BIOS 041 Exam 1

20. Oxidation is the process by which oxygen atoms are added to a target molecule. Generally, the atom that is oxidized will experience which of the following with respect to the electrons in its outer shell? a) a net gain b) a net loss c) no change d) an equal sharing

b

8. Based on size, what kind of single-celled organism is at right? a) Prokaryote b) Eukaryote c) Virus

b

The oxidation of one molecule is always coupled to the reduction of a second molecule.

True

Blueberries like to grow in slightly acidic soils. At which pH would they best grow? a) 10 b) 6 c) 7 d) 8 e) 14

b

Fatty acid hydrocarbon tails that do not contain double bonds are: a) Unsaturated b) Saturated c) hypersaturated d) antisaturated

b

Honeysuckle like to grow in sightly basic soils. At which pH would honeysuckle most likely grow? a) 14 b) 9 c) 5 d) 2

b

If neutral atoms (atoms with no overall charge) become positive ions they: a) Gain electrons b) Lose electrons c) Do not change d) Lose Protons

b

Which four elements make up 96.3% of the human body? a) oxygen, iron, hydrogen, nitrogen. b) carbon, hydrogen, nitrogen, oxygen. c) calcium, carbon, hydrogen, oxygen. d) carbon, potassium, hydrogen, nitrogen.

b

Which of the following organelles has both an outer and an inner membrane? a) endoplasmic reticulum b) mitochondrion c) lysosome d) peroxisome

b

The energy used by the cell to generate specific biological molecules and highly ordered structures is stored in the form of _____________. a) Brownian motion. b) heat. c) light waves. d) chemical bonds.

d

The polymer shown is known as a) Beta-glucose b) Deoxyribose c) Ribose d) Fructose

a

What is the value of K for this reaction? a) 10 b) 50 c) .1 d) .5

a

ΔG° = +7.3 kcal/mole ΔG° = -1.7 kcal/mole ΔG° = +5.5 kcal/mole ΔG° = -686 kcal/mole 6. If neutral atoms (atoms with no overall charge) become negative ions they: a) Gain electrons b) Lose electrons c) Do not change d) Lose Protons

a

11. Which set of amino acid side chains can all participate in electrostatic attractions? a) V aline, Serine b) Arginine, Glutamic acid c) Phenylalanine, Tyrosine d) Cysteine, Methionine

b

14. The monosaccharide shown is known as ____________. a) α-glucose b) β-glucose

b

18. Which of the following is true for a reaction at equilibrium? a) ΔG=ΔG° b) ΔG° + RT ln [X]/[Y] = 0 c) RT ln [X]/[Y] = 0 d) ΔG + ΔG° = RT ln [X]/[Y]

b

2. Carbon 14 is an unstable isotope of carbon that decays very slowly. Compared to the common, stable carbon 12 isotope, carbon 14 has two additional ______________. a) electrons. b) neutrons. c) protons. d) ions.

b

22. Prokaryotic and eukaryotic cells are distinct, but similar. Which of the following is true? a) Both eukaryotic and prokaryotic cells have a nucleus. b) Both eukaryotic and prokaryotic cells can have a cell wall. c) Both eukaryotic and prokaryotic cells can have membrane-bound organelles. d) Both eukaryotic and prokaryotic cells have linear DNA.

b

7. Chemical reactions carried out by living systems depend on the ability of some organisms to capture and use atoms from nonliving sources in the environment. The specific subset of these reactions that break down nutrients in food can be described as _____________. a) metabolic. b) catabolic. c) anabolic. d) biosynthetic

b

Prokaryotic and eukaryotic cells are distinct, but similar. Which of the following statements are true? a) Both prokaryotic and eukaryotic cells have a nucleus b) Both prokaryotic and eukaryotic cells can have a cell wall c) Both prokaryotic and eukaryotic cells can have membrane-bound organalles d) Both prokaryotic and eukaryotic cells have linear DNA

b

Which of the following is true for a reaction at equilibrium? a) delta G = delta G* b) Delta G* + RTln[X]/[Y] = 0 c) RTln[X]/[Y] = 0 d) delta G + delta G* = RTln[X]/[Y]

b

ΔG° = -0.616 ln Keq Keq = 10−ΔG°/1.42 13. Is the reaction X!Y an energetically favorable or unfavorable reaction under standard conditions? a) energetically favorable b) energetically unfavorable

b

10. Scientists currently believe that water is required for life for which of the following reasons? a) covalent bonds create surface tension b) water can be heated quickly and cools quickly c) ice is less dense than water d) all of the above

c

15. At first glance, it may seem that living systems are able to defy the second law of thermodynamics. However, on closer examination, it becomes clear that although cells create organization from raw materials in the environment, they also contribute to disorder in the environment by releasing _____________. a) water. b) radiation. c) heat. d) proteins.

