Chapter 2

lipids

Both molecule A and molecule B are classified as __________.

single covalent bonds

Bonds between carbon and hydrogen atoms (as depicted on the right side of the figure) are generally __________.

True

ATP is an unstable, high-energy molecule that provides body cells with a form of energy that is immediately usable.

a charge of +1

After the transfer of the electron, sodium will form an ion with __________.

an amine group and an acid group

All amino acids, such as the four represented in the figure, contain __________.

True

All salts are ionic compounds, but not all ionic compounds are salts?

False, The mass number of an atom is equal to the number of protons and neutrons in its nucleus. Atomic weight is a weighted average of the isotopes that exists for an element.

Atomic weight is equal to the number of protons and neutrons in the nucleus?

17

Based on the information in this figure, what is the atomic number of chlorine?

A substance that is dissolved in a solution.

Define Solute

a homogeneous mixture consisting of a solute dissolved into a solvent.

Define Solution

A substance that dissolves other materials to form a solution

Define Solvent

a structural variation in which different atoms of the same element have different numbers of neutrons

Describe an isotope.

8

Except for elements with atomic number 1 and 2, all other elements are stable with how many electrons in their outermost (valence) energy level?

four

How many hydrogen atoms will a single carbon atom bond with to form a stable molecule?

4

How many valence shell electrons does the element carbon have?

a peptide bond

If the molecules indicated by (A) are amino acids, then the line in the figure indicated by (D) is __________.

False, In a solution, the solute is the substance present in lesser amounts. There may be many solutes.

In a solution, the solute is the substance present in the greatest amount?

impaired nerve impulse transmission -Salts are ionic compounds that contribute to the ability of nerves to conduct an electrical current.

Kidneys play a major role in helping to maintain proper levels of Na+ and K+ ions in the blood. If the kidneys fail to function properly, one of the direct consequences would be_________.

phospholipid

Molecule A is a __________.

False, Polar molecules are the result of unequal electron pair sharing. Nonpolar molecules are electrically balanced because of the equal sharing of electrons between the atoms of the molecules.

Nonpolar molecules are the result of unequal electron pair sharing?

2 double bonds

One carbon atom can combine with two oxygen atoms to form carbon dioxide. Use the diagram to predict the type of bond that would be necessary to join the oxygens to the carbon to form a stable molecule.

Weakest- hydrogen Ionic Strongest- covalent

Rank the chemical bonds from relatively weakest to strongest. I. Ionic II. Covalent III. Hydrogen

Ionic

Sodium has one valence electron, while chlorine has seven. What type of chemical bond is most likely to occur between sodium and chlorine?

Oxygen

Sulfur has an atomic number of 16. Sulfur will form chemical bonds in a similar manner as __________.

two

Suppose that the carbon atom pictured here as a reactant had already formed a double bond with another carbon atom. How many hydrogen atoms would now be required to fill the carbon's outer shell?

table sugar, or sucrose (C12H22O11) -Sucrose is a molecule that dissolves in water but does not release ions, which are required for a solution to conduct electricity.

Suppose the following compounds were all dissolved in separate beakers of water in the same manner as the salt in the figure. Which of the resulting solutions would NOT conduct electricity? potassium chloride (KCl) ammonia (NH3) table sugar, or sucrose (C12H22O11) hydrochloric acid (HCl)

a hydrogen atom within a water molecule

The chloride ion (Cl−) indicated by the arrow is interacting most closely with which of the following?

True

The major function of DNA is to provide the genetic instructions for protein synthesis?

is based on the concentration of hydrogen ions in a solution

The pH scale __________. ranges from 1 to 7 is based on the salinity of a solution is based on the concentration of hydrogen ions in a solution is linear

R group

The presence of what group differentiates most amino acids from each other?

the mass number of the corresponding atom

The superscript preceding each hydrogen atomic symbol (H) represents which of the following?

isotopes

The three atoms shown represent different __________.

elements

The three atoms shown represent three unique __________.

Transport Work Mechanical Work Chemical Work

Top to Bottom:

tritium

Which of these elements would be MOST likely to be radioactive?

can form hydrogen bonds

Water is an important molecule because it __________.

water -The reaction is called a dehydration synthesis, in which the H from the glycerol's alcohol group and the OH from the fatty acid's acid group are removed as water. The valence electrons are then made up by the forming of an ester bond.

