Waters importance to living systems reflects (a) its polarity and solvent properties

Which of the following forms of energy is the stimulus for vision? (a) chemical, (b) electrical, (c) mechanical, (d) radiant.

All of the following are examples of the four major elements contributing to body mass except (a) hydrogen, (b) carbon, (c) nitrogen, (d) sodium, (e) oxygen.

The mass number of an atom is (a) equal to the number of protons it contains, (b) the sum of its protons and neutrons, (c) the sum of all of its subatomic particles, (d) the average of the mass numbers of all of its isotopes.

A deficiency in this element can be expected to reduce the hemoglobin content of blood: (a) Fe, (b) I, (c) F, (d) Ca, (e) K.

Which set of terms best describes a proton? (a) negative charge, massless, in the orbital; (b) positive charge, 1 amu, in the nucleus; (c) uncharged, 1 amu, in the nucleus.

The subatomic particles responsible for the chemical behavior of atoms are (a) electrons, (b) ions, (c) neutrons, (d) protons.

In the body, carbohydrates are stored in the form of (a) glycogen, (b) starch, (c) cholesterol, (d) polypeptides.

Which of the following does not describe a mixture? (a) properties of its components are retained, (b) chemical bonds are formed, (c) components can be separated physically, (d) includes both heterogeneous and homogeneous examples.

In a beaker of water, the water-water bonds can properly be called (a) ionic bonds, (b) polar covalent bonds, (c) nonpolar covalent bonds, (d) hydrogen bonds.

When a pair of electrons is shared between two atoms, the bond formed is called (a) a single covalent bond, (b) a double covalent bond, (c) a triple covalent bond, (d) an ionic bond.

Molecules formed when electrons are shared unequally are (a) salts, (b) polar molecules, (c) nonpolar molecules.

Which of the following covalently bonded molecules are polar?

Identify each reaction as one of the following: (a) a synthesis reaction, (b) a decomposition reaction, (c) an exchange reaction. ______________ (1) 2Hg 1 O2 S 2HgO ______________ (2) HCl 1 NaOH S NaCl 1 H2O

Factors that accelerate the rate of chemical reactions include all but (a) the presence of catalysts, (b) increasing the temperature, (c) increasing the particle size, (d) increasing the concentration of the reactants.

Which of the following molecules is an inorganic molecule? (a) sucrose, (b) cholesterol, (c) collagen, (d) sodium chloride.

Waters importance to living systems reflects (a) its polarity and solvent properties, (b) its high heat capacity, (c) its high heat of vaporization, (d) its chemical reactivity, (e) all of these.

Acids (a) release hydroxyl ions when dissolved in water, (b) are proton acceptors, (c) cause the pH of a solution to rise, (d) release protons when dissolved in water.

A chemist, during the course of an analysis, runs across a chemical composed of carbon, hydrogen, and oxygen in the proportion 1:2:1 and having a six-sided molecular shape. It is probably (a) a pentose, (b) an amino acid, (c) a fatty acid, (d) a monosaccharide, (e) a nucleic acid.

A triglyceride consists of (a) glycerol plus three fatty acids, (b) a sugar-phosphate backbone to which two amino groups are attached, (c) two to several hexoses, (d) amino acids that have been thoroughly saturated with hydrogen.

A chemical has an amine group and an organic acid group. It does not, however, have any peptide bonds. It is (a) a monosaccharide, (b) an amino acid, (c) a protein, (d) a fat.

The lipid(s) used as the basis of vitamin D, sex hormones, and bile salts is/are (a) triglycerides, (b) cholesterol, (c) phospholipids, (d) prostaglandin.

Enzymes are organic catalysts that (a) alter the direction in which a chemical reaction proceeds, (b) determine the nature of the products of a reaction, (c) increase the speed of a chemical reaction, (d) are essential raw materials for a chemical reaction that are converted into some of its products.

Define or describe energy, and explain the relationship between potential and kinetic energy.

Some energy is lost in every energy conversion. Explain the meaning of this statement. (Direct your response to answering the question: Is it really lost? If not, what then?)

Provide the atomic symbol for each of the following elements: (a) calcium, (b) carbon, (c) hydrogen, (d) iron, (e) nitrogen, (f) oxygen, (g) potassium, (h) sodium.

Consider the following information about three atoms: 12 6 C 13 6 C 14 6 C (a) How are they similar to one another? (b) How do they differ from one another? (c) What are the members of such a group of atoms called? (d) Using the planetary model, draw the atomic configuration of 12 6 C showing the relative position and numbers of its subatomic particles.

How many moles of aspirin, C9H8O4, are in a bottle containing 450 g by weight? (Note: The approximate atomic weights of its atoms are C 5 12, H 5 1, and O 5 16.)

Given the following types of atoms, decide which type of bonding, ionic or covalent, is most likely to occur: (a) two oxygen atoms; (b) four hydrogen atoms and one carbon atom; (c) a potassium atom ( 39 19 K) and a fluorine atom (19 9F).

What are hydrogen bonds and how are they important in the body?

The following equation, which represents the oxidative breakdown of glucose by body cells, is a reversible reaction. Glucose 1 oxygen S carbon dioxide 1 water 1 ATP (a) How can you indicate that the reaction is reversible? (b) How can you indicate that the reaction is in chemical equilibrium? (c) Define chemical equilibrium.

Differentiate clearly between primary, secondary, and tertiary protein structure.

Dehydration and hydrolysis reactions are essentially opposite reactions. How are they related to the synthesis and degradation (breakdown) of biological molecules?

Describe the mechanism of enzyme action.

Explain the importance of molecular chaperones.

Explain why, if you pour water into a glass very carefully, you can stack the water slightly above the rim of the glass.