IMMS Flashcards
Water distribution: how much water is there in:
a) the ECF?
b) the ICF?
a) 14L
b) 28L
Water distribution: how much water is there in the (ECF):
a) interstitial fluid
b) plasma
a) interstitial - 11L
b) plasma - 3L
What is the predominant electrolyte(s) in the ICF?
K+
What is the predominant electrolyte(s) in the ECF?
Na+, Cl-, HCO3-
What is the definition of osmosis?
Movement of H2O across a partially permeable membrane from an area of high water potential to an area of low water potential.
What is the definition of osmolarity?
The number of solute particles per L of fluid. (A high osmolarity has more solute particles per L).
What is the definition of oncotic pressure?
Oncotic pressure is a form of osmotic pressure exerted by proteins, notably albumin, that tends to pull fluid into its solution.
What is the definition of osmotic pressure?
The pressure that must be applied to a solution to prevent inward osmosis through a partially permeable membrane.
Electrolyte homeostasis: what is the cause(s) of hypernatremia? And what are the risks?
Cause - water deficit (poor intake, diabetes insipidus etc).
Risks - Dehydration.
(High sodium = low H2O which dehydrates the brain).
Electrolyte homeostasis: What is the cause(s) of hyponatremia and what are its risks?
Causes: Excess water due to IV fluids, diuretics.
Risks: Over hydration - headache, confusion.
Electrolyte homeostasis: What is the cause(s) of hyperkalemia and what are its risks?
Causes: renal failure, acidosis, diuretic inhibitors.
Risks: Cardiac arrest.
Electrolyte homeostasis: What is the cause(s) of hypokalemia and what are its risks?
Causes: D+V, alkalosis, diuretics.
Risks: weakness and dysrhythmia.
Electrolyte homeostasis: What is the cause(s) of hypercalcemia and what are its risks?
Causes: hyperparathyroidism, Vit D toxicity, malignancy.
Risks: renal stones and metastatic calcification.
Electrolyte homeostasis: What is the cause(s) of hypocalcemia and what are its risks?
Causes: renal disease, Vit D deficiency, intestinal malabsorption.
Risks: tetany (spasms).
What is the function of rough ER?
Protein synthesis
What is the function of smooth ER?
Lipid synthesis
What is the function of the golgi apparatus?
Processes and modifies ER products.
What is the cis face of the golgi apparatus?
The cis face is nearest the nucleus and receives ER vesicles.
What does the medial Golgi do?
It modifies products by adding sugars forming oligosaccharides
What does the trans face of the golgi do?
It sorts molecules into vesicles.
What are the functions of vesicles?
Transports and stores materials. These are membrane bound organelles.
What are desmosomes?
Attach cells via the intermediate filaments.
What are tight junctions?
Binds cells together to prevent leakage of molecules in between them.
What is the function of gap junctions?
Conduct electrical signals.
List 4 functions of a plasma membrane.
- Physical boundary for the cell.
- Regulates the movement of substances.
- Has receptors for cell to cell signalling.
- Attaches the cell to the external environment.
Name 4 molecules you’d find in a plasma membrane.
- Cholesterol
- Glycoproteins
- Glycolipids
- Integral proteins
Define genotype.
The genetic constitution of an individual.
Define phenotype.
The appearance of an individual due to the environment and genetics.
Water distribution: How much water is there in the ICF?
28L
What is an example of type 1 collagen?
Bone, skin and teeth.
What is an example of type 2 collagen?
Cartilage.
What is an example of type 3 collagen?
Arteries, liver, kidneys, spleen, uterus
What is an example of type 4 collagen?
Basement membranes
What is an example of type 5 collagen?
Placenta
Define allele.
An alternative form of a gene at a specific locus.
Give an example of an autosomal dominant condition.
Huntingtons disease.
Give an example of an autosomal recessive condition.
Cystic fibrosis.
Summarise autosomal dominant inheritance.
- Manifests in the heterozygous state.
- Male to Male transmission is seen.
- Both males and females are affected equally.
- The disease is present in several generations.
- There is a 50% chance of offspring having the disease.
Summarise autosomal recessive inheritance.
- Manifests in the homozygous state.
