BIOL001 Exam 1 Lec. 2 --> 13

Which of the following correctly describes polar bonds and polar molecules? A. If a molecule has polar bonds, it must be a polar molecule. B. Some polar molecules do not have polar bonds. C. All molecules have polar bonds, but not all molecules are polar molecules. D. All polar molecules have at least one polar bond.

D. All polar molecules have at least one polar bond. A polar molecule has a part that is partially negative and a part that is partially positive. For this to occur, it must contain polar bonds. However, a molecule can have polar bonds and NOT be a polar molecule if it is symmetrical. For example, there are polar bonds in carbon dioxide (CO2), but it's not possible to define a "side" of the molecule as partially positively or negatively charged.

Which statement accurately describes the roles of the light reactions, the Calvin cycle, and cellular respiration? A. The light reactions convert light energy into chemical energy, the Calvin cycle breaks down sugars to produce ATP, and cellular respiration uses energy to convert carbon dioxide into sugars. B. The light reactions use energy to convert carbon dioxide into sugars, the Calvin cycle converts light energy into chemical energy, and cellular respiration breaks down sugars to produce ATP. C. The light reactions use energy to convert carbon dioxide into sugars, the Calvin cycle breaks down sugars to produce ATP, and cellular respiration converts light energy into chemical energy. D. The light reactions convert light energy into chemical energy, the Calvin cycle uses energy to convert carbon dioxide into sugars, and cellular respiration breaks down sugars to produce ATP.

D. The light reactions convert light energy into chemical energy, the Calvin cycle uses energy to convert carbon dioxide into sugars, and cellular respiration breaks down sugars to produce ATP.

What piece(s) of information do you need to determine whether the bond between two atoms is non polar or polar?

Electron distribution, electronegativity.

Ionic bonds are bonds form between atoms with ___ charges

FULL

Look back at the image that illustrates the structure of a trans-fat. Does formation of trans-fats from unsaturated fats increase, decrease, or not change the melting temperature of the fat? Explain your answer.

Increases melting temperature.

How are ionic bonds formed? In ionic bonds, one atom gives up an electron to a second atom. Ionic bonds are formed only between isotopes. Ionic bonds are formed when electrons are shared. Ionic bonds are formed by the transfer of a hydrogen atom from one molecule to another.

Ionic bonds are formed when electrons are shared. For example, CaCl2 (calcium chloride) is formed by the give and take of electrons. Calcium gives up 2 electrons, and each chlorine atom absorbs an electron.

Compare and contrast the three types of noncovalent interactions we discussed. What type is the strongest? Weakest?

Ionic, Hydrogen, and Van de Waals interactions. Strong -> Weak: Ionic(full opposite) , hydrogen(partial opp), van de Waals (temp opp charges)

If the temperature suddenly decreased, how could a cell alter the composition of phospholipid tails in its membrane to prevent the membrane from freezing? Explain how this change would prevent the membrane from freezing.

It could become a trans fat by adding hydrogen atoms to hydrogenate and remove double bonds which would straighten out the kinks making it harder to freeze.

If two atoms are connected by a covalent bond, what does that mean?

It means the atoms are sharing one or more pairs of electrons.

For a reaction, if the free energy of the reactants is MORE than the free energy of the products, what, if anything must be true? -It releases energy. -It will occur more quickly than a reaction where the free energy of the reactants is less than the free energy of the products. -It does not require activation energy. -All of the above. -None of the above.

It releases energy. The difference in free energies of reactants versus products tells you whether reaction requires or releases energy and how much energy is released/required. In this case, the reaction releases energy. Whether a reaction requires or releases energy and the amount required released tells you NOTHING about the rate of a reaction! And ALL reactions require activation energy to get going!

Difference between low and high entropy?

Low entropy: molecules are close with little movement. Higher concentration in one spot High entropy: Molecules are spread out and less concentrated.

Which of the following correctly describes the relationships between ATP, processes that release energy, and processes that require energy in cells?

Processes that require energy convert ATP to ADP and phosphate; processes that release energy convert ADP and phosphate to ATP.

Describe the relationship between the terms amino acid, polypeptide, and protein.

Proteins are made from amino acids linked by peptide bonds. A chain of amino acids is a polypeptide.

Describe the three types of subatomic particles we discussed and the overall structure of an atom. Explain why the electron cloud is attracted to the nucleus.

Protons, Electrons, Neutrons. The electron cloud is negatively charged while the nucleus has a positive charge.

