Many mammals control their body temperature by sweating. Which property of water is most directly responsible for the ability of sweat to lower body temperature?

the absorption of heat by the breaking of hydrogen bonds

the nucleus of a nitrogen atom contains 7 neutrons and 7 protons. which of the following is a correct statement concerning nitrogen?

the nitrogen atom has a mass number of 14 and an atomic mass of approx. 14 daltons

a localized group of organisms that belong to the same species is called a

population

prokaryotes are classified as belonging to two different domains. what are the domains?

bacteria and archaea

which of the following molecules contains the most polar covalent bond

h2o

fluorine has an atomic number of 9 and a mass number of 19. how many electrons are needed to complete the valence shell of a fluorine atom?

1

why does ice float in liquid water

hydrogen bonds stabilize and keep the molecules of ice farther apart than the water molecules of liquid water.

through time, the lineage that led to modern whales shows a change from four-limbed land animals to aquatic animals with two limbs that function as flippers. this change is best explained by

natural selection

organisms interact w/ their environments, exchanging matter and energy. For example, plant chloroplasts convert the energy of sunlight into

chemical energy

which brand of biology is concerned with the naming and classifying of organisms?

taxonomy

a slice of pizza has 500 kcal. if we could burn the pizza and use all the heat to warm a 5-L container a cold water, what would be the approx. increase in the temperature of the water? (Note: a liter of cold water weighs about 1Kg)

10 degrees C

knowing just the atomic mass of an element allows inferences about which of the following

the number of protons plus neutrons in the element.

the partial negative charge in a molecule of water occurs because

the electrons shared between the oxygen and hydrogen atoms spend more tie around the oxygen atom nucleus than around the hydrogen atom nucleus

what coefficients must be balanced in the following blanks so that all atoms are accounted for in the products?

C6H12O6 -> __ C2H6O + __CO2

2,2

which of the following statements is false?

virtually all organisms require the same elements in the same quantities

Hydrophobic substances such as vegetable oil are

nonpolar substances that repel water molecules

what is the max number of covalent bonds an element w/ atomic number of 8 can make w/ hydrogen

2

which of the following is a hydrophobic material?

butter

the application of scientific knowledge for some specific purpose is known as

technology

which of the following best describes he logic of scientific inquiry?

if my hypothesis is correct I can expect certain test results

in a single molecule of water, two hydrogen atoms are bonded to a single oxygen atom by

polar covalent bonds

according to darwinian theory, which of the following exhibits the greatest fitness for evolutionary success?

the individuals within a population that have the greatest reproductive success

what is the hydrogen ion {H+} concentration of a solution of pH 8?

18-8 M

if the pH of a solution is increased from pH 5 to pH 7, it means that the

concentration of OH- is 100 times greater than what it was at pH 5

a dietary calorie equals 1 kilocalorie. which of the following statements correctly defines 1 kilocalorie

1000 calories or the amount of heat required to raise the temperature of 1 kg of water by 1 degree C

systems biology is mainly an attempt to

understand the behavior of entire biological systems

all the organisms on your campus make up

a community

in what way are elements in the same column of the periodic table the same

they have the same number of electrons in their valence shell

one difference between carbon -12 is that carbon - 14 has

two more neutrons than carbon-12

electrons exist only at fixed level of potential energy. however if an atom absorbs sufficient energy a possible result is that

the atom would become a negatively charged ion, or anion

why is each element unique and different from other elements in chemical properties

each element has a unique number of protons in its nucleus

one mole (mol) of glucose (molecular mass = 180 Daltons' ) is

both 180 grams of glucose and 6.02 x 10^23 molecules of glucose

which of the following solutions would require the greatest amount of base to be added to bring the solution to neutral pH

gastric juice at pH 2

which of the following is an example of qualitative data

the spider spun its web in a circular motio

nitrogen (N) is much more electronegative than hydrogen (H). which of the following statements is correct about the atom in ammonia (NH3)

each hydrogen atom has a partial positive charge; the nitrogen atom has a partial negative charge

we can be sure that a mole of table sugar and a mole of vitamin v are equal in their

number of molecles

the main source of energy for producers in an ecosystem is

light energy

which type of bond must be broken for water to vaporize

hydrogen bond

what is the maximum number of electrons in a single 2 p orbital of an atom

2

slight negative charge at one end of one water molecule is attracted to the slight positive charge of another water molecule. what is this attraction called

hydrogen bond

which of the following explains most specifically the attraction of water molecules to one another.

hydrogen bond

when applying the process of science, which of these is tested?

prediction

a solution contains 0.000001 (10-7) moles of hydroxyl ions [OH-]per liter. which of the following best describes this solution?

neutral

an atom with atomic number 12 would have what type of chemical behavior in bonding with other elements?

it would form ions with a =2 charge

why is it important that an experiment include a control group?

without a control group, there is no basis for knowing if a particular result is due to the variable being tested

which statement is true of all atoms that are anion?

the atom has more electrons than protons

which of the following takes place as an ice cube cools a drink?

