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biochemistry
the study of the chemistry of life
looks at all chemical processes/reactions in a living organism
ammonium ion and amine group
ion= -NH3+
group= -NH2
hydroxyl group
-OH
Carboxyl group, carboxylate ion, carboxylic acid
carboxyl= -COOH
carboxylic ion= -COO-

carbonyl group
C double bonded to O

Amide
amine connected to a carbonyl group

thiol, sulfide, disulfide
thiol= -SH
sulfide= -S-
disulfide= -S-S-
enzymes
catalyze biochemical reactions
called biological catalyst
hormones
messengers that regulate bodily functions
storage protein
stores essential substances for immediate availability
transport proteins
carry substances through blood and cell membranes
structural proteins
support and maintain shape of the cell
protective proteins
provide defense against invaders, protect from injury
contractile proteins
do mechanical work
(like muscle actin and myosin)
amino acid
-protein building block
-20 different kinds, 9 essential
-amine group, carboxylic acid group, alpha carbon, and side chain

constitutional isomer
isomers that differ from bonding order of atoms
stereoisomer
isomer with same order but different arrangements
enantiomers
mirror images of each other
would fold on top of one another

diastereoisomers
not mirror images
only small part/element is mirrored, rest are not

amino acid is classified by the properties of the….
side chain
non polar
-alkane and arene side chain→ AA as side chain
-hydrophobic, van der Waals interaction
MAPPLIG TV
Methionine, Alanine, Phenylalanine, Proline, Leucine, Isoleucine, Glycine, Tryptophan, Valine
!WATCH! tryptophan is non polar but has NH

neutral polar
-hydroxyl, thiol, or amide group side chain → HAT side chain
-hydrophillic, H-bonding
C STYNQ (see stink) with proper letters
STAT CG with actual starting letters
Cysteine, Serine, Threonine, Tyrosine (Y), Asparagine(N), Glutamine(Q)

acidic
-carboxylic acid group as side chain AC acidic=carboxylic
-NEGATIVE charge
-hydrophilic
-electrostatic (ionic), and hydrogen bonds
AGA
Acidic= Glutamate and Aspartate

basic
-amine group as side chain. BA basic=amine
-POSITIVE charge
-hydrophilic
-electrostatic (ionic), and hydrogen bonds
BLAH
Basic= Lysine, Arginine, Histidine

zwitterion
-(amine)positive and (carboxylic acid)negative charge DIPOLAR
-all amino acids are zwitterionic at pH~7
-pH less than 2→ fully protonated, positive
-pH greater than 9→ deprotonated, negative
peptide bond
two amino acids are covalently linked together by an peptide/amide bond to form a dipeptide
basically the bond between two amino acids

shape determining interactions
-covalent bonds→ IM bonds, amino acids, peptides, disulfides
-electrostatic interactions(salt bridges)→ ionic bond btwn acidic and basic side chain, btwn amino and carboxyl termini
-H bonds→ btwn donors and acceptors
-van der Waals forces→ btwn all atoms
hydrophobic effect
hydrophobic groups cause the protein to fold so they are on the inside away from the water
structural amino acids
cysteine→ thiol groups form disulfide bonds in extracellular proteins
glycine→ flexible, no organic side chain
proline→ secondary amine forms tertiary amide upon formation of peptide bond
primary structure
-protein sequence
-IM covalent bonds btwn atoms of amino acids through peptide and disulfide bonds

secondary structure
-a helix and B sheet
-noncovalent interactions where h-bonds occur btwn backbone peptide/amide groups

tertiary structure
-1 folded protein chain
-folding due to hydrophobic effect
-R group/side chain interactions
-covalent forces stabilizing protein sequence(primary structure)
-electrostatic interactions/ salt bridges
-H bonds
-Van der Waals forces
disulfide bonds form covalent bonds that stabilizes protein structure once it is folded into a tertiary structure

