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anatomy ch2
Question | Answer |
---|---|
The smallest stable units of matter are | atoms |
The "atomic number" of an atom is determined by the number of __ it has | protons |
The "atomic weight" of an atom reflect the average number of | protons+ neutrons+ electrons |
One mole of any element | has the same number of atoms |
The nucleus of an atom consists of | protons + neutrons |
Isotopes of an element differ in the number of | neutrons in the nucleus |
The mass number represents the number of | protons + neutrons |
The innermost electron shell in an atom holds up to __ electrons | 2 |
Radioisotopes have unstable | nuclei |
By weight, which element is the most plentiful in the human body? | Oxygen |
Indicated which of these lists contains only trace elements | Silicon, fluorine, tin |
The atomic number represents the number of | protons in an atom |
Helium (He) has an atomic number 2. It is chemically stable because it | has a full outer electron shell |
Which element commonly has only a proton as its nucleus? | Hydrogen |
By weight, which element is the second most abundant in the human body? | Carbon |
The mass of an atom is largely determined by the number of __ it has | protons + neutrons |
If an isotope of oxygen has 8 protons, 10 neutrons, and 8 electrons, its mass number is | 18 |
If an element is composed of atoms with an atomic number of 6 and a mass number of 14, then a neutral atom of this element contains | 6 protons and 8 electrons |
The molecule NO is known as | Nitric oxide |
The molecule CO2 is known as | carbon dioxide |
The molecule H2 is known as | Hydrogen |
When electrons are transferred from one atom to another, and the two atoms unite as a result of the opposite charges, | an ionic bond is formed |
Magnesium atoms have two electrons in the outermost shell. As a result, you would expect magnesium to form ions with a charge of | +2 |
Which of the following statements about hydrogen bonds is false? | Hydrogen bonds are strong attractive forces between hydrogen atoms and negatively charged atoms. |
The molecule O2 is known as | Oxygen |
H2O is an example of a | compound |
Which of the following is not a cation? | Cl- |
A dust particle floating on a water surface illustrates | surface tension |
In an aqueous solution, cations are attracted toward | anions |
In an aqueous solution, sodium would move toward | a negative terminal |
The chemical behavior of an atom is determined by | The outermost electron shell |
Ions with a + charge are called | cations |
The weakest bond between two atoms is the __ bond | hydrogen |
When atoms complete their outer shell by sharing electrons, they form | covalent bonds |
Ionic bonds are formed when | an electron or electrons are completely transferred from one atom to another. |
If a pair of electrons is unequally shared between two atoms, a __ occurs | polar covalent bond |
Elements that have atoms with full outer shells of electrons | are inert gases |
Ions in an ionic molecule are held together due to | The attraction of opposite electrical charges |
An unequal sharing of electron results in what type of chemical bonds? | Polar covalent |
Sodium (Na) has an atomic number of 11. How many electrons are in the outer electron shell of a neutral sodium atom? | 1 |
Oxygen( atomic number 8) requires how many additional electrons to fill its outer electron shell? | 2 |
The formula for methane gas is CH4. What does the formula 4CH4 represent? | 4 molecules, each containing a carbon and 4 hydrogen atoms |
In an ionic bond, the electron donor is the __ whereas the electron acceptor is the __ | cation; anion |
In a molecule of nitrogen, three pairs of electrons are shared by two nitrogen atoms. The type of bond that is formed is an example of a | triple covalent bond |
In chemical notation, the symbol Ca2+ means ___ | a calcium ion that has lost two electrons |
Magnesium atoms have two electrons in the outermost shell and chlorine atoms have seven. The compound magnesium chloride would contain | 1 magnesium and 2 chlorine |
AB -> A+B is to decomposition as A+B->AB is to | synthesis |
The reaction N2 +3H2-> 2NH3 is an example of a | synthesis reaction |
The reaction A+B+ energy->AB in an example | endergonic reaction |
In hydrolysis reactions, compounds react with | water, causing decomposition |
Which one of the following statements is not correct about the reaction H2+Cl2->2HCl? | This reaction is easily reversible |
In dehydration synthesis reactions, compounds | lose water molecules |
In the reaction listed below, what coefficient needs to be added to balance the equation? 6CO2+6H2O->C6H12O6+_____O2 | 6 |
Chemical reactions that yield energy, such as heat, are said to be | exergonic |
All of the following are true concerning enzymes, except that they | are consumed during the reaction |
