Ch 2 Flashcards
Protons
determine the element (atomic number)
Neutrons
determine the isotope
Protons + neutrons in nucleus = _______
atomic mass
Electrons
- form covalent bonds
- gained or lost create ions
- capture and store energy
- create free radicals
Free Radicals
(unpaired electrons): want to bind to something, can attack proteins etc
Molecules
2 or more atoms sharing electrons
Covalent Bonds
- Share a pair of electrons in outer shell; require LOTS of energy to break
- Single, double, and triple bonds (more bonds = stronger)
- Polar (positive and negative end, water soluble, charge unevenly distributed) VS nonpolar (no region of charge, not water soluble) molecules
Ionic Bonds
- Atoms gain or lose electrons
- Opposite charges attract
Hydrogen Bonds
- Weak and partial
- Water surface tension
Van der Waals forces
Weak and nonspecific
Aqueous
water based
Solution
solute dissolved in solvent (ex. sweet tea: solute (sugar) + solvent (tea))
Solubility
ease of dissolving (how readily we can dissolve the solute into the solvent)
Hydrophilic
likes to dissolve in water, high solubility
Hydrophobic
doesn’t like to dissolve in water, low solubility (ex. oil in water)
pH
Measure of the concentration of free H+
-very narrow window in which we need to function properly
Acid
Contributes to H+ solution –> can add H to the solution, lower pH
Buffer
moderates changes in pH
ex. in blood plasma, pH is stabilized by bicarbonate (HCO3-)
Carbohydrates
- Most abundant biomolecule; carbon + water
- (CH2O)n or CnH2nOn
- Monosaccharides
- Disaccharides
- Polysaccharides
Polysaccharides
important because they give structural components, big players in cellular recognition *FUEL SOURCE
Lipids
- Carbon and Hydrogen (NO water)
- Backbone of glycerol and 1-3 fatty acids
- Nonpolar (charge is equally distributed across chain, not easily solulize in water)
- Fats (animal, solid at room temperature)
- Oil (plant, liquid at room temperature)
- Saturation refers to double bonds
Saturated VS Unsaturated Fats
Saturated: no double-bonds, equally bound between C and H, NO more room for H
Unsaturated: had room to bind more H, double-bonds between C
Triglycerides
- glycerol backbone
- lose water and attach to fatty acids
- three open spots to conjugate w/fatty acids
Lipid-Related Molecules
- not just fat, have other purposes
- don’t worry about structure, important for regulating cell function/signaling processes
1. Eicosanoids
2. Steroids
3. Phospholipids
Phospholipids
non-polar fatty acids —> now part of larger polar molecule
Proteins (Amino Acids)
- Enzymes
- Membrane transporters
- Signal molecules
- Receptors
- Binding proteins
- Immunoglobulins
- Regulatory proteins
Peptide Bond
- hydroxyl end
- carboxyl end
- R: where proteins vary
Protein Structure
- primary structure
- secondary structures (helix or pleated sheet)
- tertiary structure (folding back on itself to make intricate shapes)
- quaternary structure (two different peptide chains come together to make a structure)
- -> complex structure = complex function
What types of bonds do proteins use?
ALL
- ionic
- hydrogen
- covalent
- van der waals forces
Nucleic Acids
= Genetic Code
- conserve structure
- important for genetic code (DNA: chain of nucleic acids)
- -> DNA = linking all together, “polysaccharide form of nucleic acid”
- important for cellular energy (ATP: energy= cleaning off one bond off of ATP)
DNA vs. RNA
DNA: deoxyribose/thymine
RNA: ribose/uracil
Alpha-helix structure
sugar phosphate backbone complementary base pairing sugar phosphate backbone
*hydrogen bonds
