Deck 1: The Cell: a Microcosm of Life

Question 1

What is the role of cholesterol in plasma membrane structure?

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

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 reticulum
C) integral proteins
D) Golgi apparatuses

Answer 2

C

Question 3

What is the major route for ATP production?

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

Answer 3

A

Question 4

Which of the following nitrogenous bases is unique to RNA?

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

Question 5

What type of cell depends solely on energy produced through anaerobic mechanisms?

A) hepatocyte
B) enterocyte
C) glucocyte
D) erythrocyte

Question 6

Which of the following is NOT an attribute common to all membranes?

A) Membranes are symmetrical.
B) Membranes form sheet-like structures.
C) Membranes are fluid structures.
D) Membranes protect cellular components.

Question 7

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

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

Question 8

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

Question 9

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

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

Question 10

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 11

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 12

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

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

Question 13

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

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

Question 14

Membrane proteins serve as all of the following EXCEPT _____.

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

Question 15

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 16

Enzymes of metabolic pathways that are associated with the cytoplasmic matrix so that the product of one enzyme is released in close proximity to the next enzyme for which it is a substrate to facilitate velocity of the overall pathway include enzymes of _____.

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

Question 17

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 18

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 19

Membrane lipid bilayers consist primarily of _____.

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

Question 20

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 21

For active transport (e.g., of glucose), you need:

A) ATP.
B) a Na-K pump.
C) Na.
D) an integral protein.
E) all of the above

Question 22

If an exothemic reaction releases -3,300 cal/mol of energy, how much energy is required for the reaction to be reversed?

A) +3,300
B) -3,300
C) +6,600
D) -6,600

Question 23

Maintaining balance in the regulation of metabolic pathways necessary for life of the organism includes all of these catalytic regulatory mechanisms EXCEPT _____.

A) increasing the synthesis of constitutive enzymes
B) covalent modification through hormone stimulation
C) modulation of allosteric enzymes
D) increasing adaptable enzyme concentration by induction

Question 24

The energy pool that serves as the major linking intermediate between energy-yielding and energy-demanding chemical reactions is:

A) activation energy.
B) NAD.
C) ATP.
D) free energy.

Question 25

The energy needed to raise the energy of a reactant sufficiently to cause an exothermic reaction to occur is referred to as the

A) transition state.
B) barrier state.
C) activation energy.
D) free energy.

Question 26

When the terminal phosphate group of ATP is removed by hydrolysis, forming ADP and inorganic phosphate, the type of reaction that occurs is _____.

A) endothermic
B) exothermic
C) standard
D) free

Question 27

A high K_m means _____ affinity and is stated in units of _____.

A) low; concentration (e.g., M; mM; μM)
B) high; rate (e.g., molecules/sec; moles/min)
C) high; time (e.g., hours; min; sec)
D) low; does not have any units

Question 28

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

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

Question 29

The quantity of energy released in an exothermic reaction is _____ the quantity required for the reverse endothermic reaction.

A) the same as
B) greater than
C) less than
D) not related to

Question 30

Leader sequences attached to the amino end of newly synthesized proteins that remain within the cell are required for proteins

A) destined for degradation.
B) to move to the appropriate site for proper function.
C) to function within lysosomes and peroxisomes.
D) requiring post-translational activation.

Question 31

Phosphorylation of ADP is an example of _____.

A) an exothermic reaction
B) an endothermic reaction
C) an energy-releasing reaction
D) a downhill reaction

Question 32

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 33

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 34

Which of the following enzymes has diagnostic value for disease?

A) isocitrate dehydrogenase
B) ornithine carbomoyl transferase
C) isozymes of lactate dehydrogenase
D) isozymes of phosphofructokinase

Question 35

Most human enzymes are synthesized intracellularly and function

A) within the same cell.
B) in another location after secretion.
C) in the bloodstream due to leakage from the synthesizing cell.
D) to promote tumors unless quickly degraded.

Question 36

The net energy transformation when nutrients are systematically oxidized to carbon dioxide and water is _____.

A) reversible
B) catalytic
C) endothermic
D) exothermic

Question 37

Highly specialized membrane proteins that modify the cell's response to its environment are _____.

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

Question 38

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 39

If you measure the abundance of an enzyme (or any other protein) and it increases, that increase is most likely due to:

A) decreased transcription.
B) increased translation.
C) posttranslational modification.
D) allosteric regulation.
E) two of the above

Question 40

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

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

Question 41

The discipline of nutritional genomics studies _____.

A) the interactions among genes and bioactive components in food that change gene expression without changing the DNA nucleotide sequence (nutritional epigenetics)
B) inborn changes in DNA nucleotide sequences or gene variants (nutrigenetics)
C) genetic alterations that can be compensated for by increasing or decreasing specific nutrients (nutrigenomics)
D) all of the above

Question 42

The primary mechanism by which gene expression is modified by bioactive factors in food appears to be _____.

A) mutations causing cancer
B) interactions with transcription factors
C) production of SNPs
D) downregulation of translation

Question 43

A common mutation in the 5,10-methylenetetrahydrofolate reductase enzyme (MTHFR) _____.

A) prevents the individual from activating the B vitamin folate
B) diminishes the activity of the enzyme
C) increases the activity of the enzyme
D) both a and b

Question 44

What lifestyle change would be most important to individuals with a common variant in the GST gene that impairs protections against toxins?

A) increasing levels of daily exercise
B) eating a low-fat diet
C) increasing ingestion of cruciferous vegetables
D) increasing intake of omega-3 fats

Question 45

In electron transfer, an electron donor reduces the electron receptor and in the process becomes

A) oxidized.
B) transformed.
C) reduced.
D) flavin mononucleotide.