Deck 4: Cellular Metabolism

Question 1

A cofactor is ________. Examples are ________. 

A)an inorganic molecule that all enzymes require; cholesterol and calcium
B)an inorganic molecule that some enzymes require; vitamin B₁₂ and B₆
C)a necessary part of some enzymes; copper, iron, and zinc
D)a molecule that destabilizes substrates; carbonic acid

Answer 1

C

Question 2

Which of the following is not a characteristic of enzymes?

A)They speed up the rate of chemical reactions but are not used up in the process.
B)Most are proteins.
C)They are most active at temperatures above 53 degrees C.
D)They have active sites and interact with specific substrates.

Answer 2

C

Question 3

Three factors that increase the rates of enzyme-controlled reactions are the

A)number of enzyme molecules, number of substrate molecules, and efficiency of the enzyme.
B)temperature of the reaction, number of H₂O molecules, and bond strength.
C)number of enzyme and substrate molecules formed, and strength of the enzyme.
D)size of the enzyme compared to the substrate, the number of active sites, and the ratio of enzyme to substrate molecules.

Answer 3

A

Question 4

The basic steps of an enzyme-catalyzed reaction are

A)substrate and product combine, forming an S-P complex. The reaction occurs, enzymes are released, and the unchanged substrate is released and recycled.
B)substrate and enzyme combine, forming an E-S complex. The reaction occurs, products are released, and the unchanged enzyme is released and recycled.
C)substrate, enzyme, and product combine, forming an S-E-P complex. The reaction occurs, products are released, and the unchanged enzyme is released and recycled.
D)enzyme and product combine, forming an E-P complex. The reaction reverses, enzymes are released, and the unchanged substrate is released and recycled.

Question 5

Lactose is a disaccharide found in milk. Individuals who are lactose intolerant lack the enzyme to break this sugar down into monosaccharides. Based on enzyme nomenclature, what enzyme is deficient in these individuals?

A)Lact ese
B)Lact ose
C)Lacto gen
D)Lact ase

Question 6

The enzyme catalase acts on the substrate

A)oxygen.
B)hydrogen.
C)hydrogen peroxide.
D)peroxidase.

Question 7

An example of an anabolic reaction is

A)many monosaccharides bonding, forming glycogen.
B)a dipeptide breaking down into two amino acids.
C)glycerol reacting with three fatty acid molecules to yield water and proteins.
D)glycogen breaking down into many monosaccharides.

Question 8

An important mechanism that controls metabolic pathways under physiological conditions is

A)positive feedback.
B)signal transduction.
C)negative feedback.
D)genetic control.

Question 9

Humans require vitamins in their diets because these nutrients

A)provide energy.
B)are broken down by catabolic reactions.
C)bond with minerals.
D)act as coenzymes.

Question 10

When a sucrose molecule is broken down to yield a glucose molecule and a fructose molecule,

A)dehydration synthesis occurs.
B)a water molecule is released.
C)a water molecule is used.
D)starch is consumed.

Question 11

Dehydration synthesis reactions ________ , whereas hydrolysis reactions ________.

A)lose H₂O as bonds are broken; use H₂O to form bonds
B)break large molecules into smaller ones; build large molecules from smaller ones
C)use H₂O to form bonds; lose H₂O as bonds are broken
D)lose H₂O as bonds are formed; use H₂O to break bonds

Question 12

Which of the following best describes the interaction between an enzyme and its substrate?

A)The enzyme surrounds and completely contains the substrate.
B)The substrate surrounds and completely contains the enzyme.
C)The enzyme temporarily deactivates the substrate.
D)Part of the enzyme temporarily binds part of the substrate molecule.

Question 13

The term metabolism refers to

A)the reactions in the body that synthesize proteins and nucleic acids.
B)the reactions in the body that break down proteins and nucleic acids.
C)all of the chemical reactions in a cell.
D)the breakdown of glucose molecules to release energy.

Question 14

Which of the following is an example of catabolism?

A)The assembly of the cell membrane from precursor molecules
B)The increase in muscle tissue with exercise
C)The formation of secretory proteins in the pancreas
D)The breakdown of glucose in the cytoplasm and mitochondria

Question 15

Some insecticides, such as chlorpyrifos, work by inhibiting the enzyme acetylcholinesterase (AChE), which normally breaks down the neurotransmitter acetylcholine. Where does this insecticide most likely bind to inhibit the enzyme's activity?

