BIOL 2457:Chapter 2
144 Cards in this Set
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What are chemical elements?
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Substances that cannot be split into simpler substances by ordinary chemical means
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What is a chemical symbol?
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The letter abbreviation given to elements
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What are atoms.
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units of matter of all chemical elements
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What is an element?
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a quantity of matter composed of atoms of the same type
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What is the charge of protons?
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positive (+)
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What is the charge of neutrons?
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No charge, they are neutral
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What charge are electrons?
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Negative
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What indicates the atomic weight (mass) of an element?
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Number of protons and neutrons in the nucleus
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What is the atom number of an element?
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The number of protons in the nucleus
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How many electrons can the 1st electron shell contain?
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2.
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How many electrons can the second shell contain?
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8
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What is a valance electron shell?
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The outermost shell, determines whether or not the element wants to react or not.
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If the valance shell of an element is already full this means the element is?
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Inert, and doesn't want to bond
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If the valance shell of an element is not full this means?
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The element is reactive and wants to bond to fill the outer shell.
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What is an ion?
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An atom that gained or gave up an electron, written with its chemical symbol and (+) or (--)
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What is a cation?
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Atoms with a positive charge
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What is a molecule?
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Formed when atoms share electrons, such as (h2O)
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What is a free radical?
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An electrically charged atom with an unpaired electron in its outermost shell. They are unstable and highly reactive but they can become stable.
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How do free radicals become stable?
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By giving up an electron or by taking an electron from another molecule.
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What are antioxidants?
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substances that inactivate oxygen-derived free radicals (they fill the free radical)
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What fills a free radical and makes the stable?
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An antioxidant.
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What are chemical bonds?
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forces of attraction that hold the atoms of molecules together
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What determines the likelihood that an atom will form a chemical bond with another atom depends on what?
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The number of electrons in it outermost, or valance shell.
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What forms ions?
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When an atoms gains or looses a valance electron
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Positively charged ions are attracted to what?
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Negatively charged ions (and vice versa)
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What are cations?
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positively charged ions that have given up one or more electrons. (electron donors)
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What are anions?
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negatively charged ions that that have picked up a one or more electrons that another molecule has lost ( electron acceptors)
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Sodium Chloride is an example of what type of bond?
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an ionic bond. In NaCl, sodium gave up an electron making it cation (+), Chloride took the electron making it an anion (-). The opposite charges attract making table salt.
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What is a covalent bond?
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Bonds formed by atoms of molecules that share 1, 2 or 3 pairs of their valence electrons.
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What is the strongest type of chemical bond in the body?
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Covalent bonds
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Covalent bonds can be either..?
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Polar or non-polar
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What is a non-polar covalent bond?
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Atoms share the electron equally: one atom does not attract the shared electrons more strongly than the other atom
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What is a polar covalent bond?
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Formed by unequal sharing of electrons between atoms
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Water is an example of what type of bond?
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Polar covalent bond (in water, oxygen attracts the hydrogen more strongly )
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What are hydrogen bonds?
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Weak intermolecular bonds serving as links between molecules, they can help determine the shape of some molecules. result from the attraction of oppositely charged parts of molecules rather than from sharing electrons.
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What is a hydrogen bond?
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A weak bond, they have a sticky relationship due to polarity.
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Water tension is formed by what type of bond?
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Hydrogen bonds
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What is a chemical reaction?
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They occur when new bonds form and/ or old bonds are broken.
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What is metabolism?
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the sum of all the chemical reactions in the body
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What is the law of conservation of energy?
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The total mass of the reactants equals the total mass of products.
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Chemical bonds all relate to what?
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The number of electrons in an elements valance shell
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What is energy?
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The capacity to do work
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What is kinetic energy?
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The energy associated with matter in motion
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What is potential energy?
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The energy stored by matter due to its position.
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Why is stored energy important in an organism?
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So the organism can do catabolic or anabolic processes.
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What is an exergonic reaction?
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when the bond being broken has more energy than the one being formed so the extra energy is released, usually as heat (occurs during catabolism of food molecules)
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What is an endergonic reaction?
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just the opposite of an exergonic reaction and requires that energy to be added, usually from a molecule called ATP, to form a bond, as in bonding amino acids molecules together to form proteins
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What is activation energy?
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energy required to break the chemical bonds in the reactant molecule so a reaction can start
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What are some factors that can cause collision and chemical reaction?
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Concentration
Temperature
Catalyst
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The higher the temperature, the faster molecules are moving, increasing the possibility of what?