c

16. Atoms that are covalently bonded are in a constant tug of war for the shared electrons. An atom's attraction for the electrons refers to its a) nucleus b) valence electrons c) electronegativity d) protons

c

17. If the isotope 32S has 16 protons and 16 neutrons, how many protons, neutrons, and electrons will the isotope 35S have, respectively? a) 16, 20, 15 b) 16, 19, 15 c) 16, 19, 16 d) 16, 19, 17

c

19. You are trying to make a synthetic copy of a particular protein but accidentally join the amino acids together in exactly the reverse order. One of your classmates says the two proteins must be identical, and bets you $20 that your synthetic protein will have exactly the same biological activity as the original. After having read this chapter, you have no hesitation in staking your $20 that it won't. What particular feature of a polypeptide chain makes you sure your $20 is safe and that the project must be done again? a) Peptide bond planarity b) Noncovalent bonds c) N & C termini chemical polarity d) Hydrophobic interactions

c

24. Which of the following statements about giant viruses, such as pandoravirus, is false? a) They have much larger genomes than normal viruses. b) They are large in size, about the size of prokaryotes. c) They do not need a host cell to replicate. d) Their genome contains sequences for some gene expression proteins.

c

4. Blueberries like to grow in slightly acidic soils. At which pH would most likely grow? a) 14 b) 9 c) 5 d) 2

c

Atoms that are covalently bonded are in a constant tug of war for the shared electrons. An atom's attraction for the electrons refers to its a) nucleus b) valence electrons c) electronegativity d) protons

c

Consider the reaction X!Y in a cell at 37°C. At equilibrium, the concentrations of X and Y are 50 μM and 5 μM, respectively. Use this information and the equations below to answer the next two questions: ΔG = ΔG° + 0.616 ln [Y]/[X] ΔG° = -1.42 log10 Keq 12. What is the value of Keq for this reaction? a) 10 b) 50 c) 0.1 d) 0.5

c

3. Cholesterol is an essential component of biological membranes. Although it is much smaller than the typical phospholipids and glycolipids in the membrane, it is a(n) _________________ molecule, having both hydrophilic and hydrophobic regions. a) polar b) oxygen-containing c) hydrophobic d) amphipathic

d

5. ΔG° indicates the change in the standard free energy as a reactant is converted to product. Given what you know about these values, which reaction below is the most favorable? a) ADP + Pi!ATP b) glucose 1-phosphate + glucose 6-phosphate c) glucose + fructose!sucrose d) glucose + CO2 + H2O

d

9. NADH and NADPH are activated carrier molecules that function in completely different metabolic reactions. Both carry two additional ________ and one additional _____________. This combination can also be referred to as a hydride ion. a) protons, electron. b) electrons, phosphate. c) hydrogens, electron. d) electrons, proton.

d

Human proteins, such as insulin, can be produced by bacterial cells. This is possible because _____. a) All organisms have the same type of cells b) Recently researchers have produced a totally synthetic cell that is entirely controlled by synthetic DNA c) Bacteria and humans share common genes d) All organisms share a common genetic code

d

In the case of a simple conversion reaction such as X to Y, which value of ΔG° is associated with a larger concentration of X than Y at equilibrium? (Hint: How is ΔG° related to K?) a) ΔG° = -5 b) ΔG° = -1 c) ΔG° = 0 d) ΔG° = 1

d

Scientists currently believe that water is required for life for which of the following reasons? a) hydrogen bonds create surface tension b) water moderates heat gain and loss c) ice is less dense than water d) water is essential in many chemical reactions e) all of the above

e

Covalent bonds are stronger than both ionic and hydrogen bonds.

True

All cells have nuclues

False

Condensation reactions between monosaccharides form phosphodiester bonds.

False

Enzymes catalyze reactions by lowering the standard change in free energy.

False

H2 is the most stable and abundant form of hydrogen in the environment.

False

There are three purines: cytosine, uracil and thymine.

False

True or False: CO2 gas is fixed in a series of reactions that are light-dependent.

False

True or False: The second law of thermodynamics states that the total amount of energy in the Universe does not change.

False

True or False: The ultimate source of energy for living systems is chlorophyll.

False

21. The synthesis of glutamine from glutamic acid requires the production of an activated intermediate in the activation step, followed by a condensation step that completes the process. Both amino acids are shown in the figure. Which molecule is added to glutamic acid in the activation step? a) phosphate b) NH3 c) ATP d) ADP

a

23. Oligosaccharides are short sugar polymers that can become covalently linked to proteins and lipids through condensation reactions. These modified proteins and lipids are called glycoproteins and glycolipids, respectively. Within a protein, which of the amino acids shown below is the most probable target for this type of modification? a) serine b) glycine c) phenylalanine d) methionine

a

Choose the pair of terms that correctly completes this sentence: Nucleotides are to _____ as _____ are to proteins. a) DNA/RNA; amino acids b) amino acids; polypeptides c) glycosidic linkages; polypeptide linkages d) polymers; polypeptides

a