A)Any location on the amino acid chain that forms the AChE enyzme
B)A sequence of DNA nucleotides that encodes the AChE enzyme protein molecule
C)It does not need to bind with the enzyme directly
D)The part of an enzyme that combines with acetlycholine

Question 16

Which of the following would NOT be an example of an enzyme?

A)A molecule that remains unchanged after assisting in a chemical reaction
B)A molecule that assists in the breakdown of proteins into amino acids in the stomach
C)A molecule that helps to form the cytoskeleton of a cell
D)A molecule that breaks down sucrose into glucose and fructose

Question 17

One reason why protein synthesis is important is

A)enzymes are proteins and enzymes are essential to metabolism.
B)proteins release energy for metabolic reactions.
C)proteins encode DNA sequences.
D)the diet does not provide the building blocks of protein.

Question 18

The term catabolism refers to

A)chemical reactions that acquire energy.
B)chemical reactions that release energy.
C)synthesis of large molecules.
D)the formation of genetic material.

Question 19

In dehydration synthesis of a carbohydrate,

A)larger molecules are broken down into smaller ones.
B)monosaccharides are joined.
C)water molecules bond to monosaccharide molecules.
D)the molecule is broken down into carbon dioxide and water.

Question 20

The term anabolic metabolism refers to

A)biochemical reactions that synthesize compounds.
B)all processes required to maintain life.
C)biochemical reactions that break down compounds.
D)biochemical reactions that release energy from nutrients.

Question 21

Anaerobic reactions of cellular respiration

A)break down glucose into 2 pyruvic acid molecules.
B)occur in the absence of oxygen.
C)transfer energy to ATP molecules.
D)all of the answer choices are correct.

Question 22

What is the function of ATP molecules in living cells?

A)They form a genetic material.
B)They capture energy from the oxidation of fuels in their high-energy phosphate bonds, and the energy is used in various cell processes.
C)They act as coenzymes so that fats can be synthesized.
D)They are an integral part of the cell membrane, important in transporting water molecules.

Question 23

Energy is defined as

A)something important for chemical reactions.
B)the ability to do work.
C)the heat given off from chemical reactions.
D)the heat required to start a reaction.

Question 24

If a cell was unable to produce pyruvate, this cell may have a mutation in an enzyme in which process?

A)Glycolysis
B)The citric acid cycle
C)Gluconeogenesis
D)The electron transport system

Question 25

Which of the following is true?

A)The genome consists of entirely protein-encoding genes.
B)An amino acid encodes a gene.
C)DNA has five types of nucleotide bases.
D)Much of the genome does not encode proteins.

Question 26

DNA replication occurs

A)when a cell requires energy.
B)outside of the nucleus.
C)during interphase of the cell cycle.
D)during mitosis.

Question 27

How does oxidation during cellular respiration differ from burning?

A)Respiration doesn't use enzymes to lower the activation energy.
B)Respiration requires a relatively large amount of energy to start the process.
C)Respiration uses enzymes to lower the activation energy.
D)Respiration releases more energy as heat and light.

Question 28

How many codons specify the twenty types of amino acids?

A)61
B)23
C)46
D)3

Question 29

The anaerobic reactions of cellular respiration take place in the

A)cytoplasm.
B)mitochondria.
C)nucleus.
D)ribosomes.

Question 30

Which of the following substances increases in abundance during cellular respiration?

A)Oxygen
B)Glucose
C)ATP
D)Glycogen

Question 31

Name the molecule that is common to carbohydrate and lipid metabolic pathways and connects these two pathways metabolically.

A)Glucose
B)Pyruvic acid
C)Acetyl coenzyme A
D)Glycogen

Question 32

A molecule that carries energy in a form the cell can use is

A)glucose.
B)glycogen.
C)vitamin C.
D)ATP.

Question 33

In the citric acid cycle,

A)carbon dioxide is released.
B)oxygen atoms are released.
C)4 ATP molecules are formed.
D)hydrochloric acid is released.

Question 34

In cellular respiration,

A)mitochondria release glucose molecules.
B)energy is released from molecules and is transferred to other molecules.
C)cells breathe, or take in, O₂ and give off CO₂.
D)energy is absorbed from glucose and is transferred to CO₂.

