enzymes are specific to substrates because of the shape of their

enzymes are specific to substrates because of the shape of their

Asked by 2 years ago
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The most abundant element in the human body, by weight, is a. nitrogen. b. hydrogen. c. carbon. d. oxygen. e. calcium.d. oxygen.
The chemical properties of an atom are determined by its a. protons. b. electrons. c. neutrons. d. protons and neutrons. e. particles.b. electrons.
______ account for 98.5% of the body's weight. a. Carbon, oxygen, hydrogen, sodium, potassium, and chlorine b. Carbon, oxygen, iron, sodium, potassium, and chlorine c. Carbon, nitrogen, hydrogen, sodium, potassium, and chlorine d. Carbon, oxygen, hydrogen, nitrogen, sodium, and potassium e. Carbon, oxygen, hydrogen, nitrogen, calcium, and phosphoruse. Carbon, oxygen, hydrogen, nitrogen, calcium, and phosphorus
In general, ______ have a 2:1 ratio of hydrogen to oxygen. a. enzymes b. proteins c. lipids d. carbohydrates e. nucleic acidsd. carbohydrates
Molecules composed of two or more atoms are called compounds.false
Potassium, sodium, and chlorine are trace elements.false
Sodium has an atomic number of 11 and an atomic mass of 23. Sodium has a. 12 neutrons and 11 protons. b. 12 protons and 11 neutrons. c. 12 electrons and 11 neutrons. d. 12 protons and 11 electrons. e. 12 electrons and 11 protons.a. 12 neutrons and 11 protons.
Sodium, which has an atomic number of 11, will react with chlorine, which has an atomic number of 17. When these two atoms react, both become stable. To become stable, sodium will ____________, while chlorine will ____________. . accept one electron; give up one electron b. give up one proton; accept one proton c. share one electron with chlorine; share one electron with sodium d. become an anion; become a cation e. give up one electron; accept one electrone. give up one electron; accept one electron
Consider oxygen, which has an atomic number of 8 and an atomic mass of 16. How many valence electrons does it have? a. 2 b. 4 c. 6 d. 8 e. 16c. 6
Minerals are organic elements extracted from the soil by plants.false
Hydrogen, deuterium, and tritium are three isotopes of hydrogen.true
Varieties of elements called ________ differ from one another only in number of neutrons and therefore in atomic mass. a. cations b. anions c. isotopes d. electrolytes e. free radicalsc. isotopes
Which of these is a cation? a. O2 b. K c. Na d. Ca2+ e. Cl-d. Ca2+
Ionic bonds break apart in water more easily than covalent bonds do.true
Oxygen has an atomic number of eight. When two oxygen atoms come together, they form a__________ bond. a. hydrogen b. nonpolar covalent c. polar covalent d. ionic e. Van der Waalsb. nonpolar covalent
When table salt, sodium chloride (NaCl), is placed in water a. Na+ and Cl- form ionic bonds with each other. b. Na+ and Cl- form polar covalent bonds with each other. c. Na+ and Cl- form hydrogen bonds with water. d. Ionic bonds between Na+ and Cl- are broken. e. Na+ and Cl- become separated by their Van der Waals forces.d. Ionic bonds between Na+ and Cl- are broken.
The bonding properties of an atom are determined by its a. electrons. b. protons. c. positrons. d. neutrons. e. photons.a. electrons.
