Test 1 Lecture 1 Flashcards
chemical reactions and enzymes that convert glucose to pyruvate (glycolysis) to ethanol and CO2 (frementation)
Phosphorylated sugars
What are coenzymes?
vitamin-derived cofactors
What are the types of coenzymes?
thiamine pyrophosphate, riboflavin, coenzyme A, coenzyme Q (lowers statins), cobamide coenzyme
What is the importance of biochem for healthcare?
- understanding and maintenance of health
- effective treatment of disease
all chemical processes that occur in an organism
metabolism
What are examples of metabolism?
- glucose homeostasis
- DNA replication, RNA splicing
glycolytic enzyme, glucose transporters, glycogen synthetases, disaccharidases, gluconeogenic enzymes
glucose homeostasis
What are the types of error that can occur in genetic metabolic processes?
- gene deletion
- frameshifts
- sequence mutations
termed inborn errors of metabolism
inherited or congenital disorders that are due to a defective enzyme causing a disruption in a specific metabolic pathway, the way that DNA or the genes communicate
What is the central dogma?
What is sickle cell anemia
- autosomal recessive homozygous
- Glutamic acid codon (GAG) to a valine codon (GTG)
- mutated gene is hemoglobin beta (HBB), located on chromosome 11
- causes the body to produce a new hemoglobin HbS which behaves differently than HbA
- Causes the cell to sickle
What is familial hypercholesterolemia?
- very high levels of low- density lipoprotein (bad cholestrol)
- common
- mutation in the LDLR gene encodes LDL receptor protein which removes LDL from circulation
Who does Familial hypercholesterolemia affect?
-heterozygote (recessive) for LDLR gene can lead to cardiovascular disease by the age of 30 to 40
- Homozygotes ( dominant) causes severe cardiovascular disease in childhood may lead to heart attack or death by 30
unrestrained, uncontrolled growth of cells, failure of cell cycle control
cancer
What are the two kinds of genes that disturb the cell cycle when mutated?
- tumor-suppressor genes
- Proto-oncogenes
What are the tumor suppressor genes?
P53 protein
retinoblastoma susceptibility gene (first tumor suppressor identified)
protein that monitors integrity of DNA
p53 protein
If DNA is damaged what do enzymes and p53 do to the DNA?
-repair enzymes are stimulated
- if DNA damage is irreparable, p52 directs cell to kill itself
What must occur for the cancerous phenotype to develop?
both copies of the tumor-suppressor gene must lose function
_ is absent or damaged in many cancerous cells
p53
predisposes individuals for a rare form of cancer that affects the retina of the eye
Retinoblastoma susceptibility gene
normal cellular genes that become oncogenes when mutated
proto-oncogenes
What can oncogenes cause?
cancer
Proto-oncogenes can encode for?
- receptors for growth factors
- signal transduction proteins
Only one copy of a proto-oncogene is needed for?
- mutation of cell no longer depending on growth factors
- uncontrolled division
Diseases are manifestations of abnormailities in?
genes, proteins, chemical reactions, or biochemical processes
What are examples of biochemical processes involved in disease?
electrolyte imbalance, defective nutrient ingestion or absorption, hormonal imbalances, toxic chemicals or biologic agents, and DNA based genetic disorders
building substances (molecules)
anabolism
breaking substances (molecules)
catabolism
What serves as a catalyst to speed up anabolism and catabolsim?
enzymes
What are anabolic reactions?
What are catablic reactions?
predominant chemical component of living organisms
water
What are the physical properties of water?
- excellent solvent or organic and inorganic molecules
- electrically neutral (due to waters dipolar sructures and exceptional capacity for forming hyrogen bonds)
- polar
- multipurpose
What does hydrophilic ad hydrophobic mean?
any substance that dissociates in water to increase the (H+) and lower the pH
acid
What happens as acids get stronger?
the more hydrogen ions it produces and the lower its pH
substance that combines with H+ dissolved in water and thus lowers the H+
Base
What dissociates into hydroxide ions, extra proton (-) and hydrogen ions, proton donor (+)?
water
measures the concentration of hydroxine ions (protons) in a solution (acidity)
pH
What maintains the pH of extracellular fluid and to what pH?
bicarbonate and other buffers
7.35 to 7.45
Suspected disturbances of acid-base balance are verified by measuring what?
