Chem 1010 chapter 13 smartbook

How do plants protect themselves against foreign DNA?

Cell wall

Genetic engineering may be advantageous for reasons other than crop production for human consumption. Which of the following fit this description? Select all that apply.

Creation of plants that absorb toxic metals from contaminated soil Creation of bacteria to detect and remediate radioactive contamination

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

Nonpolar side chains group toward matches Choice, the inside of the protein. Polar side chains group toward matches Choice, the outside of the protein.

Match each level of protein structure to the appropriate description.

Primary structure matches Choice, The unique identity and sequence of the amino acids that make up each protein Secondary structure matches Choice, The folding pattern within a segment of the protein chain Tertiary structure matches Choice, The overall molecular shape of the protein

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

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

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

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

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

A ________ is a modified plasmid that is used to carry DNA back into the bacterial host.

Vector

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

amine carboxylic acid side chain (R)

A vector is a new _____ DNA plasmid that is used to carry DNA back into the bacterial host.

interspecies

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

nitrogen; phosphate

Genetic engineering is the direct manipulation of the _____ in an organism.

DNA

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

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

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

Deoxyribose sugars Phosphate groups Nitrogen-containing bases

"GM" food is _____ food.

genetically modified

The complete set of inheritable traits of an organism is known as the _______ of the organism.

genome

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

intramolecular hydrogen bonds

Rings of DNA that exist in bacteria in addition to their chromosomes are called _____. These can easily be removed, altered, or replaced.

plasmids

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

polar nonpolar

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

secondary

Genetic modifications that develop in response to changes in environment or to domestication by humans are examples of _____.

selection

What is the role of insulin in the human body?

Insulin regulates blood sugar levels.

Match each type of selection (human, natural, or both) listed below with the appropriate description.

Selection by human agriculture matches Choice, Plants are selected that look and taste better. Selection in nature matches Choice, Plants are selected that are more self-sufficient. Selection by both human agriculture and nature matches Choice, Selection results in changes in the genome of the plants.

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

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

When is food classified as GMO food?

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

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.

An organism is genetically engineered by modifying the _____ in the cell.

deoxyribonucleic acid

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

Scientists may modify an organism by creating an environment in which the organism must evolve new traits in order to survive. This process is called _______.

directed evolution

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

Adenine matches Choice, Thymine Guanine matches Choice, Cytosine

Match each characteristic of synthetic production of chemicals with its classification as an advantage or a disadvantage.

Advantage matches Choice, yields desired chemicals Disadvantage matches Choice, may require high temperatures

Which of the following are reasons that farmers might suggest for gene modification of crops? Select all that apply.

Greater disease resistance of the crop Greater herbicide resistance of the crop Greater pest resistance of the crop Improved nutritional quality of the crop

Which of the following options correctly identify factors that make the insertion of foreign DNA more complicated for a scientist? Select all that apply.

Many organisms have chemical mechanisms that detect and destroy foreign DNA. Plants have thick cell walls that help to protect them from foreign DNA.

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

Plasmids are found in small single-celled bacteria in addition to their chromosomes. Plasmids are rings of DNA.

What is directed evolution?

The creation of an environment such that an organism must evolve a new trait to survive

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

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

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

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

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

Human cultivation of plants through crossbreeding is an example of ______.

gene modification

Humans have been manipulating _______ throughout history. This has been done by growing plants with specific traits and rejecting others, crossbreeding different strains, etc.

genes or DNA

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

primary

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

side chains

In what ways has insulin been produced for use by humans? Select all that apply.

Initially, diabetics were treated with insulin from pigs and cattle. Bacteria have been engineered to produce human insulin.

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

Inside each cell is a complete set of instructions (the genome) on how to grow and reproduce. The genome is a "guidebook" on how to grow and reproduce. The genome is a complete set of inheritable traits of an organism.

A vector is created by scientists and used to create new copies of a "guest" gene over several steps (given below). Order theses steps appropriately, starting with the first step at the top of the list.

1. The host plasmid is removed from a cell 2. Special enzymes cut open the plasmid at specific sites. 3. DNA from another organism is inserted into the plasmid ring from the host. 4. The modified plasmid (Vector) is placed back into the bacterial host. 5. The bacterium grows rapidly and produces new cells with copies of the "guest" gene and its protein product.

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

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. The base pairs lie parallel to one another and are separated by a distance of 0.3 nm.

Which of the following is an example of genetic engineering?

A scientist replaces a gene in a plant with a new gene of particular interest

When scientists modify DNA within a cell what changes are observed in the cell? Select all that apply.

Different proteins will be synthesized by the genes. The chemistry of the cell changes.

Large-scale chemical synthesis may be carried out using traditional methods as well as enzyme-driven methods. Match each method to the appropriate description

Enzyme-based synthesis matches Choice, Reactions are carried out at low temperatures, require fewer toxic reagents, and produce less waste. Traditional chemical synthesis matches Choice, Reactions are often carried out at high temperatures, may require toxic chemicals, and produce very large amounts of waste.

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

False Reason: Correct. A DNA strand is directional, so that the base sequence ATC is not the same as the sequence CTA. The sequence of bases in the strand determine the genetic code contained within the strand.

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

False Reason: X-rays are scattered at certain angles that are related to the distance between atoms and that information can be used to determine the structures of a variety of crystalline materials.

Match each description of genetic modification made correctly with the type of modifying force.

Human-made genetic modification matches Choice, A farmer "weeds out" all of the tall and scrawny plants from his/her crop. Genetic modification occurring in nature matches Choice, A plant resists a new pathogenic bacterium and is able to survive and pass on its genes.

Which of the following correctly identify possible disadvantages of large-scale traditional chemical production compared to enzyme-driven syntheses? Select all that apply.

Large amounts of solvents may be required. High temperatures may be required. Toxic chemicals may be required. Large quantities of waste may be produced.

Which of the following is an advantage of using enzymes in chemical synthesis?

Low temperatures Faster Safer Reusable reagents Low toxicity

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 side group matches Choice, Group tightly (through London forces) to avoid unfavorable interactions with water Side groups containing acidic or basic sites matches Choice, Often become charged ions and attract their opposites in salt bridges Polar noncharged side groups matches Choice, May form hydrogen bonds

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

Proteins are large molecules formed by the linking of amino acid residues. Proteins are long chains containing 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 options correctly describe natural selection both in the wild and in human agriculture? Select all that apply.

The process is a somewhat random route to modifying the gene pool. These are slow ways of modifying the gene pool.

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

amino acid

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

β-pleated sheet α-helix