Co-ordination and Control Flashcards
Cells can respond to signals by modulating the activity of…? A) Genes B) Ribosomes C) Enzymes D) The cytoskeleton E) All the above
E) All of the above
Turning genes on and off is important because it? A) Increases cellular metabolism B) Changes protein expression C) Triggers cell division D) Protects cells from apoptosis E) Releases second messengers
B) Changes protein expression
What 2 would you analyse to see which genes are up-regulated and down-regulated by testosterone. A) DNA B) RNA C) Proteins D) Second messengers E) Lipids
B) RNA
C) Proteins
What proportion of your genes codes for a GPCR? A) 1 in 20 B) 1 in 100 C) 1 in 1,000 D) 1 in 10,000 E) 1 in 100,000
A) 1 in 20
How do we know how many different GPCRs humans have? A) Genome sequencing B) RNA sequencing C) Ligand binding studies D) Western blotting E) Phosphorylation analysis
A) Genome sequencing
What would you expect to happen if you added a GaS specific GTPase inhibitor to these Leydig cells? A) Nothing B) Increased testosterone production C) Decreased testosterone production D) Decreased AMP concentration E) Decreased ligand binding affinity
B) Increased testosterone production
What is a feature of a second messenger system? A) Can cross cell membranes B) Specificity of signal C) Amplification of signal D) Binds DNA directly E) Triggers apoptosis
C) Amplification of signal
What does a kinase do? A) Adds phosphate to things B) Stimulates translocation of things C) Cleaves things D) Links things E) Removes polysaccharides from things
A) Adds phosphate to things
What effects does phosphorylation have on the target protein?
A) Stimulates its activity
B) Represses its activity of things
C) Provides a binding site for other proteins
D) Triggers degradation
E) Changes its charge
ALL
An effective cyclin B dependent kinase inhibitor would inhibit what? A) DNA replication B) Receptor phosphorylation C) Mitosis D) Retinoblastoma phosphorylation E) E2F activity
C) Mitosis
If someone injures their head and loses vision in the left field, what brain region is damaged? A) Left Parential Lobe B) Right Parential lobe C) Left occipital lobe D) Right occipital lobe E) Left optic nerve
D) Right occipital lobe
Which part of the peripheral nervous system is responsible for control of skeletal muscle contraction? A) Sympathetic B) Parasympathetic C) Enteric D) Somatic
D) Somatic
The movement of which ion initially depolarises the membrane to activate Ca2+ channels? A) Calcium B) Chloride C) Magnesium D) Potassium E) Sodium
E) Sodium
What type of receptor is the nicotinic acetylcholine receptor? A) A voltage-gated ion channel B) A metabotropic receptor C) An enzyme-linked receptor D) An ionotropic receptor
D) An ionotropic receptor
Which neurotransmitter is used in the post-ganglionic sympathetic innervation of sweat glands in the skin? A) Noradrenaline B) Acetylcholine C) Dopamine D) Glycine E) Serotonin
B) Acetylcholine
Adrenaline is central to the ‘fight or flight’ response. Which of the following isNOT a response to adrenaline? A) Bronchodilation B) Bronchoconstriction C) Smooth muscle contraction D) Smooth muscle relaxation
B) Bronchoconstriction
Which of these could be used to treat myasthenia gravis?
A) Choline acetyltransferase inhibitors
B) SNARE inhibitors
C) Nicotinic acetylcholine receptor inhibitors
D) Acetylcholine esterase inhibitors
D) Acetylcholine esterase inhibitors
From which amino acid are catecholamine neuro-transmitters derived? A) Lysine B) Glutamate C) Glycine D) Tryptophan E) Tyrosine
E) Tyrosine
Identify the sequence of some key events that occur during action potentials, where 1= depolarisation, 2= hyperpolarisation, 3= repolarisation, 4= potassium ion exit, 5= sodium ion entry:
A. 1 5 2 3 4 B. 4 1 2 5 3 C. 5 1 4 3 2 D. 5 2 3 4 1 E. 5 3 4 1 2
Answer: C
Learning Point: Action potential physiology
- Botulinum toxin interferes with neuronal signalling by blocking exocytosis.
What type of biological molecule is normally released in this situation?
A. Neurotransmitter B. Peptide hormone C. Phospholipid D. Prostaglandin E. Steroid hormone
Answer: A
Learning point: toxins and the SNARE hypothesis
- A 65 year old man is diagnosed with bladder cancer. Analysis of DNA from the tumour cells shows a mutation in the ras GTPase oncogene. This mutation locks the Ras protein into a state where it permanently binds GTP.
What effect does this have on the Ras protein?
A. It is inactivated B. It is constitutively activated C. It is degraded D. It is dephosphorylated E. It translocates to the nucleus
Answer: B
Learning point: oncogenes
The movement of which ion initially depolarises the membrane to activate Ca2+ channels?