(NADH)Reduced Electron Carriers ________ electrons Ready to accept or have electrons

Reduced Electron Carriers have electrons.

Processes that _______ energy convert ADP + P to ADT require or release?

Release (energy goes to formation of ATP)

covalent bonds are _____ than non covalent bonds

STRONGER

Explain the difference between saturated and unsaturated lipid carbon-hydrogen tails.

Unsaturated fatty acids have double bonds in the carbon chain which usually cause kinks in the tails. Saturated fatty acids have no double bonds in its hydrocarbon chain. Straight tails, allowing them to pack closely together. Making them solid at room temp.

van der Waals interactions occur between atoms with

VERY temporary partial charges

hydrophobic

Water fearing

Why is understanding the properties of water important for understanding cells/organisms?

Water is used as the "solvent of life" it is used in blood and most other biological fluids due to its polarity and solubility.

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 interactions between the molecules. Based on this information and what you learned in class, which of the properties of water listed below explains why water has a much higher melting temperature than other molecules its size? -Water molecules can interact with each other via covalent bonds, but most other molecules its size cannot. -Water molecules have many more covalent bonds than other molecules it size. -Water molecules can form ionic bonds with each other, but most other molecules its size cannot. -Water molecules can form many more hydrogen bonds with each other compared to other molecules it size.

Water molecules can form many more hydrogen bonds with each other compared to other molecules it size. Water has a much higher melting (and boiling) temperature compared to similar molecules like ammonia (NH3). This is because each water molecule can form hydrogen bonds with four other water molecules, which means there are LOTS of hydrogen bonds holding the water molecules together. Other molecules it size are not able to form as many hydrogen bonds with each other, and are therefore held together less tightly.

hydrogen bonds

bond between atoms with opposite partial charges - MUST involve partially positive hydrogen atom

energy storage

carbs

DNA and RNA

chains of nucleotides connected by covalent bonds

Which of the following bonds are arranged from strongest to weakest in a biological system? hydrogen, ionic, covalent hydrogen, covalent, ionic covalent, ionic, hydrogen ionic, covalent, hydrogen

covalent, ionic, hydrogen

Mannose is a polar molecule. Based only on this information, mannose -must have at least one polar bond and lack nonpolar bonds. -must have more than one polar bond. -must have at least one polar bond. -must have more than one polar bond and lack nonpolar bonds.

-must have at least one polar bond ALL polar molecules must have at least one polar bond. Most nonpolar molecules lack polar bonds (that's why they're nonpolar), however some nonpolar molecules (e.g. carbon dioxide) have polar bonds that are arranged symmetrically so that the partial charges cancel each other out. Any molecule can have nonpolar bonds.

Which of the following changes when a protien becomes denatured? Select ALL that change. -the three-dimensional structure -the number of amino acids -its ability to function -its ability to dissolve in water -the sequence (order) of amino acids

-the three-dimensional structure -its ability to function During denaturation a protein loses its three dimensional structure and therefore, its function since proper function requires a specific structure. Conversely, changing the 3D structure does not affect whether it can dissolve in water since the amino acid sequence of a denatured protein stays the same. Denaturation does not affect the covalent bonds between amino acids, so it cannot alter the order or the number of amino acids.

Come up with your own analogy (not a factory) to describe the four common cellular features and biomolecules we discussed.

...

Explain why an experiment CANNOT prove that a hypothesis is true.

...

Which of the following, if any, correctly describes the relationship between the terms atoms and molecules? Two molecules with the same types and numbers of atoms will always be identical. All molecules are composed of more than one type of atom. A molecule always has more than one atom. None of the above

A molecule always has more than one atom.

(NAD+) Oxidized Electron Carriers ________ electrons Are Ready to accept or have electrons

Are Ready to accept electrons

hydrophilic

Attracted to water

The carbon-hydrogen tails in the triglycerides in coconut oil have fewer double bonds, while the tails in corn oil have more double bonds. Use this information to explain why coconut oil is solid at room temperature, but corn oil is liquid. Include the terms saturated and unsaturated in your description.

Corn oil has more double bonds making it closer to unsaturated. While Coconut oil has fewer double bonds making it closer to saturated. Unsaturated fats are liquid at room temp while saturated fats are often solid.

Describe the key difference between covalent and noncovalent bonds.

Covalent bonds share electrons within atoms while non covalent bonds connect molecules.

