unit 2 microbiology

List the three components of ATP.

A high energy compound that gives off energy when the bond b/w the 2nd and 3rd (outermost) phosphate is broken. It releases energy to do cellular work. Generates ADP that can be converted back to ATP.

Explain the relationship between atoms and elements.

A particular atom will have the same number of protons and electrons and most atoms have at least as many neutrons as protons. An element is a substance that is made entirely from one type of atom.

Name the nitrogen bases of DNA and RNA.

Adenine (A), Guanine (G), and Cytosine (C)

______ are variant forms of the same element that differ in the number of neutrons.

Isotopes

Name the four main families of biochemicals.

carbohydrates, lipids, proteins, and nucleic acids

Positively charged ions are termed _____, and negatively charged ions are termed _____

cations anions

The ______ of molecules and compounds result when two or more atoms share, donate (lose), or accept (gain) electrons

chemical bonds

Molecules that are combinations of two or more different elements are termed ______

compounds

what are organic chemicals>

compounds containing both carbon and hydrogen atoms

The _______ of a solution expresses the amount of solute dissolved in a certain amount of solvent. It can be calculated by weight, volume, or percentage.

concentration

7.A solution with a pH of 2 ____ than a solution with a pH of 8.

has more h+

Molecules such as salt or sugar that attract water to their surface are termed _____. Nonpolar molecules, such as benzene, that repel water are considered _____. A third class of molecules, which includes the phospholipids in cell membranes, is considered ______ because these molecules have both hydrophilic and hydrophobic properties.

hydrophilic hydrophobic amphipathic

A chemical is called _____ if it does not contain both carbon and hydrogen.

inorganic

Molecules with ionic bonds are electrically neutral, but they can produce charged particles when dissolved in a liquid called a solvent. This phenomenon, called _____, occurs when the ionic bond is broken and the atoms dissociate (separate) into unattached, charged particles called _____

ionization ions

The compounds in these groups are assembled from smaller molecular subunits, or building blocks, and because they are often very large compounds, they are termed _____

macromolecules.

All such tangible materials that occupy space and have mass are called

matter

A ______ is a distinct chemical substance that results from the combination of two or more atoms.

molecule

All macromolecules except lipids are formed by polymerization, a process in which repeating subunits termed _____ are bound into chains of various lengths termed _____

monomers polymers

A _____ is a simple sugar containing from 3 to 7 carbons; a ______ is a combination of two monosaccharides; and a ______ is a polymer of five or more monosaccharides bound in linear or branched-chain patterns

monosaccharide disaccharide polysaccharide

Aqueous solutions containing both acids and bases may be involved in ____ reactions, which give rise to water and other neutral by-products.

neutralization

When covalent bonds are formed between atoms that have the same or similar electronegativity, the electrons are shared equally between the two atoms. Because of this balanced distribution, no part of the molecule has a greater attraction for the electrons. This sort of electrically neutral molecule is termed ____

nonpolar

Electrons move around the nucleus of an atom in pathways called

orbitals

8.Proteins are synthesized by linking amino acids with ____ bonds.

peptide

A molecule with such an asymmetrical distribution of charges is termed ____

polar

2.The ____ charge of a proton is exactly balanced by the ____ charge of a(an) ____.

positive, negative, electron

10.RNA plays an important role in what biological process?

protein synthesis

An atom derives its properties from a combination of subatomic particles called ______, which are positively charged; ______, which have no charge (are neutral); and ______, which are negatively charged.

protons (p+) neutrons (n0) electrons (e-)

Molecules entering or starting a reaction are called _____, and substances left by a reaction are called _____

reactants products

What is a catalyst?

substance that speeds up the rate of a chemical reaction

In a ______ reaction, the reactants bond together in a manner that produces an entirely new molecule (reactant A plus reactant B yields product AB

synthesis

Recall three characteristics common to all cells.

tend to be spherical, polygonal, cubical, or cylindrical. have chromosomes containing DNA and ribosomes for protein synthesis. are exceedingly complex in function.

