Chapter 3 Biology

How many polypeptides are present in a protein whose highest level of structure is tertiary structure?

1 polypeptide only

Match each interaction that can potentially contribute to a protein's shape with the phrase that best describes it. 1. disulfide bridge, 2. ionic bond, 3. van der Waals attraction, and 4. hydrophobic exclusion a. weak attraction between atoms due to oppositely polarized electron clouds. b. formation of a covalent bond between 2 cysteine side chains. c. hydrophobic portions of the protein gather in the interior of the protein. d. formation of a bond between groups with opposite charge.

1-b 2-d 3-a 4-c

__________________ is often referred to as the "energy currency of the cell."

ATP

Match the bases that pair in DNA molecules. Adenine Guanine Thymine Cytosene

Adenine-Thymine Guanine-Cytosine

The two major functional groups found in all amino acids are the basic __________________ group and the acidic ___________________ group.

Amino Carboxyl

What are the building blocks of proteins?

Amino Acids - there are 20 different kinds;

Proteins are made up of one or more unbranched chains of _______________ ______________.

Amino acids

The peptide bond in this molecule is located where?

Between the red C and the red N.

___________________________ atoms form the framework of biological molecules.

Carbon

What are the three major structural components of an amino acid?

Carboxyl group Amino group Side chain (R)

What are the two major classes of nucleic acids?

DNA and RNA

Describe the structure of DNA

DNA is a double stranded molecule that forms a double helix when the two strand wind around one another.

Which type of interaction involves the formation of a covalent bond between two different amino acid side chains?

Disulfide bridge

The structure of DNA consists of two strands coiled around each other to form a _____________________ ______________________.

Double helix

What type of bonds keep the two strands of DNA joined to each other?

Hydrogen

Which type of interaction plays a key role in determining both the secondary and tertiary structures of protein<

Hydrogen bonds

Organisms use sequences of _____________________ in their DNA to specify the sequences of ___________________ _____________________ in their proteins.

Nucleotides Amino acids

What are the three basic components of a nucleotide?

Pentose sugar Phosphate group Nitrogenous base

What type of bond connects adjacent nucleotides in a single strand of a nucleic acid?

Phosphodiester

The term _____________________________________ refers to a single, long chain of amino acids, while a _________________________ can be composed of one or more long amino acid chains.

Polypeptide Protein

The structure of ________________________ is usually discussed in terms of a hierarchy of 4 levels.

Proteins

Which of level of protein organization involves two or more polypeptide chains?

Quaternary

The unique properties of the 20 common amino acid are determined by their __________ ________________.

R goups

The two classes of nucleic acids are __________ and ___________.

RNA and DNA

What are the functions of ATP?

To drive energetically unfavorable reactions. To power the movement of cells. To power transport across cell membranes.

What are the two basic types of secondary structure in proteins?

a(lpha) helix and b(eta) pleated sheets

The sequence of amino acids in a protein is specified by which of the following? a. The sequence of nucleotides in a segment of DNA. b. The alternating sugar-phosphate groups in the DNA backbone. c. The overall 3-dimensional shape of the protein. d. Special protein-synthsizing enzymes.

a. The sequence of nucleoides in a segment of DNA.

Which of the following are functions of proteins? a. They provide structural support for many animal tissues. b. They catalyze chemical reactions. c. They are the main component of plant cell walls. d. They are the most efficient molecules for storing energy. e. They transport ions and molecule across cell membranes f. They play a key role in the contraction of muscles.

a. They provide structural support fro many animal tissues. b. They catalyze chemical reactions d. They are the most efficient molecule for storing energy. e. The transport ions and molecules across cell membranes f. They play a key role in the contraction of muscles.

