Bio 001 HW Problems

Which of the following correctly describes a difference between covalent bonds and noncovalent bonds?

Covalent bonds can only occur between atoms in the same molecule, while noncovalent bonds can occur between atoms in the same or different molecules.

A scientist designs an experiment to assess whether adding spicy flavoring affects the number of chicken wings a person consumes. Participants are given 10 minutes and an unlimited number of spicy wings, and allowed to eat as many as they choose. What would be an appropriate control group for the experiment?

A group given 10 minutes and an unlimited number of wings cooked the same way without any added flavoring

Which of the following, if any, correctly describe(s) the relationship between the terms atoms and molecules?

A molecule always has more than one atom.

A drug allows protons to pass freely through the inner membrane of mitochondria. If this drug was added to a eukaryotic cell, which of the following processes would be affected?

ATP synthesis by ATP synthase

The light reactions of photosynthesis involve two photosystems, photosystem I and photosystem II. Which of the statements below correctly describe(s) BOTH photosystems? A. light energy is required for the electron transfer reactions B. reaction center chlorophylls transfer electrons to electron carriers C. antenna pigments transfer energy to reaction center chlorophylls D. located in the thylakoid membrane

All of the above

Which of the following are true statements about polar and nonpolar covalent bonds? A. A molecule with polar covalent bonds has atoms with different electronegativities. B. A molecule with only nonpolar covalent bonds will not have any atoms with charges. C. A molecule with nonpolar covalent bonds has atoms with similar electronegativities.

All of the above

Which of the following correctly describe(s) atoms? A. Different types of atoms have different numbers of protons. B. Electron shells are regions (spheres) around the nucleus where electrons are most likely to be located. C. The electrons of an atom stay in a cloud around the nucleus because they are attracted to the positively charged nucleus. D. An individual atom is uncharged (i.e. has a charge of zero) because it has equal numbers of protons and electrons.

All of the above

Which of the following correctly describe(s) glycolysis in prokaryotic AND eukaryotic cells? A. NAD+ is converted to NADH B. takes place in the cytoplasm C. glucose (a 6-carbon molecule) is split into two molecules of pyruvate (a 3-carbon molecule) D. ATP is formed from ADP and phosphate (Pi)

All of the above

Why are cellular organelles beneficial? A. Molecules required for specific functions can be attached to the membrane of an organelle to hold them in a specific place. B. Organelles concentrate molecules required for a specific process in a particular location. C. Different cellular processes occur in different types of organelles, which helps to organize cellular functions. D. Potentially dangerous molecules can be isolated in an organelle.

All of the above

Which of the following correctly describes the activation energies of energy-releasing and energy-requiring reactions?

Both energy-releasing and energy-requiring reactions require activation energy. Submit

Sort each process below into the bins that correctly describe it. Each process can be used more than once (i.e. you can put a process into multiple bins) and ALL processes should be sorted. HINT - For each process, write a list of the products it generates. Then sort the processes, one by one, into the correct bin(s)

Generates Carbon Dioxide: Formation of acetyl-CoA, citric acid cycle Produces ATP: Citric acid cycle, glycolysis, ATP synthesis by ATP synthase produces reduced electron carriers: glycolysis, formation of acetyl-CoA, citric acid cycle converts reduced electron carriers to oxidized forms (e.g. NAD+, FAD): electron transport chain

Sort the phrases below to indicate whether they correctly describe hydrogen bonds only, van der Waals interactions only, ionic bonds only, all three types of noncovalent bonds, or none of the three types of noncovalent bonds. IMPORTANT: Each statement can be sorted only once, and there's at least one statement that belongs in each box.

Hydrogen Bonds ONLY: Requires hydrogen atom with partial positive charge Ionic Bonds ONLY: Requires atoms with full charges Van der Waals Interactions ONLY: Interacting atoms have temporary partial charges, Can form between nonpolar molecules All Three: Weaker than covalent bonds, attraction between opposite charges None of Three: Electrons shared between two atoms

Which of the following statements is true regarding chemical bonds?

Hydrogen bonds and van der Waals interactions both involve interactions between atoms that have only partial charges.

