Biology 135 JCCC

There are four levels of protein structure. These figures show primary, secondary, tertiary, and quaternary protein structure. Which level(s) of protein structure may be stabilized by covalent bonds?

Primary, tertiary, and quaternary levels of protein structures

The type of bonding and the numbers of covalent bonds an atom can form with other atoms is determined by _____.

the number of unpaired electrons in the valence shell

Knowing the atomic mass of an element allows inferences about which of the following?

the number of protons plus neutrons in the element

An ionic bond is formed when _____.

one atom transfers an electron to another atom

A dehydration reaction (or condensation reaction) is the process in which _____.

water molecule is produce as a polymer is formed by monomers

The characteristic that all lipids have in common is that _____.

none dissolve in water

Starch and cellulose _____.

are polymers of glucose

Saturated fats

-solid at room temperature

-contain more hydrogen than unsaturated fats that consist of the same number of carbon atoms are -more common in animals than in plants

Carbohydrates consist of:

Starch, disaccharide, polysaccharides, and monosaccharides

The label on a container of margarine lists "hydrogenated vegetable oil" as the major ingredient. Hydrogenated vegetable oil _____.

is solid at room temperatures

Sucrose is formed when glucose is joined to fructose by a(n) _____.

glyosidic linkage

In a single molecule of water, two hydrogen atoms are bonded to a single oxygen atom by _____.

polar covalent bonds

The partial negative charge at one end of a water molecule is attracted to the partial positive charge of another water molecule. What is this attraction called?

a hydrogen bond

Which type of bond must be broken for water to vaporize?

hydrogen bond

Hydrophobic substances such as vegetable oil are _____.

nonpolar substances that repel water molecules

An acid is a substance that _____.

increases the hydrogen ion concentration of an aqueous solution

A pH of 6 is how many times more acidic than a pH of 9?

1,000

A solution contains 0.0000001 (10-7) moles of hydroxyl ions [OH-] per liter. Which of the following best describes this solution?

neutral

What is the pH of a solution with a hydroxyl ion (OH-) concentration of 10-12 M?

pH 2

What is the hydrogen ion (H+) concentration of a solution of pH 8?

10^-8

Plasmodesmata in plant cells are most similar in function to which of the following structures in animal cells?

gap junctions

Mitochondria are found in _____.

plant and animal cells

Motor proteins provide for molecular motion in cells by interacting with what types of cellular structures?

components of the cytoskeleton

What is the most likely pathway taken by a newly synthesized protein that will be secreted by a cell?

ER, Golgi apparatus, vesicles that fuse with plasma membrane

The diameter of a typical eukaryotic cell is approximately ten times the diameter of a typical prokaryote. What is the ratio of the volume of typical eukaryotic: prokaryotic cells?

1,000:1

Some regions of a polypeptide may coil or fold back on themselves. This is called _____, and the coils or folds are held in place by _____.

secondary structure...hydrogen bonds

A hydrophobic amino acid R group (side group) would be found where in a protein?

on the inside of the folded chain, away from water

The tertiary structure of a protein is the _____.

unique three-dimensional shape of the fully folded polypeptide

The flow of genetic information in a cell goes from _____.

DNA to RNA to protein

The building blocks or monomers of nucleic acid molecules are called _____.

nucleotides

One of the primary functions of RNA molecules is to _____.

function in the synthesis of proteins

Which of the following descriptions best fits the class of molecules known as nucleotides?

nitrogenous base, phosphate group, and a sugar

Which molecule is a nucleotide?

ATP

The structural level of a protein least affected by a disruption in hydrogen bonding is the

primary level

Which level of protein structure do the α-helix and the β-pleated sheet represent?

secondary structure

What is the function of the nuclear pore complex found in eukaryotes?

it regulate the movement of proteins and RNA into and out of the nucleus

Which of the following macromolecules leaves the nucleus of a eukaryotic cell through pores in the nuclear membrane?

mRNA

Which structure is the site of the synthesis of proteins that may be exported from the cell?

Rough ER

The liver is involved in detoxification of many poisons and drugs. Which of the following structures is primarily involved in this process and, therefore, abundant in liver cells?

Smooth ER

Which of the following produces and modifies polysaccharides that will be secreted?

Golgi Apparatus

Carbohydrate monomer

monosaccharide

carbohydrate polymer

polysaccharide