From the list below, select all that are polysaccharides. a. cellulose b. starch c. glycogen d. cholestrol e. fructose f. chitin

a. cellulose b. starch c. glycogen f. chitin

Which of the following describe monosaccharides? a. monosaccharides are composed of carbon, hydrogen and oxygen b. monosaccharides are monomers that can be joined together to form more complex carbhydrates c. monosaccharides are the simplest carbohydrates d. monosaccharides are polymers that are formed by joining monomers and polymers

a. monosaccharides are composed of carbon, hydrogen, and oxygen b. monosaccharides are monomers that can be joined together to form more complex carbohydrates c. monosaccharides are the simplest carbohydrates

You are studying a protein and notice that it contains two regions made of beta sheets connected by an alpha helix. This type of recurring structure that can be found in proteins with very different functions is called a a. motif b. conserved structure c. primary structure d. domain

a. motif

What are the three basic components of a nucleotide? a. nitrogenous base b. phosphate group c. carboxyl group d. amino group e. pentose sugar

a. nitrogenous base b. phosphate group e. pentose sugar

The part of the is molecule shaded in purple is a a. nitrogenous group b. phosphate group c. sugar

a. nitrogenous group

Select the 4 main group of biological macromolecules. a. Nucleic acid b. Carbohydrates c. Nucleotides d. Fatty acids e. Amino acids f. Lipids g. proteins h. sugars

a. nucleic acid b. carbohydrates f. lipids g. proteins

Select amino acids that are most likely to be found in the interior of a protein. a. phenylalanine b. valine c. lysine d. leucine e. glutamic acid

a. phenylalanine b. valine d. leucine

Carbon-oxygen and carbon-nitrogen bonds are described as a. Polar covalent b. Non polar covalent c. Ionic d. Formed by an unequal sharing of electrons e. Formed by an equal sharing of electrons

a. polar covalent d. formed by an unequal sharing of electrons

A long molecule built by linking together a large number of small, similar molecules termed monomers is which of the following. a. polymer b. monomer c. isomer d. micromolecule

a. polymer

A proteins final structure can include either which of the following regions shaped like a a helix or regions shaped like a b-pleated sheet but not both. a. regions shaped like an a-helix and regions shaped like a B-pleated sheet. b. Regions shaped like a B-pleated sheet only. c. Regions shaped like an a-helix only.

a. regions shaped like an a-helix and regions saped like a B-pleated sheet.

Select the characteristics of chaperone proteins. a. They have been found in virtually every organism that has been examined. b. They are not required for viability. c. Cells increase the production of many chaperone proteins they are exposed to high temperatures. d. They are used both to accomplish the original folding of proteins and to restore the structure of incorrectly folded proteins.

a. they have been found in virtually every organism that has been studied. c. cells increase the reproduction of many chaperone proteins they are exposed to high temperature. d. they are used both to accomplish the original folding of proteins and to restore the structure of incorrectly folded proteins

When two amino acids are linked together, a peptide bond is formed between the __________________ group of one and the _______________________ group of another.

amino carboxyl

At it's 3' end, a polynucleotide has an a. nitrogenous base b. -OH group c. phosphate group d. amino acid

b. -OH group

Which of the following best describes the relationship between temperature and enzyme activity? a. Changes in temperature have little effect on enzyme activity, as long as the temperatures are not too extreme. b. Each enzyme has an optimum temperature where it functions best. c. As temperature increases, enzyme activity always increases. d. As temperature increases, enzyme activity always decreases.

b. Each enzyme has an optimum temperature where it functions best.

How are the nucleotides in a single polynucleotide chain linked together? a. The nitrogenous base of one nucleotide is covalently linked to the nitrogenous base of the next nucleotide. b. The phosphate group of one nucleotide is covalently linked to the sugar of the next nucleotide. c. The nitrogenous base of one nucleotide is covalently linked to the sugar of the next nucleotide. d. Nucleotides are linked together by hydrolysis reactions that covalently bind adjacent pentose sugars.

b. The phosphate group of one nucleotide is covalently linked to the sugar of the next nucleotide.

How can scientists use protein motifs? a. They can be used to determine if a protein has any domains (and how many). b. They can be used to predict the function of a protein. c. They can be used to determine how a protein folds in different conditions.

b. They can be used to predict the function of a protein.