Compounds that can be synthesized or broken down by chemical reactions inside the body are called | metabolites |
Each of the following is an example of an inorganic compound, except | carbohydrates |
Identify which of the following is both an anion and a compound: | HCO3- |
Nonpolar organic molecules are good examples of | hydrophobic compounds |
During ionization, water molecules disrupt the ionic bonds of a salt to produce a mixture of ions. These ions can carry a current and so are called | electrolytes |
Oppositely charged ions in solution are prevented from combining by | hydration spheres |
An example of an inorganic substance is | water and carbon dioxide |
Hydrophilic molecules readily associate with | water molecules |
Which of the following statements about water is not correct? | It has a relatively low heat capacity |
Which property of water helps keeps body temperature stabilized? | Thermal Inertia |
Of the list below, which has the highest concentration of hydroxide ions? | pH14 |
Which pH is closest to normal body pH? | pH7 |
A___ removes hydrogen ions and a ___ releases hydrogen ions. | base; acid |
An excess of hydrogen ions in the body fluids can have fatal results because this can | break chemical bonds, disrupt tissue functions, change body fluid pH, change the shape of large complex molecules, rendering them nonfunctional |
A solution containing equal numbers of hydrogen ions and hydroxide ions is | neutral |
The chemical notation that indicates concentration is represented as | [] |
If a substance has a pH that is greater than 7, it is | alkaline |
Which pH of the following is the most acidic? | pH 1 |
Which pH of the following is the least acidic? | pH 6 |
An important buffer in body fluids is | NaHCO3 |
Which of the following substances would be most acidic? | Stomach secretions, pH = 1 |
Of the following choices, the pH of the least acidic solutions is | 12.0 |
Which has the greater concentration of hydrogen ions, a substance with a pH of 5 or a substance with a pH of 4 ? | A pH of 4 is greater. |
In the body, inorganic compounds | can serve as buffers |
When placed in water, an inorganic compound dissociates 99 percent, forming hydrogen ions and anions. This compound would be | a strong acid |
When a small amount of HCL or NaOH is added to a solution of Na2HPO4, the pH of the solution barely changes. Based on these observations, all of the following are true concerning the compound Na2HPO4, except | Na2HPO4 absorbs excess H+ and OH- directly onto the surface of its crystalline structure |
Carbohydrates, lipids, and protein are classified as | organic molecules |
A functional group is best described as reoccurring clusters of | atoms that greatly influence the chemical properties of molecules they are part of. |
Artificial sweeteners | are usually not broken down by the body |
Fructose is | a hexose. a carbohydrate. found in male reproductive fluids. an isomer of glucose. |
Molecules that have the same molecular formula but different structural formulas are called | isomers |
The most important metabolic fuel molecule in the body is | glucose |
A polysaccharide that is formed in liver and muscle cells to store glucose is | glycogen |
The group of organic compounds containing carbon, hydrogen, and oxygen in a near 1:2:1 ratio is defined as a | carbohydrate |
An example of an organic substance is | sucrose |
Carbohydrate molecules | are the body's most readily available source of energy |
When two monosaccharides undergo a dehydration synthesis, | a disaccharide is formed |
To bond two monomers together, a molecule of water must be ___ to/(from) from monomers. This process is called___ | removed; dehydration synthesis |
Lipids | cushion organs against shocks. provide a significant energy reserve. help to maintain body temperature. form essential structural components of cells |
A fatty acid that contains two or more double covalent bonds is said to be | polyunsaturated |
Alaska Natives have a lower incidence of heart disease even though their diets are high in fat and cholesterol. This may be due to the large amount of ___ in their diets | omega-3 fatty acids |
Which of the following is/are needed to form a triglyceride molecule? | 3 fatty acid molecule and 1 glycerol molecule |
A shortage of steroids in the body would result in a shortage of | sex hormones and plasma membrane |
Most of the fat found in the human body is in the form of | triglycerides |
Lipids that are produced by nearly every tissue in the body and act as local regulators are the | prostaglandins |
Cholesterol, phospholipids, and glycolipids are examples of | structural lipids |
A fatty acid with no double bonds between carbon atom is | saturated |
Lipids are composed of fatty acids and | glycerol |
The monomers of protein are | amino acids |
