CH 2 Flashcards - EXAM 1.txt

• basic unit of all matter
• made of protons, neutrons and electrons

number of protons (or # of electrons if atom is neutral)

# of protons plus # of neutrons

• 1st inner orbital holds 2 electrons (lowest energy)
• 2nd and 3rd outer orbitals hold 8 electrons each (the farther out, the HIGHER energy)

• # of electrons that are required to complete the outermost shell
• ie: carbon, has a valency of 4...so needs 4 electrons to fill the 2nd shell & get 8 total in that shell

Hydrogen bonds produces a polar molecule�so can DISSOLVE compounds. It makes up about 70% of organisms by weight. Acidity is based on ionization of water to H+ (acid) and OH- (base), so when equal, pH is neutral.

Hydrogen bonds produces a polar molecule�so can DISSOLVE compounds.

• STRONGEST of bonds. Involves sharing of electrons between atoms. These are difficult to break. They can be polar or non-polar.
• Non-polar involves no charge, atoms with similar electronegativies
• Polar has a slight charge, ie: O-H, with oxygen having the higher electronegativity it is slightly negative, and H is slightly positive.

• Formed by an atom GAINING or LOSING electrons
• Ie: NaCl, where Na gives up its electron to Cl. So it�s Na+ and Cl-

• WEAKEST of the three bonds. Formed from attraction of positively charged hydrogen (H) atom. This can be with Nitrogen or Oxygen commonly.
• Hydrogen bonds occur in molecules such as water, or in DNA between molecules (C & G and A & T creating double helix)

• very large molecules. All macromolecules are polymers and when they join, water is lost, so the reaction is a dehydration synthesis
• divided into 4 classes
• 1. proteins
• 2. polysacchardies (carbs)
• 3. lipids
• 4. nucleic acids

occurs when water is lost due to polymers joining together to form macromolecules

happens when macromolecules breakdown into smaller subunits, and water is added

• Functional parts of the cell
• Function depends on the SHAPE of the protein
• 50% of cell dry weight
• made of AMINO ACIDS (AA's)

• peptide bonds: occur between an amino group (-) and the carboxyl group (+) of AA's.
• the peptide bond formation is a dehydration synthesis reaction
• 2 AA's = dipeptide
• >2 AA's = polypeptide
• 3 AA's = tripeptide

A protein is a polymer, and an Amino Acid is a monomer

• enzymes that catalyze reactions
• aid in shaping of certain BACTERIAL structures
• involved in GENE regulation
• nutrient procurement (takes nutrients)

• primary: made of peptide bonds
• secondary: hydrogen bonds
• tertiary: hydrogen bonds plus Ionic bonds b/w side chains
• quaternary: same as tertiary

• contain Carbon, hydrogen and Oxygen
• 1:2:1 ratio
• polysaccharides: large molecules made of carbohydrates
• oligosaccharide: short chain of carbohydrates
• monosaccharide: 1 carbohydrates

• classified by number of carbons present in the carbohydrate
• ie: five carbon sugars = pentose (ribose & deoxyribose)
• ie: six carbon sugars = hexose (glucose, fructose, galactose)

• 2 monosacchardies joining thru dehydration synthesis
• ie: glucose + galactose = lactose
• ie: glucose + fructose = sucrose
• ie: glucose + glucose = maltose

• cellulose most abundant, STRUCTURAL component of cell wall formed by many glucose molecules together
• glycogen is carbohydrate STORAGE molecule
• Dextran STORES carbon & energy for bac

• FXN: Determine specific properties of the cell
• 2 types: RNA and DNA
• subunits are nucleotides

• composed of 3 units
• 1. nitrogenous base (C,G,A or T..or U)
• 2. phosphate group
• 3. 5 carbon sugar (deoxyribose..ribose)

• Nucleotides joined by covalent bonds: b/w phosphate of one nucleotide and teh sugar of the other.. 5' to 3' direction
• carbon 5 of phosphate is attached to carbon 3 of sugar

• hydrogen bonds connect the two strands to make dsDNA
• A2T, C3G
• PURE As Gold (A & G are purines)

• same as DNA, but..
• thymine replaced by uracil
• sugar is ribose vs. deoxyribose
• exists as SINGLE strand

• SMALLEST of the 4 macromolecules
• insoluble in H20
• 2 classes: simple and compound lipids

• Contain ONLY C, H & O
• ie: Fats, made of glycerol and Fatty acids
• glycerol has OH groups which allow for binding of 3 fatty acids (triglyeride)
• ie: steroids

• contain fatty acid, glycerol & OTHER ELEMENTS
• ie: phospholipid

• Major component in lipid CELL MEMBRANE
• made of phosphate & 2 Fatty acids attached to a glycerol
• phosphate is polar & soluble in water, fatty acids non polar & hydrophobic

have all SINGLE bonds in fatty acid chain