Structure of fatty acids and how energy is released from them
long chains of carbons truncated at one end by a carboxylic acid (COOH)
-energy liberated through oxidation of fatty acids->released large amounts of chemical energy for a cell
Structure of triglycerides and include examples + function
3-Carbon backbone called glycerol, which is attached to 3 fatty acids
(fats and oils)
function: thermal insulation and padding
Structure of adipocytes
also called fat cells, are specialized cells whose cytoplasm contains almost nothing but triglycerides
Structure of steroids and include example
include some hormones, vitamin D, and cholesterol, an imp. membrane component
Function of eicosanoids
(20 C lipid) includes prostaglandis, thromboxanes, and leukotrienes.
They are released from cell membranes as local hormones regulating blood pressure, body temp., and smooth muscle contraction (among other funxs)
Aspirin is commonly used inhibitor of prostaglandis
Major function of phospholipids ***
serve as a structural component of membranes
Major function of triglycerols ***
store metabolic energy, provide thermal insulation, and padding
Major function of steroids ***
regulate metabolic activities
Major function of some fatty acids (eicosanoids ***
serve as local hormones
Amino Acids in solution ______ one or more charges. What does this depend on?
position and nature of the charge depend on the pH of solution
What are proteins comprised of? and commonly reffered to as?
chain of AA by polypeptide bonds
How many AA are essential? What does this mean?
10, they aren't manufactured by the body
**Primary structure of a protein
sequence of AA in a polypeptide
**secondary structure of proteins
(conformation of protein) alpha helix and beta pleated sheet reinforced by H-bonds b/w carbonyl oxygen and H on amino group
**tertiary structure of proteins
(twisted polypep, pretzel shape) 3-d shape formed when peptide chain curls and folds created by 5 forces:
1) disulfide bonds
2)electrostatic (ionic) interaction mostly b/w acidic and basic chains
3) H bonds
4) van der waals
5) hydrophobic side chains pushed away from water (twd center of protein)
**quarternary structure of proteins
2 or more polypeptide chains bind together and same 5 forces as tertiary
lost most of its secondary, tertiary and quaternary structure
very often, when denaturing agent removed, protein spontaneously refolds to original structure
List 5 denaturing agents and forces disrupted
-Urea- H bonds
-Salt or change in pH- electrostatic
-mercaptoethanol- disulfide bonds
-organic solvents- hydrophobic
When you see nitrogen, what should you think of?
*Basic structure of Carbs
also called sugars or saccharides
most commonly occuring 6-C carb (80% for human carb consumption)
-essentially all digested carbs broken into glucose by liver or enterocytes
-it exists in (aq) solution in unequal equilibrium heavily favoring ring form (2 anomers)
-cell can oxidize glucose transferring its chem. energy to more readily usable form, ATP
branched glucose polymer with alpha linkages
*Humans eat which form of glucose? bacteria?
humans- alpha linkages
bacteria- beta linkages
(note: some animals can break b-linkages b/c of their gut bacteria)
What regulates blood sugar levels and how is it specialized?
liver. Liver cells are one of few cells capable of reforming glucose from glycogen and releasing it back into the blood stream
Where can glucose be absorbed against a conc. gradient?
certain epithelial tissues in digestive tract and proxiaml tubule of kidney
how: 2ndary active transport down conc. gradient of Na
*3 parts of nucletides
1) 5-C sugar
2) Nitrogenous base
3) phosphate group
In nucleic acids, how are nucleotides joined?
Name 4 imp. nucleotides and their respective funct.
1) ATP- readily available energy
2) cyclic amp- imp. component in many 2ndary messanger systems
3 & 4) NADH & FADH2 - coenzymes in Krebs cycle
Minerals and their function
dissolved inorganic compounds inside and outside the cell
-assist in tranpoting substance in and out of cell by creation of electrochemical gradients across membranes
they can combine and solidify to give strength to a matrix, such as hydroxyapatite in bond
also act as cofactors assiting enzyme or protein function
Function of enzymes
act as a catalyst, lowering Ae for a bio rxn and increasing the rate of rxn in BOTH directions
-act on substrates
-do NOT alter equilibrium
as relative conc. of substrate increases, rate of rxn increases but to a lesser & lesser degree until Vmax achieved.
