study modules

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?

1.0M

How does cholesterol affect membrane fluidity?

At body temperature, it makes the membrane less fluid.

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

Surars have a _____ group that interacts with a _____ group that forms ring structures when the dry molecule is placed in water

Carbonly (-C=O); Hydroxyl (-OH)

Which of the following is a polymer?

Cellulose, a plant wall component

What is FALSE in respect to cells chromosomes?

Chromosomes are only visible as a cell is about to divide

Which statement about the cytoskeleton is true?

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

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

DNA

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.

After completion of the citric acid cycle, most of the usable energy from the original glucose molecule is in the form of __________.

NADH

In what molecules is the majority of the chemical energy from pyruvate transferred during the citric acid cycle?

NADH and FADH2

What is TRUE about passive transport?

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.

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

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

The sequence of amino acids in proteins 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

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

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

The ATP synthase in a human cell obtains energy for synthesizing ATP directly from what processes?

The flow of H+ across the inner mitochondrial membrane through the ATP synthase enzyme

The energy from the electrons in NADH and FADH2 fuel what process in the electron transport chain?

The pumping of H+ across the crustal of the mitochondrion

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

The solution is hypotonic

A small amount of ATP is made in glycolysis by which process?

Transfer of a phosphate group from a fragment of glucose to ADP by substrate-level phosphorylation

Sugars are molecules that have _____ C:H:O and acre called

a 1:2:1 ratio of; carbohydrates

what plant cell would exhibit the most turgor pressure?

a cell placed in a hypotonic solution

The peptide bond is

a covalent bond joining amino acids together to form a polypeptide

What is least likely to diffuse through a plasma membrane without the help of a transport molecule?

a large polar molecule

The components of nucleic acids are

a nitrogenous base, a pentose sugar, and a phosphate

What substance would be most likely to pass through the plasma membrane without help of a transport protein?

a non polar molecule, such as a hydrocarbon

Sickle cell anemia is a disease caused by _____ in the _____ of the protein

a single amino acid change; primary structure

what is a TRUE difference between active transport and facilitated diffusion?

active transport requires energy from ATP

Nitrogenous bases are classified as either purines or pyrimidines. Examples of purines are

adenine and guanine

Protein molecules are polymer (chains) of

amino acid molecules

What function do carbohydrates fulfill in the plasma membrane?

cell-to-cell recognition

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 ______

centrosomes; centrioles

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; carrier

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

chaperonins

At a conference, the speaker's grand finale was sautéing mealworms in butter and serving them to the audience. They were crunchy because their exoskeletons contain the polysaccharide

chitin

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

cholesterol

When comparing saturated and naturally occurring unsaturated fats, the unsaturated fats have _____ and are ______ at room temperature

cis double binds; liquids

What pairs of pathway and their locations is incorrect?

citric acid cycle: cytosol

the type pf bond that forms to join monomers (such as sugars and amino acids) into polymers (such as starch and proteins) is a _______ bond.

covalent

The network of fibers that organizes structures and activities in a cell is the

cytoskeleton

In living organisms, DNA exists as a _________ with the strands __________

double helix; running antiparallel

fermentation is essentially glycolysis plus and extra step in which pyruvate is reduced to form lactate or alcohol and carbon dioxide. this last step

enables the cell to recycle the reduced NADH to oxidized NAD+

Carbohydrates are used in our bodies mainly for

energy storage and release

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

eukaryotic cells are compartmentalized, which allows for specialization

The function of cellular respiration is to

extract usable energy from glucose

Cells must regulate their metabolic pathways so that they do not waste resources. What is the most common mechanism that regulates cellular respiration in most cells?

feedback inhibition of glycolysis

Fermentation by itself produces no ATP but keeps glycolysis going, which produces a small amount of ATP. How does fermentation do this?

fermentation oxidizes NADH to NAD+, which facilitates the production of ATP in glycolysis

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

glycogen

In which processes is glucose oxidized to form two molecules of pyruvate?

glycolysis

Which metabolic pathway is common to both fermentation and cellular respiration of a glucose molecule?

