IMMS Flashcards
Which of the following is not a component of cell membranes or the receptors associated with them?
- Cholesterol
- Dihydrogen oxide
- Glycolipids
- Lipoproteins
- Phospholipids
- Dihydrogen oxide
Which enzyme catalyses 1,3-bisphosphoglycerate to 3-phosphoglycerate in the aerobic glycolysis pathway
- Aldolase
- Phosphofructokinase
- Phosphoglucose isomerase
- Phosphoglycerate kinase
- Triose phosphate isomerase
- Phosphoglycerate kinase
Which of the following enzymes is not involved in either aerobic or anaerobic glycolysis?
- Aldolase
- ATPase
- Hexokinase
- Phosphoglucose isomerase
- Triose phosphate isomerase
- ATPase
A 45-year-old man is trying to lose weight. How many kcal are there in one unit of alcohol?
- 28 kcal
- 40 kcal
- 56 kcal
- 72 kcal
- 90 kcal
- 56 kcal
Which of the following factors will lower the basal metabolic rate of an individual?
- Caffeine
- Dieting
- Fever
- Obesity
- Hyperthyroidism
- Dieting
A 60-year-old woman has a lack of cortisol. Which of the following statements concerning steroid hormones is TRUE?
- They act on plasma membrane receptors
- They are formed from tyrosine
- They are stored in secretory granules
- They are transported in plasma bound to proteins
- They are water soluble
- They are transported in plasma bound to proteins
Which of the following statements concerning early embryonic life is TRUE?
- During implantation the morula penetrates the endometrial stroma
- Epiblasts in a three-week embryo will become ectoderm
- Implantation occurs 3-4 days following fertilization
- Paraxial plate mesodermal cells will give rise to the circulatory system
- The midgut is in continuity with the amniotic cavity
- Epiblasts in a three-week embryo will become ectoderm
What proportion of body water is found within plasma?
- 7%
- 26%
- 33%
- 66%
- 100%
- 7%
Which of the following substances is transported into cells by facilitated diffusion?
- Cholesterol
- Ethanol
- Glucose
- Oxygen
- Potassium ions
- Glucose
In a slim adult male standing in the anatomical position, which of the following structures lies most distal from the umbilicus?
- Apex of the heart
- Glans penis
- Left patella
- Right acetabulum
- Urinary bladder
- Left patella
A genetic disease is present within multiple generations of a family. With each generation, the disease presents earlier and is more severe. What is this an example of?
- Anticipation
- Gonadal mosaicism
- Haploinsufficiency
- Penetrance
- Variable expression
- Anticipation
In Evidence Based Medicine, the PICO principle is used to frame and answer clinical questions. What does the C in PICO stand for?
- Cochrane
- Computer
- Consent
- Control
- Critical
4. Control P Patient, problem or population I Intervention C Control, comparison or comparator O Outcomes
Concerning the safe disposal of sharps, which of the following is TRUE?
- Items accidentally discarded into a sharps bin should be removed with forceps
- Sharps bins should be filled to the top before disposal
- Sharps bins should be kept on the floor
- Sharps bins should only be carried by their handles
- Sharps should be carried to the sharps bin in a tray
- Sharps bins should only be carried by their handles
In Sickle Cell disease hypoxia causes the abnormal HbS to... A. Stay the same B. Flip from levo- to dextro-isomer C. Polymerise D. Deform E. Dimerise
C. Polymerise
Sickle cell disease can be treated with hydroxyurea because it…
A. Increases the synthesis of normal HbA
B. Interferes with the translation of mutant RNA
C. Increases the synthesis of HbF (Foetal Hb)
D. Prevents the transcription of mutated DNA
E. Reverses the hydrophobic site caused by the point mutation
C. Increases the synthesis of HbF (Foetal Hb)
Hydroxyurea (hydroxycarbamide) is a myelosuppressive agent and is the only treatment known to reduce the frequency of painful episodes. It causes a shift towards production of red cells with HbF. Exact mechanism of action is not completely understood.
HbF is composed of 2 alpha chains and 2 gamma (not beta) chains. It also has a greater affinity for oxygen than HbA.
This enzyme causes the double helix to unzip: A. Topoisomerase B. DNA polymerase C. Glycosylase D. Helicase E. Amylase
D. Helicase
The process in which mRNA is used to specify the amino acids required for protein formation is known as: A. Translocation B. Transcription C. Translation D. Transference E. Telophase
C. Translation
Transcription – is where DNA is transcribed / copied into mRNA which then leaves the nucleus
Translocation – is where genetic material is exchanged between chromosomes
Translation – is where mRNA is used to specify the amino acids required to make proteins
Transamination – is the reaction in which an amino group is removed from an amino acid during metabolism
Telophase – is a phase during cell division
Concerning ribosomes, which of the following is false?
