Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key

image

Play button

image

Play button

image

Progress

1/165

Click to flip

165 Cards in this Set

  • Front
  • Back
  • 3rd side (hint)
which aa's have 4 enantiomers?
isoleucine
threonine
which aa is the simplest aa known?
glycine
how do aa's exist at pH 7.4?
dipolar zwitter ions
which aa is the hydroxylated form of alanine?
serine
where are hydrophilic aa's found?
on the surface of proteins
which aa is found in the bends of folded polypeptide chains?
proline
is arginine an aa that is hydrophobic or hydrophilic?
hydrophilic
which of the aa's has branched side chains?
leucine
isoleucine
valine
which are the aromatic aa's?
phenylalanine, tyrosine, tryptophan
what is the most abundant protein in the mammalian organism?
collagen
vitamin C is required in the formation of which aa?
hydroxyproline
which modified aa is a constituent of elastin?
isodesmosine
which modified aa is associated with blood coagulation?
gamma-carboxyglutamate
which aa is used in the hepatic conjugation of bile acide?
taurine
name an inhibitory NT in the brain
gamma-aminobutyrate and glycine
is alanine an essential aa in young cats?
no
which aa's are essential in cats?
methionine
phenylalanine
taurine
arginine
which aa's are routinely oxidized in muscle tissue?
branched chain aa's:
leucine
isoleucine
valine
do benzodiazepines (valium) act by blocking the action of GABA at post-synaptic receptor sites?
no
is the formation of highly organized amyloid aggregates a generic property of polypeptides?
yes, it may be
what directly influences the secondary, tertiary, and quaternary structure of proteins?
primary structure
how is the secondary structure of aa's held together?
H-bonds between carboxyl and amino groups of the peptide bond
are disulfide bonds part of the secondary structure of all mammalian proteins?
no
what is the tertiary structure of a protein?
the overall 3D arrangement of its polypeptide chain
how are alpha helixes stabilized?
H-bonding between amide H's and carbonyl O's of different peptide bonds
how are the beta pleated sheets stabilized?
H-bonding between separate chains that run either parallel or antiparallel to one another
What do chaperones do?
guide polypeptide chains to their tertiary structure while the primary sequence is being formed
what level of organization does protein denaturation affect?
affect all levels of protein structure
what do globular proteins look like
spherical and hydrophilic
what is joined in a peptide bond?
alpha carboxyl group of one aa and the alpha amino group of another aa
how many aa residues are there in the active form of insulin?
51
what are coenzymes?
small, organic, non-protein molecules that carry chemical groups between enzymes
what do phosphatases do?
remove phosphate groups from phosphorylated compounds
which enzyme is activated irreversibly?
pepsinogen
what is the characteristic enzymatic activity in the digestive lumen?
hydrolysis
how many different types of enzymes are normally present in a mammalian cell?
2000
what do hydrolases catalyze?
the cleavage of bonds between carbon and some other atom by the addition of water across the bond
what hormone acts by increasing enzyme synthesis in its target cells?
cortisol
what is urease?
an enzyme found in microbes of the rumen
what do synthases do?
stimulate synthesis without using ATP
which suffix refers to an enzuyme?
-ase
which is the variable that measures the affinity of an enxyme for its substrate?
Km (read K sub m)
what are temperature and pH known to affect?
Km and Vmax
what happens to the maximal velocity of an enzyme-catalyzed reaction in the presence of an irreversible inhibitor?
decreased in the presence of an irreversible inhibitor
which tissue type has the highest concentration of MB dimer for creatine phosphokinase?
heart
which therapeutic inhibitor is considered to be a suicide substrate?
aspirin
what is the y-intercept on a Lineweaver-Burk plot?
1/Vmax
what is the Mechaelis-Menten equation?
V=Vmax[S]/(Km+[S])
what are competitive inhibitors and what do they do?
structural analogues of the substrate; Vmax remains unchanged; can be used as therapeutics to control the activity of target enzymes; effects can be reversed by increasing the substrate concentration
which type of enzyme inhibitor is known to affect both Vmax and Km?
uncompetitive
which aa is needed for hepatic tyrosine biosynthesis?
phenylalanine
which aa is needed for cysteine formation
methionine
which aa is needed for serotonin and melatonin formation?
tryptophan
which amino acids are considered "essential" in adults?
leucine
isoleucine
valine
taurine (cats)
threonine
lysine
phenylalanine
tryptophan
methionine
li(v)ttlptm
which amino acids are considered "essential" in young animals?
histidine
arginine
glycine (chickens)
how do G-proteins work as control proteins?
the combination of G-prots with GTP activates them,
then adenylate cyclase is either activated or inhibited,
intracellular cAMP concentration changes
....................
calmodulin is activated after binding with 4 molecules of Ca++,
the activated protein then binds with intracellular enzymes and modifies their activities
what are 2 example of irreversible proteolytic enzymes found in the pancreas?
exopeptidases
endopeptidases
what is ALKALINE PHOSPHATASE?
enzyme that removes PO4 groups,
most active at alkaline pH
what are the most imporatant ALP serum sources?
liver (L-ALP) bile duct cells
bone (B-ALP) osteoblasts
leukocytes
dog liver (C-ALP)
what does an elevated ALP indicate?
L-ALP: bile duct damage
B-ALP: bone growth/fractures
Leuk-ALP: increase in all blood cell types, cancer
what does ASPARTATE AMINOTRANSFERASE do?

