Chapter 4&5

Streptomycin is an antibiotic that interferes with the function of the 30S subunit of the prokaryotic ribosome. What is the consequence of treating a bacteria with streptomycin?

Correct!

Impaired protein synthesis

Impaired ATP synthesis

Impaired DNA synthesis

Impaired oxygen synthesis

Question 2

10 / 10 pts

The "X" shaped chromosomal hereditary material can be packaged in this organelle in eukaryotic cells but not in prokaryotic cells. This organelle is the:

mitochondria.

chloroplast.

Correct!

nucleus.

ribosomes.

nucleoid.

Question 3

0 / 10 pts

Alcohol consumption adversely affects the synthesis of molecules involved in protein degradation, which can eventually lead to liver damage. Given this information, which organelle in liver cells is most directly affected by alcohol consumption?

Nucleus

Golgi apparatus

Correct Answer

Rough endoplasmic reticulum

You Answered

Lysosome

Question 4

10 / 10 pts

Microfilaments such as actin, microtubules, and the intermediate filaments form the cell-supporting structure called the:

cytoplasm.

Correct!

cytoskeleton.

plasma membrane.

nucleus.

Question 5

10 / 10 pts

Some of the functions of the eukaryotic organelles are performed in bacteria by the:

flagella/cilia.

cell wall.

Correct!

plasma membrane.

nucleoid area.

capsule.

Question 6

10 / 10 pts

In eukaryotes, mitochondria are the organelles primarily involved in:

phospholipid assembly.

lipid synthesis.

Correct!

energy release/capture.

protein synthesis.

export of enzymes.

Question 7

0 / 10 pts

A protein that is destined to reach the plasma membrane is making its way through the Golgi. At that moment, a drug was added to cells, blocking trafficking at the trans face of the Golgi. As a result, what would happen to the protein?

The protein would continue on to the cell surface.

You Answered

The protein would return to the endoplasmic reticulum via the trans face of the Golgi.

Correct Answer

The protein would be stuck in the Golgi.

The protein would exit the Golgi, but instead be targeted to the cytoplasm.

Question 8

10 / 10 pts

Many antibiotics kill bacteria because they hinder translation by prokaryotic _________.

cytoplasm

capsules

nucleoids

cytoskeleton

Correct!

ribosomes

Question 9

10 / 10 pts

Prokaryotic cells are smaller than eukaryotic cells. What is a plausible explanation?

Prokaryotic cell walls limit their cell growth.

Prokaryotes have more diverse energy sources.

Prokaryotes lack the genetic material needed for protein synthesis.

Eukaryotes are immobile allowing them to grow larger.

Correct!

Eukaryotes have compartmentalization, which allows for specialization.

Question 10

0 / 10 pts

The nucleolus is the site of:

lipid synthesis.

Correct Answer

ribosome assembly.

protein synthesis.

You Answered

chromosome replication.

uncoiling and unraveling of chromosomes.

Question 11

10 / 10 pts

Prokaryotic cell movement is attributed to:

Correct!

flagella.

cytoskeleton proteins.

capsules.

ribosomes.

pili.

Question 12

10 / 10 pts

Given what is known about the minimal essential functions of cellular life, if you could create an artificial cell, what cellular structures must you include?

nucleus

Correct!

ribosomes

mitochondria

cell wall

Question 13

0 / 10 pts

A cytologist is examining a tissue under an electron microscope. He notices that the endoplasmic reticulum of each cell is extremely rough in appearance and he knows that the rough appearance is because of the ribosomes embedded there. He asks why there are so many ribosomes. You respond,

You Answered

"This tissue exports various nucleic acids, hence the large number of ribosomes present on the endoplasmic reticulum in each of those cells."

Correct Answer

"This tissue exports proteins to other areas of the body."

"This tissue exports lipids and is very involved with mRNA production."

Question 14

10 / 10 pts

Integrins are glycoproteins that help link the cytoskeleton and the:

Correct!

extracellular matrix.

cytoplasm.

cell wall.

ribosomes.

Question 15

10 / 10 pts

A dish of cells is treated with centrinone, a centriole inhibitor. These cells would no longer be able to _________.

synthesize proteins

Correct!

divide

produce lysosomes

make ATP

conduct photosynthesis

Question 16

0 / 10 pts

Based on the function of mitochondria, what substance is able to pass through the outer membrane of the mitochondria easily?