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Reactants coming together
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What is a catalyst?
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chemical compound that speeds up chemical reactions by lowering the activation energy needed for the reaction to occur. A catalyst helps to properly orient the colliding particles of matter so that the reaction can occur at a lower collision speed. the catalyst itself is unchanged in the …
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What is a synthesis reaction?
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Anabolism
A+B --> AB
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What is a decomposition reaction?
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Catabolism
AB--> A+B
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What is an exchange reaction?
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AB+CD--> AD+CB
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What is a reversible reaction?
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AC<--> A+C
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What is an inorganic compound?
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Does not contain carbon and are structurally simple molecules
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What are inorganic compounds?
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Always contains carbon: usually contain hydrogen: always have covalent bonds: usually are large molecules
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What is the most important and abundant inorganic compound in all living things?
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Water
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What is waters most important property?
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Polarity, the uneven sharing of valence electrons which enables reactants to collide to form products
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In a solution, the the solvent is usually what?
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Water
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In a solution, the water ___ the solute?
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Dissolves
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What is hydrophilic?
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Substances that contain polar covalent bonds and dissolve in water.
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What is hydrophobic?
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Substances which contain non-polar covalent bonds
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What property of water is due to the large number of hydrogen ions in water?
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waters high heat capacity, it can absorb or release relatively large amounts of heat with only a modest change of its own temperature
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What is a mixture?
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A combination of elements or compound that are physically blended together but not chemically
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What is a solution?
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a substance called the solvent dissolves another substance called the solute, usually there is more solvent than solute in a solution
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What is a colloid?
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differs from a solution because the particles are big enough to scatter light (similar to fruit in jello)
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What is suspension?
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The suspended material may mix with the medium for sometime but will eventually settle out
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What is concentration?
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the amount of a certain molecule in a solution
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In a concentration gradient, the more substrates the more ability to produce?
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a product
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What does the PH scale go to?
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0-14
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A pH of 7 is?
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Neutral
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A ph less than 7 is?
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Acidic
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A ph greater than 7 is?
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Basic (alkaline)
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What determines whether a solution is acid or basic?
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the number of (H+) and (OH-)
Hydrogens and free hydroxyls
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A strong acid (SA) + a weak base (WB) equals?
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Weak acid plus salt
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A strong base + a weak acid equals?
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Weak base + salt
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A SA + SB equals?
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water and salt
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What is a buffer system?
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maintain the pH values of different parts of the body, usually consist of a weak acid and a weak base, and convert strong acids or bases into weak acids or bases
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What functional groups can attach to a carbon skeleton?
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esters, amino, carboxyl, phosphate groups:
Very large molecules are called macromolecules (or polymers is the monomer subunits are similar )
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What is an isomer?
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have the same molecular formulas but different structures (glucose and fructose are both C6H12O6
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What are carbohydrates?
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Provide most of the energy needed for life and include sugars, starches, glycogen and cellulose
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What is glycogen?
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the storage of glucose
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What is one form of carbohydrate that humans cannot digest?
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cellulose
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What are the 3 main groups carbohydrates are divided into based on they size?
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Monosaccharides
Disaccharides
Polysaccharides
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What are saccharides?
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Sugars, organic compounds ending in "ose".
Sugars are made up of the elements C, H and O.
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What is the ratio of H to O in sugars?
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2:01
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What is a monosaccharide?
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A single sugar molecule or simple sugar. include glucose and fructose
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What is a disaccharide?
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A double sugar, two simple sugars.
include lactose, sucrose (table sugar), and maltose
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What is a polysaccharide?
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many simple sugar molecules joined together.
Glycogen, starches, cellulose
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What is another name for complex sugars and starches?
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Carbohydrate
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What is dehydration synthesis?
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the formation of large molecules from small ones by removing a water molecule
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Deoxyribose are found in what?
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DNA and are a pentose sugar
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What are two pentose sugars?
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Deoxyribose and ribose
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Disaccharides is combing?
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two monosaccharides by dehydration synthesis releases a molecule
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Sucrose is made of?
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Glucose a fructose
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Maltose is made of?
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glucose and glucose
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Lactose is made of?
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glucose and galactose
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What is the principle polysaccharide in the body?
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glycogen, it is stored in the liver or skeletal muscles. When blood sugar drops, the liver hydrolyzes glycogen to yield glucose which is reassessed from the liver into the blood
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What are lipids?
