Chapter 23

Draw the structure of the open-chain form of fructose. Circle all chiral carbons, and then calculate the number of stereoisomers with the same formula as fructose.

Sugars Compare and contrast the molecular formula, molecular weight, and functional groups found in glucose and fructose.

Historical Perspective Carbohydrates are not hydrates of carbon as the name suggests. Explain how this misconception occurred.

Complex Carbohydrates Stachyose is a tetrasaccharide that contains two D-galactose units, one D-glucose unit, and one D-fructose unit. Each sugar unit has a molecular weight of 180 g/mol before it is linked together in this tetrasaccharide, and one water molecule is released for each two sugar units that come together. What is the molecular weight of stachyose?

Compare and contrast the structures of a triglyceride and a phospholipid.

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

Where and in what form are fatty acids stored in the human body?

What type of lipid 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 g/mL at 62°C. What will be the mass of a 0.886-L sample of palmitic acid at that temperature?

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?

Describe the types of bonds and attractions that link the monomers together in a DNA molecule.

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? $$C-C-G-T-G-G-A-C-A-T-T-A$$

Life Processes Compare the net reactions for photosynthesis 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 peptide 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?

Energy Calculate and compare the total energy in kJ that is converted to ATP during the processes of cellular respiration and fermentation.

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

Describe the functions of proteins, carbohydrates, lipids, and nucleic acids in living cells.

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 respiration. If the heat of combustion for 1 mol of glucose is \(2.82 \times 10^{3} kJ / mol\) and each mole of ATP stores 30.5 \(kJ\) 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?

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

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?

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. \(HBr+H_{2} O \rightarrow H_{3} O^{+}+Br^{-}\) b. \(NH_{3}+HCOOH \rightarrow NH_{4}^{+}+HCOO^{-}\) c. \(HCO_{3}^{-}+H_{2} O \rightarrow CO_{3}^{-}+H_{3} O^{+}\)

What is a voltaic cell? (Chapter 20)

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 following 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?

Which type of fish had the most omega fatty acids?