Questions | Answers |
Q: What is the maximum amount of electrons an atom can have in its innermost shell? | A: Two. |
Q: What is the maximum amount of electrons an atom can have in its outermost shell? | A: Eight. |
Q: The outermost shell of an atom is referred to as what? | A: The valence shell. |
Q: The way in which atoms react with one another is based on what? | A: The electrons in the outermost shell referred to as valance electrons. |
Q: True or False? Atoms will always gain electrons in order to fill their outer shells. | A: False! Atoms with incompletely filled outer shells tend to GAIN, LOSE, or SHARE electrons in ways to EMPTY or FILL their outer shells and create a stable structure. |
Q: What is the "Rule of Octets" or the "Octet Rule"? | A: Except for the first energy level, atoms react with other atoms so they will have 8 electrons in their valence shell. |
Q: What is another name for an electrovalent bond? | A: An ionic bond. |
Q: What is an ion? | A: An atom that has lost or gained electrons to fill their valence shell. |
Q: A negative ion is referred to as what? | A: An anion. |
Q: A positive ion is referred to as what? | A: A cation. |
Q: What is an ionic bond? | A: A bond formed between two oppositely charged ions. |
Q: Give an example of an ionic interaction found in biological molecules. | A: Salt bridges. |
Q: What is a covalent bond? | A: A bond formed when atoms share electrons. |
Q: True or false? A covalent bond is a strong bond. | A: True! |
Q: What is a nonpolar covalent bond? | A: A covalent bond where electrons are shared equally. |
Q: Give an example of a nonpolar covalent bond. | A: Hydrogen (H2), Oxygen (O2). |
Q: What is a polar covalent bond? | A: A covalent bond where electrons are shared unequally causing partial negative and positive regions. |
Q: Give an example of a polar covalent bond. | A: Water (H20) |
Q: What is a hydrogen bond? | A: A hydrogen bond is a weak bond formed between hydrogen atoms (that are covalently bonded to another atom) and another atom. |
Q: True or false? Hydrogen bonds are important in intra-molecular bonds. | A: True! They bind different parts of the same molecule, which helps maintain structure of protein molecules and DNA chains. |
Q: What is the most abundant component in cells? | A: Water, making up about 70% of cells and 2/3 of human body weight. |
Q: True or false? Most biochemical reactions occur in aqueous solution. | A: True! |
Q: Give two examples of the importance of water discussed in class. | A: Transport of chemicals into the body and thermoregulation. |
Q: What is the approximate percentage of water compostion in humans? | A: 63% for males, and 52% for females. |
Q: What are the two major fluid compartments in humans and what is the relative percent of each? | A: The intracellular fluid compartment (ICF), about 63% of total water and the extracellular fluid compartment (ECF), about 37% of total water. |
Q: What contains more water, the ICF or ECF? | A: The ICF. |
Q: True or false? Water is wierd. | A: True! |
Q: Water is liquid in what temperature range. | A: 0-100 degrees celsius. |
Q: What is meant by high heat capacity? | A: Absorbs and releases large amounts of heat very slowly before temperature changes appreciably. |
Q: What is meant by high heat of vaporization? | A: Requires a lot of heat to change from a liquid to a gas. |
Q: Define an amphipathic molecule. | A: A molecule with both polar and nonpolar groups. |
Q: Give an example of an amphipathic molecule. | A: Phospholipids. |
Q: True or false? Hydrophilic molecules are soluble in water. | A: True! Hydrophilic molecules are polar and suluble in water. |
Q: True or false? Hydrophobic molecules are soluble in water. | A: False! Hydrophobic molecules are nonpolar and insoluble in water. |
Q: What is dehydration (synthesis)? | A: Dehydration (synthesis) is when water is removed from adjacent atoms (of molecules) to form a bond between them. |
Q: What is hydrolysis (degradation)? | A: Hydrolysis (degradation) is when water is used to break bonds between molecules. |
Q: What is osmosis? | A: Diffusion of water molecules through a selectively permeable membrane from a region of higher concentration to a region of lower concentration. |
Q: What is osmotic pressure? | A: The pressure required to stop the net flow of water across the membrane. |
Q: What is a hypertonic solution? | A: A solution with a higher solute concentration relative to a cell... cell will crenate. |
Q: What is a hypotonic solution? | A: A solution with a lower solute concentration relative to a cell... cell will swell or lyse. |
Q: What is an isotonic solution? | A: A solution with the same solute concentration relative to a cell... causes no change in a cell. |
Q: For our purposes in this class, what is an acid? | A: A proton donor; donates hydrogen ions (H+) to a solution. |
Q: For our purposes in this class, what is a base? | A: A proton acceptor; removes hydrogen ions (H+) from solution. |
Q: True or false? Weak acids and bases do not completely dissociate in water. | A: True! |
Q: True or false? Strong acids and bases rapidly & completely dissociate in aqueous solution. | A: True! |
Q: Did you know... ? | A: Most acids and bases in the extracellular fluid are weak acids and bases. |
Q: The stronger the acid, the _______ the Ka. | A: Larger. |
Q: The stronger the acid, the _______ the pKa. | A: Lower. |
Q: What does the acid dissociation constant (Ka) indicate? | A: The tendency of the acid (HA) to lose its proton and form its conjugate base (A-). |
Q: What is the formula for Ka? | A: Ka = [H+][A-] / [HA] |
Q: What is the formula for pKa? | A: pKa = -log Ka |
Q: What is the formula for pH? | A: pH = -log [H+] |
Q: What is the pH of water (neutral)? | A: Seven. |
Q: A solution whose hydrogen ion [H+] concentration is less than its hydroxide ion [OH-] concentration is said to be _______. | A: Basic or alkaline. |
Q: A solution whose hydrogen ion [H+] concentration is greater than its hydroxide ion [OH-] concentration is said to be _______. | A: Acidic. |
Q: Having a pH less than 7.35 is referred to as what? | A: Acidosis. |
Q: Having a pH greater than 7.45 is referred to as what? | A: Alkalosis. |