How are dissacharides formed? a. Two monosaccharides are linked togethr through a hydrolysis reaction b. Two monosaccharides are linked together through dehydration synthesis. c. Two monosaccharides are linked together through an ionic bond.

b. Two monosaccharides are linked together through dehydration synthesis

Which of the following accurately describes the chemical structure of a typical amino acid found in protein? a. a central carbon is bound to a carboxyl group, an amino group, and two R groups. b. a central carbon atom is bound to an amino group, carboxyl group, a side chain , and a hydrogen atom. c. A central carbon is double bonded t both an amino group and a carboxyl group.

b. a central carbon atom is bound to an amino group, carboxyl group, a side chain, and a hydrogen atom.

When a carbohydrate is formed by linking two monosaccharides by a condensation reaction, we get water plus which of the following? a. a polypeptide b. a disaccharide c. a polysaccharide d. a dipeptide

b. a disaccharide

Where are the peptide bonds located in a polypeptide? a. between the amino groups of 2 different amino acids in the polypeptide chain. b. between the amino group of one amino acid and the carboxyl group of another. c. Between 2 adjacent polypeptides. d. Between the R groups of 2 different amino acids in the polypeptide chain.

b. between the amino group of one amino acid and th carboxyl group of an other.

What type of reaction is responsible for linking amino acids together to form polypeptides? a. hydrolysis b. dehydration synthesis c. polymerization synthesis d. peptide systhesis

b. dehydration synthesis

In general, where are nonpolar and polar amino acids found in a folded protein? a. non-polar - exterior; polar - interior b. non-polar - interior; polar - exterior c. non-polar - C terminus; polar - N terminus d. non-polar - N terminus; polar - C terminus

b. non-polar -interior; polar - exterior

C-C and C-H bonds are best described as which of the following? a. Strong polar b. Nonpolar c. Moderately polar d. Ionic

b. nonpolar

Which of the following bonds is essentially nonpolar? a. C-N b. O-H c. C-H d. C-O e. N-H

c. C-H

What are the monomers of nucleic acids? a. DNA strands b. Nitrogenous bases c. Nucleotides d. Amino acids

c. Nucleotides

What are the two major functional groups found in an amino acid, which allow for it to form a peptide bond with another amino acid? a. side chain b. phosphate group c. amino group d. carboxyl group e. carbon

c. amino group d. carboxyl group

How is information stored in a molecule of DNA? a. By varying the way the nitrogenous bases pair up with each other. b. By varying the width of the double bond. c. By varying the sequence of the four types of nucleotides that make up each strand. d. By varying the sequence of the sugar and phosphate groups. e. By varying the location of the phosphate groups.

c. by varying the sequence of the four types o nucleotides that make up each strand.

The framework or backbone of biological molecules consists predominantly of which of the following atoms? a. hydrogen b. oxygen c. carbon d. nitrogen

c. carbon

A protein is initially driven into its tertiary structure by what type of interaction? a. hydrogen bond b. ionic bond c. hydrophobic exclusion d. disulfide bridge

c. hydrophobic exclusion

Which of these bonds is found in a single strand of DNA? a. hydrogen b. peptide c. phosphodiester d. disulfide bridges

c. phosphodiester

Regular interaction of groups within the polypeptide backbone make up which level of the protein's structure? a. Tertiary b. Primary c. Secondary d. Quatetrnary

c. secondary

Which characteristic of a protein determines its function? a. molecular weight b. electrical charge c. shape d. molecular formula

c. shape

Glucose and fructose can be described as which of the following. a. stereoisomers b. isotopes c. structural isomers d. enentiomers

c. structural isomers

The 4 main groups of biological macromolecules are nucleic acids, _______________________, ____________________________ and _________________________.

carbohydrates proteins lipids

Diseases caused by the improper folding of proteins may be due to deficiencies in ____________________________ proteins.

chaperone

The structure of proteins is usually discussed in terms of hierarchy of how many levels? a. 5 b. 2 c. 3 d. 4

d. 4

Why do cells increase the production of many chaperone proteins when they are exposed to high temperature? a. heat provides the energy needs to synthesize chaperone proteins. b. as temperature increases, new proteins are manufactured at a faster rate and more chaperone proteins are needed to help them fold correctly. c. heat provides the energy needed for chaperone proteins to function correctly. d. high temperatures cause proteins to unfold and more chaperones are needed to help them refold correctly.

d. high temperatures cause proteins to unfold and more chaperones are needed to help them refold correctly.