A mutation occurs that alters a plant's chlorophyll molecules so that they are only able to absorb wavelengths between 400nm and 500nm. What is the most likely effect of this mutation on the rate of the light reactions and the Calvin cycle? - the rate of the light reactions and the Calvin cycle will both increase - the rate of the light reactions and the Calvin cycle will both decrease - the rate of the light reactions will decrease, but the rate of the Calvin cycle will increase - the rate of the light reactions will decrease, but the Calvin cycle will not be affected

the rate of the light reactions and the Calvin cycle will both decrease -This mutation reduces the wavelength range that can "power" the light reactions. Therefore, the mutation will decrease the ability of a plant to carry out the light reactions, and thus reduce the amount of ATP and NADH available for the Calvin cycle.

Which of the following features of a reaction is/are changed when you add an enzyme that can catalyze the reaction? Select ALL that apply. -the free energies of the products -the total amount of free energy released or required by the reaction -the rate of the reaction -the free energies of the substrates (reactants) -the activation energy

the rate of the reaction the activation energy Enzymes lower the activation energy for a reaction by lowering the free energy of the transition state, and therefore increase the rate (speed) at which the reaction can occur. Enzymes do NOT alter the free energy of the substrates or products of the reaction, and therefore do NOT change the total amount of energy released or required by the reaction.

In cellular respiration, the main role of glycolysis, formation of acetyl-CoA, and the citric acid cycle is -to generate oxygen that can act as the final electron acceptor in the electron transport chain. -to remove electrons from carbons originally present in fuel molecules (e.g. glucose), generating reduced electron carriers. -to provide carbon dioxide requred for ATP synthesis in oxidative phosphorylation. -to transfer electrons to oxygen in order to regenerate oxidized electron carriers.

to remove electrons from carbons originally present in fuel molecules (e.g. glucose), generating reduced electron carriers. At the end of the citric acid cycle, all of the carbons originally found in a molecule of glucose have been released as carbon dioxide, which organisms breathe out (or release through their cell membranes). Although some ATP has been made, the vast majority of the energy originally present in glucose is stored in the reduced electron carriers (NADH and FADH2), generated by removal electrons from the two carbon unit donated to the cycle by acetyl-CoA.

molecule

two or more atoms connected by covalent bonds

what kinds of bonds can occur in-between oil

van der Waals forces

A study tests the ability of a new drug to reduce pain in cancer patients. The data show a 10% reduction in the average pain for patients receiving the drug as compared to the control group. What, if anything, do you need to know to evaluate the results of this study? -whether 10% is a statistically significant difference -whether the people in the control group were given a "fake" pill or no pill -how many people participated in the study -how long participants were treated with the drug and control pills

whether 10% is a statistically significant difference

To determine whether a covalent bond between two atoms is polar or non polar, what do you need to know?

whether one atom has a stronger attraction for electrons that the other

Greatly increasing the amount of an enzyme's substrate will _______ the effectiveness of a competitive inhibitor and ________ the effectiveness of a noncompetitive inhibitor. -decrease; decrease -increase; not affect -decrease; not affect -increase; decrease -not affect; decrease -not affect; increase

decrease; not affect. Because competitive inhibitors interact in the active site of an enzyme, addition of more substrate decreases the ability of a competitive inhibitor to function - with lots of substrate around, the enzyme is much more likely to interact with its substrate than the inhibitor. Noncompetitive inhibitors interact at a site that's different from the active site. Therefore, no matter how much substrate is around, the enzyme can still interact with the inhibitor. And this means that increasing the amount of substrate will have no effect on the ability of a noncompetitive inhibitor to decrease the enzymes' function.

Cell molecules

determine the properties and functions of cells

An atom and an ion of the same element differ in the number of _____. -either protons or electrons -protons -neutrons -electrons

electrons

the more electronegative an atom is, the more strongly it pulls ___ toward itself

electrons

atoms share electrons

from covalent bonds

What type(s) of bond(s) is/are present in a mixture of water and olive oil? Select ALL that apply. ionic bonds hydrogen bonds covalent bonds van der Waals interactions

hydrogen bonds covalent bonds van der Waals interactions Covalent bonds exist in both the water and oil (triglyceride) molecules. Hydrogen bonds can from between water molecules. The tails of the oil triglycerides can interact via van der Waals interactions. Water and triglyceride molecules both lack atoms with full charges, and thus ionic bonds are NOT present

The process of hydrogenation can change the structure of double bonds in the tails of triglycerides to form trans fats. Formation of trans fats ______ the melting temperature of the triglycerides. Hint - Review your notes and look at the structure we saw in class of a trans fat. -increases -decreases -does not change

increases Both unsaturated and trans fats have double bonds, however the shape of the bonds, and therefore the tails is different. The carbon-hydrogen tails of trans fats are straight rather than kinked like unsaturated fats. This allows the tails to form more interactions with each other. Triglyceride molecules that can form more interactions have higher melting temperatures because it takes more energy (heat) to disrupt the interactions and go from solid to liquid.