(AST)
transfers an amino group from aspartate->glutamate
oxaloacetate->a-ketogluterate
what are the primary sources for AST?
liver
skeletal/cardiac muscle
what does ALANINE AMINOTRANSFERASE do?

(ALT)
transfers an amino group from alanine->glutamate
pyruvate->a-ketogluterate
what are the primary sources for ALT?
liver
skeletal/cardiac muscle
what are the tetramer combinations of LACTATE DEHYDROGENASE?

(LDH)
HHHH
HHHL
HHLL
LLLL
LLLL
what does LDH do?
involved with conversion of pyrvate to lactate and vice versa along with the conversion of NADH to NAD+
what can LDH tell you?
if a cardiac event has taken place
what does GAMMA GLUTAMYL TRANSFERASE do?

(GGT)
involved in transport of aa's into cells
where is GGT found?
biliary epithelial cells
pancreas
renal tubular cells
mammary glands (some species)
what does elevated serum GGT indicate?
choleostasis, escessive bile back-up (esp in horses)
what does high urine GGT indicate?
injury to renal epithelial cells
what is the function of CREATINE KINASE?

(CK)
energy vault
creatine phosphate + ADP <-> creatine + ATP
CK1-brain (CSF)
CK2-cardiac musc
CK4-skeletal muscle
CK4-mitochondria
what does an elevated serum CK3 indicate?
injury to skeletal muscle, muscular dystrophy, myopathy, rhabdomyolysis
what does SORBITOL DEHYDROGENASE do?

(SDH)
sorbitol + NAD+ <-> fructose + NADH
it is a cytoplasmic protein
what does an elevated SDH indicate?
liver damage
-especially helpful in LA where ALT is not informative
what do AMYLASES do?

(AMS)
break down starches into smaller polysaccharides
what are the primary sources of AMS?
pancreas
liver
salivary glands (not in Ar or Ca)
what does elevated AMS indicate?
pancreatic disease
pancreatitis

check LPS and TLE
what does LIPASE do?

(LPS)
break down triglycerides into FAs
what is the primary source of LPS?
pancreas
what does elevated LPS indicate?
pancreatic disease

check AMS and TLE
what does an elevated TRYPSIN-LIKE ENZYME indicate?

