Lecture 1 Flashcards
What is metabolism
All chemical processes that occur in an organism
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
Transcription occurs between
Dna and rna
translation occurs between
rna and protein
What does sickle cell anemia cause
Causes the body to produce a new form of hemoglobin called HbS, which behaves very differently to regular hemoglobin (HbA).
Example of autosomal recessive homozygous
Sickle cell anemia
Hypercholesterolemia
specifically very high levels of low-density lipoprotein (LDL, “bad cholesterol”)
What does the LDLR gene encode
encodes the LDL receptor protein.
How is Hypercholesterolemia diagnosed?
Diagnosed with blood tests, genetic testing and presence of xanthomas (waxy build up)
What is the treatment for Hypercholesterolemia?
treatment is statins but may require surgical intervention in more severe cases
What is Unrestrained, uncontrolled growth of cells
Cancer
What two kinds of genes can disturb the cell cycle when they are mutated
- Tumor-suppressor genes
- Proto-oncogenes
Which protein monitors integrity of dna?
p53 protein. p53 is absent or damaged in many cancerous cells
What does the p53 direct the cell to do?
If DNA damage is irreparable, p53 directs cell to kill itself
How does cancerous phenotype develop
Both copies of a tumor-suppressor gene must lose function for the cancerous phenotype to develop
What was the First tumor-suppressor identified
retinoblastoma susceptibility gene (Rb)
What does retinoblastoma susceptibility gene (Rb) do?
Predisposes individuals for a rare form of cancer that affects the retina of the eye
What are tumor supressor genes?
What are Proto-oncogenes?
Normal cellular genes that become oncogenes when mutated.
Oncogenes can cause cancer
How many copies of a proto-oncogene needs to undergo this mutation for uncontrolled division to take place
only one
Anabolism
building substances (molecules)
Catabolism
breaking substances (molecules)
Anabolic reactions
use up energy. They are endergonic. In an anabolic reaction small molecules join to make larger ones.
Catabolic reactions
release energy = exergonic. Large molecules are broken down into smaller ones.
example of a catabolic reaction
that occurs in cells is the decomposition of hydrogen peroxide into water and oxygen
Example of anabolic reaction:
Example of a polar molecule
water
Polar or non polar dissolve in water?
Polar because they are hydrophilic
What causes acidosis?
diabetic ketosis and lactic acidosis. Alkalosis (pH >7.45) may follow vomiting of acidic gastric contents
Carbonic anhydrases (enzyme)
promote rapid H+ buffering and thus the stability of pH-sensitive
processe
What does oxidative metabolism produce?
CO2
Which organs keep your acid-base balance normal?
Lungs and kidneys
Oxygen saturation (O2Sat).
This measures how much oxygen your red blood cells are carrying
Partial pressure of oxygen (PaO2)
This measures the pressure of oxygen that’s dissolved in your blood. It helps show how well oxygen moves from your lungs to your bloodstream.
Partial pressure of carbon dioxide (PaCO2).
This measures the amount of carbon dioxide in your blood. It also shows how easily carbon dioxide can move out of your body.
Acidosis
Too much acid
Respiratory acidosis
state in which there is usually a failure of ventilation and an accumulation of carbon dioxide.
Metabolic acidosis pH?
pH<7.35
Metabolic alkalosis ph?
pH >7.45
Respiratory acidosis ph?
pH <7.35
Respiratory alkalosis ph
pH >7.45 ex. hyperventilation (blowing off CO2) due to fever, pain, or anxiety
Human diet must include how many essential amino acids that cannot be synthesized
9
How many grams does kidney filter over of amino acids from the arterial renal blood??
50
Non essential amino acids
can be created in the body from essential amino acids
Essential amino acids
cannot be created in the body from essential amino acids
What are the 9 essential amino acids?
histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine
Thalidomide
contains teratogenic S-enantiomer in addition to the therapeutic
(anti-morning sickness) R-enantiomer
Warfarin
- The S-enantiomer is five times more potent than the R-enantiomer
Ibuprofen
S-enantiomer three times more potent than the other
molecular chaperones
Protein binding polypeptides called molecular chaperones stabilize unfolded protein intermediates
* Prevents aggregation and facilitates trafficking of newly formed proteins
Where do proteins orginate from?
Proteins originate from a ribosome which got its instruction
from tRNA -> mRNA and DNA
peptide
Protein is classified by size. Fewer than 50 amino acids
polypeptide
More than 50 amino acids
structural molecules (proteins)
ex: collagen, keratin
* Lack catalytic activity, but can still signal
* Example: collagen acts as an extracellular activating ligand for cell surface adhesion molecules
Functional molecules
- Enzymes (proteases, glycosylases)
- Signaling molecules (transcription factors and receptors)
- Transport/storage molecules(transferrin, ferritin, hemoglobin) * Antibodies(IgG,IgM)
List hydrophobic proteins
(water-insoluble, greasy) amino acids * Valine, leucine, isoleucine, tryptophan, phenylalanine
List hydrophobic proteins
(water-soluble) amino acids
* Glutamate & aspartate (Acidic) lysine & arginine (basic)
hydrophobic effect
The influence of hydrophilic and hydrophobic interactions on structure of proteins
Hydrophobic residues embed themselves where
in the interior of large proteins – mutations that eliminate the hydrophobicity of key amino acids may create destabilizing cavities within the protein
Hydrophilic residues stud themselves where
around the exterior of the protein where they provide interaction sites for proteins involved in cell signaling
missense mutation
Replacement of a hydrophobic by a hydrophilic amino acid or vice versa
Nonsense mutations
stop codons that result in chain termination – severity depends on the extent of protein truncation
ASA inhibits
cyclooxygenase
ACEI inhibits
angiotensin-converting enzyme
Pravastatin- inhibits
hydroxymethylglutaryl (HMG) CoA reductase
Omeprazole – inhibits
gastric H+/K+ ATPase pump
rate- limiting reaction
Zymogen
enzyme that acts as a proteases that is activated by the complement cascade
What is the advantage of zymogen?
enzymes remain inactive until the appropriate tissues destination is reached
How is pepsinogen activated?
intragastric acidity (pH <3) partly denatures the peptide exposing the enzymes active site leading to its cleavage, which activates the enzyme