DNA

information storage

nucleic acids

instructions required to create and maintain cells

membranes

lipids

electronegativity

measure of attraction for shared electrons

RNA

messages and more

Which four elements are the primary components of important biological molecules, such as proteins, fats, and carbohydrates? (ebook Module 2.1) -sodium, hydrogen, carbon, and oxygen -nitrogen, radon, carbon, and hydrogen - nitrogen, water, carbon, and oxygen -nitrogen, carbon, hydrogen, and oxygen

nitrogen, carbon, hydrogen, and oxygen

Compare and contrast polar and nonpolar bonds. Can a nonpolar bond exist between two atoms that are the same type?

non polar bonds share electrons equally with similar electronegativity while polar bonds involve the unequal sharing of electrons since the electrons pull towards the more electro-negative atom. Yes, for example in H2 and O2.

genetic information

nucleic acids

quantitative data

obtained by direct observation

qualitative data

obtained by indirect observation

In what step of cellular respiration is MOST of the energy obtained from glucose captured as ATP? -oxidative phosphorylation -citric acid cycle -glycolysis -formation of acetyl-CoA

oxidative phosphorylation Glycolysis and the citric acid cycle each generate two ATP per molecule of glucose. Formation of acetyl-CoA does NOT generate ATP. Most of the ATP produced by breaking down glucose (~28 ATP) is generated by oxidative phosphorylation (electron transport chain and ATP synthase).

cellular "machines"

proteins

Processes that _______ energy convert ATP to ADP + P require or release?

require (energy taken from ATP breaking it down)

In hydrochloric acid (HCl), chlorine has greater electronegativity than hydrogen. Therefore, _____ -the H side of an HCl molecule would have a slight negative charge -the H side of an HCl molecule would have a slight positive charge -HCl is a nonpolar molecule H- and Cl cannot interact chemically

the H side of an HCl molecule would have a slight positive charge. The more electronegative an atom, the more strongly it pulls shared electrons toward its nucleus. This would give the Cl side a slight negative charge and the H side a slight positive charge.

what distinguishes one atom from another

the charge on the atom

Review the experiment we discussed carried out by Engelmann, et. al. that assessed the effects of different wavelengths of light on the rate of photosynthesis. Thinking about how Engelmann set up his experiments, did his analyses directly measure the rate of the light reactions, the Calvin cycle, or both? -the Calvin cycle -the light reactions only -both the light reactions and the Calvin cycle

the light reactions only

Atoms

- two different kinds of atoms must have different numbers of protons - negativity charged electrons are found in a cloud around the positively charged nucleus - currently, we do not have the technology to see atoms

Water

- very cohesive - many interactions hold water together - can form hydrogen bonds with four other water molecules

In what way(s) is glycolysis similar in prokaryotic cells and eukaryotic cells? -it takes place in the cytoplasm -NAD+ is converted to NADH -glucose (a 6-carbon molecule) is broken down to two molecules of pyruvate (a 3-carbon molecule) -ATP is formed from ADP and phosphate -All of the above describe glycolysis in both eukaryotic and prokaryotic cells.

-All of the above describe glycolysis in both eukaryotic and prokaryotic cells. The reactions of glycolysis are virtually identical in ALL cells!

Red blood cells in your body carry out lactic acid fermentation. What is/are the purpose(s) of lactic acid fermentation in red blood cells? Select ALL that apply. -To regenerate NAD+. -To allow glycolysis to continue when oxygen is not available. -To convert pyruvate to a molecule that can be processed by the citric acid cycle. -To make lactate, which is required for other cellular processes. -To produce additional ATP by further breaking down the products of glycolysis.

