Biochemistry Chapter 4 Flashcards

Questions and Answers

Which molecule shown above contains a functional group that cells use to transfer energy between organic molecules?

D (correct)

Which molecule shown above can function as a base?

A (correct)

A chemist wishes to make an organic molecule less acidic. Which of the following functional groups should be added to the molecule in order to do so?

Sulfhydryl

Phosphate

Amino (correct)

Carboxyl

Hydroxyl

Organic chemistry is currently defined as:

The study of carbon compounds. Signup and view all the answers

Which functional group is not present in this molecule?

Sulfhydryl Signup and view all the answers

Which chemical group is most likely to be responsible for an organic molecule behaving as a base?

Amino Signup and view all the answers

Which of the following hydrocarbons has a double bond in its carbon skeleton?

C₂H₄ Signup and view all the answers

Choose the term that correctly describes the relationship between these two sugar molecules:

Structural isomers Signup and view all the answers

Identify the asymmetric carbon in this molecule.

B Signup and view all the answers

Which action could produce a carbonyl group?

The replacement of the OH of a carboxyl group with hydrogen Signup and view all the answers

The element present in all organic molecules is

Carbon Signup and view all the answers

The complexity and variety of organic molecules is due to

The chemical versatility of carbon atoms Signup and view all the answers

The experimental approach taken in current biological investigations presumes that

Living organisms can be understood in terms of the same physical and chemical laws that can be used to explain all natural phenomena Signup and view all the answers

Differences among organisms are caused by

Differences in the types and relative amounts of organic molecules synthesized by each organism Signup and view all the answers

Which of the following people was the first to synthesize an organic compound, urea, from inorganic starting materials?

Friedrich Wohler Signup and view all the answers

Stanley Miller's 1953 experiments proved that

Organic molecules can be synthesized abiotically under conditions that may have existed on early Earth Signup and view all the answers

Hermann Kolbe's synthesis of an organic compound, acetic acid, from inorganic substances that had been prepared directly from pure elements was a significant milestone for what reason?

It proved that organic compounds could be synthesized from inorganic compounds and disproved the concept of vitalism Signup and view all the answers

Stanley Miller's 1953 experiments assumed that early Earth's atmosphere contained

Ammonia, methane, hydrogen gas, and water vapor Signup and view all the answers

When Stanley Miller applied heat and electrical sparks to a mixture of simple inorganic compounds such as methane, hydrogen gas, ammonia, and water vapor, what compounds were produced?

Both simple organic compounds and more complex organic compounds such as amino acids and hydrocarbons Signup and view all the answers

How many electron pairs does carbon share in order to complete its valence shell?

4 Signup and view all the answers

A carbon atom is most likely to form what kind of bond(s) with other atoms?

Covalent Signup and view all the answers

Which of the following statements best describes the carbon atoms present in a seed-eating bird?

They were incorporated into organic molecules by plants, they were processed into sugars through photosynthesis, and they are ultimately derived from carbon dioxide Signup and view all the answers

Which of the following statements best describes the carbon atoms present in a seed-eating bird?

The carbon atoms ultimately came from carbon dioxide incorporated into sugars through photosynthesis Signup and view all the answers

Why are hydrocarbons insoluble in water?

The majority of their bonds are nonpolar covalent carbon-to-hydrogen linkages Signup and view all the answers

How many structural isomers are possible for a substance having the molecular formula C₄H₁₀?

2 Signup and view all the answers

Which of the following statements correctly describes cis-trans isomers?

They have variations in arrangement around a double bond Signup and view all the answers

Research indicates that ibuprofen, a drug used to relieve inflammation and pain, is a mixture of two enantiomers; that is, molecules that

Are mirror images of one another Signup and view all the answers

What determines whether a carbon atom's covalent bonds to other atoms are in a tetrahedral configuration or a planar configuration?

The presence or absence of double bonds between the carbon atom and other atoms Signup and view all the answers

Compared to a hydrocarbon chain where all the carbon atoms are linked by single bonds, a hydrocarbon chain with the same number of carbon atoms, but with one or more double bonds, will

Be more constrained in structure Signup and view all the answers

Organic molecules with only hydrogens and five carbon atoms can have different structures in all of the following ways except

By forming enantiomers Signup and view all the answers

A compound contains hydroxyl groups as its predominant functional group. Which of the following statements is true concerning this compound?

It should dissolve in water Signup and view all the answers

Which of the following is a false statement concerning amino groups?

They are nonpolar Signup and view all the answers

Which two functional groups are always found in amino acids?

Carboxyl and amino Signup and view all the answers

Amino acids are acids because they always possess which functional group?

Carboxyl Signup and view all the answers

A carbon skeleton is covalently bonded to both an amino group and a carboxyl group. When placed in water it

Would function as both an acid and a base Signup and view all the answers

Which functional groups can act as acids?

Carboxyl and phosphate Signup and view all the answers

Testosterone and estradiol are

Structural isomers of each other Signup and view all the answers

Testosterone and estradiol are male and female sex hormones, respectively, in many vertebrates. In what way(s) do these molecules differ from each other?

Testosterone and estradiol have different functional groups attached to the same carbon skeleton Signup and view all the answers

Which of the following people used this apparatus to study the formation of organic compounds?

