Chapter 5-8 BSC 1010C Exam Review

The internal solute concentration of a plant cell is about 0.8 M. To demonstrate plasmolysis, it would be necessary to suspend the cell in what solution?

1.0 M

Green olives may be preserved in brine, which is a 30% salt solution. How does this method of preservation prevent microorganisms from growing in the olives?

A 30% salt solution is hypertonic to the bacteria, so they lose too much water and undergo plasmolysis.

The concentration of solutes in a red blood cell is about 2%, but red blood cells contain almost no sucrose or urea. Sucrose cannot pass through the membrane, but water and urea can. Osmosis would cause red blood cells to shrink the most when immersed in which of the following solutions?

A hypertonic sucrose solution

Which of the following would be least likely to diffuse through a plasma membrane without the help of a transport protein?

A large, polar molecule

Which of the following lists represents the chemical components of a nucleotide?

A nitrogenous base, a phosphate group, and a pentose sugar

What do Alzheimer's, Parkinson's, and mad cow disease have in common?

All are associated with the buildup of misfolded proteins in cells.

Which of the following is/are likely to limit the maximum size of a cell?

All of the choices are correct.

Enzyme molecules require a specific shape to perform their catalytic function. Which of the following might alter the shape of an enzymatic protein?

All of the listed responses are correct.

Which statement about the sidedness of the plasma membrane is correct?

All of the listed responses are correct.

Which of the following is true regarding complementary base pairing in DNA and RNA molecules?

Although the base pairing between two strands of DNA in a DNA molecule can be thousands to millions of base pairs long, base pairing in an RNA molecule is limited to short stretches of nucleotides in the same molecule or between two RNA molecules.

Cells A and B are the same size, shape, and temperature, but cell A is metabolically less active than cell B, and cell B is actively converting oxygen to water in cellular respiration. Oxygen will diffuse more rapidly into cell __________ because __________.

B; the diffusion gradient in cell B is steeper

Which of the following statements correctly describes a common characteristic of a plant cell wall and an animal cell extracellular matrix?

Both are permeable to water and small solutes.

Seawater is hypertonic to cytoplasm in vertebrate cells and in plant cells. If a red blood cell and a plant cell were placed in seawater, what would happen to the two types of cells?

Both cells would lose water; the red blood cell would shrivel, and the plant plasma membrane would pull away from the cell wall.

Which of the following molecules is a monosaccharide?

C6H12O6

Which of the following molecules is most likely to passively diffuse across the plasma membrane?

Carbon dioxide

Which of the following is the simplest collection of matter that can live?

Cell

Which of the following statements is true about cell fractionation?

Cell fractionation separates cells into their component parts.

Which of the following components of a tossed salad will pass through the human digestive tract and be digested the least?

Cellulose (in the lettuce)

Which of the following structures is found in animal cells but not in plant cells?

Centrioles

Which of the following statements about chloroplasts and mitochondria is true?

Chloroplasts and mitochondria synthesize some of their own proteins.

High cholesterol levels are considered a major risk factor for heart disease. If it is so bad for humans, why does the body make cholesterol in the first place?

Cholesterol is the precursor for many important molecules such as sex hormones.

Which of the following is false in respect to eukaryotic chromosomes?

Chromosomes appear in an obvious form only as a cell is about to divide.

A shortage of phosphorus in the soil would make it especially difficult for a plant to manufacture __________.

DNA

Consider a protein that is made in the rough endoplasmic reticulum. You observe that when the synthesis of the protein is completed, the protein is located in the ER membrane. Where else in the cell might this protein be found?

Embedded in the plasma membrane, functioning in the transport of molecules into the cell

Which of the following is not a function of membrane proteins?

Energy, carbon, and nitrogen storage

In terms of cellular function, what is the most important difference between prokaryotic and eukaryotic cells?

Eukaryotic cells are compartmentalized, which allows for specialization.

Which of these statements describes some aspect of facilitated diffusion?

Facilitated diffusion of solutes may occur through channel or transport proteins in the membrane.

Which of the following is false in regard to facilitated diffusion?

Facilitated diffusion requires the hydrolysis of ATP.

Nutritionally, saturated triacylglycerols are considered to be less healthful than unsaturated triacylglycerols. What is the difference between them?

For carbon skeletons of equal length, saturated triacylglycerols have more hydrogen atoms than unsaturated triacylglycerols do.

A researcher made an interesting observation about a protein made by the rough endoplasmic reticulum and eventually found in a cell's plasma membrane. The protein in the plasma membrane was actually slightly different from the protein made in the ER. The protein was probably altered in the __________.

