CHEM CHT. 13 DNA

Which of the following options correctly describe advantageous genetic modifications made to foods? Select all that apply.

- Golden rice has been modified to produce significant quantities of vitamin A. - Papayas have been developed that have resistance to the ringspot virus.

Which of the following options correctly describes the sequence of bases in a strand of DNA? Select all that apply.

- The sequence of bases in one strand of DNA determines the sequence of bases in its complementary pair. - The backbone of a DNA strand determines its directionality. - A piece of DNA with the base sequence ATCCG is not the same as a piece with the sequence GCCTA.

Amino acid side chains are broadly characterized as either _____ or _____.

- nonpolar - polar

Within the DNA double helix each base is hydrogen-bonded to another specific base. Match each base given to its complementary base.

ADENINE - THYMINE GUANINE - CYSTOSINE

There are four different nitrogen-containing bases in DNA. Match the bases given below with their appropriate description. Instructions

Adenine (A) and guanine (G) - Consist of a six-membered ring and a five-membered ring of atoms fused together Cytosine (C) and thymine (T) - Consist of only a six-membered ring

Which of the following are the three fundamental units of DNA? Select all that apply.

- Phosphate groups - Nitrogen-containing bases - Deoxyribose sugars

Which of the following options correctly describe proteins and their synthesis? Select all that apply.

- Protein synthesis is directed by DNA. - Proteins perform important structural functions.

Which of the following options correctly describe amino acid residues? Select all that apply.

- Proteins are long chains containing amino acid residues. - Proteins are large molecules formed by the linking of amino acid residues. - Amino acid residues are amino acids that have lost an -H and an -OH in the process of bonding together.

Which of the following scientists were major contributors to the research that led to the discovery of the structure of DNA? Select all that apply.

- Rosalind Franklin - James Watson - Francis Crick

Which of the following is the correct structure for deoxyribose? HOCH2

B

How does a change in the primary structure of a protein affect its properties?

Changing the primary structure may have a profound effect on its properties.

A strand of _____ is formed when many deoxyribonucleotides are joined together through a condensation polymerization reaction.

DNA

DNA determines the characteristics of an organism by directly controlling the synthesis of _____.

PROTEIN

The _____ site of an enzyme has a specific three-dimensional shape, allowing the enzyme to bind specifically to certain substrates.

active

The structure shown in the figure below is a typical _____.N-C-C

amino acid

An amino acid that has lost a -H atom and an -OH group in the process of bonding together is called a(n) _____.

amino acid residue

During mitotic cell division, each new cell produced contains ____ as the parent cell.

an identical set of chromosomes

The _____ structure describes the folding pattern within a segment of the protein chain.

secondary

The tertiary structure of a protein results from interactions between the ______ of the amino acid residues.

side chains

In sickle-cell anemia, a glutamic acid residue in the sequence of hemoglobin is replaced with a ______ residue.

valine

"GM" food is _____ food.

genetically modified

The α-helix and β-pleated sheet depend on the tendency of the protein backbone to form _____.

intramolecular hydrogen bonds

"Golden rice" is an example of a GM that is used to help fight _____.

malnutrition

All DNA is composed of _____-containing bases, sugars, and _____ groups.

nitrogen; phosphate

The structure shown is a(n) _____.O=P-O-O

nucleotide

What percent of corn is estimated to be genetically modified in the United States?

over 90%

Nucleic acids such as DNA contain _______ groups, which can have the form PO43-, HPO42-, or H2PO4-.

phosphate

The unique identity and sequence of the amino acids in a protein defines its _____ structure.

primary

Place the steps in the replication of DNA in the correct order, starting with the first step at the top of the list.

1. The double helix rapidly, but only partially, unwinds2. A region of two separated strands of DNA is formed3. Free nucleotides in the cell are selectively hydrogen-bonded to the two single strands4. The nucleotides bond together with the action of an enzyme5. Two identical daughter molecules are formed

How many three-letter words could be generated using an alphabet of five letters?

125

An alphabet of six letters can generate as many as _____ different four-letter words.

