Ch 4 Hw

structural isomers The two molecules differ in the covalent bond relationships among their atoms.

These molecules are _____. -amines -enantiomers -thiols -cis-trans isomers -structural isomers

enantiomers -These molecules are mirror images.

These molecules are _____. -thiols -enantiomers -cis-trans isomers -structural isomers -R-dopa and L-dopa

cis-trans isomers -These molecules differ in how their atoms are arranged about a double bond.

These molecules are _____. -ATP and ADP -structural isomers -enantiomers -thiols -cis-trans isomers

It should dissolve in water.

A compound contains hydroxyl groups as its predominant functional group. Which of the following properties of the molecule can be predicted with the information provided? -It should dissolve in a nonpolar solvent. -It lacks an asymmetric carbon and is probably a fat or lipid. -It should dissolve in water. -It will not form hydrogen bonds with water.

differ in the arrangement of their atoms about a double bond -This is the definition of cis-trans isomers.

Cis-trans isomers are molecules that _____. -differ in their molecular formulas -are mirror images -differ in the arrangement of their atoms about a double bond are isomers that -differ in the covalent partnerships between their atoms -are isomers in which one of the molecules contains an amino group and the other contains a phosphate group

are mirror images -This is the definition of enantiomers.

Enantiomers are molecules that _____. -contain an -OH group -are mirror images -contain a carboxyl group -are isomers that differ in the covalent partnerships between their atoms -differ in the arrangement of their molecules about a double bond

four

How many electrons must one carbon atom share with other atom or atoms to complete its valence shell? -four -two -three -eight

Amino and carboxyl are functional groups. -Read about the variety of biologically important functional groups and note the structure and functional properties of amino and carboxyl groups.

Identify the functional groups. -DNA and RNA are functional groups. -Lipids and proteins are functional groups. -Amino and carboxyl are functional groups.

Parkinson's disease -People with Parkinson's disease lack dopamine.

L-dopa is used to treat _____. -muscle sprains -laryngitis -Parkinson's disease -Alzheimer's disease -Marfan's syndrome

isomers -Isomers of carbon compounds can arise in several different ways.

Molecules that have the same chemical formula (same numbers of each type of atom) but different three-dimensional shapes are called __________. -enantiomers -hydrocarbons -isotopes -isomers -functional groups

carbon, hydrogen, oxygen, nitrogen Carbon, hydrogen, oxygen, and nitrogen are the four main atoms comprising organic molecules.

Most organic compounds contain which atoms? -carbon, hydrogen, oxygen, sulfur -carbon, hydrogen, nitrogen, phosphorus -hydrogen, oxygen, nitrogen, phosphorus -carbon, oxygen, nitrogen, phosphorus -carbon, hydrogen, oxygen, nitrogen

F -By donating hydrogen ions, carboxyl groups act as an acid.

Which of functional groups listed below behaves as an acid? -E -D -C -F -A

not isomers -These molecules have different molecular formulas.

This pair of molecules are _____. -structural isomers -not isomers -identical -cis-trans isomers -enantiomers

B

Use the figures to answer the following question. Which molecule shown has a carbonyl functional group in the form of a ketone? -A -B -C -D

C

Use the schemes to answer the question. Which functional group shown in the figure can accept protons and raise the pH of the surrounding solution? -A -B -C -D

Carbon skeletons can vary in length, exhibit different branching structures, contain double bonds at different positions, and contain rings of carbon atoms -This is correct. Carbon chains can vary in length, branching structure, double bond position, and contain carbon chain rings.

Variation in carbon chains is an important source of molecular complexity. How can carbon skeletons vary? -Carbon skeletons can vary in length, exhibit different branching structures, contain double bonds at different positions, and contain rings of carbon atoms -Carbon skeletons can vary in length and contain rings of carbon atoms -Carbon skeletons can vary in length and exhibit different branching structures -Carbon skeletons can vary in length and contain double bonds at different positions -Carbon skeletons only vary in length

the presence or absence of functional groups -Functional groups are the most common participants in chemical reactions.