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Organic compounds composed of C, H and O.
fats, oils, waxes, cholesterols
The ratio of H to O is greater than 2:1
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What is the most abundant lipid in the body?
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Triglyceride, composed of one glycerol and three fatty acids
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More complex lipids are formed by?
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Dehydration synthesis
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Complex lipids are broken down by what?
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Hydrolysis
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Lipids have few..?
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Polar covalent bond, they are hydrophobic and mostly insoluble in polar solvents such as water
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Lipids combine with what to transport in blood?
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Proteins
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What are phospholipids?
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important membrane components, they are amphipathic with both polar and non polar regions
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The head of a phospholipid is?
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Polar and hydrophilic
forms hydrogen bonds with water
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The two non polar fatty acid tails of a phospholipid are?
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Hydrophobic and only interact with lipids
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Steroids include?
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Sex hormones, bile slats, some vitamins,
cholesterol
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What is cholesterol?
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important component of cell membranes and starting material for synthesizing other steroids
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Vitamins that are water soluble can?
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Require effort to go through the cell membrane
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Fat soluble vitamins can?
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Go straight through the cell membrane and too many can kill you.
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Too many of what type of vitamins can kill you?
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Fat soluble (A, D, E, K)
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What is a protein?
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organic compounds made up of polymers and amino acids
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What is an amino acid?
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The basic building blocks of protein: contain a central carbon with an amino group, an R group and a single group hydrogen. composed of C, O, H, N
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What is a peptide bond?
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the bind joining the carboxyl of one amino with the amino acid group of the next amino acid
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What is a polypeptide?
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many amino acids joined together by peptide bonds
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How are proteins assembled?
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By combining amino acid monomers into peptide polymers via dehydration synthesis
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How is a protein disassembled?
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by breaking the peptide bonds between amino acids in hydrolysis.
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What is a dipeptide?
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formed from 2 amino acids joined by a covalent bond called a peptide bond, formed through dehydration synthesis. (removal of a water molecule)
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A polypeptide chain contains how many amino acids?
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Oct-00
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What is the simplest amino acid?
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Glycine
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What are the levels of protein structural organization?
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Primary
Secondary
tertiary
quaternary
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A primary structure looks similar to a?
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Train
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A secondary structure is either..?
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A helix or a pleated sheet, hydrogen bonds determine the shape.
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The shape of a protein greatly influences what?
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its ability to recognize an bind to other molecules
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What is denaturation of a protein?
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Causes the protein to loose its characteristics of shape and function.
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Hemoglobin is an example of what protein structure?
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Quaternary
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What is an enzyme?
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Catalysts in living cells. enzymes are highly specific in terms of the substrate in which they react.
Enzymes speed up chemical reactions by increasing the frequency of collisions and lowering the activation energy and properly orient the colliding molecules.
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If to much heat it added to an enzyme what can happen?
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The heat can change the confirmation and the product can't be produced
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What are the steps of chemical reaction?
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Substrate bind the active part of the enzyme, aided by enzyme, substrates interact to form product, product detaches from enzyme, and process can now be repeated
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What is another name for catalyst?
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Vitamin
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What are nucleic acids?
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huge organic molecules that contain C, H, N, O, P
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What is a deoxyribonucleic acid?
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DNA, forms the genetic code inside each cell and thereby regulates most of the activities that take place in our cells throughout our lifetime
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What is ribonucleic acid?
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Relays instructions from genes in the cell's nucleus to guide each cells assembly of amino acids into proteins by the ribosome
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What are nucleotides?
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The basic units of nucleic acids, composed of a nitrogenous base, a pentose sugar, and a phosphate group
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What is in a purine?
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A and G * think of pure silver AG
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What is in pyrimidines ?
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T, C, U. Think of how tcu is the top of the pyramid.
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What does "ase" mean when replicating DNA?
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Catabolise
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What is the structure of DNA?
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A double helix held together by hydrogen bonds
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How does RNA differ from DNA?
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They are single stranded, ribose sugar replaces deoxyribes sugar and has uracils
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What is ATP?
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Temporary molecular storage of energy as it is being transferred from exergonic catabolic reactions to cellular activities
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What is hydrolysis of ATP?
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is the removal of terminal phosphate group by enzyme -- ATPase. Releases energy and leaves ADP
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What is the synthesis of ATP?
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Enzyme ATP synthase catalyzes the addition of the terminal phosphate group ADP
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BIOL 2457:ChapterOne Review