chapter 3

Proteins impart mobility to entire cells and molecules within cells.

Proteins are critical in living organisms. What is one example of the many important functions of proteins in organisms?

It is a covalent bond formed via a condensation reaction.

Which of the following is true of the peptide bond?

Leucine

Which of the following amino acids is more likely to come together in aqueous solutions?

Prions cause changes in the shape of normal proteins that can lead to cell death.

Which statement about prions is true?

The formation of α-helices and β-pleated sheets

In the diagram of a protein structure, letter (b) best represents which of the following descriptions?

primary structure of hemoglobin

Sickle-cell anemia results when valine replaces glutamate at position six of the β-globin subunit of hemoglobin. The sickling seen in red blood cells with the defective hemoglobin subunit results from a change in the __________.

Organic compounds formed from chemicals present in the atmosphere and oceans of ancient Earth.

What is the first step in the chemical evolution theory?

The tertiary structure

A chemical that breaks disulfide bonds might destroy which level of protein structure?

The sequence of amino acids in a polypeptide

In the diagram of protein structure, letter (a) best represents which of the following descriptions?

the bonds that form secondary and tertiary structure are energetically favorable

Many proteins fold spontaneously because __________.

buried in the interior of a protein

A hydrophobic R group would most likely be found __________.

They rarely participate in chemical reactions.

Which of the following statements is true regarding the amino acids that have R groups or side chains that consist solely of carbon and hydrogen atoms?

have electrically charged side chains or R groups

Aspartate and glutamate are two amino acids that are highly soluble in water. This is best explained by the fact that they __________.

The sequence of amino acids in a polypeptide

In the diagram of protein structure, letter (a) best represents which of the following descriptions?

proteins do not serve as a good template for replication

Researchers doubt that proteins were the first living entity because __________.

The shape produced when two or more polypeptides associate to form a functional protein

In the diagram of a protein structure, letter (d) best represents which of the following descriptions?

Enzyme B, which functions best at a pH of 3 and a temperature of 90o Celsius

Enzymes function best at particular temperature and pH conditions. What is the most likely enzyme to be present in a bacterium found in a hot water vent in an acidic current?

The side chain (R group)

The chemical structure of valine and asparagine differ in which of the following?

Proteins impart mobility to entire cells and molecules within cells.

Proteins are critical in living organisms. What is one example of the many important functions of proteins in organisms?

The formation of α-helices and β-pleated sheets

In the diagram of a protein structure, letter (b) best represents which of the following descriptions?

proteins do not serve as a good template for replication

Researchers doubt that proteins were the first living entity because __________.

The shape produced when two or more polypeptides associate to form a functional protein

In the diagram of a protein structure, letter (d) best represents which of the following descriptions?

Enzyme B, which functions best at a pH of 3 and a temperature of 90o Celsius

Enzymes function best at particular temperature and pH conditions. What is the most likely enzyme to be present in a bacterium found in a hot water vent in an acidic current?

When a self-replicating molecule evolved

At which step of chemical evolution did life become possible?

They rarely participate in chemical reactions.

Which of the following statements is true regarding the amino acids that have R groups or side chains that consist solely of carbon and hydrogen atoms?

Glycine

Which of the following amino acids is hydrophobic?

Tertiary

Which level of protein structure results from five types of interactions involving the side chains—ionic bonds, hydrogen bonds, van der Waals interactions, covalent bonds, and hydrophobic interactions?

have electrically charged side chains or R groups

Aspartate and glutamate are two amino acids that are highly soluble in water. This is best explained by the fact that they __________.

Enzyme B, which functions best at a pH of 3 and a temperature of 90o Celsius

Enzymes function best at particular temperature and pH conditions. What is the most likely enzyme to be present in a bacterium found in a hot water vent in an acidic current?

The presence of mineral surfaces for the amino acids to adhere to

What may have aided the polymerization of amino acids into peptides in the oceans of early prebiotic Earth?

The shape produced when two or more polypeptides associate to form a functional protein

In the diagram of a protein structure, letter (d) best represents which of the following descriptions?

Tertiary

Which level of protein structure results from five types of interactions involving the side chains—ionic bonds, hydrogen bonds, van der Waals interactions, covalent bonds, and hydrophobic interactions?

Enzyme B, which functions best at a pH of 3 and a temperature of 90o Celsius

Enzymes function best at particular temperature and pH conditions. What is the most likely enzyme to be present in a bacterium found in a hot water vent in an acidic current?