quaternary structure
-multiple folded protein chains
-hydrophobic effect
-electrostatic interactions
-H bonds
-Van der Waals
-can have disulfide bonds if structure is outside of the cell like blood or hair because it is an oxidizing environment (ex: hair, nails, teeth
L-chirality
Amine group on left side
amino acid type of chirality
L-chirality
L amino acids are found in nature
D-chirality
Amine on right side
alpha helix
stabilized by amide groups
L-chirality of aa produces right hander alpha helix
peptide bonds form btwn adjacent residues
H-bonds from btwn amide groups 4 residues away
helical secondary structures are stabilized by H-bonds forming btwn peptide bonds
B-pleated
stabilized by amide groups
made of B strands
form peptide bonds btwn adjacent residues and H bond btwn amide groups on adjacent strands
globular
forms globe like structure, typically water soluble as hydrophilic residues are on the surface
ex: enzymes
fibrous
forms fibers or sheets, insoluble containing small hydrophobic residues that pack tightly together in layers
glycoproteins
-covalently bound to carbohydrates
-form receptors on cell surface
lipoproteins
-covalently bound to lipids
-transport cholesterol through the blood
metalloproteins
metal ions for structure stabilization or catalytic function
phosphoproteins
-covalently bound to phosphate groups
-used to deactivate or activate a protein
-provide binding sites for protein attachment
hemoproteins
-contain heme groups or porphyrin rings
-oxygen transporters, drug metabolizing enzymes, E producing enzymes
nucleoproteins
-contain ribonucleic acids
-ribosomes used in protein synthesis
myoglobin
-found in the muscle
transports oxygen
-tertiary structure
-has higher affinity for oxygen than hemoglobin
(to remember think how many letters before “global” myo=3 so tertiary)
hemoglobin
-found in RBC
-transports oxygen
-quaternary structure
(to remember think how many letters before “global” hemo=4 so quaternary)
sickle cell anemia
-acidic residue is changed to a hydrophobic residue
-residue # 6 changes from glutamate to valine
-sickled RBC only last 10-20 days vs normal 90-120 days so there is lack go hemoglobin to carry oxygen
electrophoresis helps with determining what regarding proteins
protein charge and size(molecular weight)
collagen
-tropocollagen (3 strands)
-quaternary structure stabilized by H-bonds
in amino acid
-every 3rd residue is glycine (interior coil is all glycine for close packing of strands)
-predominant residues are proline and hydroxylated proline
in connective tissue
-covalent disulfide bonds occur btwn strands
bones and teeth
-Ca5(PO4)3OH calcium hydroxyapatite deposit in gaps
collagen related diseases
Scurvy
-vitamin C deficiency
-vitamin C is needed to created hydroxylated proline
-curable with diet
-symptoms: skin lesions, bruising, joint pain, swelling, gum or nasal bleed
Brittle bone disease:
-Type 1: normal collagen, insufficient amounts (bone fractures, brittle teeth, loose joints)
-Type 2: poor amounts and quality of collagen (fracture before birth, severe respiratory problems)
a and B keratin=fibrous protein in hair which is stabilized by what bond
disulfide bonds
chaperones
proteins and protein complexes that assist in folding of other proteins and protein assemblies; keeps proteins from forming nonfunctional units
prions
-proteins in the CNS→ brain
-Converts a helices to B sheets
-infections agents because they induce other normally folded prions to change shape
-converted proteins then also become infectious agents
transmissible spongiform encephalopathies(TSEs)
-result of prion malformation
-rare degenerative brain disorder
-brain has spongy appearance bc of tiny holes
-rapidly progressive, always fatal
-cant sterilize materials to prevent transmission of TSEs
-can be transmitted through infected tissue, bodily fluids, or medical instruments.
protein degradation/digestion/proteolysis
cellular process that breaks down unneeded, damaged, or short lived proteins into peptides and amino acids for recycling
autophagy
-self eating
-important for balancing sources of energy in critical times in development and response to nutrient stress
-housekeeper that removes misfiled or aggregated proteins, clear damaged organelles, eliminate intracellular pathogens
lysosomes
-recycle center
-degrades unwanted/unneeded material within cell and release nutrients
proteosomes
