Deck 1: The Cell: A Microcosm of Life

Question 1

The cell organelle responsible for the initiation and regulation of most cellular activity is the ____.

A)cytoplast
B)nucleus
C)mitochondrion
D)nucleolus

Answer 1

B

Question 2

Proteins attached to the membrane through hydrophobic interactions and embedded in the membrane are called ____.

A)peripheral proteins
B)rough endoplasmic reticula
C)integral proteins
D)Golgi apparatuses

Answer 2

C

Question 3

The carbohydrate moieties of the plasma membrane glycoproteins and glycolipids are oriented ____.

A)outwardly, away from the cytoplasmic matrix
B)inwardly, toward the lumen
C)equally inwardly and outwardly to maintain symmetry
D)between the bilayers of the membranes

Answer 3

A

Question 4

DNA in the nucleus is wrapped around ____.

A)proteins called histones
B)the nucleolus
C)the nuclear envelope
D)ribosomal RNA

Question 5

Which organelle is capable of performing both fission and fusion?

A)Golgi apparatus
B)mitochondria
C)rough endoplasmic reticulum
D)nucleus

Question 6

In addition to the mitochondria,which organelle possesses an inner and outer membrane?

A)lysosome
B)lysosome
C)Golgi apparatus
D)nucleus

Question 7

Encoded within the nuclear DNA of each cell is ____.

A)the entire genome for that organism
B)the genes coding for proteins needed by that particular cell in the organism
C)chromatin
D)a cell-specific histone

Question 8

In the cell structure,the ____ provides support and controls the movement of cell organelles.

A)endoplasmic reticulum
B)mitochondrion
C)cytoskeleton
D)matrix space

Question 9

What is the major route for ATP production?

A)oxidative phosphorylation
B)hydrolysis
C)peroxidation
D)transformation

Question 10

Membrane proteins do not serve as ____.

A)pumps
B)detoxifiers
C)receptors
D)enzymes

Question 11

The fluid portion of the cytoplasmic matrix does not contain ____.

A)amino acids​
B)glucose
C)carbon dioxide
D)urea

Question 12

Membrane lipid bilayers consist primarily of ____.

A)phospholipids
B)cholesterol
C)proteins
D)saturated fatty acids

Question 13

All components of the electron transport chain are embedded in the ____.

A)mitochondrial inner membrane
B)mitochondrial outer membrane
C)mitochondrial matrix
D)cytoplasmic matrix

Question 14

Signals generated at one part of a cell are transmitted quickly to other parts of the cell due to the interconnection of the cytosol and ____.

A)glycoproteins
B)filaments
C)glycolipids
D)integral proteins

Question 15

Microtubule organization centers (MTOCs)on the outer nuclear membrane are associated with which cellular process?

A)oxidative phosphorylation
B)electron transport
C)mitosis
D)protein synthesis

Question 16

Enzymes of metabolic pathways within the cytoplasmic matrix are often oriented so that the product of one enzyme is released in close proximity to the next enzyme for which it is a substrate,to facilitate the velocity of the overall pathway.This arrangement includes enzymes of ____.

A)beta-oxidation
B)glycolysis
C)ketone production
D)the Krebs cycle

Question 17

In which organelle do the TCA cycle and fatty acid oxidation occur?

A)Golgi apparatus​
B)nucleus
C)microsomes
D)mitochondrion

Question 18

The organelle responsible for production of most of the metabolic energy (ATP)is the ____.

A)Golgi apparatus
B)endoplasmic reticulum
C)nucleus
D)mitochondrion

Question 19

What is the role of cholesterol in plasma membrane structure?

A)to produce bile
B)to regulate fluidity and permeability
C)to reduce stability
D)to produce hormones

Question 20

Genes contained in mitochondrial DNA are inherited only from the mother and code for ____.

A)all proteins functioning within the mitochondrial matrix
B)nonfunctional ancient proteins considered remnants of evolution
C)proteins vital to the production of ATP
D)antioxidant proteins

Question 21

The smooth endoplasmic reticulum (SER)is associated with ____.

A)lipid synthesis
B)protein synthesis
C)the calcium ion pump necessary for the contractile process
D)ribosomes and cytochrome P450 enzymes

Question 22

Translation is the process by which ____.

