Microbiology Chapter 2 The chemistry of microbiology. Q&A

Functional group

an arrangement of atoms common to all members of a class of organic molecules, such as the amine group found in all amino acids

Ion

an atom or group of atoms that has either a full negative charge or a full positive charge

Chemical Bond

an interaction between atoms in which electrons are either shared or transferred in such a way as to fill their valence shells

Neutron

an uncharged subatomic particle

Lipid

any of a diverse group of organic macromolecules not composed of monomers and insoluble in water

matter

anything that takes up space and has mass

A synthesis reaction is also considered which of the following types of reactions? a. decomposition b. endothermic c. hydrolysis d. catabolism

b

Sucrose is an example of which of the following? a. nucleotide b. disaccharide c. steroid d. dipeptide

b

Two atoms with vastly different electronegativities can form which of the following? a. a nonpolar covalent bond b. an ionic bond c. either a polar or a nonpolar covalent bond d. a polar covalent bond

b

Which of the following subatomic particles does NOT have a charge? a. protons b. neutrons c. protons and neutrons d. electrons

b

All of the following are sources of organic acids EXCEPT: a. lemon juice b. tea c. baking soda d. black coffee

c

Which of the following is a polysaccharide produced by animals? a. cellulose b. amylose c. glycogen d. amylopectin

c

Which of the following nitrogenous bases are purines? a. thymine and cytosine b. uracil and adenine c. adenine and guanine d. cytosine and guanine

c

Which of the following pairs of terms is an INCORRECT match? a. anabolism: forming chemical bonds. b. exothermic: release of energy c. synthesis: exothermic d. decomposition: catabolism

c

Which of the following the most alkaline pH? a. pH 7.0 b. pH 2.0 c. pH 13.0 d. pH 9.0

c

Which of the following types of molecules is used in the transport of substances into and out of the cell? a. carbohydrate b. nucleic acids c. proteins d. lipids

c

Which of the following is NOT a type of lipid? a. steroids b. waxes c. triglycerides d. peptidoglycan

d

Which of the following pairs of terms is an INCORRECT match? a. nucleotides: genetic material b. polysaccharides: cellulose c. proteins: peptide bonds d. fats: pentoses

d

What type of protein is covalently bound to a carbohydrate?

glycoprotein

Two atoms that have vastly different electronegativities can form an

ionic bond.

Pure water has a neutral pH because

it dissociates into equal numbers of hydrogen and hydroxyl ions

Phospholipid

phosphate-containing lipid made up of molecules with two fatty acid chains

What is a buffer?

A buffer is a solution that releases or absorbs H+ to keep the pH from changing.

Catabolism

All of the decomposition reactions in an organism taken together

Electronegativity

The attraction of an atom for electrons

In discussions of atomic mass, electrons are often ignored because _____.

Their mass makes a negligible contribution to the atom's overall mass.

Catabolism includes all the following types of reactions EXCEPT: a. dehydration synthesis reactions b. exothermic reactions c. decomposition reactions d. hydrolysis reactions

a

What is the common trait of ALL lipids?

They have atoms linked by nonpolar covalent bonds.

Water is important for life for all of the following reasons EXCEPT a. water does not absorb heat energy b. water can participate in many cellular reactions c. water has enough surface tension to form a layer on the surface of cells d. water remains a liquid over a wide range of temperatures

a

Synthesis reaction

a chemical reaction involving the formation of larger, more complex molecules

Protein

a complex, macromolecule consisting of carbon, hydrogen, oxygen, nitrogen, and sulfur and important to many cell functions

Peptide bond

a covalent bond between amino acids in proteins

Hydrolysis

a decomposition reaction in which a covalent bond is broken and the ionic components of water are added to the products

Which type of molecule tends to be water soluble?

a molecule containing either ionic or polar covalent bonds

anion

a negatively charged ion

Electron

a negatively charged subatomic particle

Cation

a positively charged ion

Proton

a positively charged subatomic particle, which is also the nucleus of a hydrogen atom

buffer

a substance, such as a protein, that prevents drastic changes in pH

monomer

a subunit of a macromolecule such as a protein

Saturated Fat

a triglyceride in which all but the terminal carbon atoms are covalently linked to two hydrogen atoms

Ionic bond

a type of bond formed from the attraction of opposite electrical charges. electrons are NOT shared

An endothermic reaction ______

absorbs energy

Anabolism

all of the synthesis reactions in an organism taken together

KH2PO4 acts as a buffer by

combining with hydrogen ions

Acid

compound that dissociates into one or more hydrogen ions and one or more anions

Ions that can conduct electricity in an aqueous solution are called _____.

electrolytes

Nucleotide

monomer of a nucleic acid, which is composed of a nucleoside and a phosphate

Carbohydrate

organic macromolecule consisting of atoms of carbon, hydrogen, and oxygen

Polymer

repeating chains of covalently linked monomers found in macromolecules

Denaturation _______.

results in the disruption of the tertiary structure of a protein

Valence

the combining capacity of an atom

Hydrogen bond

the electrical attraction between a partially charged hydrogen atom and a full or partial negative charge on a different region of the same molecule or another molecule

Atomic number

the number of protons in the nucleus of an atom

Covalent bond

the sharing of a pair of electrons by two atoms

atomic mass

the sum of the masses of the protons, neutrons, and electrons in an atom

All proteins have a minimum of how many levels of protein structure?

three

Polar covalent bond

type of bond in which there is unequal sharing of electrons between atoms with opposite electrical charges

Nonpolar covalent bond

type of chemical bond in which there is equal sharing of electrons between atoms with similar electronegativities

Exchange reaction

type of chemical reaction in which atoms are moved from one molecule to another by means of the breaking and forming of covalent bonds

Dehydration synthesis

type of synthesis reaction in which two smaller molecules are joined together by a covalent bond, and a water molecule is formed