Substrate molecules bind to enzymes at the __ site | active |
You would expect a peptide bond to link | two amino acids |
Each amino acid differs from another in the | nature of the side chain |
The term ____ means each enzyme catalyzes only one type of reaction. | specificity |
A side chain on an amino acid is sometimes called | an R group |
The alpha-helix and pleated sheet are examples of ___ protein structure | secondary |
Interaction between individual polypeptide chains to form a protein complex is ___ structure | quaternary |
Glycoproteins and proteoglycans are combinations of amino acids and | carbohydrates |
Which of the following is the symbol for an amino group | -NH2 |
The maximum rate of an enzyme reaction occurs at | saturation limit |
How would the lack of a cofactor for an enzyme affect that enzyme's function? | the enzyme would not be able to function |
An example of an organic substance is: | lipids, nucleic acid, and protein |
Molecules that store and process genetic information are the | nucleic acids |
An amino acid is to protein as ___ is to nucleic acid | a nucleotide |
A nucleotide consists of | a five- carbon sugar, a nitrogenous base, and a phosphate group |
According to the rules of complementary base pairing in nucleic acids, cytosine would pair with the base | guanine |
Adenine and guanine are | purines represented by A and G |
The structure of RNA differs form DNA in that | the backbone of RNA contains ribose |
The most abundant high-energy compound in cells is | adenosine triphosphate |
A high-energy bond in ATP is present | between phosphate groups 1 and 2 and between phosphate groups 2 and 3 |
The phosphorylation of adenosine forms | AMP |
Identify the product formed from the phosphorylation of ADP | adenosine triphosphate |
AMP+P-> | ADP |
The average time between synthesis and breakdown is known as the ___ time | turnover |
Muscle proteins are destroyed after 17 days and then replaced. This is an example of | metabolic turnover |
Continuous breakdown and replacement of cellular molecules is termed | metabolic turnover |
A __ is a pure substance composed of atoms of only one kind | element |
The center of an atom is called | nucleus |
Electrons whirl around the center of the atom at high speed, forming an ___ | electron cloud |
Electrons in an atom occupy an orderly series of electron shells or ___ | energy levels |
The actual mass of an atom is known as its ___ ___ | atomic weight |
Atoms of the same element whose nuclei contain the same number of protons, but different number of neutrons, are called | isotopes |
The ___ of a radioactive substance is the time required for 50 percent of a given amount of radioisotope to decay | Half-life |
Ions with a positive charge are called | cations |
Ions with negative charge are called | anions |
Kinetic energy is stored as ___ energy when a spring is stretched | potential |
Chemical reactions that release energy are called | exergonic |
Chemical reactions that absorb energy are called | endergonic |
The three familiar states of matter are solid, liquids and | gases |
Chemical reactions that occur in the body are accelerated by | enzymes |
In living cells, complex metabolic reactions proceed in a series of steps called ___ | pathway |
Compounds that contain carbon as the primary structural atom are called___ molecules | organic |
Compounds that do not usually contain carbon as the primary structural atom are called___ molecules | inorganic |
A ___ is a homogeneous mixture containing a solvent and a solute | solution |
Soluble inorganic compounds whose solutions will conduct an electric current are called | electrolytes |
Molecules that do not readily interact with water are called | hydrophobic |
The ___ of a solution is the negative logarithm of the hydrogen ion concentration expressed in moles per liter | pH |
All fatty acids contain a functional group at one end called the___ | carboxylic acid group |
In water, phospholipids tend to form tiny droplets with hydrophobic tails buried inside called ____ | micelles |
Molecules with two fatty acid chains and a phosphate group that form biological membranes are called | phospholipids |
Individual steroids differ in the ___ attached to the carbon rings | side chains |
The molecule DNA contains a five-carbon sugar called | droxyribose |
The purines found in DNA are ___ and guanine | Adenine |
The pyrimidine base found in DNA are ___ and cytosine | thymine |
The three structural components of a nucleotide are a pentose, a phosphate group, and a __ base | nitrogenous |
A ___ is a covalent bond that stores an unusually large amount of energy | high-energy bond |
In the process of ___ a phosphate group is transferred to a molecule | phosphorylation |
The hydrolysis of ATP yields ADP, phosphate ion, and ____ | energy |