Section 1 Flashcards
pH of arterial plasma
7.35-7.45
pH of extracellular fluid
6.8-7.8
pH within cells
6.9-7.4
If pH<pKa, then what form predominates?
acid
If pH>pKa, then what form predominates?
basic
what is the buffer system of blood?
bicarbonate
What is the intracellular buffer system?
phosphate
What is this condition?
increase in partial pressure of CO2
resipratory acidosis
What is this condition?
decrease in partial pressure of CO2
respiratory alkalosis
What is this condition?
decrease in HCO3- concentration
metabolic acidosis
What is this condition?
increase in HCO3- concentration
metabolic alkalosis
What condition is due to decrease in lung function and how will the body do to compensate?
Respiratory Acidosis
- kidneys will try to compensate by increasing bicarbonate
- all compensatory reaction by the kidneys will take several days
What condition is due to hyperventilation and what will the body do to compensate?
Respiratory Alkalosis
- kidneys will try to compensate by excreting bicarbonate in urine
What condition can be caused by decreased kidney function or body trying to compensate for an already existing acidosis, such as DKA? How will the body try to compensate?
Metabolic Acidosis
- lungs will attempt to compensate by “blowing off” CO2
- this effect will take place within minutes and complete within 12 - 24 hours
What condition can be caused by an excess administration of bicarbonate or loss of H+ (from prolonged vomiting or use of diurectics)? How will the body compensate?
Metabolic Alkalosis
- lungs will attempt to compensate by breathing less (hypoventilation), trying to keep as much CO2 as possible
What type of protein structure is this?
structure results from hydrogen bonding interactions between C=O and H-N of the backbone
Secondary structure
What type of protein structure is this?
subunits associate with each other through non-covalent interactions?
quaternary
What type of protein structure is this?
sequence of amino acid residues in a polypeptide chaing
- determines 3-D structure and biological function of the protein
primary
What type of protein structure is this?
non-covalent interactions are the major element in formation of this structure (H-bonding, hydrophobic forces and van der Waal’s)
tertiary
What type of enzyme is this?
catalyzes cleavage of bonds with water
hydrolases
Ex. glucosidases, ATPases
What type of enzyme is this?
catalyzes redox reactions, transfer of electrons
oxidoreductase
Ex. NAD+»NADH
What type of enzyme is this?
catalyzes transfer of functional groups
transferases
Ex. kinases, aminotransferases
What type of enzyme is this?
catalyzes formation of bonds between carbons and other atoms
ligases
Ex. synthase, synthetase, carboxylase
What type of enzyme is this?
cleaves bonds without water
lyases
Ex. aldose B
What type of enzyme is this?
changes stereochemistry
isomerase
Holoenzyme
apoenzyme with prosthetic group
- active
Apoenzyme
apoenzyme without its prosthetic group
- inactive
Vmax, conditions
more substrate will not increase reaction rate, but more enzymes will
- does not depend of concentration of subtrate
Km, conditions
- more enzymes will not change this value
What does a low Km mean?
increase substrate affinity
- takes more substrate to be at Vmax/2
this explains why glucokinase can turn over more G6P from glucose than hexokinase
What does a high Km mean?
decrease substrate affinity
- takes only small amount of substrate to be at Vmax/2
Conditions of competitive inhibition
Vmax - no change because it's independent of substrate concentration Km increases (substrate concentration dependent) - less substrates are binding
Conditions of non-competitive inhibition
Vmax decreases (number of enzymes changed due to the inhibition) Km - no change - fewer working enzymes
Gs G-proteins
stimulates adenylate cyclase to form cAMP
Gi G-proteins
inhibits adenylate cyclase
Gq G-proteins
stimulates phospholipase C to form IP3/DAG
Which is better at binding to oxygen during low levels of O2, myoglobin or hemoglobin?
myoglobin
What is better at binding to oxygen during high levels of O2, myoglobin or hemoglobin?
hemoglobin
Which form of Hb has a higher affinity for O2, T or R?
R form
What kind of allosteric modulator is O2 on Hb? What about 2,3-BPG, CO2 and H+?
O2 is a positive allosteric modulator of Hb, all the others are negative allosteric modulators of Hb
CO2 can bind to N-terminal ends of Hb subunits and form carbamates, what effect will this have on the structure of Hb?
stabilizes T-form, facilitate release of O2 in peripheral tissues
