Chapter 23

Predict whether a triglyceride from beef fat or a triglyc- eride from olive oil will have a higher melting point. Explain your reasoning.

Soaps and Detergents Explain how the structure of soaps makes them effective cleaning agents.

Draw a portion of a lipid bilayer membrane, labeling the polar and nonpolar parts of the membrane.

Draw a portion of a lipid bilayer membrane, labeling the polar and nonpolar parts of the membrane.

What type oflipid does not contain fatty acid chains? Why are these molecules classified as lipids?

Soap Draw the structure of the soap sodium palmitate (palmitate is the conjugate base of the 16-carbon saturated fatty acid, palmitic acid). Label its polar and non polar ends.

The fatty acid palmitic acid has a density of 0.853 \(\mathrm{g} / \mathrm{mL}\) at \(62^{\circ} \mathrm{C}\) . What will be the mass of a 0.886 -L sample of palmitic acid at that temperature?

Polyunsaturated Fats How many moles of hydrogen gas are required for complete hydrogenation of 1 mol of linolenic acid, whose structure is shown below? Write a balanced equation for the hydrogenation reaction. \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}=\mathrm{CHCH}_{2} \mathrm{CH}=\mathrm{CHCH}_{2} \mathrm{CH}=\mathrm{CH}\) \(\left(\mathrm{CH}_{2}\right)_{7} \mathrm{COOH}\)

What three structures make up a nucleotide?

Name two nucleic acids found in organisms.

Explain the roles of DNA and RNA in the production of proteins.

Where in living cells is DNA found?

In the double-helical structure of DNA, the base guanine is always bonded to cytosine, and adenine is always bonded to thymine. What do you expect to be the relative proportional amounts of \(A, T, C,\) and \(G\) in a given length of DNA?

DNA Replication One strand in a DNA molecule has the following base sequence. What is the base sequence of the other strand in the DNA molecule? $$\mathrm{C}-\mathrm{C}-\mathrm{G}-\mathrm{T}-\mathrm{G}-\mathrm{G}-\mathrm{A}-\mathrm{C}-\mathrm{A}-\mathrm{T}-\mathrm{T}-\mathrm{A}$$

Life Processes Compare the net reactions for photo- synthesis and cellular respiration with respect to reactants, products, and energy.

The genetic code is a triplet code, that is, a sequence of three bases in RNA codes for each amino acid in a pep- tide chain or protein. How many RNA bases are required to code for a protein that contains 577 amino acids?

DNA Comparisons A cell of the bacterium Escherichia coli has about \(4.2 \times 10^{6}\) base pairs of DNA, whereas each human cell has about \(3 \times 10^{9}\) base pairs of DNA. What percentage of the size of the human genome does the E. coli DNA represent?

Draw the carbonyl functional groups present in glucose and fructose. How are the groups similar? How are the groups different?

List the names of the monomers that make up proteins, complex carbohydrates, and nucleic acids.

List the names of the monomers that make up proteins, complex carbohydrates, and nucleic acids.

Write balanced equations for photosynthesis, cellular respiration, and the hydrolysis of lactose.

Write a balanced equation for the synthesis of sucrose from glucose and fructose.

Calculate Approximately 38 mol of ATP are formed when glucose is completely oxidized during cellular res- piration. If the heat of combustion for 1 mol of glucose is \(2.82 \times 10^{3} \mathrm{kJ} / \mathrm{mol}\) and each mole of ATP stores 30.5 \(\mathrm{kJ}\) of energy, what is the efficiency of cellular respiration in terms of the percentage of available energy that is stored in the chemical bonds of ATP?

Some diets suggest severely restricting the intake of lipids. Why is it not a good idea to eliminate all lipids from the diet?

Calculate If a double-strand section of DNA has adenine as 20\(\%\) of its bases, what percent of the other three bases are present in the DNA strand?

Calculate how many moles of ATP a human body can produce from the sugar in a bushel of medium-sized Red Delicious apples. Use the Internet to find the information you need to solve this problem.

a. Write the balanced equation for the synthesis of ethanol from ethene and water. b. If 448 L of ethene gas reacts with excess water at STP, how many grams of ethanol will be produced? (Chapter 13\()\)

Identify whether each of the reactants in these reactions is acting as an acid or a base. (Chapter 18\()\) a. \(\mathrm{HBr}+\mathrm{H}_{2} \mathrm{O} \rightarrow \mathrm{H}_{3} \mathrm{O}^{+}+\mathrm{Br}^{-}\) b. \(\mathrm{NH}_{3}+\mathrm{HCOOH} \rightarrow \mathrm{NH}_{4}^{+}+\mathrm{HCOO}^{-}\) c. \(\mathrm{HCO}_{3}^{-}+\mathrm{H}_{2} \mathrm{O} \rightarrow \mathrm{CO}_{3}^{-}+\mathrm{H}_{3} \mathrm{O}^{+}\)

What is a voltaic cell? (Chapter 20)

Cholesterol Use the library or the Internet to research cholesterol. Write a newspaper article about cholesterol that is written for a teenage audience. Make sure the fol- lowing questions are answered in the article. Where is this molecule used in your body? What is its function? Why is too much dietary cholesterol considered to be bad for you? Is genetics a factor in high cholesterol?