Correct Answer

Oxygen

Sugars

You Answered

Amino acids

Potassium ions

Question 17

10 / 10 pts

A circular molecule of DNA devoid of any histone proteins describes the chromosome of a (an):

protozoa

flowering plants

yeasts

insects

Correct!

bacteria

Question 18

10 / 10 pts

The organelle involved in the oxygen-requiring process by which the energy harvested from macromolecules is used to generate ATP is the:

Correct!

mitochondria.

nucleus.

chloroplasts.

ER.

lysosome.

Question 19

10 / 10 pts

A cell biologist has developed a new drug that blocks vesicle transport at the cis face of the Golgi apparatus. What will this drug prevent from happening inside a cell?

The movement of vesicles from mitochondria to the Golgi apparatus.

Correct!

The movement of the lipids and proteins from the endoplasmic reticulum to the Golgi apparatus.

The movement of materials from the Golgi apparatus to the plasma membrane.

The synthesis of proteins or lipids on the endoplasmic reticulum.

Question 20

0 / 10 pts

Photosynthetic pigments in bacteria are located in the:

cell wall.

You Answered

plasmids.

nuclei.

chloroplasts.

Correct Answer

plasma membrane.

Question 21

10 / 10 pts

Mitochondria and chloroplasts are the other organelles besides the nucleus that contain:

channels.

Correct!

DNA.

pores.

pigments.

plasma membranes.

Question 22

0 / 10 pts

You stain a cell with a dye that reacts with an enzyme found in the lysosome. You would also expect to see this dye in the:

You Answered

cytoplasm.

nucleus.

Correct Answer

endoplasmic reticulum.

mitochondria.

Question 23

10 / 10 pts

Plant cells often have a large membrane-bound sac that is used for storing water and other substances called a:

Golgi body.

chloroplast.

nucleus.

Correct!

central vacuole.

centriole.

Question 24

10 / 10 pts

Cilia and flagella of eukaryotic cells are composed of:

nine triplets of microtubules in a circle.

Correct!

microtubules in a 9 + 2 arrangement.

protein fibers in a helical arrangement.

actin filaments in a 9 + 2 arrangement.

Question 25

0 / 10 pts

Matthew noticed that his house plants were wilting badly. Which cell structure had most likely contracted?

cytoplasm

plasma membrane

You Answered

cell wall

Correct Answer

vacuole

Question 26

0 / 10 pts

A type of molecule movement of that is specific and passive and becomes saturated if all of the protein carriers are in use:

endocytosis.

Correct Answer

facilitated diffusion.

exocytosis.

You Answered

osmosis.

active transport.

Facilitated diffusion allows movement of specific molecules though transport proteins without the use of energy (ATP).

Question 27

10 / 10 pts

The movement of substances from regions where their concentration is higher to regions where their concentration is lower is called:

exocytosis.

pinocytosis.

pumping.

Correct!

diffusion.

active transport.

When a solute moves from high concentration to low concentration, it does not need energy. Movement without using energy is not active, and only one choice here does not need an energy source such as ATP

Question 28

10 / 10 pts

A scientist performs an experiment in which they create an artificial cell with a selectively permeable membrane through which only water can pass. They inject a 5M solution of glucose into the cell and then place the cell into a beaker of water. After an hour, what effect do you expect to observe?

Glucose moves out of the cell

Glucose moves into the cell

Correct!

Water moves into the cell

No net change in cell weight

Water moves out of the cell

Question 29

0 / 10 pts

Membrane potential will affect the directional movement of

Glucose (

)

Oxygen (

)

Correct Answer

Potassium (

)

You Answered

Cholesterol

Question 30

0 / 10 pts

A phospholipid molecule has a polar and a nonpolar end. Because of this, water molecules form:

hydrogen bonds with the nonpolar end of the phospholipid molecule.

polar bonds with the polar end of the phospholipid molecule.

polar bonds with the nonpolar end of the phospholipid molecule.

You Answered

covalent bonds with the nonpolar end of the phospholipid molecule.

Correct Answer

hydrogen bonds with the polar end of the phospholipid molecule.

