Fundamentals of Microbiology: Microbiology Chapter 2 Flashcards

What are the six most common elements needed in large amounts in living things?

1. Carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur.
2. Carbon, hydrogen, oxygen, sodium, calcium and nitrogen.
3. Carbon, hydrogen, nitrogen, oxygen, potassium and sodium.
4. Hydrogen, copper, zinc, oxygen, iron, manganese and sodium.

The smallest indivisible part of an element is the

1. atom.
2. isotope.
3. electron.
4. neutron.

The mass number of an atom is determined by adding the number of

1. protons and electrons.
2. neutrons and protons.
3. isotopes and protons.
4. electrons and neutrons.

All the following are components of an atom except

1. electrons.
2. neutrons.
3. lipids.
4. protons.

What is the densest part of an atom that has the greatest amount of the mass of the atom?

1. electron cloud.
2. electron shell.
3. atomic nucleus.
4. orbit.

What makes up the atomic number of an element?

1. electrons + protons.
2. protons.
3. neutrons.
4. neutrons + protons.

What makes up the atomic weight of an element?

1. electrons + neutrons.
2. protons.
3. electrons.
4. neutrons + protons.

How many electrons are in a neutral atom?

1. The same number as the neutrons in the atom.
2. The same number as the protons in the atom.
3. The same number as the neutrons plus the protons.
4. You can't tell, it varies from one atom to the next.

What is the difference between ions and atoms of an element?

1. number of electrons they possess.
2. placement of their neutrons.
3. number of neutrons they possess.
4. number of protons in the atomic nucleus.

What do you get when an atom gains an electron?

1. An isotope.
2. A cation.
3. An anion.
4. An ionic bond.

Carbon enters into an enormous number and variety of chemical combinations partly because

1. it has four electrons in its outer shell.
2. it has no protons in its nucleus.
3. it is part of a protein molecule.
4. it forms isotopes.

What is an inert element?

1. An element where the proton number and neutron number are equal.
2. An element where the atomic number is higher than its atomic weight.
3. An element that forms ions occurs readily.
4. An element where the outer shell will not hold additional electrons.

The formation of a chemical bond that combines atoms in molecules depends in large measure on the

1. number of neutrons.
2. placement of electrons in the shells.
3. presence of organic matter in the environment.
4. proton configuration of the nucleus.

What happens in the formation of an ionic bond?

1. the addition of neutrons.
2. a loss of protons.
3. a transfer of electrons.
4. All of the above are correct.

What happens when two oppositely-charged atoms are attracted and are held together?

1. They form a covalent bond.
2. They form a hydrogen bond.
3. They form an ionic bond.
4. They form a strong bond.

What happens when a chemical bond is formed between the electropositive sodium ion and the electronegative chloride ion?

1. A covalent bond forms.
2. A hydrogen bond forms.
3. A biological bond forms.
4. An ionic bond forms.

What is the result of two or more atoms joining together?

1. An isomer.
2. An isotope.
3. An ionic bond.
4. A molecule.

What kind of bond is found in water, H₂O?

1. It has a hydrogen bond.
2. It has a polar covalent bond.
3. It has a nonpolar covalent bond.
4. It has an ionic bond.

Which one of the following statements does not apply to hydrogen bonds?

1. They form between water molecules.
2. They involve H and O atoms.
3. They are very strong bonds.
4. They are important in the formation of proteins and nucleic acids.

All the following characterize hydrogen bonding except

1. a strong and stable chemical force.
2. an attraction between nitrogen and hydrogen atoms.
3. the force between water molecules.
4. the shaping of proteins and nucleic acids.

In the chemical reaction A + B => AB, which are the reactants?

1. A
2. B
3. AB
4. A and B

What happens in a dehydration or synthesis reaction?

1. water is removed in the formation of a covalent bond.
2. monosaccharides are produced from polysaccharides.
3. water is incorporated into a molecule.
4. water is removed from a bacterial cell.

An acid is a chemical substance that

1. releases protons in solution.
2. has a sour taste.
3. has a lower pH value.
4. All the above are correct.

A substance whose pH is 8 contains

1. more hydroxyl ions than water.
2. less protein than water.
3. no hydrogen ions.
4. more hydrogen ions than water.

Why is a buffer important?

1. It maintains a neutral pH inside the cells.
2. It maintains a neutral pH outside the cells.
3. It maintains a stable pH in living things.
4. It isn't really very important, most cells don't have it.

Which one of the following is not an organic molecule?

1. Table salt
2. Nucleic acids
3. Glucose
4. Deoxyribose

The carboxyl group is important biologically. What is its chemical formula?

1. —OH.
2. —COOH.
3. —CHO.
4. —NH₂.

What is a functional group symbolized by –NH₂ known as?

1. hydroxyl group.
2. phosphate group.
3. amino group.
4. carboxyl group.

What is an important difference between monosaccharides and polysaccharides?

1. the number of nitrogen atoms in the molecule.
2. the presence of glycerol in monosaccharides.
3. the number of carbohydrate monomers in the molecule.
4. the specific amino acids present.

Carbohydrates are so named because

1. they contain carbon and hydrogen.
2. the numbers of carbon and hydrogen atoms are the same.
3. they react readily with water.
4. they can be hydrolyzed by the enzymes contained in water.

Glucose units may be linked in chains of hundreds or thousands in

1. proteins.
2. nucleic acids such as DNA.
3. polysaccharides.
4. disaccharides.

Fatty acids that contain many double bonds and lack hydrogen atoms are commonly said to be

1. saturated.
2. glycerol.
3. denatured.
4. polyunsaturated.

Guanine and cytosine are important constituents of

1. most acid solutions.
2. the chromosome of a cell.
3. most protein molecules.
4. the cellular membrane.

. All the following are components of a RNA molecule except

1. cytosine.
2. ribose.
3. thymine.
4. uracil

Nucleic acids are composed of all the following except

1. phosphate.
2. carbohydrate.
3. amino acids.
4. nitrogenous bases.

What nucleotide is a universal form of energy for cells?

1. ATP
2. glucose
3. ribose
4. deoxyribose

The peptide bond is a type of covalent bond that forms

1. in DNA.
2. only if ions are present.
3. between amino acids.
4. within water molecules.

In the formation of proteins, ______react with one another to form a linkage called a(n) ______.

1. fatty acids, peptide bond
2. glycerol molecules, ionic bond
3. amino acids, ionic bond
4. amino acids, peptide bond

Which one of the following is not associated with proteins?

1. Nitrogen-containing amino acids
2. Peptide bonds
3. Primary and secondary structures
4. Saturated fatty acids

There are ________ amino acids that build proteins.

1. four
2. twelve
3. twenty
4. sixty four

The sequence of amino acids in a protein is referred to as its

1. primary structure.
2. secondary structure.
3. tertiary structure.
4. quaternary structure.

Which one of the following is not found in the secondary structure of proteins?

1. Random coil
2. Pleated sheet
3. Disulfide bridge
4. Alpha helix

The tertiary structure of a protein is determined by the folding back on itself and forming of ionic and hydrogen bonds between the

1. amino groups
2. R groups
3. phosphate groups
4. carboxyl groups

A denatured protein is one that

1. has lost its three dimensional structure.
2. has reverted to a carbohydrate.
3. lacks amino acids.
4. lacks covalent bonds.

Which of the following organic elements is the most abundant in microorganisms?

1. carbohydrates
2. lipids
3. protein
4. nucleic acids