What additional molecule is produced when fatty acids are bonded to glycerol to make a triglyceride?

They all have an incomplete valence electron shell.

What do these four elements have in common?

ionization, followed by formation of an ionic bond

What does this figure depict?

Oxygen atoms have a stronger pull on the electrons shared within a covalent bond formed between oxygen and hydrogen.

What explains the negative charge on the oxygen atom within the water molecule?

bonding of amine group to acid group

What functional group pairing allows one amino acid to bond with another?

an electrical attraction between opposite charges

What holds the sodium and chloride ions together in a chemical bond?

protein

What is represented by the chemical at B?

substrates

What is represented by the chemicals at A?

alkaline solution (basic)

What is the classification of a solution of NaOH with a pH of 8.3?

Kinetic energy is energy in action, while potential energy is stored energy.

What is the difference between kinetic and potential energy?

4 amu

What is the mass number of the helium atom?

the sharing of electron pairs between two atoms

What is the most significant factor in the formation of a covalent bond?

ATP

What is the primary energy-transferring molecule in cells?

the kinetic energy of the reactants

What is the source of the activation energy in these reactions?

synthase -This figure shows a dehydration synthesis reaction between two monomers forming, resulting in a larger molecule. Such reactions are synthesis reactions.

What term would best classify the enzyme represented in the figure?

hydrogen bond

What type of bond is formed between the oxygen atom of one water molecule and the hydrogen atom of another water molecule?

False, Buffers resist abrupt and large swings in the pH of body fluids by releasing hydrogen ions (acting as acids) when the pH begins to rise and by binding hydrogen ions (acting as bases) when the pH drops. Buffers can do this because they consist of a combination of a weak acid and a corresponding weak base. Weak acids and bases dissociate (ionize) partially and reversibly, whereas strong acids and bases dissociate completely and irreversibly.

When an acid is added to a solution containing a weak base, the weak base will buffer the drop in pH by completely dissociating and accepting all of the hydrogen ions released from the acid?

carbon, oxygen, hydrogen, and nitrogen.

Which four elements comprise approximately 96% of our body weight?

proteins

Which organic molecules form the major structural materials of the body?

proton

Which particle is indicated by the arrow?

Mixtures are homogeneous while compounds are heterogeneous. -Some mixtures are homogenous, while others are heterogeneous. All compounds are homogeneous.

Which of the following is NOT a difference between a compound and a mixture? -Some mixtures are homogenous, while others are heterogeneous. All compounds are homogeneous. -No chemical bonding occurs between the components of a mixture. The properties of atoms and molecules are not changed when they become part of a mixture. -Mixtures can be separated by physical means, such as straining, filtering, or evaporation. Compounds can only be separated into their constituent atoms by breaking chemical bonds. -Mixtures are homogeneous while compounds are heterogeneous.

molecule

Which of the following is NOT a subatomic particle? molecule electron neutron proton

The substrate absorbs chemical energy from the enzyme after binding to its active site. -Enzymes do not provide energy to their substrates. In fact, enzymes are completely unchanged by their catalytic role and can act again and again.

Which of the following is NOT one of the three basic steps involved in enzyme activity? -The substrate absorbs chemical energy from the enzyme after binding to its active site. -The enzyme's active site binds to the substrate(s) on which it acts, temporarily forming an enzyme-substrate complex. -The enzyme-substrate complex undergoes internal rearrangements that form the product(s). -The enzyme releases the product(s) of the reaction.

hyperbolic

Which of the following is NOT one of the three major types of chemical reactions? hyperbolic synthesis decomposition exchange

The chemical composition of carbohydrates includes two oxygens and one hydrogen for every carbon present. -The correct ratio is two hydrogens and one oxygen for every carbon.

Which of the following is a FALSE statement about carbohydrates? -Dietary glucose is primarily used to drive our metabolic pathways that produce energy. -Glycogen is a complex carbohydrate formed by dehydration synthesis of glucose molecules. -Carbohydrates consist of monomers called simple sugars. -The chemical composition of carbohydrates includes two oxygens and one hydrogen for every carbon present.

energy storage

Which of the following is a primary function of molecule B?

