Question 1

State the two main ways that cells regulate the activity of their enzymes and provide one example of each.

Accepted Answer

(1) Allosteric or feedback inhibition or

Question 2

The fluid mosaic model of cell membranes was proposed by

Accepted Answer

A)  Frye and Edidin. 
B)  Singer and Nicolson. 
C)  Gorter and Grendel. 
D)  Watson and Crick. 
A)  Frye and Edidin. 
B)  Singer and Nicolson. 
C)  Gorter and Grendel. 
D)  Watson and Crick.

Question 3

A researcher is trying to determine the contents of a viral genome. Upon chemical analysis, the nucleic acid is found to contain 27% cytosine, 27% adenine, 23% uracil, and 23% guanine. Based on this data, the viral genome most likely consists of

Accepted Answer

A)  single-stranded DNA. 
B)  double-stranded DNA. 
C)  single-stranded RNA. 
D)  double-stranded RNA. 
A)  single-stranded DNA. 
B)  double-stranded DNA. 
C)  single-stranded RNA. 
D)  double-stranded RNA.

Question 4

Under the mild conditions of temperature and pressure that are compatible with life, most biological reactions are so slow that they would not occur in the absence of _______.

Accepted Answer

enzymes (e

Question 5

Like ribonuclease, insulin is a small protein. However, upon renaturation, insulin is much less efficient in resuming its native conformation. Why is this?

Accepted Answer

Insulin is composed of two polypeptide c

Question 6

In most proteins, α helices and β sheets fold into globular domains with _______ on the inside.

Accepted Answer

hydrophobi

Question 7

Lipids with unsaturated fatty acids

Accepted Answer

A)  decrease fluidity of membranes. 
B)  increase the charge associated with the inner face of a membrane. 
C)  increase fluidity of membranes. 
D)  are present only on the inner side of the plasma membrane. 
A)  decrease fluidity of membranes. 
B)  increase the charge associated with the inner face of a membrane. 
C)  increase fluidity of membranes. 
D)  are present only on the inner side of the plasma membrane.

Question 8

The side chains of basic amino acids such as lysine and arginine are _______ charged while those of acidic amino acids such as aspartic acid and glutamic acid are _______ charged at normal cellular pH.

Accepted Answer

positively

Question 9

Anfinsen's experiments on denatured ribonuclease showed that

Accepted Answer

A)  protein denaturation is irreversible. 
B)  proteins can renature to regain their activity only with the assistance of specialized enzymes. 
C)  proteins have unique amino acid sequences. 
D)  the conformation of the folded protein is determined by its amino acid sequence. 
A)  protein denaturation is irreversible. 
B)  proteins can renature to regain their activity only with the assistance of specialized enzymes. 
C)  proteins have unique amino acid sequences. 
D)  the conformation of the folded protein is determined by its amino acid sequence.

Question 10

The fundamental building block of cellular membranes is

Accepted Answer

A)  the glycolipid. 
B)  the phospholipid. 
C)  cholesterol. 
D)  protein. 
A)  the glycolipid. 
B)  the phospholipid. 
C)  cholesterol. 
D)  protein.

Question 11

Proteins are polymers of how many different amino acids?

Accepted Answer

A)  16 
B)  20 
C)  24 
D)  36 
A)  16 
B)  20 
C)  24 
D)  36

Question 12

Christian Anfinsen and colleagues showed in the 1950s that proteins contain all the information to spontaneous fold into an active enzyme. Yet sixty years later, we can still not predict the three-dimension shape of a protein from its amino acid sequence.

Accepted Answer

A) True 
 B)False

Question 13

How does NAD+ act as a chemical carrier?

Accepted Answer

NAD⁺ can accept a hydrogen ion and two el

Question 14

Suppose that an organic chemist wishes to synthesize an inhibitor of an important enzyme in pyrimidine biosynthesis. What two different kinds of molecules should be considered the most effective inhibitors?

Accepted Answer

Pyrimidines are heterocyclic bases found

Question 15

Coenzymes are chemically related to

Accepted Answer

A)  amino acids. 
B)  inorganic phosphate. 
C)  glucose. 
D)  vitamins. 
A)  amino acids. 
B)  inorganic phosphate. 
C)  glucose. 
D)  vitamins.

Question 16

RNA in cells can serve as a

Accepted Answer

A)  regulator of gene expression. 
B)  carrier of information from the nucleus to the cytoplasm. 
C)  catalyst or enzyme. 
D)  All of the above 
A)  regulator of gene expression. 
B)  carrier of information from the nucleus to the cytoplasm. 
C)  catalyst or enzyme. 
D)  All of the above

Question 17

Cells can both make cholesterol and utilize cholesterol from the diet. High levels of cholesterol depress cholesterol biosynthesis by cells. What is the biochemical term applied to this type of enzyme regulation, and what are the implications of lowered dietary cholesterol for the rate of cellular cholesterol biosynthesis?

Accepted Answer

The inhibition of product biosynthesis b

Question 18

The trypsin substrate binding site contains an aspartate residue, which is able to form an ionic bond with which amino acids in its polypeptide substrates?

Accepted Answer

A)  Lysine or arginine 
B)  Glutamate or glutamine 
C)  Leucine or phenylalanine 
D)  Serine or threonine 
A)  Lysine or arginine 
B)  Glutamate or glutamine 
C)  Leucine or phenylalanine 
D)  Serine or threonine

Question 19

Phospholipid bilayers are permeable only to molecules that are _______ and _______.