Stanley Miller Signup and view all the answers

The two molecules shown in the figure above are best described as

Structural isomers Signup and view all the answers

The figure above shows the structures of glucose and fructose. These two molecules differ in the

Arrangement of carbon, hydrogen, and oxygen atoms Signup and view all the answers

The figure above shows the structures of glucose and fructose. These two molecules are

Structural isomers Signup and view all the answers

The two molecules shown in the figure above are best described as

Cis-trans isomers Signup and view all the answers

Three or four of the following illustrations depict different structural isomers of the organic compound with molecular formula C₆H₁₄. For clarity, only the carbon skeletons are shown; hydrogen atoms that would be attached to the carbons have been omitted. Which one, if any, is NOT a structural isomer of this compound?

Choice C Signup and view all the answers

Which of the pairs of molecular structures shown below depict enantiomers (enantiomeric forms) of the same molecule?

Pair D Signup and view all the answers

Which of the pairs of molecular structures shown below do NOT depict enantiomers (enantiomeric forms) of the same molecule?

Pair C Signup and view all the answers

Which pair of molecules shown below are not enantiomers of a single molecule?

Pair B Signup and view all the answers

Thalidomide and L-dopa, shown below, are examples of pharmaceutical drugs that occur as enantiomers, or molecules that

Are mirror images of one another Signup and view all the answers

What is the name of the functional group shown in the figure above?

Carboxyl Signup and view all the answers

Which of the structures illustrated above is an impossible covalently bonded molecule?

Structure C Signup and view all the answers

Which of the structures illustrated above contain(s) a carbonyl functional group?

Structure D Signup and view all the answers

In which of the structures illustrated above are the atoms bonded by ionic bonds?

None of the structures Signup and view all the answers

Which of the structures illustrated above cannot form hydrogen bonds with water molecules?

Structure B Signup and view all the answers

Which functional group shown above is characteristic of alcohols?

Structure A Signup and view all the answers

Which functional group(s) shown above is (are) present in all amino acids?

Structures C and D Signup and view all the answers

Which of the groups shown above is a carbonyl functional group?

Structure B Signup and view all the answers

Which of the groups shown above is a functional group that helps stabilize proteins by forming covalent cross-links within or between protein molecules?

Structure E Signup and view all the answers

Which of the groups above is a carboxyl functional group?

Structure C Signup and view all the answers

Which of the groups above is an acidic functional group that can dissociate and release H⁺ into a solution?

Structure C Signup and view all the answers

Which of the groups above is a basic functional group that can accept H⁺ and become positively charged?

Structure D Signup and view all the answers

Which molecule shown above would have a positive charge in aqueous solution at pH 7?

Molecule E Signup and view all the answers

Which molecule(s) shown above is (are) ionized in aqueous solution at pH 7?

Molecule A Signup and view all the answers

Which molecules shown above contain a carbonyl group?

Molecules B and C Signup and view all the answers

Which molecule shown above has a carbonyl functional group in the form of a ketone?

Molecule C Signup and view all the answers

Which molecule shown above has a carbonyl functional group in the form of an aldehyde?

Molecule B Signup and view all the answers

Which molecule shown above contains a carboxyl group?

Molecule D Signup and view all the answers

Which molecule shown above can increase the concentration of hydrogen ions in a solution and is therefore an organic acid?

Molecule D Signup and view all the answers

Which molecule shown above can form a dimer linked by a covalent bond?

Molecule B Signup and view all the answers

Which molecules shown above will form hydrogen bonds with water?

All of these molecules except B will form hydrogen bonds with water Signup and view all the answers

Study Notes

Organic Molecules and Carbon

Carbon is the essential element in all organic molecules, highlighting its importance in biological chemistry.
The versatility of carbon atoms contributes to the complexity and variety of organic molecules.

Experimental Biology

Current biochemical research operates under the premise that organisms follow physical and chemical laws, allowing the study of life processes using lab-synthesized compounds.

Organic Compound Synthesis

Friedrich Wohler was the first to synthesize an organic compound, urea, from inorganic materials, challenging the concept of vitalism.
Stanley Miller's 1953 experiments demonstrated that organic molecules can form abiotically under conditions mimicking early Earth.

Isomers and Molecular Structures

Structural isomers have the same molecular formula but differ in the arrangement of their atoms.
Cis-trans isomers differ in the arrangement around double bonds, while enantiomers are mirror images and possess an asymmetric carbon.

Functional Groups and Their Properties

Hydroxyl groups increase water solubility in organic compounds.
Amino acids contain both an amino and a carboxyl group, contributing to their acidic and basic nature.

Chemical Properties

Hydrocarbons, primarily with nonpolar covalent bonds, are insoluble in water.
Carbon atoms can form single (covalent) and double bonds, affecting the structural flexibility of molecules.

Biological Molecules

Testosterone and estradiol are structural isomers with the same molecular formula, differing primarily in the functional groups attached to their carbon skeletons.
Amino groups can function as bases, and carboxyl groups can donate protons, influencing the acidity of organic compounds.

Acids and Bases in Chemistry

Carboxyl and phosphate functional groups can act as acids in biological molecules, releasing H⁺ ions into solutions.
Functional groups such as amino groups can accept protons and exhibit basic properties.

Hydrogen Bonds and Solubility

Molecules containing functional groups like hydroxyl or carbonyl can form hydrogen bonds with water, enhancing solubility.

Hydrocarbons and Double Bonds

Molecules with double bonds in their carbon skeleton are categorized under alkenes, while saturated hydrocarbons only contain single bonds.

Organic Chemistry Definition

Organic chemistry is defined as the study of carbon compounds, encompassing a wide range of structures and functions in biological systems.

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Test your knowledge on Chapter 4 of Biochemistry with these flashcards. Explore key concepts about organic molecules, their elements, and the significance of carbon in biological structures. Perfect for revision or quick learning!