Question 35

Which choice lists structures in order of increasing size?

A)nitrogenous base - nucleotide - gene - chromosome - genome
B)nitrogenous base - nucleotide - gene - genome - chromosome
C)genome - nucleus - chromosome - nucleotide - gene
D)cell - organelle - tissue - organ

Question 36

A molecule that is a storage form of carbohydrate is

A)glycogen.
B)glycerol.
C)DNA.
D)an amino acid.

Question 37

If one strand of DNA has the sequence TCAGGCTATTCCCG, then the complementary sequence of the other strand is

A)AGUCCGAUAAGGGC.
B)AGTCCGATAAGGGC.
C)TCAGGCTATTCCCG.
D)UCAGGCUAUUCCCG.

Question 38

ATP is important to cellular processes because it

A)is formed by muscles contracting or whenever cellular work occurs.
B)provides energy for cellular work when the terminal, high-energy bond is broken.
C)releases oxygen when high-energy phosphate bonds are broken.
D)is a by-product of all catabolic reactions.

Question 39

The anaerobic reactions of cellular respiration occur in the ________ , whereas the aerobic reactions of cellular respiration occur in the  ________. 

A)mitochondria with O₂ required; cytoplasm with O₂ required
B)cytoplasm without O₂ required; cytoplasm with CO₂ required
C)mitochondria without O₂ required; mitochondria with O₂ required
D)cytoplasm without O₂ required; mitochondria with O₂ required

Question 40

During DNA replication,

A)tRNAs bring specific amino acids to an mRNA molecule.
B)two single strands of DNA come together, restoring complementary base pairing.
C)amino acids are joined.
D)the DNA double helix comes apart, and new nucleotides are brought in, forming two double helices.

Question 41

In what molecule are codons found? 

A)mRNA
B)tRNA
C)rRNA
D)Proteins.

Question 42

A mutation is

A)a change in a DNA sequence in less than 1% of a population that affects anatomy and/or physiology.
B)a common genetic variant.
C)always beneficial to health.
D)always harmful to health.

Question 43

Copying DNA information into an mRNA molecule is called

A)translation.
B)synthesis.
C)replication.
D)transcription.

Question 44

If you were to isolate a molecule containing uracil, all of the following are most likely true EXCEPT

A)it contains codons that represent amino acids.
B)it is single stranded.
C)it also contains guanine.
D)it contains deoxyribose sugar.

Question 45

A peptide bond forms between

A)a tRNA and an mRNA.
B)adjacent amino acids.
C)an mRNA and an rRNA.
D)a gene and a protein.

Question 46

If an E. coli bacterium were to have a protein with the correct amino acid sequence, but not the correct shape, which of the following is a logical explanation for what could be wrong?

A)Peptide bonds were not able to form between the amino acids.
B)The shape-coding region of the DNA sequence related to this protein is mutated.
C)The chaperone protein associated with protein folding is not functional.
D)An error in transcription occurred.

Question 47

The codon that will signal where to begin making a polypeptide is ________.

A)TAC
B)AGG
C)AUG
D)TTA

Question 48

Synthesis of a protein stops when

A)any of three specific anticodons are encountered in the mRNA.
B)there is no more DNA.
C)any of three "stop" codons are encountered in the mRNA.
D)the ribosome becomes fatigued.

Question 49

Three types of genetic changes are

A)replication, transcription, and translation.
B)A to C, G to C, and U to A.
C)mutations, SNPs, and changes in copy number.
D)adenine, guanine, and cytosine.

Question 50

A part of a gene that is a DNA sequence 333 nucleotides long encodes ________ amino acids.

A)333
B)111
C)999
D)444

Question 51

Which DNA sequence can encode the amino acid sequence ile-asp-ser-cys-his-tyr?

A)TAGCTGTCAACAGTGATA
B)TAACTGTCGACGGTGATG
C)TAACTAAGTACGGTGATG
D)All of the answer choices are correct

Question 52

A DNA sequence AACGGTGCACCACGG encodes a portion of a protein of sequence

A)ile-gly-ala-pro-arg.
B)leu-pro-arg-gly-ala.
C)ala-gly-arg-pro-leu.
D)arg-pro-ala-gly-ile.