Water molecules can form hydrogen bonds with other molecules due to their dipolar charge, and are attracted to polar molecules due to the ability of the water to interact with them.

A phospholipid molecule has a polar head and a non-polar tail, so water is only attracted to one side of the molecule.

Water molecules can form hydrogen bonds with other molecules due to their dipolar charge, and are attracted to polar molecules due to the ability of the water to interact with them.

A phospholipid molecule has a polar head and a non-polar tail, so water is only attracted to one side of the molecule.

Question 31

10 / 10 pts

While water continually orients phospholipids into a lipid bilayer, it does not fix the lipids permanently into position. Thus, the bilayer is considered to be_________.

fluctuating

Correct!

fluid

charged

static

The proteins and phospholipds move around within the lipid bilayer, but the bilayer does not separate

Question 32

10 / 10 pts

In a single pump cycle where sodium and potassium are exchanged and ATP is used, the following is expected:

Correct!

3 sodium ions leave and 2 potassium ions enter.

sodium and potassium ions enter and water leaves.

2 sodium ion leaves and 1 potassium ion enters.

3 sodium ions enter and 2 potassium ions leave.

2 sodium ion enters and 1 potassium ion leaves.

Na+ is kicked out of the cell, and K+ is drawn in. More Na+ is removed (3 ions) than K+ (2 ions) is brought in, leading to a net negative change in the cell.

Question 33

10 / 10 pts

Membrane proteins serve many functions. One of the functions is transportation of substances across the membrane. If a cell biologist placed cells into an environment in which a chemical has been added that blocks the function of only carrier proteins, the process that will be affected is

osmosis.

Correct!

active transport.

simple diffusion.

phagocytosis.

pinocytosis.

Question 34

0 / 10 pts

Cyclodextrins are a group of compounds capable of removing cholesterol from membranes. The effect most likely to have a large impact on cells as a result of cyclodextrin treatment would be

Correct Answer

increased membrane fluidity at higher temperatures.

increased membrane fluidity at lower temperatures.

disruption of transmembrane protein structure.

You Answered

increased permeability of the membrane.

increased concentration of transmembrane proteins.

Question 35

10 / 10 pts

If a cell has the same internal concentration of dissolved molecules as its outside environment, the cell's condition is referred to as being

hypotonic.

hydrophilic.

hypertonic.

Correct!

isotonic.

hydrophobic.

Hydrophobic and hydrophilic refer to the chemical relationship with water. Hypertonic and hypotonic are when the concentrations are different between the cell and the environment.

Question 36

0 / 10 pts

Facilitated diffusion is an important method cells use to obtain and remove necessary molecules. Requirements for facilitated diffusion include:

The carrier molecule is nonspecific to the molecule that is transported. The direction of movement is always with the concentration gradient, never against the gradient.

The carrier molecule is nonspecific to the molecule that is transported. The direction of movement is always against the concentration gradient, never with the gradient.

Correct Answer

The carrier molecule must be specific to the molecule that is transported. The direction of movement is always with the concentration gradient, never against the gradient.

You Answered

The carrier molecule must be specific to the molecule that is transported and an ATP molecule must be attached to the specific carrier. The direction of movement is always against the concentration gradient, never with the gradient.

Facilitated diffusion is the same as diffusion, but is more closely controlled using membrane proteins that allow a specific molecule to cross.

Question 37

10 / 10 pts

The fluid nature of the membranes is attributed to a lateral movement of

Correct!

phospholipid molecules.

the entire lipid bilayer.

protein channels.

antigen molecules.

pumps such as the proton pump.

The phospholipids are not bound to each other so they are free to move around and allow proteins to move between them

Question 38

10 / 10 pts

The accumulation of amino acids and sugars within animal cells can occur through:

glucose pumps.

Correct!

coupled transport.

ATP pumps.

proton pumps.

sodium-potassium pumps.

Coupled transport links the movement of two molecules, and uses the energy of diffusion of one molecule to help drive the reaction. Additional ATP is also required.

Question 39

0 / 10 pts

The plasma membrane is a thin sheet of lipid molecules embedded with

Correct Answer

proteins.

You Answered

carbohydrates.

polymers.

nucleotides.

sodium and potassium ions.