-To regenerate NAD+. -To allow glycolysis to continue when oxygen is not available. The purpose of fermentation (lactic acid AND alcoholic) is to transfer the electrons carried by NADH to pyruvate, which forms either lactate or carbon dioxide and ethanol. This regenerates the NAD+ that is necessary for glycolysis to continue in the absence of oxygen, and allows a cell still get some ATP from breaking down glucose.

polar covalent bonds

- EQUAL sharing of electrons - distinct poles (sides)

non covalent bonds

- attractions between atoms with opposite charges - temporary interactions between molecules - do not share electrons

Describe the two main forms of energy in cells.

- chemical energy: number and kinds of chemical bonds - entropy: degree of disorder

covalent bonds

- connect atoms to form molecules - connect atoms in molecules

Cells

- determine the properties and functions of organisms - energy transformation - cell division (explains patterns of inheritance) - patterns of inheritance help explain how populations change through microevolution

3 types of non covalent bonds

- ionic bonds - hydrogen bonds - van der Waals forces

Process of science

- observations - hypothesis - data collection

nucleotides

- smaller molecules used to form DNA and RNA - some also act as energy currency in cells - transfer energy between cellular reactions

Which of the following correctly describes a difference between covalent bonds and noncovalent interactions? -Covalent bonds connect atoms in different molecules, while noncovalent interactions allow atoms in the same molecule to associate with each other. -Covalent bonds can exist between atoms in the same or different molecules, while noncovalent interactions only occur between atoms in the same molecule. -Covalent bonds can only occur between atoms in the same molecule, while noncovalent interactions can occur between atoms in the same or different molecules. -Covalent bonds connect atoms in the same molecule, while noncovalent interactions only occur between atoms in different molecules.

-Covalent bonds can only occur between atoms in the same molecule, while noncovalent interactions can occur between atoms in the same or different molecules. Covalent bonds involve sharing of electrons between two atoms and are the type of bond that link atoms together within a molecule. Noncovalent interactions are important for allowing different molecules to associate temporarily, and for holding the 3D shape of many types of molecules (e.g. proteins) together.

Which of the following statements reagarding the formation of ATP from ADP and phosphate in cells is/are true? Select ALL that are true. -Energy is released when ATP is formed from ADP and phosphate. -ADP and phosphate have a higher free energy than ATP. -Formation of ATP is linked to processes that release energy in cells. -The free energy of ATP is greater than the free energy of ADP and phosphate.

-Formation of ATP is linked to processes that release energy in cells. -The free energy of ATP is greater than the free energy of ADP and phosphate. The free energy of ATP is higher than the free energy of ADP and phosphate. Therefore, formation of ATP from ADP and phosphate requires an input of energy. This energy can be supplied by other processes/reactions in cells that release energy.

Why is it beneficial for chloroplasts to contain multiple types of pigment molecules? -It allows the light reactions to occur both during the day and at night. -It increases the range of wavelengths from which light energy can be gathered. -It allows electrons to be transferred more efficiently from carbon dioxide to NADP+. -It increases the number of chlorophyll molecules that can be contained within the thylakoid membranes.

-It increases the range of wavelengths from which light energy can be gathered. Different types of pigments absorb different wavelengths of light. The ability to absorb a wider range of wavelengths of light allows a plant to obtain more light energy.

Which of the following statements about prokaryotic and eukaryotic cells is/are true? Be sure to select ALL true statements. -Membranes surrounding eukaryotic cells control what goes in and out of the cell, but prokaryotic cell membranes do not. -Organelles are important for organizing processess in eukaryotic cells, but are not present in prokaryotic cells. -Eukaryotic cells are only present in multicellular organisms, while all prokaryotic cells are single-celled organisms. -Prokaryotic cells have only one chromosome, while eukaryotic cells have multiple chromosomes.

-Organelles are important for organizing processess in eukaryotic cells, but are not present in prokaryotic cells. -Prokaryotic cells have only one chromosome, while eukaryotic cells have multiple chromosomes. ALL membranes that surround cells control what goes in and out of cells (and organelles). Eukaryotic cells have organelles, prokaryotic cells do not. All cells need the "instructions" contained in the DNA sequences of chromosomes - prokaryotic cells have one chromsome, while eukaryotic cells have more than one. Eukarotic cells can make up multicellular OR unicellular organsims. It is true that prokaryotic cells are all individual organisms.

Select ALL the phrases that describe the benefits of cellular organelles. -Organelles concentrate molecules required for a specific process in one place. - Machinery required for specific functions can be held in the right place by attachment to the membrane of an organelle. -Organelles provide a way to control what goes in and out of cells. - Potentially dangerous molecules can be isolated in an organelle.