Golgi apparatus

Microtubules and microfilaments commonly work with which of the following to perform many of their functions?

Golgi apparatus

Which of the following sequences represents the order in which a protein made in the rough endoplasmic reticulum might move through the endomembrane system?

Golgi apparatus → lysosome

Consider the currently accepted fluid mosaic model of the plasma membrane. Where in the plasma membrane would cholesterol most likely be found?

In the interior of the membrane

Which of the following statements about diffusion is true?

It is a passive process.

The sex hormones estradiol and testosterone belong to which class of molecules?

Lipids

Generally, animals cannot digest (hydrolyze) the glycosidic linkages between the glucose molecules in cellulose. How then do cows get enough nutrients from eating grass?

Microorganisms in their digestive tracts hydrolyze the cellulose to individual glucose units.

Which of the following structures is found in eukaryotic but not prokaryotic cells?

Mitochondria

Which of the following is false?

Mitochondria contain ribosomes in the intermembrane space.

Which of the following five membranes is most likely to have a lipid composition that is distinct from those of the other four?

Mitochondrial outer membrane

Cilia and flagella move due to the interaction of the cytoskeleton with which of the following?

Motor proteins

Which type of cell is most likely to have the largest number of mitochondria?

Muscle cells in the legs of a marathon runner

Which of the following represents a specific description of a polypeptide?

None of the listed responses is correct.

A selectively permeable membrane separates two solutions. Water is able to pass through this membrane; however, sucrose (a disaccharide) and glucose (a monosaccharide) cannot pass. The membrane separates a 0.2-molar sucrose solution from a 0.2-molar glucose solution. With time, how will the solutions change?

Nothing will happen because the two solutions are isotonic.

Consider the currently accepted fluid mosaic model of the plasma membrane. Where in the membrane would carbohydrates most likely be found?

On the outside (external) surface of the membrane

Which of the following statements about passive transport is correct?

Passive transport permits the solute to move in either direction, but the net movement of solute molecules occurs down the concentration gradient of the molecule.

Which of the following is a true statement comparing phospholipids and triacylglycerols (fats and oils)?

Phospholipid molecules have a distinctly polar "head" and a distinctly nonpolar "tail," whereas triacylglycerols are predominantly nonpolar.

Which of the following statements about the role of phospholipids in the structure and function of biological membranes is correct?

Phospholipids form a selectively permeable structure.

Which of the following groups is primarily involved in synthesizing molecules needed by the cell?

Ribosome, rough endoplasmic reticulum, smooth endoplasmic reticulum

Which of the following organelles might be found inside other organelles?

Ribosomes

Which of the following features do prokaryotes and eukaryotes have in common?

Ribosomes, plasma membrane, and cytoplasm

The α helix and β pleated sheet represent which level of protein structure?

Secondary structure

In what polysaccharide form do plants store glucose to be available later as an energy source?

Starch

Carbohydrates can function in which of the following ways?

Structural support and energy storage

What is the functional connection between the nucleolus, nuclear pores, and the nuclear membrane?

Subunits of ribosomes are assembled in the nucleolus and pass through the nuclear membrane via the nuclear pores.

Which of the following describes a difference between DNA and RNA?

The first three listed responses correctly describe differences between DNA and RNA.

The plasma membrane is referred to as a "fluid mosaic" structure. Which of the following statements about that model is true?

The fluid aspect of the membrane is due to the mobility of phospholipids, and embedded proteins account for the mosaic aspect.

Amylase is an enzyme that breaks down starch. Why can the same enzyme not break down cellulose?

The monosaccharide monomers in cellulose are bonded together differently than those in starch.

A dish of animal cells was grown in the presence of radioactive phosphorous. The phosphorous largely ended up in nucleotides inside the actively growing animal cells. In which cellular structure or structures would you predict the majority of the radioactive phosphorous to accumulate?

The nucleus

Active transport requires an input of energy and can also generate voltages across membranes. Based on this information, which of the following statements is true?

The sodium-potassium pump hydrolyzes ATP and results in a net positive change outside the cell membrane.

Which of the following are pyrimidines found in the nucleic acid DNA?

Thymine and cytosine

A single plant cell is placed in an isotonic solution. Salt is then added to the solution. Which of the following would occur as a result of the salt addition?

Water would leave the cell by osmosis, causing the volume of the cytoplasm to decrease.

Which of the following lists ranks these molecules in the correct order by size from smallest to largest?