Question 53

Which of the nitrogenous bases is part of DNA, but not RNA?

A)Uracil
B)Thymine
C)Guanine
D)Cytosine

Question 54

A DNA sequence AACGGTGCACCACGG encodes an mRNA of sequence

A)AACGGUGCACCACGG.
B)UUGCCACGUGGUGCC.
C)AACGGTGCACCACGG.
D)UUCGGAGCUCCUCGG.

Question 55

If you were to sequence the genome of two individuals and found that their DNA is 99.9% similar, what inference could you make?

A)These two individuals must be siblings.
B)These individuals are likely identical twins.
C)These individuals must be from different species.
D)No inferences could be made because 99.9% of DNA is shared between all humans.

Question 56

The genetic code is

A)the correspondence between a sequence of three DNA nucleotides and a specific amino acid.
B)the correspondence between a DNA nucleotide and an RNA nucleotide.
C)the correspondence between a gene and a genome.
D)the correspondence between a specific amino acid and a specific gene.

Question 57

In the DNA damage response,

A)repair enzymes replace mismatched nucleotides in DNA.
B)repair enzymes replace mismatched nucleotides in RNA.
C)repair enzymes replace mismatched amino acids in protein.
D)more than one codon encodes one type of amino acid.

Question 58

Transcription and translation differ in that

A)transcription produces DNA and translation produces RNA.
B)transcription produces RNA and translation produces DNA.
C)transcription produces protein and translation produces RNA.
D)transcription produces RNA and translation produces protein.

Question 59

Which of the following is not true regarding RNA?

A)It is transcribed in the nucleus and enters the cytoplasm.
B)It includes ribose, a 5-carbon sugar.
C)It is double-stranded.
D)It has cytosine as one of its four nitrogenous bases.

Question 60

A mutation can cause disease if

A)the DNA sequence does not change.
B)the DNA sequence changes so that one amino acid is substituted for another in a way that affects the encoded protein's functioning.
C)the DNA sequence changes so that one amino acid is substituted for another in a way that does not alter the encoded protein's functioning.
D)it attracts mutagens.

Question 61

Enzymes are proteins that promote specific chemical reactions.

Question 62

Phospholipids are critical structures in cell membranes and are therefore enzymes.

Question 63

Oxidation forms chemical bonds.

Question 64

Oxidation of glucose is important because it releases energy.

Question 65

In adipose tissue, fat molecules form when fatty acid molecules and glycerol join by hydrolysis.

Question 66

An ATP molecule consists of an adenine, a ribose, and three phosphates.

Question 67

Releasing the energy in glucose molecules is an example of catabolism.

Question 68

The synthesis of an ATP molecule requires two ADP molecules.

Question 69

The metabolome includes

A)all of the genes that encode protein in the genome.
B)the DNA that does not encode protein in the genome.
C)all of the small molecules that are part of metabolism.
D)all of the enzymes that take part in aerobic respiration.

Question 70

A different enzyme may catalyze the formation and the breakdown of the same molecule.

Question 71

MicroRNAs

A)are 21 or 22 bases long.
B)control gene expression.
C)are noncoding RNAs.
D)All of these answer choices are correct.

Question 72

Dehydration synthesis is catabolic and hydrolysis is anabolic.

Question 73

Metabolism refers to all of the chemical reactions in a cell.

Question 74

A metabolic pathway is a particular sequence of enzyme-controlled reactions.

Question 75

An active site is the part of a substrate molecule that binds an enzyme.

Question 76

Catabolism builds up molecules and anabolism breaks down molecules.

Question 77

Arsenic poisoning harms the body by

A)unraveling the DNA double helix.
B)interfering with cellular extraction of energy from glucose.
C)forming more sulfur bonds in proteins.
D)rotting the teeth.

Question 78

In glycolysis, the enzyme phosphofructokinase catalyzes the slowest part of this metabolic process and can therefore be considered a rate-limiting enzyme.

Question 79

A cell may contain hundreds of different types of enzymes.

Question 80

DNA profiling

A)sequences the entire genomes of criminals.
B)sequences genes that cause disease.
C)compares the most variable parts of the genome for a variety of applications.
D)analyzes 64 highly variable regions of the human genome.