CAMPBELL BIOLOGY TENTH EDITION Reece Urry Cain Wasserman

CAMPBELL BIOLOGY TENTH EDITION Reece • Urry • Cain • Wasserman • Minorsky • Jackson 5 The Structure and Function of Large Biological Molecules Clicker Questions by Tara Stoulig © 2014 Pearson Education, Inc.

Polymers are made of connected monomer subunits that are joined by what type of

Silicon (atomic number 14, atomic weight 28) is in the same column as carbon in the periodic table of the elements (group IV). Why isn’t life on Earth based on silicon, instead of carbon? a) Silicon is far more rare in the Earth’s crust than carbon. b) Silicon cannot form polar covalent bonds with oxygen. c) Silicon has a different valence than carbon. d) Silicon compounds often have very different physicochemical properties than the analogous carbon compounds. © 2014 Pearson Education, Inc.

Silicon (atomic number 14, atomic weight 28) is in the same column as carbon in the periodic table of the elements (group IV). Why isn’t life on Earth based on silicon, instead of carbon? a) Silicon is far more rare in the Earth’s crust than carbon. b) Silicon cannot form polar covalent bonds with oxygen. c) Silicon has a different valence than carbon. d) Silicon compounds often have very different physico-chemical properties than the analogous carbon compounds. © 2014 Pearson Education, Inc.

Which polysaccharide has the greatest number of branches? a) cellulose b) chitin c) amylose

A polysaccharide you are studying is found to contain unbranched β glucose molecules and cannot be digested by humans. Which polysaccharide are you studying? a) cellulose b) DNA c) chitin d) starch e) glycogen © 2014 Pearson Education, Inc.

A polysaccharide you are studying is found to contain unbranched β glucose molecules and cannot be digested by humans. Which polysaccharide are you studying? a) cellulose b) DNA c) Chitin d) starch e) glycogen © 2014 Pearson Education, Inc.

Lipids cannot be considered polymers because a) they contain polar covalent bonds. b) their structure includes carbon rings. c) they can be artificially created. d) their monomers are connected via ionic bonds. e) they are not composed of monomer subunits. © 2014 Pearson Education, Inc.

The chemical bonds present in a molecule contribute to the properties of the molecule. Carbon is an unusual atom in that it can form multiple bonds. Which of the following statements is not true? a) A carbon-to-carbon cis double bond is the type found in nature and is associated with cardiovascular health. b) A carbon-to-carbon trans double bond that is made artificially in food processing is associated with poor cardiovascular health. c) A carbon-to-carbon double bond in the cis configuration creates a bend in the hydrocarbon chain. d) Saturated fats are those that have a carbon-tocarbon double bond are associated with good health. © 2014 Pearson Education, Inc.

All lipids a) are made from glycerol and fatty acids. b) contain nitrogen. c) have low energy content. d) are acidic when mixed with water. e) do not dissolve well in water. © 2014 Pearson Education, Inc.

Sickle-cell disease is caused by a mutation in the hemoglobin gene that changes a charged amino acid, glutamic acid, to valine, a hydrophobic amino acid. Where in the protein would you expect to find glutamic acid? a) on the exterior surface of the protein b) in the interior of the protein, away from water c) at the active site, binding oxygen d) at the heme-binding site © 2014 Pearson Education, Inc.

Which is not a function of proteins? a) help make up membranes b) carry the code for translation from the nucleus to the ribosome c) bind to hormones (hormone receptor) d) can be hormones e) speed chemical reactions © 2014 Pearson Education, Inc.

How does RNA differ from DNA? a) DNA encodes hereditary information; RNA does not. b) DNA forms duplexes; RNA does not. c) DNA contains thymine; RNA contains uracil. d) all of the above © 2014 Pearson Education, Inc.

DNA and polypeptide sequences from closely related species are more similar to each other than sequences from more distantly related species. For the remaining questions, you will look at amino acid sequence data for the β polypeptide chain of hemoglobin, often called β-globin. You will then interpret the data to hypothesize whether the monkey or the gibbon is more closely related to humans. In the alignment shown below, the letters give the sequences of the 146 amino acids in β-globin from humans, rhesus monkeys, and gibbons. Because a complete sequence would not fit on one line, the sequences are broken into segments. The sequences for the three different species are aligned so that you can compare them easily. For example, you can see that, for all three species, the first amino acid is “V” (valine) and the 146 th amino acid is “H” (histidine). © 2014 Pearson Education, Inc.

Scan along the aligned sequences, letter by letter, noting any positions where the amino acids in the monkey or gibbon sequences do not match the human sequence. How many amino acids differ between the monkey and the human sequences? a) 2 b) 6 c) 8 d) 10 © 2014 Pearson Education, Inc.

How many amino acids differ between the gibbon and the human sequences? a) 1

What percent of monkey β-globin amino acids are identical to the human sequence? (This is called the percent identity between the monkey and human β-globin sequences. Note: 146 amino acids total. ) a) 5. 48% b) 94. 5% c) 95. 9% d) 98. 6% © 2014 Pearson Education, Inc.

What percent of gibbon β-globin amino acids are identical to the human sequence? (This is called the percent identity between the gibbon and human β-globin sequences. Note: 146 amino acids total. ) a) 1. 37% b) 94. 5% c) 95. 9% d) 98. 6% © 2014 Pearson Education, Inc.

Based on the β-globin alignment, identify the best hypothesis about how humans are related to monkeys and gibbons. a) Monkeys are more closely related to humans than gibbons are because monkeys’ β-globin sequence has the lower percent identity with humans. b) Both monkeys and gibbons are equally unrelated to humans because neither monkeys nor gibbons have the exact same β-globin sequence as humans. c) Both monkeys and gibbons are equally related to humans because they both have less than a 10% difference in β-globin sequence with humans. d) Gibbons are more closely related to humans than monkeys are because the gibbon β-globin sequence is a closer match with the human sequence. © 2014 Pearson Education, Inc.

What other evidence could you use to analyze evolutionary relatedness among gibbons, monkeys, and humans? a) the amino acid sequences of other proteins from gibbons, monkeys, and humans b) the amount of habitat overlap among gibbons, monkeys, and humans c) the β-globin amino acid sequence from gorillas d) the frequency of albinism (mutants that lack hair and skin pigment) in populations of gibbons, monkeys, and humans © 2014 Pearson Education, Inc.