A)the genetic information (base sequence) in a single strand of DNA is used to specify a complementary sequence of bases in an mRNA chain
B)a daughter duplex DNA molecule that is identical to the parental duplex DNA is synthesized
C)the polypeptide chain of the protein product is extended
D)genetic information in an mRNA molecule specifies the sequence of amino acids in the protein product

Question 23

MicroRNAs are small noncoding RNAs that ____.

A)enhance gene expression by activating mRNA expression
B)silence gene expression by binding to mRNA to inhibit translation
C)modify gene expression by replacing specific nucleotides in mRNA
D)mediate DNA production in a reverse direction

Question 24

Elongation is the process by which ____.

A)the mRNA strand is formed
B)peptide bonds are formed between aligned amino acids after the amino acids are positioned
C)amino acids are activated by ATP at their carboxyl end
D)activated amino acids are transferred to their specific tRNAs that contain the anticodon complementary to each amino acid's codon

Question 25

Transcription-level control mechanisms ____.

A)determine the path by which mRNA can be translated into a   polypeptide
B)determine whether a particular mRNA is actually translated
C)determine if a particular gene can be transcribed
D)are driven by the interaction of tRNA and mRNA

Question 26

Destruction of which organelle(s)would cause the cell to cease to function due to a total loss of energy?

A)the nucleus
B)the Golgi apparatus
C)the ribosomes
D)the mitochondria

Question 27

Which organelle is composed of an extensive network of membranous channels that connects the nuclear membrane,the Golgi apparatus,and the plasma membrane?

A)the lysosome
B)the nucleolus
C)the centrioles
D)the endoplasmic reticulum

Question 28

Which are highly specialized membrane proteins that modify the cell's response to its environment?

A)transport proteins
B)enzymes
C)receptors
D)peroxisomes

Question 29

Molecular stimuli that bind specifically to receptors are known as ____.

A)ligands
B)enzymes
C)allosteric enzymes
D)hydrolases

Question 30

The organelle that detoxifies by oxidizing molecules such as hydrogen peroxide and ethanol is the ____.

A)peroxisome
B)endosome
C)lysosome
D)ribosome

Question 31

Transcription is the process by which ____.

A)the genetic information in a single strand of DNA makes a specific sequence of bases in a messenger RNA (mRNA) chain
B)genetic information in an mRNA molecule specifies the sequence of amino acids in the protein product
C)amino acids are linked together to form the primary structure of a protein
D)the primary structure of a protein is folded several times to become the quaternary structure

Question 32

The organelle that serves as the digestive system for the cell is the ____.

A)polysome
B)endosome
C)lysosome
D)ribosome

Question 33

Which enzyme is responsible for linking together the incoming nucleotides during DNA replication?

A)DNA ligase
B)helicase
C)DNA polymerase
D)reverse transcriptase

Question 34

Which nitrogenous base is unique to RNA?

A)guanine
B)uracil
C)thymine
D)cytosine

Question 35

Damage to MTOCs will interfere with which cellular process?

A)oxidative phosphorylation
B)mitosis
C)electron transport
D)creation of an mRNA molecule

Question 36

Digestive enzymes delivered to the small intestine from cells in the pancreas are able to leave those cells because of the functioning of the ____.

A)endoplasmic reticulum
B)ribosomes
C)Golgi apparatus
D)lysosomes

Question 37

Which enzyme complex,used in metabolizing many drugs,is located on the rough endoplasmic reticulum in liver cells?

A)chromatins
B)lysozymes
C)cytochromes
D)polymerases

Question 38

What structural body is made up of flattened cisternae flanked by tubular networks and thought to be an extension of the endoplasmic reticulum?

A)nucleus
B)cytoplasm
C)lysosome
D)Golgi apparatus

Question 39

The Golgi apparatus is prominent in neurons and secretory cells and functions ____.

A)to stop the synthesis of proteins that may need carbohydrate additions
B)to add polysaccharide or lipid moieties to polypeptides
C)only for constitutive secretion of proteins
D)only for regulated secretion of proteins

Question 40

Which organelle prevents proteins that have not reached their normal tertiary or quaternary structure from reaching the cell surface?

