Cell Bio Exam #1

True or False: Atoms are most stable when they have a full outer shell.

True

Which property below is not a characteristic of enzymes? a) They create energy b) They can be altered reversibly during a reaction. c) They do not alter the DG of a reaction. d) They are used over and over again. e) They do not determine whether a reaction is exergonic or endergonic.

a) They create energy

In order for a substrate to bind specifically to a particular enzyme there must be ___________. a. All of these b. complimentary charges c. a good spacial fit d. the substrate in the correct 3D orientation e. amino acids with opposing charges to substrate

a. All of these

Which of the following functional groups below would not likely engage in hydrophilic interactions? a. CH3 b. -COOH c. -COH d. -COOC- e. NH2

a. CH3

Which of the following is not a group that makes up an amino acid? a. Lipid group b. Carboxyl group c. Amino group d. Side chain (R) group

a. Lipid group

Which of the following are common components of membranes? a. Partially polar lipids b. Triacylglycerols c. Nucleic acids d. Amino acids

a. Partially polar lipids

All the following are found in both plant and animal cells, _except _ ____________ a. lysosome b. peroxisomes c. mitochondria d. endoplasmic reticulum e. Golgi

a. lysosome

When an organism takes carbon dioxide molecules from the environment they are mosy likely to ___________ it. a. reduce b. condense c. hydrolyze d. oxidize e. connect it to a phosphate

a. reduce

Coupling two reactions allows... a.+△G to occur more likely b.exergonic reactions to become more favorable c.for an endergonic reaction to occur immediately d.for an increase in the energy of the molecules

a.+△G to occur more likely

Which of the following is a TRUE statement? a.catabolic reactions involve molecule breakdown b.anabolic reactions primarily involve molecule breakdown c.catabolic reactions require net energy input d. some of the energy released in anabolic reactions is lost as heat

a.catabolic reactions involve molecule breakdown

In a reaction, when the system reaches equilibrium, the free energy will be what? a.will be at its lowest b.will equal 0 c.undefined d.will be at its highes

a.will be at its lowest

Which of the following functional groups would bind to a functional group with a negative charge? a) phosphate b) amine c) carboxylate d) O of an alcohol e) ester

b) amine

Sugars tend to be highly water soluble because they have large numbers of _____ groups. a) methyl b) hydroxyl c) sulfhydryl d) carboxyl e) amine

b) hydroxyl

Which of the following would most likely interact by forming an ionic bond? a. Fatty acid and inorganic phosphate b. ATP (adenosine triphosphate) and magnesium cations c. Urea and water d. Two strands of DNA

b. ATP (adenosine triphosphate) and magnesium cations

Carbon atoms cycle continuously through the biosphere. What is a by-product of cell respiration, and what does this by-product represent? Choose one: a. C6H12O6; completely oxidized carbon b. CO2; completely oxidized carbon c. C6H12O6; a reduced version of carbon d. CO2; a reduced version of carbon

b. CO2; completely oxidized carbon

Select the strongest type of bond in an aqueous environment: a. Ionic b. Covalent c. Hydrogen d. Van der Waal

b. Covalent

What type of bond is formed when two atoms share electrons? a.Ionic bond b. Covalent bond c.Hydrogen bond d.Van der Waals interactions

b. Covalent bond

Which of the following is not a polymer? a. Protein b. Phospholipid c. DNA d. Glycogen e. Nucleic Acid

b. Phospholipid

1. Although this turns out to not always be the case, by definition, prokaryotic cells do not possess _____. a. a separate membrane for ribosomes function b. a separate membrane around the DNA c. carrying pouch d. cytoskeleton e. linear DNA

b. a separate membrane around the DNA

The hypothesis that explains the origin of complex eukaryotic cells as the result of two or more simpler cells developing a mutually beneficial relationship with one inside the other is called: a. fusion theory b. endosymbiotic theory c. symbiosis theory d. evolution theory

b. endosymbiotic theory

Which of the following is NOT part of a nucleotide? a. ribose b. fructose c. pyrimidine base d. phosphate e. purine base

b. fructose

Which type of molecule forms the cell membrane? a. protein b. phospholipid c. nucleic acid d carbohydrate

b. phospholipid

The cytoskeleton we find in eucaryotes today seems to have evolved out of ____________. a. conversion of boney skeleton to protein b. proteins in procaryotes that have filamentous structure c. error in translation that led to cycling of mRNA and very long protein formation. d. an error in translation leading to peptide repeats e. polymers of DNA changing to amino acids

b. proteins in procaryotes that have filamentous structure

Which of the following best describes an exergonic reaction? a.reaction with a +△G b.reaction with a -△G c.an immediately occurring reaction d.an energetically unfavorable reaction

b.reaction with a -△G

. If a cell has enough of some molecule it is likely to ______________________. a) start the process of cell division b) export it from the cell c) inhibit its synthesis d) store it in a vacuole e) sell it to nearby cells for a profit

c) inhibit its synthesis

What type of bond binds together two nucleic acids? a. Peptide bond b. DNA bond c. Phosphodiester bond d. Ionic bond

