Question 1

Samples of three different triacylglycerols were tested to determine the melting point of each one. The results of the tests are shown in the graph.  The length of the fatty acids in A, B, and C is the same. Which of the three fatty acids is likely to have the MOST unsaturated fatty acids?

Accepted Answer

The answer of Samples of three different triacylglycerols were tested...

Question 2

Peptide bonds are characteristic of:

Accepted Answer

Peptide bonds join amino acids to form proteins.

Question 3

Samples of three different triacylglycerols were tested to determine the melting point of each one. The results of the tests are shown in the graph.  The number of double bonds in each of the fatty acids in A, B, and C is the same. Which of the three triacylgcerols is likely to have the fatty acids with the SHORTEST hydrocarbon chains?

Accepted Answer

The answer of Samples of three different triacylglycerols were tested...

Question 4

In DNA molecules, complementary base pairs always include one purine nucleotide and one pyrimidine nucleotide. In the DNA of certain bacterial cells, 16% of the nucleotides are adenine nucleotides. What are the percentages of the other nucleotides in the bacterial DNA?

Accepted Answer

In DNA, adenine (A) pairs with thymine (T), and guanine (G) pairs with cytosine (C). If 16% of the nucleotides are adenine, then 16% must also be thymine, because of the A-T pairing. This leaves 68% (100% - 32%) for the G-C pairings, so guanine and cytosine each make up 34% of the nucleotides.

Question 5

Pyrimidine and purine bases are found in:

Accepted Answer

Pyrimidine and purine bases are the building blocks of nucleic acids such as DNA and RNA. They are not found in carbohydrates, lipids, fatty acids, or proteins.

Question 6

Name the specific types of bonds that hold the monomers together in proteins, nucleic acids, and complex carbohydrates.

Accepted Answer

The answer of Name the specific types of bonds that...

Question 7

Samples of three different triacylglycerols were tested to determine the melting point of each one. The results of the tests are shown in the graph.  The length of the fatty acids in A, B, and C is the same. Which of the three triacylgcerols is likely to have the FEWEST number double bonds in the fatty acids?

Accepted Answer

The triacylglycerol with the highest melting point has the most saturated fatty acids, which means it has the fewest double bonds. In this case, B has the highest melting point, indicating that it has the most saturated fatty acids and the fewest double bonds. Therefore, B is the most likely to have the fewest number of double bonds in its fatty acids.

Question 8

How many hydrogen atoms are present in a five-carbon hydrocarbon molecule with four of the carbons linked by a single covalent bond, and with the fifth carbon attached by a single bond as a branch to the second carbon in the chain?

Accepted Answer

The molecule described is a branched alkane with five carbon atoms. Alkanes have the general formula CnH2n+2. Since there are four carbons in the main chain and one as a branch, the total number of carbons is still five (n=5). Plugging this into the formula gives C5H2(5)+2 = C5H12, indicating there are 12 hydrogen atoms.

Question 9

How many hydrogen atoms are present in a hydrocarbon chain of five carbon atoms with two double bonds and two single bonds?

Accepted Answer

A hydrocarbon chain with five carbon atoms and two double bonds will have the formula C5H8. Each carbon typically forms four bonds, and with two double bonds, the remaining bonds are filled with hydrogen atoms, resulting in 8 hydrogen atoms.

Question 10

Samples of three different triacylglycerols were tested to determine the melting point of each one. The results of the tests are shown in the graph.

The length of the fatty acids in A, B, and C is the same. Which of the three fatty acids is likely to have the MOST saturated fatty acids?

Accepted Answer

The answer of Samples of three different triacylglycerols were tested...

Question 11

What important feature(s) of noncovalent bonds make(s) them so important to life?

Accepted Answer

The answer of What important feature(s) of noncovalent bonds make(s)...

Question 12

How many hydrogen atoms are present in a ring of six carbon atoms held together by alternating single and double bonds?

Accepted Answer

In a ring of six carbon atoms held together by alternating single and double bonds (a benzene ring), each carbon atom is bonded to one hydrogen atom, resulting in a total of 6 hydrogen atoms.

Question 13

How many hydrogen atoms are present in a hydrocarbon chain of five carbon atoms with one double bond and the rest single bonds?