Variations in the reactive properties of different organic molecules are most closely associated with __________. -the number of asymmetric carbon atoms present the presence or absence of functional groupsthe presence or absence of double bonds -the number of carbon atoms comprising the molecule's skeletonthe nature of the carbon skeleton (either ringed or linear) Submit

phosphate -The addition and release of phosphate groups to and from ADP and ATP is how cells store chemical energy and expend it to accomplish work.

What functional group is commonly used in cells to transfer energy from one organic molecule to another? -hydroxyl -sulfhydryl -amino -phosphate -carboxyl

None. -R-dopa has no effect on Parkinson's disease.

What kind of effect does R-dopa have on Parkinson's disease? -It alleviates the symptoms. -At first it makes the symptoms worse but over the long term it alleviates the symptoms. -At first it alleviates the symptoms but over the long term it makes the symptoms worse. -It makes the symptoms of Parkinson's disease worse. None.

A, B, E -Since carbon atoms are tetravalent (able to form four bonds), atoms may branch off a carbon atom in as many as four places. The ability of a carbon atom to form four different bonds allows carbon to form many different sizes and types of molecules. Carbon atoms may form chains, rings, or combinations of chains and rings. The tetravalence of carbon makes it particularly well-suited to forming the backbone of a huge diversity of organic molecules.

Which molecules show an appropriate number of bonds around each carbon atom? Select the three that apply.

the number of particles in its valence shell

Which of the following characteristics of an atom determines the number and kind of bonds it can form? -its atomic mass -the number of particles in its nucleus -its atomic number -the number of particles in its valence shell

has 2 electrons in its first shell and 4 in the second shell

Which of the following explains why the valency of carbon is 4 even though it has 6 electrons? -has 4 electrons in its first shell and 2 in the second shell -donates its 2 electrons to another atom -shares its 2 electrons and bonds with another atom -has 2 electrons in its first shell and 4 in the second shell

C3H8 -This is a typical hydrocarbon with single covalent bonds; the number of hydrogen atoms is equal to two times the number of carbon atoms plus 2.

Which of the following is a hydrocarbon? -CCl2F2 -C3H8 -H2CO3 -CO2 -C6H12O6

A -The electronegativity of nitrogen means that amino groups tend to pick up hydrogen ions.

Which of the functional groups behaves as a base? -E -C -A -B -F

The amino group is most likely to gain a proton. -An amino group acts as a base and can pick up protons from the surrounding medium, becoming positively charged.

Which of the functional groups shown above is most likely to gain a proton and become positively charged? -The hydroxyl group is most likely to gain a proton. -The carboxyl group is most likely to gain a proton. -The amino group is most likely to gain a proton.

D -Hydroxyl groups are characteristic of alcohol.

Which of these functional groups is characteristic of alcohol? -B -D -E -C -A

E -Thiols are characterized by the presence of a sulfhydryl group.

Which of these groups is characteristic of thiols? -E -D -A -B -F

B -Phosphate groups are a component of ATP.

Which of these groups plays a major role in energy transfer? -D -A -C -E -B

C -This is a carbonyl group.

Which of these is a carbonyl group? -A -B -F -E -C

F -This is a carboxyl group.

Which of these is a carboxyl group? -E -C -B -A -F

D -This is a hydroxyl group.

Which of these is a hydroxyl group? -A -C -E -D -F

B Of the choices, this is the only one that contains phosphorus.

Which of these is a phosphate group? -A -E -F -C -B

A -This is an amino group, NH2.

Which one of these is an amino group? -E -C -B -A -D

Enantiomers differ in biological activity. -Because enantiomers are mirror images of each other, working molecules distinguish the two versions by shape. Usually, one isomer is biologically active and the other is inactive.

Which statement about isomers is correct? -Structural isomers differ in the position of double bonds within the molecule. -Cis-trans isomers are mirror image isomers. -Enantiomers differ in biological activity.