4MgO2 → Mg + O2

Which of the following is an example of a decomposition reaction? MgSO4 + 2NaCl → MgCl2 + Na2SO 4MgO2 → Mg + O2 H2 + O2 → H2O 2Na + Cl2 → 2NaCl

a solution

Which of the following is formed once the ions in the salt crystal have completely dissociated from one another?

oxygen gas- it's a molecule

Which of the following is not a compound? carbon dioxide water oxygen gas methane (natural gas)

nucleus

Which of the following is not a fundamental subatomic particle that forms elements? protons nucleus neutrons electrons

X rays- this is a form of energy

Which of the following is not considered a form of matter? blood X rays bone oxygen gas

Triglycerides are composed of three fatty acids and one glycerol and are stable because they do not dissolve in water.

Which of the following is true about lipids? -Triglycerides are composed of three fatty acids and one glycerol and are stable because they do not dissolve in water. -Lipids found in the cell membrane are composed of one glycerol and three fatty acid chains and are called phospholipids. -Lipids that serve as hormones are derived from glycolipids. -Lipids used as energy reserves in the body are stored as molecules of phospholipids.

Secondary protein structures involve hydrogen bonding between amine and carboxyl groups.

Which of the following is true of protein structure? -Tertiary protein structure emerges when there is more than one peptide chain in a protein. -Peptide bonds join the amine group on one amino acid with the R group of another amino acid. -Secondary protein structures involve hydrogen bonding between amine and carboxyl groups. -Peptide bonds are formed by hydrolysis.

Small atoms with 6 or 7 valence shell electrons tend to be electronegative.

Which of the following statements about the polarity of covalent bonds is correct? -The atoms of a polar molecule share electrons equally. -Small atoms with 6 or 7 valence shell electrons tend to be electronegative. -Nonpolar molecules have partial charges which can lead to hydrogen bonding. -Polar covalent bonds involve the transfer of electrons from electropositive atoms to electronegative atoms.

Compounds are formed by chemical bonds between different kinds of atoms.

Which of the following statements is true concerning the characteristics of either compounds or mixtures? -Mixtures are all heterogeneous. -Compounds are formed by chemical bonds between different kinds of atoms. -Compounds can be separated by physical means. -Mixtures consist of chemical bonds between the components.

Less energy input is required to start the reaction in the presence of enzyme.

Which of the following statements is true regarding the reaction without an enzyme compared to the one with an enzyme? -Less energy input is required to start the reaction in the presence of enzyme. -The reaction in the presence of enzyme will form a larger proportion of product. -The reaction in the presence of enzyme releases more energy. -All of the listed responses are true.

Both reactions are exergonic.

Which of the following statements is true regarding the reactions shown? The left reaction is exergonic, and the right reaction is endergonic. The left reaction is endergonic, and the right reaction is exergonic. Both reactions are exergonic. Both reactions are endergonic.

The reactivity of an atom is based on the number of electrons in its outer valance shell.

Which of the following statements regarding atoms is true? -The chemical reactivity of an atom is based on the overall number of electrons in the atom. -Atomic weight is determined by the number of protons in an atom of a given element. -Atomic weight is determined by the number of electrons in an atom of a given element. -The reactivity of an atom is based on the number of electrons in its outer valance shell.

The weight of matter remains constant wherever it is located.

Which of the following statements regarding matter is FALSE? The weight of matter remains constant wherever it is located. Matter exists in solid, liquid, and gaseous states. With some exceptions, matter can be seen, smelled, and felt. The mass of matter remains constant wherever it is located.

The polarity of water easily breaks the charges between the oppositely charged ions in the compound.

Which response provides the best explanation as to why ionic compounds easily dissociate in water? -The polarity of water easily breaks the charges between the oppositely charged ions in the compound. -The polarity of water allows it to easily dissociate most covalently bound compounds. -Nonpolar organic molecules such as fats and waxes dissolve well in water. -As a polar molecule, water cannot easily dissociate inorganic compounds.

No, because the difference in the pull of oxygen on the bonding electrons would be neutralized. -Like in carbon dioxide, the difference in electronegativity of the oxygen and hydrogen atoms would be neutralized by being in a straight line.

Would water still be a polar molecule if it were NOT in the form of a V but rather were linear like carbon dioxide?