What type of bond attracts one water molecule to another? a. an ionic bond b. a peptide bond c. a hydrogen bond d. a covalent bond e. a hydrolytic bondc. a hydrogen bond
The high heat capacity of water makes it a very ineffective coolant.false
When you jump off a high diving board into water, you notice great resistance of water. This resistance is called __________ and is caused by water's great ______. a. surface tension; adhesiveness b. surface tension; cohesiveness c. hydrophobic tension; adhesiveness d. hydrophilic tension; cohesiveness e. hydrophilic tension; adhesivenessb. surface tension; cohesiveness
Which of these is hydrophobic? a. sugar b. K+ c. Cl- d. water e. fate. fat
A solution is a mixture composed of two or more substances that are physically blended but not chemically combined.true
Consider a mixture of blood, which contains sodium chloride, protein, and cells or formed elements. The sodium chloride is in a ____________, the protein is in a __________, and the cells are in a ____________. a. emulsion; solution; suspension b. solvent; emulsion; colloid c. colloid; suspension; solution d. suspension; colloid; solution e. solution; colloid; suspensione. solution; colloid; suspension
Which of these is the most appropriate to express number of molecules per volume? a. molarity b. volume c. percentage d. weight per volume e. milliequivalents per litera. molarity
Blood pH is approximately 7.4, which is slightly acidic.false
A solution with pH 4 has ______ the H+ concentration of a solution with pH 8. a. b. twice c. 4 times d. 10,000 times e. 1/10,000d. 10,000 times
Which of these has the highest H+ concentration? a. lemon juice, pH = 2.3 b. red wine, pH = 3.2 c. tomato juice, pH = 4.7 d. saliva, pH = 6.6 e. household ammonia, pH = 10.8a. lemon juice, pH = 2.3
Blood has a pH ranging from 7.35 to 7.45. Slight deviations from this can cause major problems, even death. You are doing an intense workout, and your skeletal muscle cells are producing metabolic acids such as lactic acid. Your blood pH does not drop significantly in spite of the metabolic acids released into the blood. You maintain a constant blood pH because a. metabolic acids are neutralized in muscle cells before released into the blood. b. metabolic bases are produced at the same rate by muscle cells to neutralize the acids. c. the respiratory system removes excess H+ from the blood before the pH is lowered. d. the body contains chemicals called buffers that resist changes in pH. e. endothelial cells secrete excess H+ to prevent a decrease in pH.d. the body contains chemicals called buffers that resist changes in pH.
A solution that resists a change in pH when acid or base is added to it is a. a buffer. b. a catalyst. c. a reducing agent. d. an oxidizing agent. e. a colloid.a. a buffer.
The most relevant free energy in human physiology is the energy stored in a. electrolytes ionized in water. b. free radicals with an odd number of electrons. c. radioisotopes. d. the chemical bonds of organic molecules. e. Van der Waals forces.d. the chemical bonds of organic molecules.
Which of the following equations depicts an exchange reaction? a. AB A + B b. A + B AB c. AB + CD AC + BD d. AB A- + B+ e. A + B AB C + Dc. AB + CD AC + BD
In an exchange reaction, covalent bonds are broken and new covalent bonds are formed.true
The opposite of a dehydration synthesis is a hydrolysis.true
Any chemical reaction that removes electrons from an atom is called a. reduction. b. condensation. c. hydrolysis. d. anabolism. e. oxidation.e. oxidation.
The breakdown of glycogen (an energy-storage compound) is an example of a ______ reaction. a. exergonic b. endergonic c. exchange d. synthesis e. equilibriuma. exergonic
When ATP breaks down to ADP, potential energy stored in bonds is released. This energy stored in bonds is __________ energy. a. electromagnetic b. electrical c. chemical d. heat e. kineticc. chemical
Digestive enzymes breakdown the starch in a potato into thousands of glucose molecules. This exemplifies a ______ reaction. a. synthesis b. decomposition c. exchange d. anabolic e. reductiveb. decomposition
Which one of the following would not increase the rate of a reaction? a. reactants being more concentrated b. rise in temperature c. presence of a catalyst d. presence of an enzyme e. decrease in reactant concentrationse. decrease in reactant concentrations
All the chemical reactions in which larger molecules are broken down to smaller ones are called catabolic reactions.true