degrade unfolded or unneeded protein by proteolysis
protein denaturation methods
-heat→ disrupts non-covalent interactions
-mechanical agitation→ foam/air bubbles cause lack of water
-detergents→ can interact with hydrophobic sidechains and unfold the protein
-organic compounds→ polar solvents can disrupt H-bonds
-pH change→ basic and acidic side chains change charge disrupting salt bridges
-inorganic salts→ at high concentrations and disrupt salt bridges
denaturation: heat
disrupts non-covalent interactions
basic and acidic side chains change charge disrupting salt bridges
denaturation: mechanical agitation
foam/air bubbles cause lack of water
denaturation: detergents
can interact with hydrophobic sidechains and unfold the protein
denaturation: organic compounds
polar solvents can disrupt H-bonds
denaturation: pH change
disrupts non-covalent interactionsbasic and acidic side chains change charge disrupting salt bridges
denaturation: inorganic salts
at high concentrations and disrupt salt bridges
enzyme
biological catalyst(protein or RNA)
enzyme ends in ‘-ase”
substrate
reactant of an enzyme catalyzed reaction
turnover number
the number of substrate molecules converted to product in a given time period
cofactor
nonprotein substance that binds to protein and is needed for catalysis to happen (usually trace metals)
coenzyme
organic cofactor usually used in redox enzymes
apoenzyme
enzyme without the cofactor/enzyme
holoenzyme
enzyme with the cofactor/enzyme
catalytically active
active site
site where substrate binds and where catalysis takes place
proximity effect
brings reactants together
orientation effect
holds the reactions at required distance and orientation for the reaction
energy effect
lowers activation energy by putting a strain on the substrate bonds
catalytic effect
provides acidic, basic, and other types of functional groups that are required for catalysis
oxidoreductases
catalyze redox reactions
need coenzyme
transferases
transfer functional group (amino or phosphoryl) btwn substrates
hydrolases
catalyze hydrolysis of substrates
isomerases
catalyze isomerization of substrates (bond rearrangement)
lyases
catalyze elimination of functional groups by adding or removing double bond
ligases
catalyze bond formation coupling with ATP hydrolysis
subclass of oxidoreductases
dehydrogenases→ remove 2 H from substrate to form double bond (need FAD or NAD coenzyme)
(OD)
subclasses of transferases
kinase→ transfer phosphoryl group btwn substrates
transaminase→ transfer amino group btwn substrates
subclasses of hydrolase
lipases→ hydrolyze ester bonds in lipids
proteases→ hydrolyze peptide bonds in backbone amides
nucleases→ hydrolyze phosphate ester bonds in DNA/RNA
amylases→ hydrolyze 1,4 glycosidic bonds in amylose
(LANP)
subclasses of ligases
syntheses→ bond two substrate molecules together
carboxylase→ add CO2 to form carboxylate group
competitive inhibition
inhibitor resembles substrate and competes for same binding site on enzyme
noncompetitive inhibition
inhibitor does not resemble substrate and bind on separate site causing change in active site configuration thus preventing substrate from binding
uncompetitive inhibition
inhibitor does not resemble substrate and binds to enzyme-substrate complex (after substrate binds) to prevent enzyme from working
irreversible inhibition
covalent modification of enzyme, making it inactive
allosteric regulation
active site is changed by binding of molecule at allosteric site
positive→ binding makes active site more fit for substrate
negative→ binding makes active site change so substrate can’t fit
feedback control
product in metabolic pathway is allosteric regulator of enzyme that catalyzes a critical step
positive→product enhances activity of first enzyme
negative→ product inhibits first enzyme to save E
covalent modification
addition of phosphate group to tyrosine, serine, or threonine triggers conformational change in enzyme structure that activates or deactivates the enzyme
zymogens
enzyme synthesized in inactive from. Long protein segment needs to be removed before enzyme is active
genetic control
gene for enzyme is turned on or off to regulate amount of enzyme available in cell
water soluble vitamins
-hydrophilic
-have OH and COOH groups
-not stored in body
-form coenzymes
Vitamins C, B1, B2, B3, B5, B6, B7, B9, B12
fat soluble vitamins
-hydrophobic
-C and H atoms
-stored in liver
Vitamins D, E, A, K