Bio Exam 2

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

1.0 M

Which of the following plant cells would exhibit the most turgor pressure?

A cell placed in a hypotonic solution

The components of nucleic acids are

A nitrogenous base, a pentose sugar, and a phosphate

Which of the following substances would be most likely to pass through the plasma membrane without the help of a transport protein?

A nonpolar molecule, such as a hydrocarbon

Sickle-cell anemia is a disease that is caused by_________ in the ___________ of the protein

A single amino acid change; primary structure

Which of the following molecules are most abundant in the plasma membrane? A. Phospholipids B. Carbohydrates C. Cholesterol D. Proteins E. Water

A. phospholipids

Which of the following is a correct statement between active transport and facilitated diffusion?

Active transport requires ATP, and facilitated diffusion does not

Nitrogenous vases are classified as either purines or pyrimidines. Examples of purines are_________

Adenine and guanine

How does cholesterol affect membrane fluidity?

At body temperature, it makes the membrane less fluid.

Cells A and B are the same size, shape, and temperature, but cell A is metabolically less active than cell B; 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

Why is energy required for active transport?

Because it moves solutes against their concentration gradient

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 is false in respect to cells' chromosomes? A. Chromosomes are present throughout a cell's reproductive cycle B. Chromosomes exist even when cells are not actively synthesizing proteins C. Chromosomes are only visible as a cell is about to divide D. Chromosomes contain DNA and proteins

C

Which statement about the cytoskeleton is true? A. Plant cells lack a cytoskeleton because they have a rigid cell wall B. Intermediate filaments are hollow tubes of protein that provide structural support. C. Components of the cytoskeleton often mediate the movement of organelles within the cytoplasm D. Microfilaments are more permanent structures in cells compared to intermediate filaments and microtubules E. Microtubules are chains of proteins that resist stretching

C

The extracellular matrix of the animal cell has all of the following molecular components except ____________. A. Fibronectin B. Proteoglycans C. A middle lamella D. Collagen E. Integrins

C. middle lamella

Which of the following cell structures exhibits selective permeability between a cell and its external environment? A. Chloroplasts B. Endoplasmic C. Plasma Membrane D. Mitochondria E. Lysosomes

C. plasma membrane

Which of the following is a polymer?

Cellulose, a plant cell wall component

The organelle that is a plant cell's compartment for the storage of inorganic ions such as potassium and chloride is the _____________.

Central vacuole

The organelle that is a plant cell's compartment for the storage of inorganic ions such as potassium and chloride is the ______________.

Central vacuole

Animal cells have unique organelles called ____________ that are composed of structures called _____________

Centrisomes: centrioles

The proper 3D shape and folding of a protein is assisted by

Chaperonins

Which to the following is false in respect to cells' chromosomes?

Chromosomes are only visible as a cell is about to divide

When comparing saturated and naturally occurring unsaturated fats, the unsaturated fats have __________ and are _________ at room temperature

Cis double bonds; liquids

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

DNA

The tertiary structure of a protein includes all of the following interactions:

Disulfide bridge, hydrophilic, ionic, hydrophobic bonds

In living organisms, DNA exists as a ________ with the strands_________

Double helix; running antiparallel

Evidence that supports the prokaryotic origins of mitochondria and chloroplasts are all of the following except _________________. A. That the ancestral prokaryote had two outer membranes, which became the double membranes of the mitochondria and chloroplasts B. That mitochondria and chloroplasts can grow and reproduce within a cell C. That mitochondria and chloroplasts are something independent within a cell D. That mitochondria and chloroplasts have multiple copies of circular DNA molecules associated with their membranes E. That mitochondria and chloroplasts have multiple copies of linear DNA molecules associated with their inner membranes

E

The extracellular matrix of the animal cell has all of the following molecular components except _____________. A. Proteoglycans B. Intestine C. Fibronectin D. Collagen E. A middle lamella

E

Which of the following statements about diffusion is true? A. It occurs when molecules move from a region of lower concentration to a region of higher concentration B. It requires expenditure of energy by the cell C. It always requires integral proteins of the cell membrane D. It is very rapid over long distances E. It is a passive process

E. It is a passive process.

Which of the following is present in a prokaryotic cell? A. ER B. Chloroplast C. Mitochondrion D. Nuclear envelope E. Ribosomes

E. Ribosomes

Carbohydrates are used in our bodies mainly for ______________

Energy storage and release

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 the following process led and organelle(s) accounts for the replacement of lipids and proteins lost from the plasma membrane?

Exocytosis and smooth and rough ER

Which of these statements describes some aspects of facilitated diffusion?

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

The subunits (monomers) in cellulose are linked together by______

Glycosidic linkages

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

Membrane carbohydrates function primarily in cell-cell recognition.

All cells have high voltages across their membranes. This voltage is called a(n) ___________ and is often maintained by _______________.

Membrane potential; electrogenic pumps

Macromolecules, the molecule of life, include what?