Glucose is broken down in most of your cells to form carbon dioxide, oxygen, and the energy currency of the cell called ATP. What type of chemical reaction is this? a. anabolic or endergonic b. catabolic or exergonic c. anabolic or exergonic d. catabolic or endergonic e. anabolic or exothermicb. catabolic or exergonic
Which of the following words includes all of the other terms? a. catabolism b. anabolism c. metabolism d. oxidative reactions e. reductive reactionsc. metabolism
______ is not an organic compound. a. C16H18N3ClS b. Na2HPO3(H2O)5 c. CH4 d. C3H7O2Nb. Na2HPO3(H2O)5
A ______ is a group of atoms that determines many of the properties of an organic molecule. a. carboxyl group b. functional group c. hydroxyl group d. amino group e. phosphate groupb. functional group
A ______ converts a ______ to its monomers. a. hydrolysis; polymer b. dehydration synthesis; molecule c. dehydration synthesis; polymer d. polymer; molecule e. condensation; reactanta. hydrolysis; polymer
Table sugar is a disaccharide called __________ and is made up of the monomer(s) __________. a. maltose; glucose b. sucrose; glucose and fructose c. lactose; glucose and galactose d. glycogen; glucose e. glucose; galactose and fructoseb. sucrose; glucose and fructose
Which of the following is a disaccharide? a. galactose b. lactose c. glucose d. fructose e. amyloseb. lactose
______ is a monosaccharide, whereas ______ is a polysaccharide. a. Fructose; sucrose b. Galactose; maltose c. Lactose; glycogen d. Glucose; starch e. Cellulose; glucosed. Glucose; starch
Proteoglycans are macromolecules that form gels, which help hold cells and tissues together, lubricate joints, and account for the tough rubbery texture of cartilage. Proteoglycans are composed of a. carbohydrates and fats. b. nucleic acids and fats. c. carbohydrates and proteins. d. proteins and fats. e. nucleic acids and proteins.c. carbohydrates and proteins.
Unsaturated fatty acids have as much hydrogen as they can carry.false
Triglycerides are molecules consisting of one 3-carbon compound called ________ bound to three ________. a. eicosanoid; fatty acids b. steroid; glycerols c. eicosanoid; steroid d. glycerol; fatty acids e. steroid; fatty acidsd. glycerol; fatty acids
______ are major components of cell membranes, and are said to be ______. a. Triglycerides; hydrophobic b. Steroids; hydrophilic c. Bile acids; fat-soluble d. Eicosanoids; water-soluble e. Phospholipids; amphiphilice. Phospholipids; amphiphilic
Which of these is (are) always hydrophobic? a. glucose b. cholesterol c. amino acids d. proteins e. disaccharidesb. cholesterol
A dipeptide is a molecule with two peptide bonds.false
All amino acids have both a carboxyl group and an amino group attached to a central carbon.true
The formula for an amino group is ________ whereas the formula of a carboxyl group is ___________ a. -COOH; -OH. b. -CH3; -NH2. c. -OH; -SH. d. -NH2; -COOH. e. -SH; -H2PO4.d. -NH2; -COOH.
Proteins can serve all of the following functions except a. catalyze metabolic reactions. b. give structural strength to cells and tissues. c. produce muscular and other forms of movement. d. regulate transport of solutes into and out of cells. e. store hereditary information.e. store hereditary information.
A drastic conformational change in proteins in response to conditions such as extreme heat or pH will lead to loss of a protein's function. This drastic change in three-dimensional shape is called a. contamination. b. denaturation. c. saturation. d. sedimentation. e. deconformation.b. denaturation.
Proteins are ______ built from ______ different amino acids. a. monomers; 10 b. molecules; 10 c. polymers; 20 d. macromolecules; 40 e. polypeptides; 80c. polymers; 20
The folding and coiling of proteins into globular and fibrous shapes determines the ______ structure of the protein. a. primary b. secondary c. tertiary d. quaternary e. denaturedc. tertiary
Enzymes are specific to substrates because of the shape of their a. active sites. b. receptors. c. secondary structure. d. terminal amino acids. e. alpha chain.a. active sites.
______ is the substrate of ______. a. Glucose; lactose b. Lactase; glucose c. Lactose; lactase d. Galactose; lactose e. Sucrase; sucrosec. Lactose; lactase
All enzymes are ______, but not all of those are enzymes. a. cofactors b. proteins c. lipids d. carbohydrates e. nucleic acidsb. proteins
ATP is the body's most important form of long-term energy storage.false
ATP ________ endergonic and exergonic reactions. a. opposes b. decomposes c. reduces d. links e. dehydratesd. links
Nucleic acids are ______ of ______. a. molecules; monosaccharides b. monomers; ATP c. polymers; nucleotides d. polymers; cAMP e. polymers; DNAc. polymers; nucleotides
enzymes are

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Asked: 2 years ago