BIOLOGY 1 H FINAL EXAM Essay

BIOLOGY 1 H FINAL EXAM

Chemical Bonding
Elements combine to form compounds
Compound – a substance containing 2 or more elements in a fixed ratio
-Most common elements: C, H, O, N
Bonding
Ionic bonding – attractions between ions of opposite charge; includes the transfer of electrons
Ion – an atom or molecule with an electrical charge resulting from a gain or loss of 1 or more electrons
-cation – (+) charged ion
-anion – (-) charged ion
Covalent bond – bond in which 2 atoms share 1 or more pairs of outershell electrons
Forms a molecule – 2 or more atoms held together
Single bond – 1 pair of electrons being shared
Double bond – 2 pairs of electrons being shared
Triple bond – 3 pairs of electrons being shared
Nonpolar covalent bonds – equal sharing of electrons
Polar covalent bonds – unequal sharing of electrons
Caused by levels of electronegativity – the tendency for an atom to pull shared electrons towards itself more than its own electrons
Results in 1 side of the molecule being (-), and one (+)
Hydrogen bond – a weak bond between the negative side of one atom contained in a polar covalent bond and the positive side of another atom contained in a polar covalent bond
Weak because the (+) and (-) charges of each atom within the bond are not strong
Readily broken and formed
Weak individually but strong in a group
Properties of Water
Cohesion – tendency of hydrogen bonds to hold water molecules together
Hydrogen bonds give water high cohesion
Adhesion – attraction between two different substances
Hydrogen bonds give water high adhesion
Surface tension – a measure of how difficult it is to stretch or break the surface of a liquid
Hydrogen bonds give water high surface tension
Thermal buffer – water reduces the heating and cooling load on another space
Hydrogen bonds give water the ability to resist temperature change
Important to e life (i.e. our body temp. regulations)
Water can absorb heat energy without a change in temperature
Universal solvent – water can dissolve all or most substances
Solution – a liquid consisting of a uniform mixture of 2 or more substances
Solvent – dissolving agent
Solute- substance being dissolved
Aqueous solution – solution in which water is the solvent
Water’s polar molecules surround other polar molecules in a solution
Water does not mix with nonpolar substances
Capillary action – water’s tendency to use cohesive and adhesive forces to rise or fall in tubes
Molecules of Life
All living things are made up of 4 classes of large biological molecules:
Carbohydrates
Lipids
Proteins
Nucleic acids
Polymer – long molecule consisting of many similar building blocks (monomers)
3 classes of life’s organic molecules are polymers (carbohydrates, proteins, & nucleic acids)
Biological reactions within polymers
Dehydration (condensation) reaction
2 monomers bond together through the loss of a water molecule
Forms a longer polymer chain
Enzymes aid this reaction
Requires enzymes and E
Hydrolysis reaction
Breaking a polymer chain by adding a water molecule
Enzymes aid this reaction
Requires enzymes and E
Reactant – the starting material in a chemical reaction
Product – the ending material in a chemical reaction
ATP Energy – the energy currency of life
E required for a reaction to take place
Carbohydrates
Contain C, H, & O
Main functions: E source & structural purposes
Glucose
Major E source for most cells
Exist in different structural isomers
Difference in the position of the –OH group
Broken into three groups: monosaccharides, disaccharides, & polysaccharides
Mono-
Simplest carbohydrate
Contain one monomer
Primary E source utilized by the cell to carry out cellular functions
Di-
Constructed from two monosaccharides through a dehydration reaction
Primary E source utilized by the cell to carry out cellular functions
Poly-
Long chains of monosaccharides linked together by dehydration reactions
Ex. cellulose, chitin, starches
Difficult to break down; extremely fibrous
Main function is for structural purposes

Show More

Student and Mastering Biology Essay

Money: Biology and Biological Science Books Essays

What Molecule In The Body Stores The Most Energy

Essay on Federal Government of the United States and New York

study guide Essay

2014Sylabus 30651 3 Essay

Exam 3 Study Guide Essay

What Is The Physics Of Everyday Phenomena

Lecture 5 Essay

How To Do Almost Anything In EAP