kinetic energy in the drink decreases

when two atoms are equally electronegative, they will interact to form

nonpolar covalent bonds

humans can digest starch but not cellulose because

humans have enzymes that can hydrolyze the a glycosidic linkages of starch but not the b glycosidic linkages of cellulose

research indicates that ibuprofen, a drug used to relieve inflammation nd pain, is a mixture of two enantiomers; that is, molecules that

are mirror images of one another

in animal metabolism, most of the monomers releases by digestion of food macromolecules are metabolized to provide energy. Only a small portion of these monomers are used for synthesis of new macromolecules. the net result is that?

water is consumed by animal metabolism

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

primary level

Lactose, a sugar in milk, is composed of one glucose molecule joined by a glycosidic linkage to one galactose molecule. how is lactose classified?

as a disaccharide

which of the following categories includes all others in the list

carbohydrate

the element present in all organic molecules is

carbon

what is the structural feature that allows DNA to replicate

complementary pairing of the nitrogenous bases

the enzyme amylase can break glycosidic linkages between glucose monomers only if the monomers are in the a form. which of the following could amylase break down?

glycogen, starch, and amylopectin

which two functional groups are always found in amino acids?

carboxyl and amino

how many electron pairs does carbon share in order to complete its valence shell

4

at which level of protein structures are interactions between the side chains (R groups) most important?

tertiary

how many molecules of water are needed to completely hydrolyze a polymer that is 11 monomers long?

10

what is the term used for a protein molecule that assists in the proper folding of other proteins

chaperonin

on food packages, to what does the term insoluble fiber refer

cellulose

which of the following statements concerning unsaturated fats is true

they have double bonds in the carbon chains of their fatty acids

which of the following statements correctly describes cis-trans isomers?

they have variations in arrangement around a double bond

which of the following statements concerning saturated fats is not true

they have multiple double bonds in the carbon chains of their fatty acids

what is the chemical reaction mechanism by which cells make polymers from monomers

dehydration reactions

a carbon atom is most likely to form what kind of bond(s) with other atoms?

covalent

the label on a container of margarine lists "hydrogenated vegetable oil" as the major ingredient. what is the result of adding hydrogens to vegetable oil?

the hydrogenated vegetable oil stays solid at room temperature

which of the following is not a polymer

glucose

there are 20 different amino acids. what makes one amino acid different from another?

different side chains (R groups) attached to an a carbon

which type of interaction stabilizes the a helix and the b pleated sheet structures of proteins

hydrogen bonds

which of the following are nitrogenous bases of the pyrimidine type

cytosine and uracil

which of these molecules is not formed by dehydration reactions

fatty acids

if one strand of DNA molecule has the sequence of bases 5'ATTGCA3' the other complementary strand would have the sequence

5'TGCAAT3'

large organic molecules are usually assembled by polymerization of a few kinds of simple subunits. which of the following is an exception to this statement?

a steroid

when biologists wish to study the internal ultrastructure of cells they most likely would use

a transmission electronic microscope

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

gap junction

a newspaper ad for a local toy store indicates that a very inexpensive microscope available for a small child is able to magnify secimens nearly as much as the much more costly microscope available in your college lab. what is the primary reason for the price difference

the toy microscope magnifies a good deal, but has low resolution and therefore poor quality images

all of the following are part of a prokaryotic cell except

an endoplasmic reticulum

large numbers of ribosomes are present in cells that specialize in producing which of the following molecules

proteins

which type of organelle is primarily involved in the synthesis of oils, phospholipids, and steroids?

smooth endoplasmic reticulum

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

rough er

which statement correctly characterizes bound ribosomes?

bound ribosomes generally synthesize membrane proteins and secretory proteins

in animal cells, hydrolytic enzymes are packages to prevent general destruction of cellular components. which of the following organelles functions in this compartmentalization

peroxisome

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 is a compartment that often takes up much of the volume of a plant cell

central vacuole

which of the following factors would tend to increase membrane fluidity

a greater proportions of unsaturated phospholipids

grana, thylakoids, and stroma are all components found in

chloroplasts

organelles other than the nucleus that contain DNA include

mitochondria and chloroplasts

which of the following are capable of converting light energy to chemical energy

chloroplasts

a primary objective of cell fractionation is to

crack the cell wall so the cytoplasmic contents can be released

in what way do the membranes of a eukaryotic cell vary?

certain proteins are unique to each membrane

a biologist ground up some plant leaf cells and then centrifuged the mixture to fractionate the organelles. organelles in one of the heavier fractions could produce ATP in the light, while organelles in the lighter fraction could produce ATP in the dark. The heavier and lighter fractions are most likely to contain, respectively,

chloroplasts and mitochondria

which of the following is a major cause of the size limits for certain types of cells

the need for a surface area of sufficient area to allow the cell's function

which of the following processes includes all others

passive transport

cyanide binds with at least one molecule involved in producing ATP. If a cell is exposed to cyanide, most of the cyanide would be found within the

mitochondria

which cell would be best for studying lysosomes

phagocytic white blood cell

which of the following types of molecules are the major structural components of the cell membrane

phospholipids and protins

the presence of cholesterol in the plasma membranes of some animals

enables the membrane to stay fluid more easily when cell temperature drops

according to the fluid mosaic model of membrane structure, proteins of the membrane are mostly

embedded in a lipid bilayer

according to the fluid mosaic model of cell membranes, which of the following is a true statement about membrane phospholipids

they can easily move laterally along the plane of the membrane

in order for a protein to be an integral membrane protein (an integrin) it would have to be which of the following

amphipathic

which of the following is a reasonable explanation for why unsaturated fatty acids help keep any membrane more fluid at lower temperatures?