-Organelles concentrate molecules required for a specific process in one place. - Machinery required for specific functions can be held in the right place by attachment to the membrane of an organelle. - Potentially dangerous molecules can be isolated in an organelle.

Sorbose and tagatose are two monosaccharides that have the same number and type of atoms - six carbons, twelve hydrogens, and six oxygens. However, when tasted directly, sorbitose tastes slightly sweeter than tagatose. How is that possible? -The monosaccharides are produced in different locations in cells. -The arrangement of atoms differs between the two monosaccharides. -The monosaccharides are present in different types of foods.

-The arrangement of atoms differs between the two monosaccharides.

The hydrogen bonds in liquid water are less stable than in ice. Why? -In liquid water, the molecules form delicate crystals. -Ice is insulated by the liquid water below. -There is less movement of molecules in colder conditions. -Ice is denser than liquid water.

-There is less movement of molecules in colder conditions.

What's the difference between hydrogen bonds and van der Waals interactions? A. Hydrogen bonds involve interactions between atoms with permanent partial charges; van der Waals interactions involve associations between atoms that are only temporarily partially charged. B. Hydrogen bonds hold atoms together in a molecule; van der Waals interactions allow molecules to associate with each other. C. Hydrogen bonds form between water molecules; van der Waals interactions allow other types of polar molecules to interact. D. Hydrogen bonds are much weaker than van der Waals interactions.

A. Hydrogen bonds involve interactions between atoms with permanent partial charges; van der Waals interactions involve associations between atoms that are only temporarily partially charged. Hydrogen bonds are formed when a hydrogen with a partial positive charge interacts with an atom that has a partial negative charge. All noncovalent interactions allow molecules to associate or distant atoms in the same molecule to interact. Noncovalent bonds do NOT connect atoms to form a molecule (that's covalent bonds). van der Waals interactions involve association of atoms with opposite charges that are only temporary, and thus are the weakest type of noncovalent interaction.

A drug allows protons to freely pass through the inner membrane of mitochondria. If the drug were added to a eukaryotic cell, which of the following would most likely be affected? - glycolysis -the electron transport chain -ATP synthesis by ATP synthase -formation of acetyl-CoA -All of the above

ATP synthesis by ATP synthase Synthesis of ATP by ATP synthase relies on the proton gradient generated when electrons are passed from electron carriers to oxygen in the electron transport chain. If protons were able to flow freely through the inner mitochondrial membrane, the gradient would not be formed because protons would be able to move back into the matrix from higher to lower concentration without going through ATP synthase. None of the other processes depend on formation of the proton gradient and so they would not be affected.

Which of the following statements is true regarding bonds and interactions between atoms? A. Hydrogen bonds, which play a key role in the structures of many cellular molecules, are stronger than covalent bonds. B. Atoms in a polar molecule are held together by hydrogen bonds, while atoms in nonpolar molecules are held together by covalent bonds. C. Electrons are shared in a covalent bond, and an ionic bond involves an atom that has gained an electron and an atom that has lost and electron. D. Ionic bonds form between individual atoms that are not part of a molecule, while hydrogen bonds occur between atoms that are part of a moleucle.

C. Electrons are shared in a covalent bond, and an ionic bond involves an atom that has gained an electron and an atom that has lost and electron. Covalent bonds hold atoms together in ALL types of molecules (polar and nonpolar). Because noncovalent interactions involve attraction between opposite charges rather than electron sharing, they are ALL weaker than covalent bonds. Ionic bonds can form between atoms that have full charges within an molecule, or individual atoms with full charges (e.g. sodium ions, Na+).

Covalent bonds can occur where atoms share one or more pairs of electrons. Which of the following would form a double covalent bond? Cl2 NH3 NaCl CO2

CO2

Describe the main role and general structures and properties of each of the four types of biomolecules.

Carbs: Saccarides. Used for energy. (C, H, O) Lipids: Used for energy storage. Made up of a glycerol and a fatty acid (C, H, O) Proteins: (C, H, O, N,) Broken in to Amino Acids Variety of functions; -Enzymes: speed and regulate chem reactions in cells, -Transport -contractile proteins: make up fibers in ligaments -Storage proteins Nucleic Acids: ( C, H, O, N, P) -Store and transmit hereditary or genetic information. There are two kinds of nucleic acids: ribonucleic acid (RNA) and deoxyribonucleic acid (DNA).