A. They are assembled outside the nucleus
B. They consist of rRNA and proteins
C. They are assembled inside the nucleus
D. They have a large and a small subunit
E. They can attach to the rough endoplasmic reticulum
A. They are assembled outside the nucleus
Ribosomes are assembled inside the nucleus and then translocate to the cytoplasm through nuclear pores where they remain free or can be attached to the rough endoplasmic reticulum.
A protein with a number of sub units held together by cross links has this type of structure: A. Primary structure B. Tertiary structure C. Quaternary structure D. Secondary structure
C. Quaternary structure
In Sickle Cell disease an acute pain crisis is typically caused by capillary occlusion in the… A. Brain B. Skin C. Bone D. Cardiac Muscle E. Spleen
C. Bone
Early presentations can be pain in the hands and feet with severe pain in bones such as femur, humorous, ribs and pelvis occurring in older children. These are due to vaso-occlusive events in the small vessels. Repeated events in the bones can lead to chronic infarcts.
Which of the following is defined as ‘A weak attractive interaction between two atoms due fluctuating electrical charges’ A. Van der Waals force B. Hydrogen bond C. Hydrophobic force D. Disulphide bond
A. Van der Waals force
Disulphide bond – covalent bond between side chains of cysteine residues
Hydrogen bond – A type of Vander Waals force. It is the strongest of them and is the interaction between dipoles, involving an hydrogen and an oxygen/nitrogen/fluorine.
Van der Waals force – A weak attractive interaction between two atoms due fluctuating electrical charges’
Hydrophobic force - the attraction of hydrophobic protein side chains which form tightly packed cores on the interior of proteins which exclude water molecules
In Sickle Cell disease capillary occlusion is now thought to occur by…
A. The sickle cells causing capillary spasm
B. Sickle cells binding together to form a ‘plug’
C. Sickle cells binding with platelets
D. Endothelial damage causing multicellular (platelets, white cells) aggregates which occlude the capillary
D. Endothelial damage causing multicellular (platelets, white cells) aggregates which occlude the capillary
Alpha helixes and beta sheets are examples of protein… A. Primary structure B. Quaternary structure C. Secondary structure D. Tertiary structure
C. Secondary structure
Specific amino acids bind to: A. Single strand DNA B. Messenger RNA C. Transfer RNA D. Double strand DNA E. Double stranded RNA
C. Transfer RNA
tRNA carries specific amino acids to the ribosome and checks they are incorporated in the right location.
This enzyme unwinds supercoiled DNA: A. Helicase B. Glycosylase C. Amylase D. Topoisomerase E. DNA Polymerase
D. Topoisomerase
Helicase unzips the double helix
DNA polymerase is involved in the synthesis of DNA using deoxyribonucleotides. DNA polymerase reads the existing DNA strands (3’ to 5’) to create two new strands.
Topoisomerase unwinds the supercoiled DNA strand to give an uncoiled DNA strand
Glycosylases are involved in the repair of damaged bases in DNA
Amylase is an enzyme present in saliva which starts the breakdown of starch to sugars
Sickle cell anaemia (HbS) is caused by:
A. An autosomal dominant inherited condition substituting an amino acid in the beta globin chain
B. An autosomal recessive inherited condition substituting an amino acid in the alpha globin chain
C. A random genetic mutation in the beta globin chain
D. An autosomal recessive inherited condition substituting an amino acid in the beta globin chain
E. An autosomal dominant inherited condition substituting an amino acid in the alpha globin chain
D. An autosomal recessive inherited condition substituting an amino acid in the beta globin chain
Sickle cell anaemia is an autosomal recessive inherited condition which substitutes valine for the normal glutamine in the beta globin chain.
In Sickle Cell disease the HbS structural change causes sickling by…
A. Changing the charge across the cell membrane
B. Altering nuclear transcription of cytoskeletal proteins
C. Dehydrating the cell by osmotic action
D. Binding to the cytoskeleton
E. Pulling on the cell membrane
D. Binding to the cytoskeleton
Deoxygenated HbS polymerises and binds to the cell cytoskeleton which distorts the normal cell shape into the classic sickle shape.
GP suspects that his young patient has cranial diabetes insipidus. This is a disorder in which the pituitary gland fails to release ADH when stimulated to do so. She is referred for a water deprivation test during which she is nil by mouth?