-pH of arterial blood
-CO2 content of venous blood
What causes acidosis?
pH of <7.35
diabetic ketosis and lactic acidosis
What causes alkalosis?
pH> 7.45
vomiting of acidic gastric contents
What is a carbonic anhydrases?
resist a change in pH following addition of strong acid or base
buffering
What does oxidative metabolism produce?
CO2, the anhydride of carbonic acid, which if not buffered would produce severe acidosis
Biologic maintenance of a constant pH involves buffering by?
phosphate, bicarbonate, proteins (which accept or release protons to resist a change in pH)
What are the arterial blood gas levels?
Which organs keep the acid base balance normal in the body?
lungs and kidneys
this measure how much oxygen your blood cells are carrying
oxygen saturation (O2Sat)
this measures the pressure of oxygen thats dissolved in your blood. it helps show how well oxygen moves from lungs to your bloodstream
partial pressure of oxygen (PaO2)
This measures the amount of carbon dioxide in your blood. it also shows how easily carbon dioxide can move out of your body
Partial pressure of carbon dioxide (PaCO2)
this measures the acidity of your blood
acid base balance (ph level)
PH<7.35, respiratory CO2 normal, bicarb low (<24mEq/L), split into anion and non anion gap
Metabolic acidosis
pH >7.45, respiratory CO2 normal, bicarb level high
Metabolic Alkalosis
pH <7.35, CO2 elevated >45, elevated HCO3
(bicarb)
Respiratory acidosis
pH >7.45, respiratory CO2 <35
Respiratory alkalosis
What is an example of respirtory alkalosis?
hyperventilation (blowing off CO2) due to fever, pain, or anxiety
What are the primary processes of ABG?
Wha are the steps to exaluating an ABG?
There are 5 steps
is primarily due to the loss of bicarbonate
Non-gap metabolic acidosis
What are examples of non-gap metabolic acidosis?
What are the differentials for anion gap metabolic acidosis?
CAT MUDPILES
What do these lab values show?
metabolic acidosis
How many and what are the essential amino acids
there are 9 amino acids that human diet must include and can not be synthesized
Where are free amino acids found?
flitered in the kidney form the arterial renal blood and traces of free amino acids in urine
What are important components of amino acids?
What are the three amino acid enantiomers?
-thalidomine
-warfarin
-ibuprofem
contains teratogenic S-enantiomer in addition to the therapeutic (anti-morning sickness) R-enantiomer
Thalidomide
The S-enantiomer is five times more potent than the R-enantiomer
Warfarin
S-enantiomer three times more potent than the other
Ibuprofen
Where does protein folding begin?
the polypeptide chein and continues after translation
protein binding polypetides stabilize unfolded protein intermediates
molecular chaperones
What do molecular chaperones do?
prevent aggregation and facilitates trafficking of newly formed proteins
What are the diferent structures of proteins?
Human genes are transcribed and translated to form?
proteins
proteins with fewer than 50 amino acids
peptide
proteins with more than 50 amino acids
polypeptide
Proteins can be what 2 kinds of molecules?
structural or functional molecules
What are structural molecules?
What are functional molecules?
Amino acids can be __ or ___
hydrophilic or hydrophobic
the influence of hydrophilic and hydrophobic interactions on structure of protein
hydrophobic effect
Where are hydrophobic and hydrophilic residues located?
replacement of a hydrophobic by a hydrophilic amino acid or vice versa
missense mutation
What are the two examples of missense mutations?
stop codon that result in chain termination- severity depends on the extent of protein truncation
nonsense mutations
contain chemically reactive sites termed catalytic subunits
enzymes
what occurs in enzyme activation?
What are the drugs that use cellular enzymes?
What is allosteric inhibition and allosetric activation?
Explain and catabolic enzyme reaction
Explain the anabolic enzyme reaction
Explain the feedback loop
It causes a stimulus to produce the enzyme but when there is enough enzymes it will inhibit the production so no more enzymes are produced.
What is a rate limiting reaction?
enzyme that acts as a proteases that is activated by the complement cascade
zymogen
What do zymogens contain?
What are the advantages to zymogen?
enzymes remain inactive until the appropriate tissues destinatin is reached
Explain the Renin-Angiotensin system
How do enzymes aid in diagnosis?
