Flashcards in Lecture 2 Deck (77):
smallest unit of matter which can partake in chemical reaction. composed of one type of atom
formed when 2 or more atoms join together (h2o)
Every atom is composed of..
a single centrally located nucleus which contains protons (+) and neutrons
Since neutrons don't have any charge the nucleus with always carry..
net positive charge
Nuclear contents do not participate in chemical reactions thus referred to as..
exist outside of the nucleus in specialized regions of space called orbitals, carry (-) charge
Weaker bonds are ____ reactions
When chemically stable..
no longer reactive
When atom loses an electron ..
will have net + charge
When atom gains an electron ..
will have net - charge
Either too difficult or easy to fill outer shell so it becomes...
When an atom has an overall - or + charge its no longer neutral and is referred to as..
_____ of electrons is strongest chemical bond
Atoms achieve a full complement of electrons (8) by..
combining to form molecules
3 kinds of chemical bonds for in living organism
covalent, ionic, hydrogen
very strong, formed when 2 atoms come together and share electrons within their outer shell (ex: h2o)
form as a result of the attractive force in between ions of opposite charge, weaker than covalent bonds (ex: NaCl)
form when hydrogen is covalently bound to oxygen or another electron loving molecule (nitrogen), weakest bond
Since atom bound to hydrogen is "electron loving" ..
it holds the shared electrons closer to its nucleus than hydrogen
Non polar covalent bond
electrons are equally shared in between the two atoms (H and C)
Polar covalent bond
electrons are not equally shared in between the 2 atoms and are held more closely to the oxygen nucleus
What type of charge is on the hydrogen atom in a hydrogen bond
partial postive charge
What type of charge is on the electron loving atom in a hydrogen bond
partial negative charge
The partial charge on the hydrogen atom is attracted to..
partial negative charge on atoms within OTHER molecules
In hydrogen bond, more cold = ___ while more heat = ____
more bonds; less bonds
Max of H bonds for water molecule
Organic compounds are compounds that contain..
Inorganic compounds are compounds that do not contain..
carbon (ex: h2o)
Water accounts for _% of cell weight
Why water is a polar solvent
dissolves materials, and the electrons aren't shared equally between H and O
Living things are able to make such a good use of water because..
-water us excellent solvent
-every water molecule can form 4 H bonds w/ other water molecules
-water is great temp buffer because of its strong H bonds
-water is easily split into its component ion H and OH
Water can dissolve
ionic compounds while the ions remain dissolved in water and form solution
Why does the water ion solution form
partial + regions w/ in the water molecules surround the - ions and partial - regions w/ in the water molecules surround the + ions holding them in solution
Hydrogen bond allows water to form..
networks of interconnected water molecules which gives water a very high boiling point
Waters boiling point
100 degrees celcius
How does waters high boiling point benefit it
keeps water in its liquid state in most places that its found on Earth
Water being easily split into its component ions allows..
it to play key roles in many chemical reactions, break up to an acid and base
The 4 outer electrons of carbon allow it to..
form 4 covalent bonds with a large number of diff atoms
4 major classes of organic compounds found in living things
energy source that is immediately utilizable by cells, polar compounds that dissolve in water
3 major groups of carbohydrates
one sugar (glucose, fructose)
formed from two monosaccharides coming together (sucrose)
formed by hundreds of monosaccharides coming together
often too large to be water soluble
Group of lipids includes..
fats, complex lipids (phospholipids) and steroids
Lipids are essential to the ________ __ ______ of membranes
stucture and function
Lipids are polar or non polar?? and used as..
non polar therefore don't interact w/ water (hydrophobic) and used as means of NRG storage
Fats composed of..
glycerol molecule plus 1-3 fatty acids (FA)
glycerol plus 1 FA
glycerol plus 2 FA
glycerol plus 3 FA
Fatty acid can either be..
saturated or unsaturated
no double bonds, saturated with hydrogen atoms
has at least one double bond, fewer hydrogen atoms
complex lipids, include glycerol, 2 FA and phosphate group
Phospholipids are found in..
membranes of living cells, primary component of prokaryotic and eukaryotic plasma membranes
have 4 ring structure, distinct from other lipids, mostly foamed in eukaryotes
Examples of steroids
cholesterol and vitamin D
Proteins are composed of ..
individual units called amino acids
How many amino acids do we know
All amino acids (proteins) are composed of..
carbon, oxygen, hydrogen, and nitrogen (some have sulfur)
Each amino acid has... which is different on each amino acid
-amino group (NH2+)
-carboxyl group (COOH-)
-sode group (-R)
-R side group of amino acids determines..
the chemical properties of the amino acid
Individual amino acids are joined together by..
peptide bonds which are covalent bonds
Short chains of amino acids are called..
Long chains of amino acids are called..
Specific amino acid sequence is important in determining ..
shape of the protein
2 ways proteins are required in cells
-structural component (membrane channels)
increase rate of chemical reactions which occurs within the cell
3 components of nucleotide
2 types of nitrogenous bases
contain 2 rings, adenine and guanine
contain 1 ring, cytosine, thymine, and uracil
5 carbon sugar, either ribose or deoxyribose
attached to nucleotide and serves as site of attachment for next nucleotide, - charge