(TLE)
pancreatic disease
what is the primary source of TLE?
pancreas
how is TLE measured?
RIA
what does ALCOHOL DEHYDROGENASE do?
first step in the metabolism of ethanol

deficient in some asian people
what are the consequences of ethylene glycol ingestion?
crystals, cause physical damage, can rupture mito and cells
what are the stages of ethylene glycol toxicity?
1-CNS
2-Cardio
3-renal

treat with EtOH or fomepizole
what do insecticides target?
AChE

-insecticides usually OP's or carbamates
what are the signs of OP/carbamate poisioning
salivation, lacrimation, urination, defecation, dyspnea, bradycardia, mitosis, fasiculations, tremors, weakness, flacid paralysis, restlessness, hyperactivity, seizures
how can you diagnose OP/carbamate poisioning with tests?
AChE assay
how does penicillin work?
inhibits the synthesis of bacterial cell wall peptidoglycan by inhibiting glycopeptide transpeptidase by binding its active site irreversibly
how do you administer penicillin?
IM, it is unstable in the stomach
how does fosfomycin work?
inhibits synthesis of TB cell wall peptidoglycan by inhibiting the MurA enzyme
what do beta-lactamase inhibitors do?
give new life to old antibiotics
what is etoposide?
a chemotherapy drug that inhibits DNA repair enzymes and therefore increases p53 enzymes
what is an ACE inhibitor?
something that blocks the conversion of ATI to ATII
what do cholesterol statins do?
inhibit key conversion enzymes in conversion
what enzyme does glutothione peroxidase require?
needs selenium

uses glutathione to eliminate H2O2
what is the consequence of Se or Vit E deficiency?
build-up of lipid peroxidases, which in turn causes skel and cardiac musc damage...white fat accumulates in muscles- stiffness, flaccid muscles
what are some of the enzymes that require Cu as a cofactor?
superoxidase dismutase
cytochrome C oxidase
lysine amino oxidase
tyrosinase
what are the symptoms of Vit A deficiency?
vision
skin- keratin
epithelium of resp, repro, dig, tracts- BIRDS
what vitamin is required by cats?
Vitamin A, they can't convert betacarotine to retinol, eat liver
what is the result of a lysosomal storage disease?
accumulation of substrates in lysosomes, leading to physical intracellular crowding
-neurologic consequences, pressure on spinal cord
what is Gaucher?
lsd
what is Fabry?
lsd
what is Tay-Sachs?
lsd
what is Niemann-Pick?
lsd, caused by deficiency of the enzyme acid sphingomyelinase
what are the symptoms of a lysosomal storage disease?
dysmorphic features
psychomotor regression
ocular abnormalities
hepatosplenomegaly
are there some lysosomal storage diseases that are genetic and only effect certain species and breeds?
yes:
ceroid lipofuscinosis-dog, cat
fucosidosis-springer spaniel
flucocerebrosidosis (Gauchers)- australian silky spaniel
GM1 gangliosidosis-dog, cat, ovine
GM2 gangliosidosis (Tay-Sachs B)-german shorthaired pointer
mucopolysacchiridosis I- dogs, cats, mice
what is alpha mannosidosis?
an acquired lysosomal storage disease that leads to neuro problems in horses, sheep cattle
what can cause acquired lysosomal storage disease?
locoweed
poison peas
sida carpinifolia
what essential functions do proteins do in living cells?
structure, archetecture, movement of cells, tissues, catalysis, protection, hormones, receptros, lube, transport, storage, fluid retention, contraction, toxins
how much do proteins weigh?
10-1000kD
what is a conjugated protein?
protein with carbs, lipids, metals, heme, flavins
are peptide chains of aa's getetically coded?
yes
how many aa's are there?
20
19aa's
1 ia
what is a derived aa?
modified aa's after being incorporated into chain
ex: cystine, hydroxyproline, carboxyglutamate, desmosine, isodesmosine
which are the S containing aa's?
cysteine and methionine
which aa's have uncharged side chains?
asparagine
glutamine
serine
threonine
which aa's are alcohols?
serine
threonine
which are the acidic aa's?
aspartate
glutamate
which are the basic aa's?
histidine
arginine
lysine
what is protein digestion?
degradation of proteins by proteases into small peptides and free aa's
-free aa's can be reused or used as fuel
what are endoproteases?
proteases that cleve in the interior of a sequence
very specific usually