A. Calcium B. Chloride C. Hydrogen D. Potassium E. Sodium
Answer: E
Learning point: physiology of neurotransmission
- Parkinson’s disease is a neurological condition, characterised by hypokinesia (diminished motor function), tremor and muscular rigidity.
L-DOPA is used to treat this disease because?
A. Dopamine does not cross the blood-brain barrier
B. L-DOPA evokes dopamine release
C. L-DOPA selectively antagonises enzymes which inactivate dopamine
D. The chemical synthesis of dopamine is uneconomic
E. The effects of L-DOPA are longer lasting than those of dopamine
Answer: A
- You are working for a pharmaceutical company. You are screening a batch of novel G protein-coupled receptor agonists and note that one compound, PCMD101, is labelled as Gαq specific?
Measuring the production of which of the following would enable you to estimate the activity of this compound?
A. ATP B. Cyclic AMP C. Intracellular adenosine D. Intracellular Ca2+ E. Tyrosine kinase
Answer: D
- A 22 year old man presents at your surgery, very upset. His girlfriend has just walked out following an argument. As a consequence of this type of stress several hormones can be shown to be elevated.
What part of the brain mediates this neuro-hormonal response?
A. Cerebellum B. Cortex C. Hypothalamus D. Pons E. Thalamus
Correct: C
In 1997 Jen Skou won half of the Nobel Prize for Chemistry for his discovery of the Na+/K+ ATPase enzyme. This enzyme uses ATP to transport sodium and potassium ions against their concentration gradients.
What contribution does it make to the resting membrane potential of neurons?
A. Too small to measure
B. Depolarisation by a few millivolts
C. Hyperpolarisation by a few millivolts
D. Depolarisation by tens of millivolts
E. Hyperpolarisation by tens of millivolts
Answer: C
At the resting membrane potential, the membrane is most permeable to which ion? A. Calcium B. Chloride C. Magnesium D. Potassium E. Sodium
Answer: D
During an action potential in a typical neuron, which potential would see the most sodium ions crossing the membrane? A. -80 mV B. -60 mV C. -15 mV D. 60 mV E. 150 mV
Answer: C
- You have read with interest Terje Lomo’s original observations on long-term potentiation (LTP) in the rabbit hippocampus. You are convinced that subsequent research provides strong evidence for a role of LTP in memory formation.
This role depends upon which neuronal property?
A. Faster signal conduction B. Increased pre-synaptic excitability C. Increased axonal branching D. Reduced numbers of synapses E. Increased synaptic strength
Answer: E
- When bound by testosterone, the testosterone receptor moves from the cytosol to a distinct cellular compartment in order to elicit its effects.
What is the name of this cellular compartment?
A. Golgi Apparatus B. Mitochondria C. Nucleus D. Plasma membrane E. Rough endoplasmic reticulum
Answer: C
- Protein kinase A (PKA) activation occurs downstream of G-protein coupled receptor signalling mediated by Gαs. You are working for a pharmaceutical company that would like to inhibit this pathway and must decide on a suitable target.
Which target would be a good candidate for an inhibitor?
A. Adenylate cyclase B. cAMP phosphodiesterase C. C-Src D. EGF receptor E. MAP kinase
Answer: A
- The Gα subunits of trimeric G-proteins are able to bind effector molecules when bound to GTP. They possess an enzymatic activity that acts on GTP to terminate binding to their downstream targets.
This enzymatic activity results in what GTP reaction?
A. Circularisation B. Dimerization C. Hydrolysis D. Linearization E. Phosphorylation
Answer: C
What is the innermost protective layer of the brain?
A. Arachnoid membrane B. Arachnoid trabecula C. Cerebrospinal layer D. Dura mater E. Pia mater
Answer: E
What area of the brain is located in the frontal lobe?
A. Brocas speech area B. Hippocampus C. Hypothalamus D. Thalamus E. Wernicke speech area
Answer: A
Identify the 5 lobes of the cortex within the brain and describe in brief their major functions.
- Frontal Lobe- higher level functions and personality
- Parietal Lobe- sensory control, proprioception, auditory control
- Temporal Lobe- memory and interpretation of auditory stimuli
- Occipital Lobe- vision and spatial awareness
- Limbic System- Emotion, memory and olfaction
Identify the major classifications of receptors and briefly describe the mechanism by which they transduce signals.
- Ligand gated- ligand bind and channel opens allowing signal in/out
- G-protein coupled receptors- Ligand causes GDP-GTP causing cyclic AMP formation
- Enzyme linked- ligand causes activation on 2nd messengers, causing enzyme cascade
- Steroid receptors/intracellular- signaling molecule activated intracellular receptor
Identify the neurotransmitter released at the post ganglionic terminal and the receptor, of the sympathetic nervous system when inverting the heart?