Studies have found that athletes who are able to keep up high levels of activity for unusually long periods of time have more mitochondria in their muscle cells compared to the average person. Based on what you know about cellular respiration, which of the following hypotheses could explain this observation?

Muscle cells with more mitochondria can generate ATP at a faster rate via cellular respiration

A student designs an experiment to test the hypothesis that people eat more popcorn while watching scary movies than while viewing comedies. They propose to recruit 15 participants for their study, but their advisor tells them they need at least 100 participants. Which of the following, if any, correctly explain(s) why? A. To ensure that the data they collect will support their hypothesis. B. To decrease the variation in the amount of popcorn consumed within each group. C. To ensure that their results are statistically significant.

None of the above

Which of the following, if any, correctly describes a difference between the processes that convert the energy of glucose molecules into the energy currency ATP in prokaryotic cells versus eukaryotic cells? A. Eukaryotic cells require oxygen to carry out cellular respiration, but prokaryotic cells do not. B. The enzymes involved in oxidative phosphorylation are embedded in a membrane in eukaryotic cells, but are not embedded in a membrane in prokaryotic cells. C. Prokaryotic cells carry out glycolysis and fermentation, while eukaryotic cells carry out glycolysis and cellular respiration

None of the above

Which of the following statements, if any, correctly compares the two types of lipids we discussed, membrane lipids and triglycerides?

One type has a hydrophilic head group, and the other type does not.

Select ALL statements that correctly compare prokaryotic and eukaryotic cells. 1. Eukaryotic cells have DNA, while prokaryotic cells lack DNA. 2. Organelles present in eukaryotic cells, but not in prokaryotic cells. 3. Prokaryotic cells have only one chromosome, while eukaryotic cells have multiple chromosomes. 4. Eukaryotic cells are only present in multicellular organisms, while all prokaryotic cells are single-celled organisms. 5. Membranes surrounding eukaryotic cells control what goes in and out of the cell, but prokaryotic cell membranes do not.

Organelles present in eukaryotic cells, but not in prokaryotic cells and Prokaryotic cells have only one chromosome, while eukaryotic cells have multiple chromosomes. (2 and 3)

Sort the items below into the correct boxes to appropriately identify terms/phrases related to the four types of biomolecules. IMPORTANT: Sort ALL terms. You can use an item more than once (i.e. put the same item in two different boxes).

Proteins: Increase rates of chemical reactions, amino acids Carbs: Monosaccharides Nucleic Acids: Information storage, nucleotides Lipids: Membrane structure, primarily hydrophobic

A student wants to examine the effect of temperature on bread mold growth. They plan to monitor the bread daily over the course of two weeks. Which of the following experimental set-ups would provide useful data?

Put 20 slices of bread from the same loaf in separate plastic bags. Place 10 of the bags in the refrigerator and the other 10 in a drawer

Select ALL features of a reaction that change when you add an enzyme that can catalyze the reaction. A. the total amount of energy released or required by the reaction B. the rate of the reaction C. the free energy of the products D. the activation energy E. the free energy of the substrates (reactants)

Rate of reaction and activation energy (B and D)

Sorbitose and tagatose are two monosaccharides that have the same number and types of atoms: six carbons, twelve hydrogens, and six oxygens. However, if you put a spoonful of sorbitose in your mouth it tastes much sweeter than tagatose. How is that possible?

The arrangement of atoms differs between the two monosaccharides.

Select ALL features of a protein that change when it becomes denatured. 1. The number of amino acid 2. The sequence (order) of amino acids 3. The three-dimensional structure (shape) 4. Its ability to function

The three-dimensional structure (shape) and Its ability to function (3 and 4)

Certain types of bacteria carry out lactic acid fermentation under conditions of insufficient oxygen. Select ALL statements that correctly describe a purpose of carrying out lactic acid fermentation when not enough oxygen is available. A. To produce additional ATP by further breaking down the products of glycolysis. B. To allow glycolysis to continue when oxygen is not available. C. To convert pyruvate to a molecule that can be processed by the citric acid cycle. D. To regenerate the oxidized electron carrier NAD+.