A)the endoplasmic reticulum
B)the Golgi apparatus
C)the nucleus
D)the mitochondrion

Question 41

When discussing enzyme kinetics,Km refers to the substrate concentration at which the enzyme is saturated and functioning at maximal velocity.

Question 42

Cyclic AMP activates which enzymes?

A)protein kinases
B)restriction endonucleases
C)allosteric enzymes
D)adenyl (adenylyl) cyclases

Question 43

What is released when nutrient molecules are oxidized?

A)oxygen
B)potential (or free) energy
C)kinetic energy
D)hydrogen

Question 44

Most receptor proteins are most likely which type?

A)peripheral proteins
B)internal proteins
C)integral proteins
D)glycoproteins

Question 45

One trigger of apoptosis is ____.

A)overexpression of Bcl-2
B)inactivation of Casp-9
C)swelling of the cell
D)release of mitochondrial cytochrome c

Question 46

If two enzymes (e.g.,pyruvate dehydrogenase and pyruvate carboxylase)compete for the same substrate (pyruvate),the one with the higher Km has less affinity and will be more active when pyruvate concentrations are high.

Question 47

In muscle cells,creatine phosphate is used to replenish which substance?

A)glucose
B)pyruvic acid
C)ATP
D)calcium

Question 48

Most cellular reactions are irreversible because the same enzyme that catalyzes the conversion cannot catalyze the reverse reaction.

Question 49

Substances that bind with allosteric sites and alter the activity of regulatory enzymes are called ____.

A)transport proteins
B)modulators
C)Na pumps
D)sarcoplasmic reticula

Question 50

The various components within a cell (e.g.,mitochondria)are not "free-floating" in the cytosol,but rather,are held in place by the cytoskeleton.

Question 51

Peripheral proteins are involved in cell-cell recognition,whereas integral proteins function primarily as receptors/transporters.

Question 52

The lipid bilayer determines the function of the plasma membrane,while the proteins are primarily responsible for the structure of the membrane.

Question 53

Allosteric regulation of enzymes is carried out by modulators,other proteins that bind to the enzyme to inhibit its activity.

Question 54

Diagnostic enzymology focuses on ____.

A)enzymes that are widely distributed among many tissues
B)intracellular enzymes that express their activity in the blood abnormally due to a disease process
C)secreted enzymes such as clotting proteins in blood
D)nuclear enzymes

Question 55

Malformed Apaf-1 molecules in a cell might ____.

A)cause rapid apoptosis of the cell
B)inactivate cytochrome c
C)lead to the development of a tumor
D)have no effect on apoptosis

Question 56

Constitutive enzymes are ____.

A)uninfluenced by external stimuli
B)influenced by external stimuli
C)synthesized at variable rates
D)unaffected by induction

Question 57

Different cells express different proteins because they contain different sequences of DNA in the nucleus.

Question 58

Polysomes function to transcribe mRNA into proteins.

Question 59

Phosphorylation of a molecule is generally accomplished by transferring the terminal phosphate group from which substance?

A)GTP
B)pyruvic acid
C)G6PD
D)ATP

Question 60

The plasma membrane is a sheet-like structure composed solely of lipids.

Question 61

Most of the metabolic energy produced in cells is made in the mitochondria.

Question 62

Match each description to one of the following terms.
a.free energy
b.activation energy
c.cellular energy
d.transition state
e.standard reduction potential
energy derived from a series of chemical reactions,each of which exhibits a free energy change 

Question 63

Match each description to one of the following terms.
a.free energy
b.activation energy
c.cellular energy
d.transition state
e.standard reduction potential
the tendency of a compound to donate and receive electrons

Question 64

Match the correct enzyme classification with the examples provided.
a. enzymes that catalyze cleavage of C-C,C-S,and certain C-N bonds (excluding peptide bonds)without hydrolysis or oxidation-reduction
b. enzymes forming bonds between carbon and other atoms,such as acetyl-CoA carboxylase,which adds bicarbonate to acetyl-CoA to initiate fatty acid synthesis in the cytoplast
c. enzymes in the electron transport chain in the mitochondria
d. enzymes that catalyze cleavage of bonds by addition of water,such as digestive enzymes
e. enzymes that catalyze reactions,not oxidation or reduction,in which a functional group is moved from one substrate to another,such as transaminases
transferases

Question 65

List the three mechanisms that can be used to regulate the function of a protein (e.g.,an enzyme)and briefly (in one to two sentences)describe their key features.

