Wrong Formative True/False Questions Flashcards
Hydrophilic molecules are water soluble.
True
True - the term hydrophilic means “water loving” – they can dissolve readily in water by forming hydrogen bonds. Such substances travel easily in the blood.
Pathological processes are all naturally-occurring disorders that cause disease
False
Pathological processes can also arise unnaturally, for example following traumatic injury or iatrogenic (caused by healthcare) harm.
Plasma pH is proportional to carbonic acid concentration divided by bicarbonate ion concentration
False
Plasma pH is proportional to bicarbonate ion concentration divided by carbonic acid concentration (or CO2 levels as remember we can substitute CO2 for carbonic acid and get the same effect in terms of movement of pH)
In a structured patient history, “ICE” stands for “Introduction, Consent and Explanation”
False
The acronym “ICE” is commonly used to mean “Ideas, Concerns and Expectations”, and is a helpful summary of what you should cover when gathering information about your patient’s perspective.
Intracellular fluid volume can be measured directly.
False
We can only directly measure the volume of fluid compartments of which plasma is a component because we only have access to the plasma (via veins) to inject the marker and sample the diluter marker after equilibration. Plasma is not a component of intracellular fluid (ICF). However ICF is a component of total body water (TBW) so if we measure TBW using heavy water, and we measure ECF using radiolabelled Na+ (remember plasma is a component of both ECF and TBW) we can calculate ICF indirectly by subtracting ECF from TBW.
Radiolabelled albumin can be used to measure extracellular fluid volume.
False
Albumin is a plasma protein and is thus confined to the plasma compartment. It cannot move into the interstitial fluid compartment. Because extracellular fluid (ECF) is a product of plasma volume and interstitial fluid (ISF) volume you need a marker that can move freely between plasma and ISF, but not intracellular fluid, in order to be able to measure ECF volume. Sucrose or radiolabelled Na+ would do the job nicely.
The rough endoplasmic reticulum modifies protein after it has been synthesised.
True
The rough endoplasmic reticulum modifies protein after it has been synthesised.
Bicarbonate ions and phosphate ions are the major buffer systems in the body
False
These two ions form the main buffering agents that help maintain body fluid pH at 7.4.
The phospholipid bilayer forms a barrier to polar molecules.
True
Lipophilic molecules can dissolve straight through the phospholipid bilayer, polar (hydrophilic) molecules must generally travel through protein channels or with the aid of transport proteins.
Erythropoietin is primarily produced by the liver
False.
Produced by the kidneys (85% and 15% in liver).,`
In terms of the electrochemical gradient, the electrical gradient and concentration gradient of a substance are always going in the same direction, but with different magnitudes.
False
the electrical gradient and concentration gradient for any substance may be in the same direction or they may oppose each other. Potassium, for instance, has a concentration gradient favouring outward movement but because the inside of the cell is negative compared to the outside, the electrical gradient favours inward movement of the positively charged potassium ion. However, because the concentration is much greater than the electrical gradient, potassium moves out of a cell when the potassium ion channels open.
It is possible for a solution to be both hyperosmotic and hypotonic
True
Osmolarity describes the number of total solutes in a solution without describing whether they can cross the cell membrane or not. Tonicity describes the number of solutes in a solution than cannot readily cross the membrane (non-penetrating particles). A solution may be hyperosmotic if, for example, it contains a higher level of urea than normal plasma, but if at the same time it contains a lower level of sodium than normal plasma it would also be hypotonic.
The cell membrane is freely permeable to ions.
False
while ions can cross the cell membrane they need help from protein ion channels to do so at any useful speed. These ion channels tightly regulate the movement of ions across the membrane and it is this tight regulation that maintains the concentration gradients and marked differential distribution of ions either side of the cell membrane, or in other words the significant difference in composition between the ICF and ECF.
Glucose crosses the cell membrane by active transport.
False
glucose uses transporter proteins but it enters cells down a concentration gradient so active transport (using energy to drive the movement of a substance against a concentration gradient) is not required.
Erythroblasts are immature red blood cells found in the circulation
False
erythroblasts are immature red blood cells found in the bone marrow. Once released into the circulation they are called reticulocytes. Reticulocytes circulate and mature over the next 24 hours to become fully mature red blood cells (erythrocytes)
The citrate shuttle moves acetyl CoA from the mitochondria to the cytosol to make fatty acids.
True
This step is necessary to transfer the acetyl CoA from the mitochondrial matrix where it is made to the cytosol for fatty acid synthesis. This only happens where the citrate levels in the mitochondria are high and fatty acyl molecules are low in concentration.
Acetoacetate is the only ketone body detected by a urine dipstick test.
True
The test used to detect ketonuria only picks up acetoacetate not Beta-hydroxybutarate. (remember this by a-pee-to-acetate!!) Acetone is usually exhaled. Beta-hydroxybutyrate can be detected in blood using a separate test.
Glycogen in a cell is osmotically inactive
True
Conjugated proteins are those which are composed of two or more separate amino-acid chains.
False
A conjugated protein is one that functions by being attached to another non-protein group, eg glycoproteins, lipoproteins and metalloproteins.
Acetyl-CoA is the gateway for food molecules into the citric acid cycle.
True
Amino acids, fatty acids and glucose (via pyruvate) all enter the citric acid cycle via acetyl-CoA