c. Phosphodiester bond

At equilibrium, the free energy of a reaction is which of the following? Choose one: a. energetically favorable b. energetically unfavorable c. at its lowest point d. equal to ΔG°at its highest point

c. at its lowest point

Ions are formed following the process of ________. a. an atom converting one of its protons into a neutron and an electron b. one atom sharing electrons with another atom c. one atom transferring one or more electrons to another d. an atom converting one of its neutrons into a proton

c. one atom transferring one or more electrons to another

During the process of the formation of mitochondria the eukaryote was looking for ______. a) an efficient use of energy b) a way to breakdown molecules building up in the cell c) an advantage over other cells d) dinner

d) dinner

Enzymes speed up biochemical reactions by ___________. a) raising the activation energy b) raising the DG c) lowering the DG d) lowering the activation energy e) changing the free energy of the products

d) lowering the activation energy

Are cofactors organic or inorganic?

inorganic

Which of these molecules would you least expect to easily dissolve in water? Choose one: A. acetic acid B. 2-methylpropane C. sucrose D. potassium chlorideE. acetone

B. 2-methylpropane

Which term best describes a fatty acid? Choose one: A. hydrophobic B. hydrodynamic C. amphipathic D. hydrophilic

C. amphipathic

Which of the following covalent bonds is relatively nonpolar? Choose one: A. bond between nitrogen and hydrogen, -N-H B. bond between oxygen and hydrogen, -O-H C. bond between carbon and hydrogen, -C-H

C. bond between carbon and hydrogen, -C-H

On the basis of weight, which is most abundant in a living bacterial cell? Choose one: A. macromolecules B. proteins C. water D. fatty acids E. inorganic ions

C. water

Approximately how much does a mole of carbon atoms (each having an atomic weight of 12) weigh? Choose one: A. 6 × 1023 daltons B. 6 × 1023 g C. 12 daltons D. 12 g E. 1 g

D. 12 g

Which statement is true? Choose one: A. A cell takes in heat from the environment to power its biosynthetic reactions, thereby obeying the second law of thermodynamics. B. The breakdown of food molecules generates heat, which cells then use to drive the synthesis of large molecules. C. Cells obey the first law of thermodynamics but are exempt from the second law. D. The heat released by an animal cell comes from the chemical bond energy present in the food molecules it metabolizes. E. A cell generates order by decreasing the entropy of its surroundings.

D. The heat released by an animal cell comes from the chemical bond energy present in the food molecules it metabolizes.

Which type of covalent bond allows for rotation about the bond axis? Choose one: A. triple bond B. hydrogen bond C. double bond D. single bond

D. single bond

Are coenzymes organic or inorganic?

organic

Which of the following statements is not true?Choose one A. Hydrogenation reactions are oxidations, and dehydrogenation reactions are reductions. B. Oxidation and reduction reactions always occur simultaneously. C. When a sugar molecule is oxidized to CO2 and H2O, the O2molecules involved in forming the H2O are reduced. D. When a carbon atom in a C-H bond has somewhat more than its share of electrons, it is said to be reduced.

A. Hydrogenation reactions are oxidations, and dehydrogenation reactions are reductions.

In water, hydrogen bonds can form between which of the following? Choose one: A. a hydrogen atom of one water molecule and an oxygen atom of another B. the oxygen atom of one water molecule and the oxygen atom of another C. the one oxygen atom and two hydrogen atoms of one water molecule D. the hydrogen atom of one water molecule and the hydrogen atom of anothe

A. a hydrogen atom of one water molecule and an oxygen atom of another

You have developed a promising anti-cancer agent, but it has poor solubility in water. Which of the following changes should improve water solubility? Choose one or more: A. adding a carboxyl group B. adding a hydroxyl group C. adding a methyl group D. increasing the size of the drug

A. adding a carboxyl group AND B. adding a hydroxyl group

True or False: Hydrocarbons are known for being hydrophilic. Select one:

False

True or False: △G is dependent on the concentration of X in the reaction, but not dependent on the concentration of Y.

False

What reactions are responsible for putting macromolecules together? a. Reduction reaction b. Hydrolysis reaction c. Addition reaction d. Condensation reaction

d. Condensation reaction

The organelle that modifies, sorts, and packages cellular proteins is the ___________ a. endoplasmic reticulum b. ribosome c. lysosome d. Golgi apparatus e. peroxisomes

d. Golgi apparatus

Which of the following functions are carried out in eukaryotes but NOT in prokaryotes. a) gene expression through DNA - RNA - proteins b) signal response systems c) respiration d) photosynthesis e) none of the above

e) none of the above

Which of the following is NOT a characteristic of all living organisms? a. adapt to changes b. maintain homeostasis c. organize themselves d. reproduce themselves e. warm themselves in the sun

e. warm themselves in the sun

NADH and NADPH carry which of the following in their high-energy linkage? a.hydrogens b.phosphates c.electrons d.Both A and B e.Both A and C

e.Both A and C

Enzymes bind most stably to ... a.substrates b.water c.products d.reactants e.reaction intermediates

e.reaction intermediates