1296

True or false: A DNA strand is identical in both directions.

FALSE

True or false: James Watson and Francis Crick were the only scientists involved in creating a model of the structure of DNA.

FALSE

True or false: Proteins are a major source for energy for the body.

FALSE

True or false: X-rays are scattered at all angles when they hit a crystal in X-ray diffraction.

FALSE

What concerns might be raised by the possibility of GM plants spreading into the wild?

GM plants will create "super insects" that will thrive in the wild.

Match each codon sequence given below to the amino acid that is signaled for incorporation into a protein.

TTC - PHENYLALANINE CCG - PROLINE CAC - HISTIDINE

Which statement correctly describes the form of DNA in chromosomes?

The double helix becomes tightly coiled.

When is food classified as GMO food?

When the organism producing the food has undergone deliberate changes to its DNA

A rod-shaped compact coil of DNA and specialized proteins found within the nucleus of a cell is called a(n) _____.

chromosome

A sequence of three adjacent nucleotides that either guides the insertion of a specific amino acid or signals the start or end of protein synthesis is known as a(n) _____.

codon

The genetic code of an organism is carried by DNA, or ______.

deoxyribonucleic acid

x-ray _____ is an analytical technique in which a crystal is hit by a beam of X-rays to generate a pattern that reveals the positions of the atoms in the crystal.

diffraction

X-ray _____ is an analytical technique in which a crystal is hit by a beam of X-rays to generate a pattern that reveals the positions of the _____ in the crystal.

diffraction; atoms

A subtle change in the primary structure of a protein ____ on its properties.

sometimes has no effect

Match each of the following types of side groups found in proteins with the type(s) of interaction(s) that they may have with other side chains.

nonpolar - group tightly () to avoid side group - often become charged ions polar - may form hydrogen bonds

Match each level of protein structure to the appropriate description.

primary - the unique identity and sequence of the amino acids that make up secondary - the folding pattern within a segment of the protein chains tertiary - the overall molecular shape of the protein

The process of cell reproduction in which the cell must copy and transmit its genetic information to its progeny is known as _____.

replication

Which of the following options shows the correct expression for the number of unique words that can be formed from a given set of letters with n letters per word?

words = (letters)n

Which of the following options correctly describe the bases adenine, guanine, thymine, and cytosine? Select all that apply.

- All contain nitrogen atoms within a ring. - All contain at least one six-membered ring of atoms.

What human health problems have been identified as potential concerns related to foods produced by GMOs? Select all that apply.

- Cancer - Allergies

Which of the following options correctly describe chromosomes? Select all that apply.

- Chromosomes are compact coils of DNA and specialized proteins. - Chromosomes are found in the nucleus of a cell. - Chromosomes are rod-shaped.

Which of the following options correctly describe DNA and its functions? Select all that apply.

- DNA is a biological polymer. - DNA is replicated within the cell. - DNA carries genetic information in all species.

Which of the following options correctly describe deoxyribose? Select all that apply.

- Deoxyribose has the chemical formula C5H10O4. - Deoxyribose is a monosaccharide.

Which of the following statements correctly describes the phosphate group found in DNA? Select all that apply.

- Depending on the pH, phosphate may be in the form of HPO42- or H2PO4-. - Nucleic acids are acidic due to the presence of the phosphate group. - The phosphate group contains one P atom and four O atoms.

Which of the following options correctly describe the process of cell division? Select all that apply.

- Each chromosome is rapidly duplicated during cell division. - Rapidly dividing cells are more susceptible to collecting and passing on DNA damaged by ionizing radiation.

Which of the following are common functions of proteins? Select all that apply.

- Enzymes - Binding to DNA to protect the DNA molecule - Binding to DNA to send a signal - Transport of specific substances through cell membranes

The planting of GM crops has caused great concern for the public. Which of the following are rational arguments that could be used to respond to such concerns? Select all that apply.

- Most experiments have shown GM crops to have little or no effect on insect life. - Experiments have shown that hybrids are not strong enough to survive in the wild.