- The disease is often not seen in every generation.
- 25% chance of offspring having the disease.
- 50% chance of offspring being carriers.
- Healthy siblings have a 2/3 chance of being carriers.
Give an example of an X linked recessive condition.
Duchenne muscular dystrophy
What is a mis-sense mutation?
A single nucleotide change results in a codon coding for a different amino acid. This can result in a non functional protein or can have no effect (degenerative nature of the genetic code).
What is a non-sense mutation?
A single nucleotide change that produces a premature stop codon. This results in an incomplete/non-functional protein.
What are the products of glycolysis?
2 ATP, 2 NADH, 2 Pyruvate
What is the rate limiting enzyme in glycolysis?
Phosphofructokinase-1
Where in a cell does glycolysis take place?
Cytoplasm
Where in a cell does the Krebs cycle take place?
The matrix of the mitochondria
Define metabolism.
Chemical reactions that occur in a living organism.
Define BMR.
The energy needed to stay at live rest. (24kcal/Kg/day)
How much energy do carbohydrates provide?
4kcal/g
How much energy do proteins provide?
4kcal/g
How much energy do lipids provide?
7kcal/g
How much energy does alcohol provide?
9kcal/g
How much energy is stored as triglycerides?
15kg
How much energy is stored as glycogen? And where is it stored?
350g
- 200g in the liver
- 150g in muscle
How much energy is stored as protein?
6kg
What factors increase BMR?
Being overweight, pregnancy, low temperature, exercise, hyperthyroidism
What factors decrease BMR?
Increasing age, being female, starvation, hypothyroidism
What are reactive oxygen species?
Reactive molecules and free radicals derived from O2
Name 3 exogenous sources of ROS?
Smoking, UV radiation, drugs
Name an endogenous source of ROS?
Produced as a by product of O2 metabolism
Name 3 ketone bodies
- acetoacetate
- acetone
- beta hydroxybutyrate
Where does ketogenesis usually occur?
In the liver
When would ketogenesis occur?
During high rates of fatty acid oxidation too much acetyl CoA is produced; this overwhelms the Krebs cycle and so you get ketone body formation
What molecules make up ATP?
1 adenine, 1 ribose, 3 phosphate
Define buffer.
A solution that resists changes in pH when small amounts of acid/base are added.
Name 3 biological buffers.
- Protein
- Haemoglobin
- Bicarbonate
What is the equation to demonstrate the mechanism of a bicarbonate buffer?
H2O + CO2 -> H2CO3 -> HCO3- + H+
Arrows are reversible
How do protein buffers work?
If the pH falls H+ binds to the amino group of the protein.
If the pH rises H+ can be released from the carboxyl group of the protein.
What can cause respiratory acidosis?
Inadequate ventilation due to airway obstruction (COPD, asthma).
What happens to the PaCO2 levels in respiratory acidosis?
PaCO2 increases leading to an increase in H+ ions and so pH decreases.
CO2 production is greater than CO2 elimination
What can cause respiratory alkalosis?
Hyperventilation in response to hypoxia.
CO2 elimination exceeds O2 reabsorption.
List 3 causes of metabolic acidosis?
Renal failure, loss of HCO3-, excess H+ production.
List 2 causes of metabolic alkalosis.
Vomiting (loss of H+), increased reabsorption of HCO3-.
What do fatty acids produce.
Where is this product used?
Acetyl CoA
Used in the Krebs cycle
Name 4 ways in which ATP can be produced?
- Krebs cycle.
- Glycolysis.
- Oxidative phosphorylation.
- Substrate level phosphorylation.
What is gonadal mosaicism?
When there are 2 different populations of cells in the gonads. One population is normal and the other is mutated. All gametes from the mutated line are effected.
What type of cells are produced in mitosis?
2 diploid daughter cells which are genetically identical to the parent cells.
What is mitosis used for?
Growth and repair.
What are the 4 phases of the cell cycle?
G1, S, G2 and M
What phases of the cell cycle make up interphase?
G1, S and G2
What happens in prophase?
Chromatin condenses into chromosomes. Nuclear membrane begins to break down.
What happens in prometaphase?
Spindles form. Nuclear membrane completely breaks down.