Vmax is proportional to enzyme conc. as individual substrates must wait in line for an open substrate as more substrate is added
What effects enzymatic activity?
pH- they have an optimal pH
temp.- @ first increases then denatures if too far
conc.- increases with conc. to certain degree
required for enzymes to reach optimal activity
-non-protein compound...can be coenxzymes or metal ions
2 types of coenzyme
cosubstrates- reversibly bind to specific enzyme and transfer some chem. group to another substrate. It reverts to orginal form by another enzymatic rxn, which is what distinguishes it from normal substrates. ATP is an example
Prostheic group- remain covalently bound to enzyme throughout rxn
*Many coenzymes are often...
vitamins or their derivatives
*Cofactors are either....
minerals or coenzymes
*Discuss the graph of rxn rate vs. pH
*Discuss the graph of rxn rate vs. temperature
*Discuss the graph of rxn rate vs. substrate concentration
bind ccovalently to enzymes and disrupt their function. (a few bind nonconvalantly)
ex: penicillin which binds to bacterial enzyme that assists in the manufacturing of peptidoglycan cell walls
compete w/substrate, bind reversibly & noncovalantly to active site.
Classic indication: overcoming inhibition by increasing substrate concentration..indicative of CI
-they often resemble substrate
-Vmax same, Km lowered (where rxn rate = 1/2Vmax)
bind noncovalantly to an enzyme at a spot other than active site & change conformation of enzyme
-commonly act on more than 1 enzyme
-can NOT be overcome by substrate conc. increase
-do NOT lower enzymes affinity for substrate, thus Km remains the same
List the 4 primary means of enzyme regulation
1) proteolytic cleavage
2) Reverible covalent modification
3) Control proteins
irreverible covalent modification
-many enzymes are released in inactive form (zymogens or proenzymes) and when cleaved are irreversibly activated
Reversible covalent modification
some enzymes are activated or deactivated by phosphorylation or the additin of some other modifier such as AMP. Hydrolyis almost always can removed modifier. Phosphorylation almost almost occurs in presence of protein kinase
protein subunits that associate with certain enzymes to activate or inhibit their activity.
examples; G-protein or calmodulin
modification of enzyme config. resulting from the binding of an activator or inhibitor at a specific binding site on the enzyme
Allosteric regulation and include their inhibitors and activators
feedback inhibitor not resembling substrate their inhibiting but rather bind and cause conformational change
inhibitors & activators: not necessarily noncompetitive inhibitors b/c many alter Km and not Vmax.
-dont exibit typical kinetics b/c they normally have several binding sites for diff. inhibitors, activators, and even substrates
Positive cooperativity as related to allosteric regulation
phenomenon in which the first substrate changes the shape of an enzyme allowing other substrates to bind more easily
Negative cooperativity as related to allosteric regulation
cooperativity in the presence of the allosteric inhibitor 2,3 GPG that give the oxygen dissociation curve of hemoglobin its sigmoidal shape
*What is a protein that isn't an enzyme but exhibits several characteristics of enzyme regulation?
important: other proteins as well as enzymes undergo these regulations
Given a complicated question regarding complicated chemicals, what does the "ase" imply? and why is it important?
enzyme, so know it contains nitrogen and subject to denaturization
enzyme that phosphorylates somethings
enzyme which dephosphorylates something
What type of bonds do the following have (covalent or non):
-double bond of carbonyl
all covalent except H bond, a special dipole
net reaction of Glycolysis
Glucose + 2 ADP + 2Pi + 2 NAD+ -> 2 pyruvate + 2 ATP + 2 NADH