BIO EXAM 1 Q's

Which of the following contributes to water's stability in a liquid state?

-A high heat of vaporization -A high heat of fusion

Compared with liquid water, ice has

-A more orderly arrangement of water molecules -Greater hydrogen bonds between individual water molecules

10. At which temperature of liquid water would the average number of hydrogen bonds per water molecule be the lowest? (A) 0°C (B) 1°C (C) Between 0.1 and 4°C (D) 4°C (E) The number of hydrogen bonds per molecule is independent of the temperature of liquid water.

A

27. Phospholipids typically consist of a glycerol molecule attached to two fatty acid chains and a phosphate group. These molecules make up the plasma membrane of cells. How would the properties of phospholipids change if they were composed of a glycerol molecule attached to one fatty acid chain and two phosphate groups? (A) Phospholipids would be more hydrophilic (B) Phospholipids would self-assemble into bilayers better (C) The fatty acid chain of phospholipids would have to be more saturated (D) A and B are true (E) All are true.

A

Two atoms differ greatly in their electronegativities. It is likely that these atoms would form a(n)....(A)Ionic bond(B)Polar covalent bond(C)Nonpolar covalent bond(D)Hydrogen bond(E)van der Walls Interaction

A

Using the amino acids labeled above, which would most likely be found on the inside of a folded protein? (A) (B) (C) (D) (E)More than one of these

A

Which level of protein structure is most immediately coded for in DNA?(A)Primary(B)Secondary(C)Tertiary(D)Quaternary(E)There is no difference between the above answers

A

You are a doctor and your patient shows kidney failure, resulting in metabolic acidosis. Their blood pH starts to sink to near pH=7.3 (neutral blood pH is 7.4). As a result of this acidosis, how might the above equations be behaving in the blood? (A) Both equations would shift to the left, producing more bicarbonate or carbonic acid. (B) Both equations would shift to the right, freeing H+ ions and producing bicarbonate. (C) Equation 1 would be in equilibrium while equation 2 would shift right. (D) Both equations would be in equilibrium to produce an even amount of H+ ions. (E) None of these are plausible explanations.

A

26. Which of the following is true about the reaction above? (A) It is a hydrolysis reaction (B) It results in a peptide bond (C) It forms a disaccharide (D) It forms two amino acids (E) A and B

B

hich of the following could be an accurate molecular formula of a molecule with covalent bonds?(A)AC (B)BD2 (C)BC4 (D)BE2 (E)None of the above combinations would be covalent bonds

B

22. Which of the macromolecules is the most diverse in terms of function?(A)Carbohydrates(B)Lipids(C)Proteins(D)Nucleic Acids

C

39. In the above scenario, which of the following alterations would be the least disruptive to the polypeptide chain? (A) Replace a polar amino acid with a nonpolar amino acid (B) Replace a polar amino acid with a negatively charged amino acid (C) Replace a nonpolar amino acid with a different nonpolar amino acid (D) Replace a nonpolar amino acid with a polar amino acid (E) All of the above would definitely be disruptive.

C

6. Because of hydrogen bonding, water is uniquely suited for its central role in life. Many hydrophilic molecules interact freely with water, but a number of hydrophilic molecules are important for life, too. Which of the following statements best describes how the interaction between water and hydrophobic molecules help organize biological systems? (A) Because cells are not pure water (there are many substances dissolved in them), they hydrophilic/hydrophobic effect has a limited role in biological systems (B) The ionic bonds between water molecules cause hydrophobic molecules to associate with each other and not with water molecules (C) Because water molecules preferentially associate with each other, they force hydrophobic molecules to associate with each other and not with water molecules (D) DNA is located in the hydrophobic nucleus of all cells because all nucleic acids are hydrophobic. (E) All of the above are true.

C

6. The function of a protein is dependent upon the shape into which the chain of amino acids folds. Many noncovalent interactions are responsible for maintaining the protein's shape. Assume you have isolated a protein from an organism in its proper shape, and you have treatedit with an enzyme that selectively targets and breaks only the peptide bonds in the proteins. Would the protein retain its shape under these conditions? (A)Yes; once noncovalent bonding determines the shape of a protein, the peptide bonds are no longer necessary. (B)Yes; because the noncovalent interactions that determine the shape of a protein are stronger than the peptide bonds. (C)No; while the noncovalent bonds determine the shape of a protein, the peptide bonds are required to hold the amino acids together. (D)Yes; but the shape would be affected to a greater extent by changes in temperature.

C

If you were designing a molecule to be highly acidic, which functional group would you be sure to include in its sequence?(A)Hydroxyl(B)Amino(C)Carboxyl(D)Carbonyl(E)None of the above

C

Which of the following is true regarding bond strength?(A)Double bonds are stronger than triple bonds(B)Generally speaking, ionic bonds are stronger than covalent bonds(C)Van der Waals interactions are one of the weakest types of bonds(D)More than one of the above(E)All of the above

C

You and your best friend are secretly trying to make an insulin mimic protein to help cure type 1 diabetes. Your best friend suggests that you need to just adjust two amino acids in the insulin sequence that will ensure quick deliver to the blood and boom! Diabetes, you gone. You are a little more skeptical. "You can't just change the protein sequence!" You insist. Who is right and why? (A) Best friend because two changes in a long polypeptide chain won't make a big difference (B) You are right because two changes will make the insulin a completely different protein (C) Cannot say yet, depends on which amino acids are changed and how secondary and tertiary structure follow with those changes (D) Neither is right; insulin is a hormone, so it isn't a protein and you are going about it entirely wrong (E) A and D are plausible.