Nucleoc acids, proteins, carbohydrates,

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 the population of solute molecules occurs down the concentration gradient of the molecule.

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.

The sequence of amino acids in a protein is called the ____________ structure of the protein

Primary

Which of the following structural arrangements of the components in biological membranes facilitates the cell membrane's property of selective permeability?

Proteins embedded in two layers of phospholipids

How does the "fluid mosaic model" describe the structure of the plasma membrane?

Proteins in the membrane contribute to the mosaic quality of the membrane while the lateral and rotational movements of phospholipids contribute to its fluidity.

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.

Red blood cells contain approximately a 2% concentration of solutes. A red blood cell is placed into a solution that contains a 4% concentration of solutes to which the cell is not permeable. What will happen to the red blood cell?

The cell will decrease in size as water flows out of it.

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.

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

The plasma membrane

A cell is placed into a solution and the cell shrinks. Which of the following is true regarding the solution?

The solution is hypertonic.

Which of the following is correct regarding peripheral proteins?

These proteins are found only on the surface of the plasma membrane.

Which of the following is correct regarding integral proteins?

These proteins exhibit both hydrophilic and hydrophobic properties.

The sodium-potassium pump __________.

Transports sodium ions out of the cell and transports potassium ions into the cell.

I'm dehydration synthesis reaction,________is always formed as a by-product of the reaction

Water

What is always involved in hydrolysis reactions?

Water

Sugars are molecules that have __________ C:H:O and are called __________.

a 1:2:1 ratio of; carbohydrates

The peptide bond is

a covalent bond joining amino acids together to form a polypeptide

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

Protein molecules are polymers (chains) of

amino acid molecules

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

carbon dioxide

Sugars have a(n) __________ group that interacts with a _________ group that forms ring structures when the dry molecule is placed in water.

carbonyl (-C=O); hydroxyl (-OH)

What function do carbohydrates fulfill in the plasma membrane?

cell-cell recognition

In facilitated diffusion, ______________ proteins provide openings in the plasma membrane for substances to flow through without changing structure, and ____________ proteins allow passage of substances through the plasma membrane after undergoing a subtle change in shape.

channel and carrier

Which type of protein shields a newly forming protein from cytoplasmic influences while it is folding into its functional form?

chaperonins

The molecule with four fused rings that is found in animal membranes and is the precursor of vertebrate sex hormones is

cholesterol

Basal bodies are most closely associated with which of the following cell components? A. Nucleus B. The central vacuole C. Cilia D. Mitochondria E. Golgi apparatus

cilia

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

A nursing infant is able to obtain disease-fighting antibodies, which are large protein molecules, from its mother's milk. These molecules probably enter the cells lining the baby's digestive tract via which process?

endocytosis

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

Observing a fluorescent micrograph cell with intermediate filaments would help you identify the cell as a __________.

human skin cell

The secondary structure of a peptide backbone is stabilized by __________ forming either _________ or a ________

hydrogen bonds; α helix; β pleated sheet

What is the term for compounds that do not mix with water?

hydrophobic

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

in the rough endoplasmic reticulum All of the membrane proteins of the endomembrane systems are made in the rough ER.

The walls of plant cells are largely composed of polysaccharides and proteins that are synthesized __________.

in the rough endoplasmic reticulum and in the Golgi apparatus

The network of fibers that organizes structures and activities in a cell __________.

is the cytoskeleton

The sex hormones estrogen, progesterone, and testosterone belong to which class of molecules?

lipids

The endosymbiont theory explains the origins of _________.

mitochondria and chloroplasts

The endosymbiont theory explains the origins of ______________.

mitochondria and chloroplasts

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

motor proteins

Microfilaments function in cell motility including ____________.

muscle contraction, amoeboid movement, and cytoplasmic streaming in plants

The endoplasmic reticulum is part of the endomembrane system, which also includes the ____________.

nuclear envelope, the Golgi apparatus, lysosomes, and vesicles

The region of a bacterial cell that contains the genetic material is called the __________.

nucleoid

Cells are small because _______.

of the geometric relationships between surface and volume

______________ are membrane-bound metabolic compartments that specialize in the production of hydrogen peroxide (H2O2) and its conversion to water

peroxisomes

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

phospholipids

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

Cell junctions in plant cells are called ____________ and communicating junctions in animal cells are called _____________.

plasmodesmata; gap junctions

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

ribosome, rough endoplasmic reticulum, smooth endoplasmic reticulum

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

secrete a lot of protein

The plasma membrane exhibits selective permeability. This means that ___________.

the plasma membrane allows some substances to flow through it more easily than others

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

they are all disaccharides

The function of the rough endoplasmic reticulum (RER) is __________.

to synthesize proteins that are secreted as glycoproteins

Cell motility, which includes changes both in cell location and in the movement of cell parts, requires interactions of the cytoskeleton __________.

with motor proteins