How are enzymes used to diagnose MIs?
sugars that cannot be hydrolyzed into simpler carbohydrates
monosaccharides
What are Polyhydric alcohols?
are condensation products of two monosaccharide units
disaccharides
What are examples of disaccharides?
lactose, maltose, isomaltose, sucrose, and trehalose
are condensation products of 3 to 20 monosaccarhides- indigestible ( act as soluble fiber, may help prevent constipation)
oligosaccharides
> 10 sugars, starch molecules (rice, wheat), such as glycogen
plysaccharides
Where is glycogen stored?
skeletal muscle so it is readily available source for glycolysis
What is the breakdown of carbohydrates?
responsible for transporting glucose and galactose by atp dependent active transport against and concentration gradient
sodium glucose co-transporter
what are the downsides and plus sides to sodium-glucose co-transporter?
What are the location and function of glucose transporters?
What is the sodium-dependent unidirectional transporter?
process of forming glycogen molecules from glucose in order to store it
glycogenesis
The process of breakdown of glycogen to yield glucose residues. a breakdown of molecules to fuel (catabolic mechanism)
glycoogenolysis
Provides glucose when dietary intake is insufficient or absent
gluconeogenesis
This is the process of obtaining energy from glucose molecules. The process takes place in the cytosol. It is an oxygen-independent process and can occur in aerobic as well as non- aerobic conditions.
glycolysis
What catalyzes the hydrolysis of glycogen to glucose
maltase
Where and when does gluconeogenesis occur?
in the liver (hepatocytes) and celluarly in the cytoplasm, mitochondira, and ER
begins 8 hours after fastig begins
What are the products of glycolysis?
2 ATP
2 NADH
2 Pyruvate
a hormone produced during a period of fasting, made by the islets of langerhan, pancreatic alpha cells
glucagon
What is the main mediatory of glycogen breakdown in skeletal muscle?
epinephrine
What produces insulin?
Beta cells of the islets of langerhan in the pancreas
Explain how insulin and glucagon affect the regulation of blood glucose?
How does glycolysis affect muscle?
What is the concentration of blood glucose?
4.5 and 5.5 mmol/L
A sudden decrease in blood glucose in response to insulin overdose causes?
convulsions, because of the dependence of the brain on a supply of glucose
What is insulin?
secreted by the adrenal medulla as a result of stressful stimuli -”Fight or Flight” leads to glycogenolysis in liver and muscle – stimulates phosphorylase via generation of cAMP. Inhibits insulin, you need all the glucose you can get!
Epinephrine
acts in response to hypoglycemia, stimulates glycogenolysis by activating glycogen phosphorylase (liver) – does not act in the muscle
glucagon
What is diabetes mellitus?
Explain DM type 1
Explain DM Type 2
What is the importance of lipids?
loosely defined group of molecules with one main chemical characteristic, insoluble, hydrophobic
lipids
What are the three types of lipids?
What are the different types of fat?
4
the major form of dietary lipid in fats and oils, whether derived from plants or animals
triacylglycerols (triglycerol)
What are fatty acids classified as?
saturated (full of single bonds)
unsaturated (containing double or triple bonds)
What is the difference between saturated and unsaturated?
unsaturated are essential fatty acids such as monunsaturated and polyunsaturated, found in plant oils
saturated are fatty acids are found in animal fats, may be elongated, can predisopse to vascular disease when consumed in excess
process of adding hydrogen atoms to unsaturated fat to make it a solid
hydrogenation
incomplete “partially” hydrogenation, bad for you
trans fat
breakdown of lipids used to mobilize stored energy, usually occurs in fat adipocytes
lipolysis
What is the most important regulatory hormone in lipolysis?
insulin
lipoproteins transport lipids from the intestine as _ and from the liver as _
chylomicrons
very-low density lipoproteins
lipid molecules orient with polar (hydrophilic) head toward water and nonpolar (hydrophobic) tails away from water
micelles
What are the four major lipid classes?
derived from intestinal absorption of triacylglycerol and
other lipids
chylomicrons
derived from the liver for the export of triacylglycerol
VLDL
essential for carrying lipids that keep the human body alive, including in those small vessels.
LDL
involved in cholesterol transport
* absorbs cholesterol in the blood and carries it back to the liver.
HDL
What is the predominant lipid in chylomicrons and VLDL?
Triaglycerol
What are the predominant lipids in LDL and HDL?
cholestrol and phospholipid
What are the two main etiolgies of lipids?
What is alcohol and liver disease?