Accepted Answer

The formula for a hydrocarbon chain with five carbon atoms and one double bond is C5H10. Since each carbon atom has the potential to form a maximum of four bonds (either single or double), we can determine the number of hydrogen atoms by subtracting the number of bonds already present in the molecule (5 carbon-carbon single bonds + 1 carbon-carbon double bond = 7) from the total number of bonding sites available on the carbon atoms (5 carbon atoms x 4 bonds per carbon = 20). Therefore, there are 20-7=13 sites for hydrogen. Each site requires one hydrogen atom, so there are 13 hydrogen atoms in this molecule. Therefore, the answer is C.

Question 14

If one strand of the DNA double helix is known, explain how the other strand can be determined.

Accepted Answer

The answer of If one strand of the DNA double...

Question 15

Samples of three different triacylglycerols were tested to determine the melting point of each one. The results of the tests are shown in the graph.  The number of double bonds in each of the fatty acids A, B, and C is the same. Which of the three triacylgcerols is likely to have the fatty acids with the LONGEST hydrocarbon chains?

Accepted Answer

The answer of Samples of three different triacylglycerols were tested...

Question 16

Consider the structure and function of DNA. Which of the following statements is TRUE?

Accepted Answer

The sequence of one DNA strand determines the complementary sequence of the other strand through base pairing rules, where adenine pairs with thymine and cytosine pairs with guanine. This allows for precise replication and protein synthesis. The other statements are false. DNA does not contain carbohydrates, phosphodiester bonds are relatively stable, and the ionization of phosphate groups does not make DNA small enough to pass through a cell membrane.

Question 17

In general, colder temperatures reduce the fluidity of the membrane, so cells will produce different molecules to maintain the proper degree of fluidity. How would the membrane change in response to colder temperatures?

Accepted Answer

In response to colder temperatures, the membrane would increase the amount of unsaturated fatty acids. This is because unsaturated fatty acids have kinks in their tails due to double bonds, which prevent them from packing tightly together. This results in a more fluid membrane that is better able to function in colder temperatures.

Question 18

If a cell is placed in a cooler environment, the fluidity of the membrane can decrease. What change could the cell make in the membrane composition to restore the normal level of fluidity?

Accepted Answer

The answer of If a cell is placed in a...

Question 19

Which one of the following biological polymers is defined by a physical property instead of a chemical structure?

Accepted Answer

The answer of Which one of the following biological polymers...

Question 20

Two of the main ingredients in most plant fertilizers are phosphorus and nitrogen. Why are these elements so important for the growth of a plant?

Accepted Answer

The answer of Two of the main ingredients in most...

Quiz 2: The Molecules of Life

Samples of three different triacylglycerols were tested to determine the melting point of each one. The results of the tests are shown in the graph. The length of the fatty acids in A, B, and C is the same. Which of the three fatty acids is likely to have the MOST unsaturated fatty acids?

Peptide bonds are characteristic of:

In DNA molecules, complementary base pairs always include one purine nucleotide and one pyrimidine nucleotide. In the DNA of certain bacterial cells, 16% of the nucleotides are adenine nucleotides. What are the percentages of the other nucleotides in the bacterial DNA?

Pyrimidine and purine bases are found in:

Name the specific types of bonds that hold the monomers together in proteins, nucleic acids, and complex carbohydrates.

How many hydrogen atoms are present in a five-carbon hydrocarbon molecule with four of the carbons linked by a single covalent bond, and with the fifth carbon attached by a single bond as a branch to the second carbon in the chain?

How many hydrogen atoms are present in a hydrocarbon chain of five carbon atoms with two double bonds and two single bonds?

Samples of three different triacylglycerols were tested to determine the melting point of each one. The results of the tests are shown in the graph. The length of the fatty acids in A, B, and C is the same. Which of the three fatty acids is likely to have the MOST saturated fatty acids?

What important feature(s) of noncovalent bonds make(s) them so important to life?

How many hydrogen atoms are present in a ring of six carbon atoms held together by alternating single and double bonds?

How many hydrogen atoms are present in a hydrocarbon chain of five carbon atoms with one double bond and the rest single bonds?

If one strand of the DNA double helix is known, explain how the other strand can be determined.

Consider the structure and function of DNA. Which of the following statements is TRUE?

In general, colder temperatures reduce the fluidity of the membrane, so cells will produce different molecules to maintain the proper degree of fluidity. How would the membrane change in response to colder temperatures?

If a cell is placed in a cooler environment, the fluidity of the membrane can decrease. What change could the cell make in the membrane composition to restore the normal level of fluidity?

Which one of the following biological polymers is defined by a physical property instead of a chemical structure?

Two of the main ingredients in most plant fertilizers are phosphorus and nitrogen. Why are these elements so important for the growth of a plant?