To allow glycolysis to continue when oxygen is not available. and To regenerate the oxidized electron carrier NAD+. (B and D)

Heating a substance (e.g. water) causes it to go from a solid to a liquid because molecules move more at higher temperatures, which disrupts noncovalent bonds between the molecules. Based on this information and what you learned from our discussions, which of the properties of water listed below correctly explains why water has a much higher melting temperature compared to other small polar molecules?

Water molecules can form many more hydrogen bonds with each other compared to other small polar molecules.

A drug forms channels in the thylakoid membranes of chloroplasts that allow protons (H+) to move freely across the membrane. Will this drug affect the light reactions of photosynthesis? Will this drug affect the Calvin Cycle?

Yes, the drug will inhibit formation of a proton gradient, which is necessary for ATP synthase to form ATP from ADP and Pi. No

Chemical reactions that occur in cells

always rearrange chemical bonds between atoms.

The cellular reaction that converts Reactant A to Product B occurs more rapidly than the reaction that converts Reactant X to Product Y. Both reactions release energy. Use your understanding of cellular energy and this information to answer both parts of this question. The reaction that converts A to B ___________ than the reaction that converts X to Y.

could release more or less energy Submit

Significantly increasing the amount of an enzyme's substrate that's present will _______ the ability of a competitive inhibitor to decrease an enzyme's activity.

decrease

Cellular reactions and processes

do not create or destroy energy. Submit

Select ALL statements that correctly describe the conversion between ATP and ADP + phosphate (Pi) in cells. A. ADP and Pi have a higher free energy than ATP B. energy is released when ATP is converted to ADP and Pi C. formation of ATP from ADP and Pi is linked to energy-releasing processes

energy is released when ATP is converted to ADP and Pi and formation of ATP from ADP and Pi is linked to energy-releasing processes (B and C)

Carbon monoxide poisoning causes major problems in humans and other organisms because it prevents the electron transport chain from functioning. Which of the following processes would still be able to occur normally in a person suffering from carbon monoxide poisoning

glycolysis and fermentation

What types of chemical bonds are present in a mixture of water (water molecules) and oil (triglyceride molecules)?

hydrogen bonds, van der Waals interactions, and covalent bonds

Proteins embedded (stuck) in the membranes surrounding cells control movement of molecules in and out of cells. Many of these membrane proteins form channels (tunnels) in a membrane to allow specific molecules in or out of the cell. A particular membrane protein channel allows glucose, a hydrophilic molecule, to move from one side of the membrane to the other. Based on what you learned in class, it is reasonable to predict that the interior of the channel through which glucose molecules move is ________, and the exterior of the channel that contacts the center of the membrane is __________.

hydrophilic; hydrophobic

The process of hydrogenation can change the structure of double bonds in the hydrocarbon tails of triglycerides to form trans fats. Formation of trans fats ______ the melting temperature of the triglycerides.

increases

If an atom is very electronegative, this means

it has a strong attraction for shared electrons.

There are two components of free energy, chemical energy (number and types of chemical bonds) and entropy (degree of disorder). Processes that release energy generate molecules that have _______ chemical energy and/or ______ entropy compared to the starting molecules.

less; higher

Plants that live in hot, dry climates close their stomata during the day to prevent evaporation of water out of the stomata. When a plant's stomata are closed on sunny day, the levels of carbon dioxide in the plant will be _______ and the levels of oxygen will be _________ compared to when the stomata are open on a sunny day.

lower; higher

The cellular reaction that converts Reactant A to Product B occurs more rapidly than the reaction that converts Reactant X to Product Y. Both reactions release energy. Use your understanding of cellular energy and this information to answer both parts of this question. The activation energy of the reaction that converts A to B ___________ than the activation energy of the reaction that converts X to Y.

must be smaller

Significantly increasing the amount of an enzyme's substrate that's present will _______ the ability of a noncompetitive inhibitor to decrease an enzyme's activity.

not affect

In the context of cellular energy transformation processes ______ electron carriers have electrons, and transfer of electrons from molecules with lower affinity for electrons to molecules with higher affinity for electrons ______ energy.

reduced; releases

In cellular respiration, the main role of glycolysis, formation of acetyl-CoA, and the citric acid cycle is to

remove electrons from carbons originally present in fuel molecules (e.g. glucose), generating reduced electron carriers. Submit