ex: between glutamine and lysine
what are exoproteases?
chew up the protein from the ends, nonspecific
what are the classifications of proteins?
simple-only aa's
conjugated- aa's and carbs, lipids, metals

fibrous- keratin, collagen, not soluble
globular- soluble, spherical, enzymes and ab's
how is collagen synthesized?
tropocollagen's lysyl residues oxidyze to aldehydes
aldehydes cross-link with amino groups of other lysyl residues
makes collagen strong
what cofactors are needed for lysyl oxidase to turn lysine into allysine (aldehydes)
B6 (pyridoxine) and Cu
what are the main aa's in collagen?
Gly
Pro
OH-Pro
what is the result of Cu deficiency in pigs?
collagen disorders
what does beta-aminoproprionitrile do?
found in sweet peas
inhibits lysyl oxidase which leads to osteolathyrism
what vitamin is required for the hydroxylation reaction of proline and lysine?
Vit C

leads to scurvy
who can't synthesize Vit C from glucose?
monkeys
GP's
humans
fish
what are the symptoms of scurvy?
decreased wound healing
osteoporosis
hemorrhaging
anemia
bruise easily
what is the result of collagen dysplasia?
skin fragility
slow wound healing
abnormal scar formation
excessive bruising
bleeding
joint lazity
osteogenesis imperfects
osteroprosis
viscera rupture (esp spleen)
artery rupture
who does Ehlers-Danlos Syndrom affect?
people
who does Cutaneous asthenia affect?
dogs and cats
who does dermatosparaxis affect?
cattle
what happens to collagen as one ages?
cross-linking continues leading to stiffer skin BV, and other tissues
what is the result of abnormal keratin?
alopecia from brittle hair, soft nails
what does retanoic acid do?
required to prevent synthesis of high molecular weight forms of keratin and a glycoprotein for mucous thus keeping the epithelial tissues healthy, moist and pliable
what is epidermolysis bullosa?
skin and mucosal blistering due to defective keratin-4 and keratin-5 genes
what is elastin?
a yellow, fluorescent protein found in ligmanets and BV walls, skin and CT
what aa's are found mostly in elastin?
Gly and Pro

-lacks Cys and Trp
what is Cushing's disease?
excessive cortisol, catabolic degradation of elastin, increased fragility of capillary walls, tearing of skin
what is immotile cilia syndrome
abnormal ciliary mvt due to absent or abnormal dynein arms in the adoneme
what is muscular dystrophy?
disease characterized by progressive weakness and degeneration of skeletal muscle that can also cause abnormalities in SA and AV nodes and Purkinje fibers
what causes muscular dystrophy?
abnormal dystropin, a structural protein that anchors actin filaments to the extracellular matrix
ultimately what do enzymes do?
decrease activation energy
what is a holoenzyme?
complete enzyme with cofactor
what is an apoenzyme?
protein part of the enzyme only
what are metalloenzymes?
enzymes that have metallic cofactors
why does the diet need to include sufficient essential amino acids?
because enzymes are subject to turnover and replacement, the body can't store aa's, metals, or vitamins
how are reaction rates altered?
pH
temperature
ionic composition of the medium
iigands other than substrates of coenzymes
what are proenzymes?
enzyme precursors that have to be cleaved before the catalytic activity appears
what is a zymogen?
inactive proenzymes
what are isozymes?
the different molecular forms of enxymes that have different primary structure but catalyze the same reaction; enzymes with the same primary structure but differing in post-translational modification
how is enzyme activity expressed?
amt converted: umol substrate/min
specific activity: units/mg protein
turnover number: units/mole enzyme
what is enzyme inhibition?
anything that alters or interferes with substrate/activation site interaction
what is reversible inhibition?
competitive
non-competitive
allosteric
what is irreversible inhibition?
denarutation
covalent modification
what is product inhibition?
regulation of a pathway

ummmmm look this up
what is feedback control?
positive
negative
constitutive vs inducible
???
what is the enzyme cascade?
the catalytic efficiency of one enzyme is influenced by another enzyme