C

12. The 3 blobs on the right are proteins spanning the phospholipid bilayer. What type of function might these proteins serve? (A) Transport (B) Receptor (C) Motor (D) More than one of the above (E) All of the above

D

21. For the next four questions, refer to the figure on the left. In this experiment, Tyrone Hayes and his colleagues exposed atrazine to male leopard frogs in a dose-dependent fashion and assessed the frequency of males in a population of frogs. What can you conclude from this data? (A) Atrazine decreases the frequency of male frogs present. (B) Atrazine is most dangerous at lower doses when assessing frog frequency. (C) Atrazine increases the frequency of male frogs present. (D) A and B (E) B and C

D

Hydrogen bonds... (A) Are crucial in maintaining the integrity of the water molecule (B) Hold nucleotides together on the sugar-phosphate backbones of DNA (C) Are important in forming branched polysaccharides (D) Play a large role in determining secondary protein structure (E) Distinguish unsaturated from saturated fatty acids

D

In my glass, I have water and some ice cubes. Which of the following statements could be true about the contents of my glass? (A)There are more hydrogen bonds per water molecule within the ice cubes, than in the water (B)The ice cubes are more dense than the liquid, so that's why they float (C)The beverage is being chilled because the molecules in the ice cubes are absorbing thermal energy (D)A & C (E)All of the above statements are true

D

The three components of a nucleotide are the phosphate group, nitrogenous base, and...(A)Carboxyl group(B)Purine(C)Pyrimidine(D)Pentose sugar(E)Amino group

D

Which conclusion would prove that Irn-Bru is better for your teeth than Coke, and what statistical test would be most appropriate for this experiment?(A)p>0.05; reject the null hypothesis; Student's t-test(B)p<0.05; accept the null hypothesis; Student's t-test(C)p>0.05; accept the null hypothesis; Standard deviation(D)p<0.05; reject the null hypothesis; Student's t-test(E)p<0.05; reject the null hypothesis; Standard deviation

D

Ice floats in liquid water because ice has a lower ______ than liquid water.

DENSITY

Dna shape

DNA is made up of nucleotides

13. Serine is an amino acid with a polar side chain. Where might you find serine in the above diagram? (A) A only (B) C only (C) B and/or D (D) A and/or B (E) A and/or C

E

14. You are studying a mutated version of the protein on the far right in the figure (with the letter D in the center). This mutation turned a polar amino acid into a nonpolar amino acid. How might this mutation affect the structure of the far right protein above? (A) The protein might be smaller as a result of this mutation. (B) Secondary structure would definitely be disrupted, altering the protein's shape. (C) Tertiary structure would be disrupted and may change how the protein is orientated in the membrane. (D) Primary structure would be altered. (E) C and D are true.

E

15. Electronegativity... (A) Is highest in elements on the far left of the periodic table like Na and Li. (B) Indicates how strongly an atom wants to give up its electrons (C) Is not different in two atoms engaging in a polar covalent bond (D) All of the above (E) None of the above

E

16. Which of the following is/are examples of hydrogen bonding? (A) Backbone bonding between amino acids in secondary structure (B) Backbone bonding in a nucleic acid between phosphate groups and pentose sugars (C) Complementary base pairing in DNA between nitrogenous bases (D) A and B (E) A and C

E

29. In a water molecule, the bond between the H and the O in the water molecule is a _________ bond while the bond between water molecules in solution is a _________ bond. (A) Polar, nonpolar (B) Nonpolar, polar (C) Hydrogen, polar covalent (D) Hydrogen, nonpolar covalent (E) Polar covalent, hydrogen

E

40. After your first few weekends at Marquette, you have come to the conclusion that blondes under 5'4'' are crazy party animals. Why is this statement NOT a theory? (A) It isn't supported by a wide body of empirical evidence (B) It doesn't explain the natural world (C)It's just an observation (D) More than one of these (E) All of these

E

Which of the following is incorrectly paired with its function? (A)Triglycerides - rich energy stores (B)Steroids - precursors to hormones and other signaling molecules (C)Phospholipids - compose cell membranes (D)Proteins - accelerate chemical reactions (E)None of the above (i.e. all are correctly paired)

E

While working with an individual protein, you notice a problem with the secondary structure. Which of the above amino acids would likely be implicated in this problem? (A) (B) (C) (D) (E) Any of the above amino acids

E

Nucleotide shape

Each nucleotide consists a phosphate group, a sugar group and a nitrogen base 4 types of nitrogen bases are ATGC

Put the physical states of water in order based on the intermolecular distances between water molecules. The TOP position should be the state in which the molecules are the farthest apart.

Gaseous Solid Liquid

Why does ice float in liquid water?

Ice is less dense than liquid water.

statistical significance

If is less than 0.05%

Why is water the universal solvent?

It dissolves more substances than any other liquid

A base will release ____ when dissolved in water.

OH ions

Protein functions

Structural support, storage, transport, cellular communications, movement, and defense against foreign substances

What is the molarity of a solution?

The number of moles of solute in 1 L

Rank each state of water in order of increasing density, starting with the least dense state at the top of the list:

Water Vapor Ice Liquid water

When water freezes:

Water molecules are packed into a less dense formation -The rate of hydrogen bond breakage slows -The H2O molecules in ice are in a much more orderly arrangement than in the liquid state -Energy is released -Water has a high heat of fusion. This means that: much energy must be withdrawn to cause water to change from a liquid state to solid

26. A substance that releases hydrogen ions into solution is called a(n) ____

acid

Where is the N terminus located?

generally at beginning

Where is the C- terminus?

generally at end where the C double bond is

Carbohydrate function in the body

immediate energy source functional groups: hydroxyl and carbonyl

Lipids function in the body

longterm energy storage