Biochem Exam 2 Flashcards
(44 cards)
Branched Chain Ketoacid Dehydrogenases
break down the products of Val, Leu, and Ile E1 reactions (the toxic ketoacid)
MSUD- Maple Syrup Urine Disease
Absence of Branched Chain Ketoacid Dehydrogenase
Ketoacid builds up and is excreted in the urine
Can be a deadly disease.
Kidney Pressure Filtration
Blood pressure forces small molecules from the glomerulus into the Bowman’s capsule
-Water, glucose, amino acids, salts, urea, uric acid, and creatinine are transported from capillaries to kidneys
Kidney Selective Reabsorption
Diffusion and active transport return molecules to blood at the proximal convaluted tubule
–Bicarbonate HCO3 is put back into blood stream if pH is low and reabsorbed if it is high
Kidney Tubular Secretion
Active transport moves molecules from blood into the distal convoluted tubule
- -waste is sent back to the kidney
- -H+ is secreted from blood to kidney and appears in the urine if pH is low in the blood
Kidney Reabsorption of water
Along the length of the nephron and notably at the loop of Henle and collecting duct, water returns by osmosis following active reabsorption of salt
Hormone controlling water absorption
ADH- antidiuretic hormone
retain H2O in body by promoting waters removal back into the tissue fluids from last part of the nephron (vasopressin)
-Alcohol prevent the release of ADH, causing frequent urination and dehydration
Acidosis
decrease in blood pH
-Causes: starvation, diabetes, pulmonary disease
Alkalosis
increase in blood pH
-Causes: prolonged vomiting, excessive consumption of basic medicines, hyperventilation
Job of the Kidneys
Controls the pH of the blood by:
- Low pH: the specialized cells excrete proteins from the blood to the urine; reabsorb bicarbonate into the kidney capillaries
- High pH: do not secrete proteins from the blood, do not reabsorb bicarbonate into the kidney capillaries
Respiratory Control
Drop in pH: increate rate and depth of breathing to expel more carbon dioxide.
Chemical buffer system (Kidneys)
a. Bicarbonate buffer
b. Protein buffer system
c. Hemoglobin
d. Phosphate buffer
Phosphate buffer
Intracellular fluid and urine buffer
Hemoglobin
Red blood cell protein buffers the protons by metabolically producing carbon dioxide. This carbon dioxide dissociates to form bicarbonate, which is bound to hemoglobin to lower pH.
Protein buffer system
Proteins can give up protons, thus buffering
Bicarbonate buffer
the primary buffer of the extracellular fluid. Buffers against pH changes from fluctuation in carbon dioxide-generated carbonic acid.
Extracellular fluid
Plasma & interstitial fluid
Three sources of added H+
- Carbonic acid from metabolically produced Carbon Dioxide
- Acids produced from the breakdown of nutrients in the diet
- Acids produced from normal metabolism (like lactic acid from oxidized glucose)
Equation for making carbonic acid in the blood
Glucose +O2 > CO2 +H2O > H2CO3
Signs of Respiratory Acidosis
- Emphysema
- Chronic Bronchitis
- Pneumonia
- Asthma
- Overdoes of Opioids or sleep meds
Signs of Alkalosis
Metabolic: prolonged vomiting, excessive ingestion of basic compounds (baking soda, etc)
Respiratory: Hyperventilation (system tries replenishing CO2)
The Pancreas
sends bicarbonate to small intestine to increase pH for pancreatic enzymes to work in the acidic chyme from the stomach
Antifreeze
Ethylene glycol > Gycolic Acid > oxalic acid > oxylate + Calcium > CaC2O4 precipitates in kidneys causing kidney failure
Radical Mutation
A change causing the amino acid to be changed to something not similar to the original