the double bonds form kinks in the fatty acid tails, forcing adjacent lipids to be further apart

which of the following statements correctly describes the normal tonicity conditions for typical plant and animal cell

the animal cell s in an isotonic solution and the plant cell is in a hypotonic solution

of the following functions which is most important for the glycoproteins and glycolipids of animal cell membranes

a cell's ability to distinguish one type of neighboring cell from another

why are lipids and proteins free to move laterally in membranes?

hydrophilic portions of the lipids are in the interior of the membrane

the Golgi apparatus has a polarity or sidedness to its structure and function. which the following statements correctly describes this polarity?

all of the above correctly describe polar characteristics of the Golgi function

which of the following statements is correct about diffusion

it is a passive process in which molecules move from a region of higher concentration to a region of lower concentration

what is the voltage across a membrane called?

membrane potential

water passes quickly through cell membranes because

it moves through aquaporins in the membrane

a patient has had a serious accident and lost a lot of blood. in an attempt to replenish body fluids, distilled water, equal to the volume of blood lost, is transferred directly into one of his veins. what will be the most probable result of this transfusion?

the patients red blood cells will swell because the blood fluid is hypotonic compared to the cells

a cell whose cytoplasm has a concentration of 0.02 molar glucose is placed in a test tube of water containing 0.02 molar glucose. assuming that glucose is not actively transported into the cell, which of the follow terms describes the tonicity of the external solution relative to the cytoplasm of the cell

isotonic

which of the following membrane activities require energy from ATP hydrolysis?

Na+ ions moving out of the cell

which is one of the main energy transformers of cells

mitochondrion

white blood cells engulf bacteria through what process

phagocytosis

which term most precisely describes the cellular process of breaking down large molecules into smaller ones

catabolism

which of the following is a statement of the first law of thermodynamics?

energy cannot be created or destroyed

whenever energy is transformed, there is always an increase in the

entropy of the universe

which of the following is an example of potential rather than kinetic energy

a molecule of glucose

which of the following is the smallest closed system

a thermos

which of the following is true of metabolism in its entirety in all organisms

metabolism consists of all the chemical reactions in an organism

the mathematical expression for the change in free energy of a system is ▲G = ▲H - T▲S. which of the following is (are) correct?

▲G is the change in free energy

a system at chemical equilibrium

can do no work

which of the following is true for all exergonic reactions

the reaction proceeds with a net release of free energy

reactants capable of interacting to form products in a chemical reaction must first overcome a thermodynamic barrier known as the reactions

activation energy

during a laboratory experiment, you discover that an enzyme- catalyzed reaction has a ▲G of -20 kcal/mol. if you double the amount of enzyme in the reaction, what will be the ▲G for the new reaction?

-20 kcal/mol

how does a noncompetitive inhibitor decrease the rate of an enzyme reaction?

by changing the shape of the enzyme's active site

some bacteria are metabolically active in hot springs because

their enzymes have high optimal temperatures

chose the pair of terms that correctly completes this sentence:

Catabolism is to anabolism as _____ is to ______

exergonic;endergonic

most cells cannot harness heat to perform work because

temperature is usually uniform throughout a cell

in an enzyme is added to a solution where its substrate and product are in equilibrium, what will occur?

nothing, the reaction will stay at equilibrium

when a glucose molecule loses a hydrogen atom as the result of an oxidation-reduction reaction, the molecule becomes

oxidized

the molecule that functions as the reducing agent (electron donor) in a redox or oxidation - reduction reaction

loses electrons and loses potential energy

which process in eukaryotic cells will proceed normally whether oxygen (o2) is present or absent?

glycolysis

why is glycolysis described as having an investment phase and a payoff phase

it uses stored atp and them forms a net increase in ATP

which of the following intermediary metabolites enters the citric acid cycle and is formed, in part, by the removal of a carbon (CO2) from one molecule of pyruvate?

acetyl CoA

how many carbon atoms are fed into the citric acid cycle as a result of the oxidation of one molecule of pyruvate

two

where are the proteins of the electron transport chain locatd

mitochondrial inner membrane

the immediate energy source that drives ATP synthesis by ATP synthase during oxidative phosphorylation is the

H+ concentration across the membrane holding ATP synthase

what is the oxidizing agent in the following reaction?

Pyruvate + NADH + H+ -> Lactate + NAD+

pyruvate

most CO2 from catabolism is released during

the citric acid cycle