The rest of these choices are not located in the lipid bilayer

Question 40

10 / 10 pts

Membrane fluidity is affected by

hyrophillic tails, hydrophobic heads, cholesterol.

types of fatty acids, waters affinity for hydrogen bonding.

Correct!

temperature, cholesterol, types of fatty acids.

size of molecules, polarity of molecules, temperature.

The plasma membrane is a complex interaction in which like attracts like, so hydrophilic heads and hydrophobic tails bind together to create a bilayer. Cholesterol allows the phospholipids some fluidity in their interactions.

Question 41

10 / 10 pts

Osmosis occurs as water crosses the lipid bilayer through specialized channels for water movement called_________.

proteins

membrane pores

Correct!

aquaporins

transmembrane carbohydrates

Only aquaporins specifies osmosis movement

Question 42

10 / 10 pts

A scientist performs an experiment in which they create an artificial cell with a selectively permeable membrane through which only water can pass. They inject a 5M solution of glucose into the cell and then place the cell into a beaker containing 10M glucose. What effect do you expect to observe?

Correct!

Water moves out of the cell

Glucose moves into the cell

Water moves into the cell

Glucose moves out of the cell

No net change in cell weight

Question 43

10 / 10 pts

Membrane proteins are not very soluble in water because they possess long stretches of non-polar amino acids that are

too long to interact with the water molecules.

used as transport channels.

Correct!

hydrophobic.

hydrophilic.

are transmembranal.

All choices can be found in transmembrane proteins, the only choice that would make a protein non-water soluble would be hydrophobic properties

Question 44

0 / 10 pts

Turgor pressure is observed when a plant cells environment is_________.

Correct Answer

hypoosmotic

You Answered

hyperosmotic

osmosis

isosmotic

Turgor is seen when a plant is 'stiff,' or not limp. In order for this to occur, the plant cell should be filled with the maximum amount of water possible. If the environment is hypotonic, water will always want to enter the cell via osmosis, but the plant cell is prevented from bursting via the strong cell wall.

Question 45

10 / 10 pts

The lipid layer that forms the foundation of cell membranes is primarily composed of molecules called_________.

cholesterol

proteins

Correct!

phospholipids

carbohydrates

Question 46

10 / 10 pts

Which type of protein is embedded in the cell membrane for both active transport and facilitated transport?

targeted

cytoskeletal

structural

Correct!

carrier

Cytoskeletal proteins support the cell shape, as do structural proteins. "Targeted" proteins is a broad term.

Question 47

10 / 10 pts

How are the tails and heads of membrane phospholipids oriented in their environment?

The hydrophobic heads are oriented toward each other and the hydrophillic tails are oriented toward the extracellular fluid and the intracellular fluid.

The hydrophillic tails are oriented toward each other and the hydrophobic heads are oriented toward the extracellular fluid and the intracellular fluid.

The hydrophillic heads are oriented toward each other and the hydrophobic tails are oriented toward the extracellular fluid and the intracellular fluid.

Correct!

The hydrophobic tails are oriented toward each other and the hydrophillic heads are oriented toward the extracellular fluid and the intracellular fluid.

The hydrophobic tails are oriented away from the water in the environment, so they are shielded in the center. The hydrophilic heads then face the inside and outside of the cell, since they can interact with water.

Question 48

10 / 10 pts

Osmosis can only occur if water travels through the

ER.

vacuole.

cell wall.

cytoskeleton.

Correct!

semipermeable membrane.

Water should not be able to travel though any of the other structures mentioned freely, with the excpetion of the semipermeable membrane

Question 49

10 / 10 pts

If two solutions have unequal concentrations of a solute, the solution with the lower concentration is called

osmosis.

hypertonic.

isotonic.

Correct!

hypotonic.

Remember that "iso" means same, "hypo" means less, and "hyper" means more.

Also recall that osmosis only relates to the movement of water molecules, not solute.

Remember that "iso" means same, "hypo" means less, and "hyper" means more.

Also recall that osmosis only relates to the movement of water molecules, not solute.

Question 50

10 / 10 pts

GABA receptors play an essential role in neurotransmission in the central nervous system. In response to the appropriate signal, these receptors open up and allow

to flow into the cell. Given this information, GABA receptors can be classified as a

Correct!

gated ion channel.

pump.

symporter.

gated carrier protein.