Which of these statements best explains why cells in your body carry out cellular respiration if oxygen is present, as opposed to fermentation? -Cellular respiration generates ATP, while fermentation requires ATP. -Cellular respiration produces far more ATP per glucose than fermentation. -Cellular respiration involves fewer reactions than fermenation. -Fermentation does not allow NADH to be recycled to NAD+.

Cellular respiration produces far more ATP per glucose than fermentation. -Fermentation does NOT generate additional ATP, so the only ATP obtained by breaking down glucose when oxygen is not available are the two generated in glycolysis. Many more ATP can be produced by the processes of cellular respiration (which involve many more reactions) when oxygen is present.

Some studies have found that athletes who are able to keep up high levels of activity for extended periods of time have more mitochondria in their muscle cells compared to the average person. Which of the following hypotheses could explain this observation? -Muscle cells with more mitochondria are able to break down more glucose by cellular respiration in a specific period time than muscle cells with fewer mitochondria. -Having more mitochondria allows muscle cells to carry out cellular respiration and fermentation simultaneously. -Having more mitochondria allows muscle cells to carry out cellular respiration in the absence of oxygen. -Muscle cells with more mitochondria are able to generate more ATP per molecule of glucose than muscle cells with fewer mitochondria.

Muscle cells with more mitochondria are able to break down more glucose by cellular respiration in a specific period time than muscle cells with fewer mitochondria. If a muscle cell has more mitochondria, it has more cellular respiration "machinery" (enzymes) that can carry out the reactions required to obtain ATP from glucose. With more "machinery," the process can occur more quickly. Increasing the number of mitochondria will have no effect on the amount of ATP produced per glucose because the reactions of cellular respiration won't change. Oxygen is essential for cellular respiration regardless of the number of mitochondria present in cell. Fermentation yields less ATP per glucose and is carried out in the cytoplasm.

Is it possible for a polar molecule NOT to have any polar bonds?

NO. All polar molecules must have atleast one polar bond.

Which of the following, if any, correctly describes a difference between the process of cellular respiration in prokaryotic versus eukaryotic cells? -Eukaryotic cells require oxygen to carry out some of the steps of cellular respiration, but prokaryotic cells do not. -Glycolysis occurs in the cytoplasm of prokaryotic cells, and in mitochondria in eukaryotic cells. -Cellular respiration obtains energy from only glucose in prokaryotic cells, while only other fuel molecules are broken down in eukaryotic cells. -None of the above.

None of the above. Glycolysis occurs in the cytoplasm of ALL cells. ALL cells require oxygen to carry out the other processes of cellular respiration (formation of acetyl-CoA, citric acid cycle, and oxidative phosphorylation). Glucose as well as other fuel molecules are a source of energy in ALL cells.

Describe the physical properties of phospholipids that are key for their ability to form membranes and explain how these properties allow phospholipids to form membrane bilayers.

Phospholipids are similar to fats excepts two fatty acids connected to the glycerol with a phosphate group attached to the head. The two ends have different relationships with water allowing one to face the watery side of the membrane while the other faces inwards and is hydrophobic.

What gives each amino acid its unique properties? If an amino acid is classified as hydrophobic, what does that tell you about the amino acid?

The unique properties are determined by the R group of the amino acid. If amino acids are classified as hydrophobic it means they have non polar R groups (for example in leucine, the C - H bond)

What feature do ALL noncovalent interactions share? Which type is particularly important in cells? Why?

They have opposite charges between atoms.

non polar covalent bonds

UNEQUAL sharing of electrons

Is the statement "Consuming garlic has no effect on blood pressure" a valid scientific hypothesis regarding eating garlic and blood pressure? Why or why not? -Yes, because an experiment can be designed to prove consuming garlic affects blood pressure. =Yes, because it is possible to perform a test that assesses the effects of garlic on blood pressure. -No, because the statement cannot be tested by measuring something. -No, because it is not possible to prove that garlic does not affect pressure.

Yes, because it is possible to perform a test that assesses the effects of garlic on blood pressure.

Could two molecules have the same sets of atoms, but have different properties? If so, how? If not, why not?

Yes, with different arrangements. For example, Fructose and Glucose both have they same atoms with the Carbon-Oxygen double bond located differently.

capillary adhesion

a very thin layer of water acts as "glue" between two surfaces