon

chemical equilibrium

a state of balance in which the rate of a forward reaction equals the rate of the reverse reaction and the concentrations of products and reactants remain unchanged (neither a forward nor a reverse reaction is dominant)

Identifying facts about an element include:

atomic number, mass number, isotopes, and atomic weight

neutralization reaction

acid and bases are mixed together

Exchange

aka displacement reactions involve both synthesis and decomposition - bonds are both made and broken AB + C --> AC + B AB + CD --> AD + CB

building blocks of proteins

amino acids (20 types)

Matter

anything that has mass and occupies space

the functional enzyme consists of two parts:

apoenzyme and a cofactor together form a holoenzyme

Catabolic

breaking down

Anabolic

building up

Water is an important molecule because it __________.

can form hydrogen bonds

major organic compounds

carbohydrates, lipids, proteins, nucleic acids

Which four elements comprise approximately 96% of our body weight?

carbon, oxygen, hydrogen, and nitrogen

enzymes are globular proteins that act as_____

catalysts

carbohydrates

consist of monomers called simple sugars ratio of two hydrogens and one oxygen for every carbon.

acids and bases are

electrolytes, they ionize and dissociate in water

all ions are _____

electrolytes; because they can conduct electrical currents in solution

carbon is

electroneutral shares electrons; never gains or loses them

What orbits around the nucleus?

electrons

kinetic energy

energy of motion

Chemical bonds are

energy relationships between electrons of reacting atoms

Triglycerides

energy storage, insulation, protection

nonpolar covalent bonds

equal sharing of electrons

Chemical reactions are either ____ or _____.

exergonic; endergonic

Molecule

general term for 2 or more atoms bonded together

water is the most inorganic compound because of its properties

high heat capacity, high heat vaporization, polar solvent properties, reactivity, cushioning

Solutions

homogeneous mixtures, meaning particles are evenly distributed throughout

What type of bond is formed between the oxygen atom of one water molecule and the hydrogen atom of another water molecule?

hydrogen bond

phospholipids

important in a cell membrane head - polar tail - nonpolar

Chemicals are either ______ or _____

inorganic; organic

salts

ionic compounds that dissociate into separate ions in water

3 types of chemical bonds

ionic, covalent, hydrogen

ionic bond

ions are atoms that have gained or lost electrons and become chanrged

The pH scale __________.

is based on the concentration of hydrogen ions in a solution

Radioisotopes

isotopes that decompose to more stable forms

eicosanoids

lipids derived from arachidonic acid (fatty acid)

pH scale

measurement of concentration of hydrogen ions in a solution

3 classes of carbohydrates

monosaccharides, disaccharides, polysaccharides

the body is made up of many chemicals which underlies these physiological reactions:

movement, digestion, pumping of heart, nervous system

Reactivity

necessary part of hydrolysis and dehydration synthesis reactions

Electrons have a ________ charge.

negative charge

3 main parts of the structure of the nucleic acid are

nitrogen base, pentose sugar, phosphate group

Neutrons have a ________ charge.

no charge

DNA found in

nucleus

Chemical Reactions

occur when chemical bonds are formed, rearranged, or broken

Alkaline (basic) solutions

pH 7.01-14

Monnosaccharide

simple sugar molecule (ribose and deoxyribose, glucose)

Which of the following statements about the polarity of covalent bonds is correct? 1.Nonpolar molecules have partial charges which can lead to hydrogen bonding. 2. Polar covalent bonds involve the transfer of electrons from electropositive atoms to electronegative atoms. 3. The atoms of a polar molecule share electrons equally. 4. Small atoms with 6 or 7 valence shell electrons tend to be electronegative.

small atoms with 6 or 6 valence electrons tend to be electronegative small atoms with 6 or 7 valence shell electrons, such as oxygen, nitrogen, and chlorine, are electron-hungry. They attract electrons very strongly, a capability called electronegativity.

The 3 states of matter are

solid, liquid, gas

Three types of mixtures

solutions, colloids, suspensions

Compound

specific molecule that has 2 or more different kinds of atoms bonded together

potential energy

stored energy

Solute

substance dissolved in solvent, present in smaller amounts

All matter is composed of elements. What are elements?

substances that cannot be broken down into simpler substances by ordinary chemical methods

3 major types of chemical reactions

synthesis, decomposition, exchange

elements are made up of atoms

the building blocks for each element

atomic number

the number of protons in the nucleus of an atom

What is the most significant factor in the formation of a covalent bond?

the sharing of electron pairs between two atoms

biochemistry

the study of chemical composition and reactions of living matter

mass number

the total number of protons and neutrons in the nucleus of an atom

True solutions are usually

transparent

lipids

triglycerides, phospholipids, steroids

polar covalent bonds

unequal sharing of electrons

hydrogen bond

weak attraction between an electropositive hydrogen atom and another atom