What is dehydration synthesis?

the process of joining two molecules, or compounds, together following the removal of water

11.Elements have varying numbers of protons, neutrons, and electrons.T/F

true

Cysteine is the amino acid that participates in disulfide bonds in proteins. T/F

true

The number of electrons in the outermost shell of an element is known as its _____ it determines the degree of reactivity and the types of bonds an element can make.

valence

1.The smallest unit of matter with unique characteristics is

an atom

During ____ reactions, the reactants trade portions between each other and release products that are combinations of the two.

exchange

A compound is called "organic" if it is made of all-natural elements. T/F

false

Covalent bonds are those that are made between two different elements. T/F

false

Membranes are mainly composed of macromolecules called carbohydrates. T/F

false

The subunits of disaccharides and polysaccharides are linked by means of _____, in which carbons (each is assigned a number) on adjacent sugar units are bonded to the same oxygen atom like links in a chain

glycosidic bonds

The stability of atomic structure is largely maintained by

(1) the mutual attraction of the protons and electrons (opposite charges attract each other) and (2) the exact balance of proton number and electron number, which causes the opposing charges to cancel each other out.

List and define four types of chemical bonds.

-Covalent (cooperative valence) bonds form between atoms that share electrons rather than donating or receiving them. -ionic bonds, electrons are transferred completely from one atom to another and are not shared. These reactions invariably occur between atoms with valences that complement each other. -hydrogen bond, a weak type of bond that forms between a hydrogen covalently bonded to one molecule and an oxygen or nitrogen atom on the same molecule or on a different molecule. -van der Waals forces. These weak attractions occur between molecules that demonstrate low levels of polarity. Neighboring groups with only slight attractions will approach each other and remain associated. These forces are an essential factor in maintaining the cohesiveness of large molecules with many packed atoms.

Electrons fill the orbitals and shells in pairs, starting with the shell nearest the nucleus. The first shell contains ___ orbital and a maximum of ___ electrons; the second shell has ___ orbitals and up to ___ electrons; the third shell with ____ orbitals can hold up to ___ electrons; and the fourth shell with ____ orbitals contains up to ____ electrons.

1,2 4,8 9,18 16,32

radioactive isotopes play a role in a number of research and medical applications. WHY?

Because they emit detectable signs, they can be used to trace the position of key atoms or molecules in chemical reactions, they are tools in diagnosis and treatment, and they are even applied in sterilization procedures

Provide examples of cell components made from each of the families of biochemicals.

Carbohydrates: glucose, fructose, maltose, lactose, sucrose, starch, cellulose, glycogen Lipids: fats, oils, membrane components, mycolic acid, cholesterol, ergosterol Proteins: enzymes - part of cell membrane, cell wall, ribosomes, antibodies Nucleic acids: chromosomes - genetic material of viruses, ribosomes - mRNA, tRNA, small RNAs, genetic material of viruses

______ help define the chemical class of certain groups of organic compounds and confer unique reactive properties on the whole molecule

Functional groups

List the three components of nucleotides.

Pentose sugar + phosphate + nitrogen base

Differentiate among primary, secondary, tertiary, and quaternary levels of protein structure.

Primary: the type, #, and order of amino acids.Secondary: arises when functional groups exposed on the outer surface of the molecule interact by forming H bonds. (alpha helix, beta-pleated sheet, random coil).Tertiary: created by additional bonds between functional groups.Quaternary: formed when more than one polypeptide forms a large, multiunit protein.

Differentiate between a solute and a solvent.

Solute and Solvent are the part of the solution where the dissolved matter in any solution or mixture is called as the solute, while the liquid or gas that dissolves another liquid, solid or gas is called as the solvent

Provide a brief definition of pH.

a graduated numerical scale that ranges from 0 (the most acidic) to 14 (the most basic). This scale is a useful standard for rating relative acidity and basicity

5.Hydrogen bonds can form between ____ adjacent to each other.

a hydrogen atom and a oxygen atom

6.An atom that can donate electrons during a reaction is called

a reducing agent

By one definition, a solution is considered _____ when a component dissolved in water (acid) releases excess hydrogen ions4 (H+); a solution is ______ when a component releases excess hydroxyl ions (OH-), so that there is no longer a balance between the two ions.

acidic basic

On this scale, a pH below 7 is ______, and the lower the pH, the greater the acidity. A pH above 7 is _____, and the higher the pH, the greater the _____

acidic basic basicity

4.Bonds in which atoms share electrons are defined as ____ bonds.

covalent

In _______ reactions, the bonds on a single reactant molecule are permanently broken to release two or more product molecules.

decomposition

9.DNA is a hereditary molecule that is composed of

deoxyribose, phosphate and nitrogen bases

Substances such as salts, acids, and bases that release ions when dissolved in water are termed ______ (because their charges enable them to conduct an electrical current).

electrolytes

All atoms share the same fundamental structure. All protons are identical, all neutrons are identical, and all electrons are identical. But when these subatomic particles come together in different combinations, unique types of atoms called _____ result.

elements