Accepted Answer

A)  large; uncharged 
B)  large; charged 
C)  small; uncharged 
D)  small; charged 
A)  large; uncharged 
B)  large; charged 
C)  small; uncharged 
D)  small; charged

Question 20

The formation of cell membranes is based on the capacity of _______ to form a _______.

Accepted Answer

lipids (phospholipid

State the two main ways that cells regulate the activity of their enzymes and provide one example of each.

The fluid mosaic model of cell membranes was proposed by

A researcher is trying to determine the contents of a viral genome. Upon chemical analysis, the nucleic acid is found to contain 27% cytosine, 27% adenine, 23% uracil, and 23% guanine. Based on this data, the viral genome most likely consists of

Under the mild conditions of temperature and pressure that are compatible with life, most biological reactions are so slow that they would not occur in the absence of _______.

Like ribonuclease, insulin is a small protein. However, upon renaturation, insulin is much less efficient in resuming its native conformation. Why is this?

In most proteins, α helices and β sheets fold into globular domains with _______ on the inside.

Lipids with unsaturated fatty acids

The side chains of basic amino acids such as lysine and arginine are _ charged while those of acidic amino acids such as aspartic acid and glutamic acid are _ charged at normal cellular pH.

Anfinsen's experiments on denatured ribonuclease showed that

The fundamental building block of cellular membranes is

Proteins are polymers of how many different amino acids?

Christian Anfinsen and colleagues showed in the 1950s that proteins contain all the information to spontaneous fold into an active enzyme. Yet sixty years later, we can still not predict the three-dimension shape of a protein from its amino acid sequence.

How does NAD⁺ act as a chemical carrier?

Suppose that an organic chemist wishes to synthesize an inhibitor of an important enzyme in pyrimidine biosynthesis. What two different kinds of molecules should be considered the most effective inhibitors?

Coenzymes are chemically related to

RNA in cells can serve as a

The trypsin substrate binding site contains an aspartate residue, which is able to form an ionic bond with which amino acids in its polypeptide substrates?

Phospholipid bilayers are permeable only to molecules that are _ and _.

The formation of cell membranes is based on the capacity of _ to form a _.

An Overview of Cells and Cell Research

Bioenergetics and Metabolism

Fundamentals of Molecular Biology

Genomics, Proteomics, and Systems Biology

Genes and Genomes

Replication, Maintenance, and Rearrangements of Genomic Dna

RNA Synthesis and Processing

Transcriptional Regulation and Epigenetics

Protein Synthesis, Processing, and Regulation

The Nucleus

Protein Sorting and Transport

Mitochondria, Chloroplasts, and Peroxisomes

The Cytoskeleton and Cell Movement

The Plasma Membrane

Cell Walls, the Extracellular Matrix, and Cell Interactions

Cell Signaling

The Cell Cycle

Cell Death and Cell Renewal

Cancer

Filters

Exam 2: Molecules and Membranes

State the two main ways that cells regulate the activity of their enzymes and provide one example of each.

The fluid mosaic model of cell membranes was proposed by

A researcher is trying to determine the contents of a viral genome. Upon chemical analysis, the nucleic acid is found to contain 27% cytosine, 27% adenine, 23% uracil, and 23% guanine. Based on this data, the viral genome most likely consists of

Under the mild conditions of temperature and pressure that are compatible with life, most biological reactions are so slow that they would not occur in the absence of _______.

Like ribonuclease, insulin is a small protein. However, upon renaturation, insulin is much less efficient in resuming its native conformation. Why is this?

In most proteins, α helices and β sheets fold into globular domains with _______ on the inside.

Lipids with unsaturated fatty acids

The side chains of basic amino acids such as lysine and arginine are _______ charged while those of acidic amino acids such as aspartic acid and glutamic acid are _______ charged at normal cellular pH.

Anfinsen's experiments on denatured ribonuclease showed that

The fundamental building block of cellular membranes is

Proteins are polymers of how many different amino acids?

Christian Anfinsen and colleagues showed in the 1950s that proteins contain all the information to spontaneous fold into an active enzyme. Yet sixty years later, we can still not predict the three-dimension shape of a protein from its amino acid sequence.

How does NAD+ act as a chemical carrier?

Suppose that an organic chemist wishes to synthesize an inhibitor of an important enzyme in pyrimidine biosynthesis. What two different kinds of molecules should be considered the most effective inhibitors?

Coenzymes are chemically related to

RNA in cells can serve as a

The trypsin substrate binding site contains an aspartate residue, which is able to form an ionic bond with which amino acids in its polypeptide substrates?

Phospholipid bilayers are permeable only to molecules that are _______ and _______.

The formation of cell membranes is based on the capacity of _______ to form a _______.

An Overview of Cells and Cell Research

Bioenergetics and Metabolism

Fundamentals of Molecular Biology

Genomics, Proteomics, and Systems Biology

Genes and Genomes

Replication, Maintenance, and Rearrangements of Genomic Dna

RNA Synthesis and Processing

Transcriptional Regulation and Epigenetics

Protein Synthesis, Processing, and Regulation

The Nucleus

Protein Sorting and Transport

Mitochondria, Chloroplasts, and Peroxisomes

The Cytoskeleton and Cell Movement

The Plasma Membrane

Cell Walls, the Extracellular Matrix, and Cell Interactions

Cell Signaling

The Cell Cycle

Cell Death and Cell Renewal

Cancer

Filters

The side chains of basic amino acids such as lysine and arginine are _ charged while those of acidic amino acids such as aspartic acid and glutamic acid are _ charged at normal cellular pH.

How does NAD⁺ act as a chemical carrier?

Phospholipid bilayers are permeable only to molecules that are _ and _.

The formation of cell membranes is based on the capacity of _ to form a _.