- Ach is released from the post-ganglionic terminal
- It travels down the sympathetic nervous pathway where it reaches the adrenergic receptor of the heart (GPCR). Noradrenaline then causes an increase in HR
Which of these is not a part of the brain? A) Medullary cavity B) Pons C) Basal Ganglia D) Diencephalon
A) Medullary cavity
Fill in the blanks: The brain is folded inwards, producing ------ (rounded ridges). The grooves in between these are ------. Deeper versions of these are called ------. A) Sulci, Grooves, Fissures B) Fissures, Gyri, Sulci C) Gyri, Fissures, Sulci D) Gyri, Sulci, Fissures
D) Gyri, Sulci, Fissures
Broca's area is found in which brain lobe? A) Frontal B) Parietal C) Occipital D) Temporal
A) Frontal
Wernicke's area is found in which brain lobe? A) Frontal B) Parietal C) Occipital D) Temporal
B) Parietal
The parietal lobe controls: A) Speech B) Proprioception C) Personality D) Voluntary motor action
B) Proprioception
The frontal lobe controls: A) higher cognition B) memory C) Olfaction D) spatial awareness
A) higher cognition
Which lobe can be used to interpret song lyrics? A) frontal B) parietal C) temporal D) occipital
C) temporal
Which of these are not roles of the basal ganglia?
A) involuntary movement
B) some cognitive function
C) sleep
C) Sleep
Which is the order of the brain stem (downwards)
A) Diencephalon, Pons, Midbrain, Medulla Oblongata
B) Diencephalon, Midbrain, Pons, Medulla Oblongata
C) Medulla oblongata, midbrain, pons, diencephalon
D) medulla oblongata, pons, midbrain, diencephalon
B) Diencephalon, Midbrain, Pons, Medulla Oblongata
What is the purpose of an interneuron?
to connect sensory and motor neurons
Which ions cannot pass through the myelin sheath specifically? A) K and P B) Na and Cl C) Na and K D) H and O
C) Na and K
Which of these is not a type of glial cell? A) Oligodendrocytes B) Schwann cells C) Astrocytes D) Motor neuron
D) Motor neuron
Glial cells are all cells except neurons
A small molecule binds to a G protein, preventing its activation. What direct effect will this have on signaling that involves cAMP?
A) The hormone will not be able to bind to the hormone receptor.
B) Adenylyl cyclase will not be activated.
C) Excessive quantities of cAMP will be produced.
D) The phosphorylation cascade will be initiated.
B) Adenylyl cyclase will not be activated.
A student is in a car accident, and although not hurt, immediately experiences pupil dilation, increased heart rate, and rapid breathing. What type of endocrine system stimulus did the student receive? A) humoral B) hormonal C) neural D) positive feedback
C) neural
The hypothalamus is functionally and anatomically connected to the posterior pituitary lobe by a bridge of \_\_\_\_\_\_\_\_. A) blood vessels B) nerve axons C) cartilage D) bone
B) nerve axons
Which of the following is an anterior pituitary hormone? A) ADH B) oxytocin C) TSH D) cortisol
C) TSH
Which of these physiological changes would not be considered part of the sympathetic fight-or-flight response? A) increased heart rate B) increased sweating C) dilated pupils D) increased stomach motility
D) increased stomach motility
Which type of fiber could be considered the longest? A) preganglionic parasympathetic B) preganglionic sympathetic C) postganglionic parasympathetic D) postganglionic sympathetic
preganglionic parasympathetic
Which signaling molecule is most likely responsible for an increase in digestive activity? A) epinephrine B) norepinephrine C) acetylcholine D) adrenaline
C) acetylcholine
Which lobe of the cerebral cortex is responsible for generating motor commands? A) temporal B) parietal C) occipital D) frontal
D) frontal
What region of the diencephalon coordinates homeostasis? A) thalamus B) epithalamus C) hypothalamus D) subthalamus
C) hypothalamus
What level of the brain stem is the major input to the cerebellum? A) midbrain B) pons C) medulla D) spinal cord
B) pons
Which layer of the meninges surrounds and supports the sinuses that form the route through which blood drains from the CNS? A) dura mater B) arachnoid mater C) subarachnoid D) pia mater
A) dura mater
What type of glial cell is responsible for filtering blood to produce CSF at the choroid plexus? A) ependymal cell B) astrocyte C) oligodendrocyte D) Schwann cell
A) ependymal cell
What type of ganglion contains neurons that control homeostatic mechanisms of the body? A) sensory ganglion B) dorsal root ganglion C) autonomic ganglion D) cranial nerve ganglion
C) autonomic ganglion