If the patient does have diabetes insipidus and is not producing any ADH which of the following is MOST LIKELY to show her blood and urine osmolality after 3 hours of water deprivation?
(Normal serum osmolality275-295mOsm/Kg; urine osmolality varies from very dilute (50) to very concentrated (1400mOsm/Kg)
A. Blood 220/urine 100
B. Blood 220/urine 1200
C. Blood 300/urine 1200
D. Blood 300/urine 100
E. She won’t produce urine
D. Blood 300/urine 100
During the water deprivation test the body should detect an increased serum osmolality (300) and produce ADH in order to promote water retention.
As she is unable to produce ADH she will produce dilute urine (low osmolality, 100) instead of concentrated urine.
You examine a patient and note he has lower leg pitting oedema. You also note that his blood albumin level is low. Which statement correctly describes the relationship between albumin and oedema?
A. A low albumin causes an increase in oncotic pressure and water diffuses out of the blood into interstitial fluid
B. Low albumin is not related to oedema
C. A low albumin causes an increase in oncotic pressure and water diffuses from the interstitial fluid into the blood
D. A low albumin causes a decrease in oncotic pressure and water diffuses from the interstitial fluid into the blood
E. A low albumin causes a decrease in oncotic pressure and water diffuses from the blood into the interstitial fluid
E. A low albumin causes a decrease in oncotic pressure and water diffuses from the blood into the interstitial fluid
A healthy student drinks 2 litres of water in 5 mins. Which of the following correctly describes the physiological response?
A. Osmolality rises - ADH secretion stops - urine volume increases
B. Osmolality falls - ADH secretion stops - urine volume increases
C. Osmolality falls - ADH secretion increases - urine volume increases
D. Osmolality rises - ADH secretion increases - urine volume increases
B. Osmolality falls - ADH secretion stops - urine volume increases
The excess fluid causes a decrease in blood osmolality (osmolarity) which in turn causes a reduction / stopping of Anti Diuretic Hormone release. The kidneys therefore excrete more water leading to increased urine volume.
What is the site of synthesis of aldosterone?
A. Adrenal cortex
B. Distal tubules and collecting ducts of nephron
C. Juxtaglomerular cells
D. Posterior pituitary
E. Hypothalamus
F. Anterior pituitary
A. Adrenal cortex
Steroid hormone released from the adrenal cortex in response to stimulation by angiotensin II.
It promotes sodium reabsorption and potassium secretion in the distal tubules of the kidneys.
What is the principal site of renin production?
A. Juxtaglomerular cells
B. Hypothalamus
C. Anterior pituitary
D. Distal tubules and collecting ducts of nephron
E. Posterior pituitary
F. Adrenal cortex
A. Juxtaglomerular cells
Osmolarity can be calculated from blood results. Which of the following IS a factor in calculated osmolarity? A. Magnesium B. Bicarbonate C. Phosphate D. Urea E. Chloride
D. Urea
What is the most prevalent ion in intracellular fluid? A. Na+ B. K+ C. HCO3- D. Cl- E. Lactate
B. K+
Which of the following is an example of insensible fluid loss? A. Water from respiration B. Urine C. Diarrhoea D. Fluid in abdominal surgical drain E. Vomiting
A. Water from respiration
Insensible fluid loss is loss that is not easily measured e.g. sweating, water lost from respiration, evaporation during abdominal surgery.
Sensible fluid loss is that which is easily measured e.g. urine output, vomit, fluid in surgical drains.
What is the site of synthesis of ADH (antidiuretic hormone)?
A. Adrenal cortex
B. Distal tubules and collecting ducts of nephron
C. Anterior pituitary
D. Posterior pituitary
E. Hypothalamus
F. Juxtaglomerular cells
E. Hypothalamus
Synthesised by the supraoptic and paraventricular nuclei of the hypothalamus.
However it is then stored in the posterior pituitary gland.
Which of the following CORRECTLY describes the action of renin? A. Angiotensinogen to angiotensin 2 B. Angiotensin 1 to angiotensin 2 C. Angiotensinogen to angiotensin 1 D. Angiotensin 2 to angiotensin 1
C. Angiotensinogen to angiotensin 1
Renin is a proteolytic enzyme which activates angiotensinogen to produce angiotensin I.
Total body water (TBW) is distributed into three compartments (Intracellular/interstitial/intravascular). How is the TBW distributed by volume? (Assume healthy 70 Kg man) A. 28L/14L/3L B. 28L/11L/3L C. 42L/11L/3L D. 24L/11L/3L E. 24L/14L/3L
B. 28L/11L/3L