Which of the following options correctly describe nucleotides? Select all that apply.

- Nucleotides are a covalently bonded combination of a nitrogen base, phosphate group, and deoxyribose sugar. - Nucleotides are monomeric units that can polymerize to form DNA.

Which of the following options correctly describe the formation of DNA from nucleotide monomers? Select all that apply.

- Nucleotides are joined through a condensation polymerization reaction. - When two nucleotides are joined together a water molecule is produced. - Nucleotides are joined together through the reaction of a hydroxyl group on the sugar of one nucleotide with the phosphate group on another.

Which of the following options correctly describe the different levels of protein structure? Select all that apply.

- Secondary structure describes the folding within a segment of the protein chain. - Tertiary structure describes the overall molecular shape of the protein. - The tertiary structure of a protein is determined by the interactions between different parts of the polypeptide chain.

Which of the following options correctly describe the key features of sickle-cell disease? Select all that apply.

- Sickle-shaped blood cells cannot pass through the tiny openings of capillaries. - The change of a single glutamic acid to valine in the primary structure of hemoglobin gives hemoglobin S. - Sickle cells may clog organs so badly that blood supply to the organs is reduced.

Match each type of amino acid side chain correctly to the way it is oriented with respect to overall protein structure.

1. Nonpolar side chains group toward: the inside of the protein2. Polar side chains group toward: the outside of the protein

A codon is _____. (Select all the options that complete this definition correctly.)

- a three-letter grouping of nucleotides that transfers information from DNA to a protein - a sequence of three adjacent nucleotides that can signal the start of protein synthesis - a sequence of three adjacent nucleotides that can signal the end of protein synthesis

Amino acids always contain which of the following groups? Select all that apply.

- side chain (R) - amine - carboxylic acid

Which of the following are common consumer goods derived from GMOs? Select all that apply.

- soybean products - cotton - high fructose corn syrup

Which of the following are regular repeating structures that constitute the most common secondary structures of a protein? Select all that apply.

- α-helix - β-pleated sheet

Which of the following options correctly describe the active site of an enzyme? Select all statements that apply.

- The active site binds only specific reactants. - The active site is often a crevice. - The active site accelerates a desired reaction.

Which of the following options correctly describe the structure of DNA? Select all that apply.

- The base pairs lie parallel to one another and are separated by a distance of 0.3 nm. - A complete turn of the helix consists of 10 base pairs. - The DNA double helix is a spiral of two strands of DNA that coil around a central axis.

Which of the following are important factors that contribute to the secondary structure of a protein? Select all that apply.

- The formation of intramolecular hydrogen bonds between the backbone O and N-H of the amide groups - The number and spacing of hydrogen bonds

Which of the following are described by the primary structure of a protein? Select all that apply.

- The identity of all amino acids in the protein - The exact order in which amino acid residues appear in the protein

Which of the following options correctly describe the tertiary structure of a protein? Select all that apply.

- The overall molecular shape of the protein is described by the tertiary structure. - The tertiary structure is defined by interactions between amino acids far apart in sequence, but close in space.

Which of the following options describe why DNA is tightly coiled in a regulated way within chromosomes? Select all that apply.

- To organize the genetic information - To protect the genetic information - To save space

One special amino acid (cysteine) contains a thiol group (-SH) in the side chain. Which of the following options correctly describe how thiols interact within a protein? Select all that apply.

- Two -SH groups may react together and form a disulfide bond (S-S bond). - Two -SH groups may react together and form a covalent bond.

Which of the following codons code for a stop codon? (Select all that apply.)

- UAA - UGA - UAG

Which of the following correctly describes the use of X-ray analysis to determine the structure of a crystalline material? Select all statements that apply.

- X-rays are only scattered at certain angles that are related to the distance between atoms. - X-ray photons interact with the electrons of the atoms in the crystal.

Match the number of unique "words" (codes) that can be made from the four bases (A, T, C, and G) to the length of word.

2-letter word - 16 words (codes) 3-letter word - 64 words (codes) 4-letter word - 256 words (codes)