Question 66

Match the correct enzyme classification with the examples provided.
a. enzymes that catalyze cleavage of C-C,C-S,and certain C-N bonds (excluding peptide bonds)without hydrolysis or oxidation-reduction
b. enzymes forming bonds between carbon and other atoms,such as acetyl-CoA carboxylase,which adds bicarbonate to acetyl-CoA to initiate fatty acid synthesis in the cytoplast
c. enzymes in the electron transport chain in the mitochondria
d. enzymes that catalyze cleavage of bonds by addition of water,such as digestive enzymes
e. enzymes that catalyze reactions,not oxidation or reduction,in which a functional group is moved from one substrate to another,such as transaminases
ligases

Question 67

The nuclear envelope is a single membrane structure that helps to isolate the nucleus from the rest of the cell.

Question 68

Oncosis results from cell injury and is associated with cellular swelling and swelling of the mitochondrial nucleus.

Question 69

Why is cholesterol important in plasma membrane function?

Question 70

Match the correct enzyme classification with the examples provided.
a. enzymes that catalyze cleavage of C-C,C-S,and certain C-N bonds (excluding peptide bonds)without hydrolysis or oxidation-reduction
b. enzymes forming bonds between carbon and other atoms,such as acetyl-CoA carboxylase,which adds bicarbonate to acetyl-CoA to initiate fatty acid synthesis in the cytoplast
c. enzymes in the electron transport chain in the mitochondria
d. enzymes that catalyze cleavage of bonds by addition of water,such as digestive enzymes
e. enzymes that catalyze reactions,not oxidation or reduction,in which a functional group is moved from one substrate to another,such as transaminases
lyases

Question 71

Match the correct enzyme classification with the examples provided.
a. enzymes that catalyze cleavage of C-C,C-S,and certain C-N bonds (excluding peptide bonds)without hydrolysis or oxidation-reduction
b. enzymes forming bonds between carbon and other atoms,such as acetyl-CoA carboxylase,which adds bicarbonate to acetyl-CoA to initiate fatty acid synthesis in the cytoplast
c. enzymes in the electron transport chain in the mitochondria
d. enzymes that catalyze cleavage of bonds by addition of water,such as digestive enzymes
e. enzymes that catalyze reactions,not oxidation or reduction,in which a functional group is moved from one substrate to another,such as transaminases
oxidoreductases

Question 72

Transcription of DNA cannot be altered.

Question 73

Match each description to one of the following terms.
a.free energy
b.activation energy
c.cellular energy
d.transition state
e.standard reduction potential
a higher energy level or barrier at which the exothermic conversion to products takes place

Question 74

Choose three of the following terms and in one sentence per term,provide a concise definition of that term: nucleus,mitochondria,RER,transcription,translation,apoptosis,and cell replication.

Question 75

Match the correct enzyme classification with the examples provided.
a. enzymes that catalyze cleavage of C-C,C-S,and certain C-N bonds (excluding peptide bonds)without hydrolysis or oxidation-reduction
b. enzymes forming bonds between carbon and other atoms,such as acetyl-CoA carboxylase,which adds bicarbonate to acetyl-CoA to initiate fatty acid synthesis in the cytoplast
c. enzymes in the electron transport chain in the mitochondria
d. enzymes that catalyze cleavage of bonds by addition of water,such as digestive enzymes
e. enzymes that catalyze reactions,not oxidation or reduction,in which a functional group is moved from one substrate to another,such as transaminases
hydrolases

Question 76

Describe the cytoskeleton (microtrabecular lattice)and its role as an intercommunication system of proteins and other macromolecules.

Question 77

Briefly describe the role of DNA in cell replication and transcription.

Question 78

An increase in the concentration of a substrate will increase the rate of the enzyme-catalyzed reaction.

Question 79

Match each description to one of the following terms.
a.free energy
b.activation energy
c.cellular energy
d.transition state
e.standard reduction potential
potential energy released from chemical bonds upon oxidation

Question 80

Match each description to one of the following terms.
a.free energy
b.activation energy
c.cellular energy
d.transition state
e.standard reduction potential
the energy required to raise the reactants to their transition state