glycolysis

The subunits (monomers) in cellulose are linked together by

glycosidic linkages

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

have no membrane-bound organelles in their cytoplasm

The secondary structure of a peptide backbone is stabilized by _____ forming either a _____ or a _____

hydrogen bonds; α helix; β pleated sheet

Which is the term for compounds that do not mx with water?

hydrophobic

The plasma membrane exhibits selective permeability. This means that

it allows some substances to flow through it more easily than others

What is TRUE about diffusion?

it is a passive process

Which statement correctly describes the difference between alcohol fermentation and lactic acid fermentation?

lactic acid fermentation produces lactate, and alcohol fermentation produces ethanol

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

lipids

A molecule becomes more oxidized when it

loses an electron

What is TRUE concerning carbohydrates associating with the plasma membrane?

membrane carbohydrates function primarily in cell-to-cell recognition

All cells hav voltage across their membranes. This voltage is called a _______ and is often maintained by______

membrane potential; electrogenic pumps

The endosymbiont theory explains the origins of __________.

mitochondria and chloroplasts

The proper three dimensional shape and folding of a protein is assisted by

molecules called. chaperonins

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

motor protons

Microfilaments function in cell motility including

muscle contraction, amoeboid movement, and cytoplasmic streaming in plants

The endoplasmic reticulum is part of the end-membrane system, which also includes the

nuclear envelope, the Golgi apparatus, lysosomes, nd vesicles

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

nucleoid

What describes some aspect of facilitated diffusion?

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

Which of the following is a correct description of the events of cellular respiration and the sequence of events in cellular respiration?

oxidation of glucose to pyruvate; oxidation of pyruvate; oxidation of acetyl-coa, oxidative phosphorylation

All of the processes involved in cellular respiration produce ATP. Which of the following processes produces the most ATP?

oxidative phosphorylation

The tertiary structure of a protein includes all of the following interactions except ______ bonds.

peptide

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

peroxisomes

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

phospholipids

What molecules are most abundant in the plasma membrane?

phospholipids

What structure exhibits selective permeability between a cell and its external environment?

plasma membrane

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

plasmodesmata

Your intestine is lined with individual cells that are called ______, and communicating junctions in animal cells are called _______

plasmodesmata; gap junctions

In preparing pyruvate to enter the citric acid cycle, which steps occur?

pyruvate is oxidized and decarboxylated, and the removed electrons are used to reduce an NAD+ to an NADH

Most of the electrons removed from glucose by cellular respiration are used for which process?

reducing NAD+ to NADH in glycolysis and the citric acid cycle AND producing a proton gradient for ATP synthesis in the mitochondria.

Which of the following is present in a prokaryotic cell?

ribosomes

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

ribosomes, rough endoplasmic reticulum, and smooth endoplasmic reticulum

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

rough endoplasmic reticulum

You would expect a cell with an extensive Golgi apparatus to

secrete a lot of protein

Red blood cells contain approximately a 2% concentration of solutes. A red blood cell is placed into a solution that contains 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

Most of the NADH that delivers electrons to the electron transport chain comes from which of the following processes?

the citric acid cycle

Which part of the catabolism of glucose by cellular respiration requires molecular oxygen (O2) and produces CO2?

the combination of the citric acid cycle and electron transport chain

Which metabolic pathways produce the most ATP, per glucose molecule metabolized, during cellular respiration?

the electron transport chain and oxidative phosphorylation

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

the plasma membrane

What is true regarding peripheral proteins?

these proteins are found only on the surface of the plasma membrane

What is TRUE regarding integral proteins?

these proteins exhibit both hydrophilic and hydrophobic properties

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

they are all disaccharides

What is TRUE about the role of phospholipids in the structure and function of biological membranes?

they form a selective permeable structure

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

to synthesize proteins that are secreted as glycoproteins

Macromolecules, the molecules of life, include all of the following except

trace elements

The sodium-potassium pump

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

In a dehydration synthesis reaction, _____ is always formed as a by product of the reaction?

water

______ is always involved in hydrolysis reactions

water

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

with motor proteins