What type of bond forms between the amino acids during dehydration-synthesis? a. ionic bond b. gylcosidic bond c. double bond d. peptide bond

d. pepide bond

Glucose and galactose can be described as which of the following? a. isotopes b. structural isomers c. enantiomers d. stereoisomers

d. stereoisomers

During protein synthesis, amino acids are linked together using a ________________________ reaction. As a result, a peptide bond is formed.

dehydration

Changes in a protein's environment can cause the protein to unfold and lose its shape a process called ______________________.

denaturation

Which sugar is found in the backbone of DNA molecules?

deoxyribose

The tertiary structure of a protein is determined primarily by interactions involving which of the following? a. The amino groups of the amino acids b. The carboxyl groups of the amino acids c. The central carbon of the amino acids d. The peptide bonds between the amino acids e. The R groups of the amino acids

e. The R groups of the amino acids.

In proteins that only have a single polypeptide chain, what two terms are synonymous? a. Protein and amino acid b. Protein and domain c. Polypeptide and amino acid d. Polypeptide and domain e. Protein and polypeptide

e. protein and polypeptide

Small groups of atoms that are attracted to larger molecules, giving them specific chemical properties are called ___________________.

functional

A small group of atoms that are attached to larger molecules, providing them with specific chemical properties, is called ______________.

functional group

The quaternary level of protein organization is

how two or more polypeptides interact to form a protein.

A general (all-inclusive) term for organic molecules that have the same molecular formula, but that differ in their structure or in the spatial arrangement of their atoms, is ___________________________.

isomers

Organic molecules with the same molecular formula may exist in different forms called _____________________.

isotopes

Polymers are long molecules made of many small, similar units called __________________________.

monomers

The simplest carbohydrates are ____________________________.

monosaccharides

The molecule shown in this diagram is a

nucleotide

The building blocks of nucleic acids are monomers called _____________________.

nucleotides

The nucleotides of DNA molecules contain the sugar, _____________________.

pentose

The 5' end of a nucleotide chain is composed of a _________________________ group.

phosphate

In nucleic acid, adjacent nucleotides are covalently linked by _________________ bonds.

phosphodiester

"transport" forms of sugars are commonly made by linking 2 monosaccharides together to form a __________________________.

polysaccharide

Long polymers made of monosaccharides that have been linked through dehydration reactions are called

polysaccharides

The amino acid sequence is its polypeptides is called the __________________ structure of a protein.

primary

The ________________________, _________________________ and _________________________ structural levels of a protein describe a protein with a single polypeptide chain.

primary secondary tertiary

What are the levels of protein organization?

primary, secondary, tertiary, quaternary

A protein that is composed of multiple polypeptides is said to have a ____________________________ level of protein structure.

quarternary

Regarding polypeptides, the two basic types of _____________________ structure are alpha ________________ and beta-pleated sheet.

secondary helix

Hydrogen bonds between the amino and carboxyl groups of the polypeptide backbone help determine protein ______________________ structure while hydrogen bonds between the amino acid side chains help determine protein ________________________ structure.

secondary tertiary

Information is stored in DNA by varying the ________________________ of the four types of nitrogenous bases in each strand

sequence

What is the primary structure of a protein?

sequence of amino acids in a polypeptide chain

The primary level of protein organization is

the linear sequence of amino acidsWha

The tertiary level of protein organization is

the overall 3-D shape of each polypeptide

The secondary level of protein organization is

the repetitive folding patterns such as alpha, helix, and beta pleated sheet.

The sequence of amino acids in a protein is specified by

the sequence of nucleotides in a segment of DNA.

During proper base pairing in DNA, adanine pairs with ___________________ and cytosine pairs with _____________________,

thymine guanine

How are disaccharides formed?

two monosaccharides are joined by dehydration synthesis