The formation of α-helices and β-pleated sheets

In the diagram of a protein structure, letter (b) best represents which of the following descriptions?

An amino group and a carboxyl group

What two functional groups are present in every amino acid?

Proteins impart mobility to entire cells and molecules within cells.

Proteins are critical in living organisms. What is one example of the many important functions of proteins in organisms?

They rarely participate in chemical reactions.

Which of the following statements is true regarding the amino acids that have R groups or side chains that consist solely of carbon and hydrogen atoms?

The presence of mineral surfaces for the amino acids to adhere to

What may have aided the polymerization of amino acids into peptides in the oceans of early prebiotic Earth?

have electrically charged side chains or R groups

Aspartate and glutamate are two amino acids that are highly soluble in water. This is best explained by the fact that they __________.

All the levels of protein structure

The linear order of amino acids in a protein helps determine which level of protein structure?

Hydrogen

What bond type is responsible for the secondary structure of a protein?

The overall three-dimensional shape of a polypeptide

In the diagram of a protein structure, letter (c) best represents which of the following descriptions?

Only the primary protein structure was maintained.

During the denaturation of ribonuclease, which level of protein structure was maintained?

437

Upon chemical analysis, a particular protein was found to contain 438 amino acids. How many peptide bonds are present in this protein?

reactants

Substrates are also known as __________.

Only the primary protein structure was maintained.

During the denaturation of ribonuclease, which level of protein structure was maintained?

have electrically charged side chains or R groups

Aspartate and glutamate are two amino acids that are highly soluble in water. This is best explained by the fact that they __________.

When a self-replicating molecule evolved

At which step of chemical evolution did life become possible?

Prions cause changes in the shape of normal proteins that can lead to cell death.

Which statement about prions is true?

The nature of R groups or side chains determines how soluble each amino acid is in water.

Which statement best describes the R groups or side chains of amino acids?

Water is __________ when a nucleotide is added to the end of a DNA strand.

produced

Your small intestine secretes enzymes to help hydrolyze molecules from your food. If a protein is hydrolyzed, what is produced?

amino acid

-The peptide bonds of proteins would be broken, using up water and releasing the monomers of proteins, amino acids.

Many antibiotic drugs prevent bacteria growth by inhibiting DNA polymerization. What type of bond formation are these drugs most likely inhibiting?

Phosphodiester bonds

-Phosphodiester bonds are created during the polymerization of DNA strands.

What is another name for a condensation reaction?

dehydration

What is the name of the process during which a bond between two monomers is broken?

hydrolysis

Protein polymers are made up of _______________ monomers.

amino acid

Nucleic acid polymers are made up of _______________ monomers.

nucleotide

Carbohydrate polymers are made up of _________________ monomers.

simple sugar

What type of bond joins the monomers in a protein's primary structure?

peptide

The secondary structure of a protein results from _____.

HYDROGEN BONDS

-Electronegative oxygen and nitrogen atoms leave hydrogen atoms with partial positive charges.

Tertiary structure is NOT directly dependent on _____

peptide bonds

-Peptide bonds link together the amino acids of a protein's primary structure.

______ structure is achieved when a protein folds into a compact, three-dimensional shape stabilized by interactions between side-chain R groups of amino acids.

tertiary

________ structure is the sequence of amino acids in a protein.

primary

_________ structure describes the alpha-helices and beta-sheets that are formed by hydrogen bonding between backbone atoms located near each other in the polypeptide chain.

secondary

_________ structure is the result of two or more protein subunits assembling to form a larger, biologically active protein complex.

Quaternary

Which of these does NOT contain a structural protein?

ovalbumin

Defensive proteins are manufactured by the _____ system.

immune

Which of the following is not attached to the central carbon atom in an amino acid?

an oxygen

What is attached to the central carbon atom in an amino acid?

1.) An amino functional group
2.) A side chain ("R group")
3.) A carboxyl functional group

Which part of an amino acid is always acidic?

Carboxyl functional group

Which monomers make up RNA?

nucleotides

Which of the following statements about the formation of polypeptides from amino acids is true?

A bond forms between the carboxyl functional group of one amino acid and the amino functional group of the other amino acid.

True or false? Enzymes in the digestive tract catalyze hydrolysis reactions.

true yo