Water, glucose, sucrose, protein

If a small droplet of triacylglycerol molecules is suspended in water, the fat molecules form a "ball of spaghetti" with no particular orientation. But if a droplet of phospholipid molecules is put in water, all the molecules point outward, toward the water. Phospholipids are forced into this orientation because phospholipids have __________.

a charged or polar end and an uncharged or nonpolar end

The peptide bond is __________.

a covalent bond joining amino acids together to form a polypeptide

A glucose molecule is to starch as __________.

a nucleotide is to a nucleic acid

A particular cell has a nucleus and chloroplasts in addition to the fundamental structures required by all cells. Based on this information, this cell could be __________.

a photosynthetic protist cell or a plant cell

In a hydrolysis reaction, __________, and in this process, water is __________.

a polymer is broken up into its constituent monomers; consumed

Manufacturers make vegetable oils solid or semisolid at room temperature by __________.

adding hydrogen atoms to the fatty acid hydrocarbon chains, thereby converting carbon-carbon double bonds to single bonds

Based on complementary base pairing, you would expect the percentage of __________ to be equal to the percentage of __________.

adenine; thymine

Protein molecules are polymers (chains) of __________.

amino acid molecules

Lipids differ from other large biological molecules in that they __________.

are not truly polymers

Consider two cells with the same volume but with very different surface areas due to differences in their shapes. The cell with the larger surface area is likely to __________.

be involved in the rapid uptake of compounds from the cell's environment

At a conference, the speaker's grand finale was sautéing mealworms (insect larvae) in butter and serving them to the audience. They were crunchy (like popcorn hulls) because their exoskeletons contain the polysaccharide __________.

chitin

The type of bond that forms to join monomers (such as sugars and amino acids) into polymers (such as starch and proteins) is a(n) __________ bond.

covalent

Carbohydrates are used in our bodies mainly for __________.

energy storage and release

A polysaccharide that is used for storing energy in human muscle and liver cells is __________.

glycogen

The subunits (monomers) in cellulose are linked together by __________.

glycosidic linkages

Bacterial cells are prokaryotic. Unlike a typical eukaryotic cell, they __________.

have no membrane-bounded organelles in their cytoplasm

Which of the following terms can be correctly used to describe compounds that do not mix with water?

hydrophobic

The fatty acid tails of a phospholipid are __________ because they __________.

hydrophobic; have no charges to which water molecules can adhere

Chloroplasts and mitochondria are thought to be of prokaryotic origin. One piece of evidence that supports this hypothesis is that these organelles contain prokaryotic-like ribosomes. These ribosomes are probably most similar to ribosomes found __________.

in bacterial cells

A protein that ultimately functions in the plasma membrane of a cell is most likely to have been synthesized __________.

in the rough endoplasmic reticulum

The lipids that form the main structural component of cell membranes are __________.

phospholipids

Dye injected into a plant cell might be able to enter an adjacent cell through __________.

plasmodesmata

You would expect a cell with an extensive Golgi apparatus to __________.

secrete large amounts of protein

The polysaccharide that you are most likely to have eaten recently is __________.

starch

The overall three-dimensional shape of a single polypeptide is called its __________.

tertiary structure

A substance moving from outside the cell into the cytoplasm must pass through __________.

the plasma membrane

The "primary structure" of a protein refers to __________.

the sequence of amino acids along a polypeptide chain

One characteristic shared by sucrose, lactose, and maltose is that __________.

they are all disaccharides

A researcher wants to film the movement of chromosomes during cell division. Which type of microscope should she choose, and why is it the best choice?

Light microscope because the specimen is alive

Which of the following categories best describes the function of the rough endoplasmic reticulum?

Manufacturing

Basal bodies are most closely associated with which of the following cell components?

Cilia

Which statement about the cytoskeleton is true?

Components of the cytoskeleton often mediate the movement of organelles within the cytoplasm.

What is the process by which monomers are linked together to form polymers?

Dehydration reaction

When a protein is denatured, why does it lose its functionality?

Denaturation breaks the intramolecular bonds, such as hydrogen bonds and van der Waals interactions, that hold the protein in its three-dimensional shape. Without the proper shape, the protein cannot function.

Which of the following statements concerning carbohydrates associated with the plasma membrane is correct?

Membrane carbohydrates function primarily in cell-cell recognition.

Which of the following functions of membrane proteins is important in tissue formation during embryonic development in animals?

Membrane proteins with short sugar chains form identification tags that are recognized by other cells.

Your intestine is lined with individual cells. No fluids leak between these cells from the gut into your body. Why?

The intestinal cells are bound together by tight junctions.

Some lipids are formed when fatty acids are linked to glycerol. These subunits are linked together by __________.

ester linkages