PCS 1 Flashcards
What is an amphiobolic reaction?
A catabolic and anabolic reaction together e.g. Krebs
What is mean by the term ‘Accommodation’?
Slow and prolonged depolarization due to inactive sodium channels.
Sodium cannot be transported into the cell therefore depolarization occurs slowly.
What is the function of a tight junction? What are the proteins that make them up called?
They link epithelial cells together. Claudins are transmembrane proteins present in tight junctions .
What is the main regulatory point in glycolysis? What steps does it catalyse?
PFK.
Fructose-6-Phosphate –> Fructose-1,6-Bisphosphate
What are the three most commonly fractured carpal bones?
- Scaphoid 2. Triquetrum 3. Lunate
What is the function of the Biceps Brachii?
FLEXES and SUPINATES the forearm at the elbow joint.
In which muscle type(s) are the contractile filaments organized into sarcomeres?
Cardiac and Skeletal muscles.
Which cell type gives rise to osteoblasts?
Osteoprogenitor cell
What is the definition of a motor unit?
One lower motor neurone and all the skeletal muscle fibers that it innervates.
What makes up ground substance?
GAGs and Proteoglycans.
In which muscle type(s) are satellite cells present?
Skeletal. Satellite cells are stem cells.
Go through the steps of muscle contraction with actin and myosin including the power stroke.
- ATP bind to myosin.
- Binding of ATP to myosin causes the myosin to dissociate from actin.
- ATP hydrolysis into ADP and Pi. This causes myosin to change the angle of its head.
- With ADP and Pi still present, myosin binds to actin at a new angle.
- When Pi leaves, myosin pulls against actin, causing the power stroke (contraction!)
What is calculated using the Nernst Equation?
Equilibrium Potenital
What is the resisting membrane potential for sodium and potassium?
Sodium +60mV
Potassium -90mV
Name the FOUR major classes of simple epithelia.
Squamous, cuboidal, columnar, pseudostratified
What enzyme catalyses the link reaction? Steps involved?
Pyruvate dehydrogenase.
Pyruvate –> Acetyl CoA.
Irreversible reaction.
What is the function of the carnitine shuttle?
Transporting fatty acids from the intermembranous space of the mitochondria to the mitochondrial matrix.
Without this shuttle, the fatty acids would not be able to be transported into the matrix, meaning fatty acids would not be available to be metabolised, making it the rate limiting factor.
What reaction does Hexokinase catalyse?
Glucose –> Glucose-6-Phosphate (via the transfer of a phosphate molecule from ATP to glucose)
1st step in glycolysis
What are the three main controls in glycolysis?
Phosphofructokinase
Hexokinase
Pyruvate Kinase
What determines the contraction speed of skeletal muscle fibers?
ATPase activity of myosin
What is the action of Myosin Light chain kinase?
Phosphorylates myosin, allowing it to bind to actin for contraction to occur.
What is the action of Myosin Light chain phosphotase?
Dephosphorylates myosin light chain / detatches cross bridges. Inhibits muscle contraction.
Name the epithelium lining the tongue.
Non-keratinised stratified squamous epithelium.
What proteins form gap junctions?
Connexons. They require 6 connexins to form one connexon.















