IMMS Flashcards
Name 2 double membrane organelles within a cell
Nucleus
Mitochondria
Where is DNA found in the cell
Nucleus
AND MITOCHONDRIA
In what type of cells is heterochromatin likely to found in higher concentrations? How does is appear on an electron miscroscope
Inactive cells
Darkly stained
In what type of cells is euchromatin likely to found in higher concentrations? How does is appear on an electron miscroscope
Active cells
Lightly stained
What it the role of the nucleous
Synthesis ribosomal RNA
What is the role of mitochondria?
Site of aerobic resp/oxidative phosphorylation
What role do the outer membranes of mitochondria have?
Lipid synthesis
Fatty acid metabolism
Where in the mitochondria does the ETC take place?
Inner membrane
Where in the in mitochondria does the Krebs/TCA cycle take place
Matrix
What are the extensions of the inner mitochondrial membranes called?
Cristae
Where are proteins systhesised
Ribosomes/RER
What is the function of the SER
Lipid synthesis
Ca2+ storage
Protein processing
What are the 3 parts of the golgi apparatus and what are their individual roles?
Cis golgi - entry of molecules, some phosphorylation
Middle golgi - main processing centre, addition of sugars
Trans golgi - proteolysis (cut ends of proteins - active form), exit in vesicles
Give the 5 types of vesicles that may be found in a cell
1) Golgi derived
2) Cell surface derived
3) ER derived
4) Lysosomes
5) Peroxisomes
Describe the features of a lysosome
H+-ATPase on surface - acidic
Hydrolytic enzymes
What is an peroxisome? What is it role?
A type of vesicle that takes in O2. Removes from hydrogen from organic molecules, forms H2O2 and oxidised long chain fatty acids.
What enzymes are found in a peroxisome
D-amino acid oxidase
Catalase
Ureate oxidase
What are the 3 component of a the cell cytoskeleton
Microfilament
Intermediate filament
Microtubule
What is microfilament composed of? (5nm) And what is it role?
F-actin
Form mesh inside cell surface for structural support
Allows membrane to move - phagocytosis
Give 3 examples of intermediate fillament? (10nm) And state the roles of microfilaments
Laminin
Desmin
Keratin
Anchored to transmembrane proteins and spread tensile forces throughout the tissue
What is microtubule filament composed of?(25nm) Describe its structure
Tubulin
alpha and beta molecules arranged into groups of 13 to give a hollow tube-like structure
Give two used of microtubules
Axonal transport
Chromosome separation, arise from centrosomes
What is a centrosome?
Two centrioles
What are the 4 different types of proteins found in the plasma membrane?
Transport proteins
Receptor proteins
Enzymes
Cell adhesion molecules
What is endocytosis?
Region of plasma membrane that fold into the cell, forming intracellular vesicles
What percentage of the body weight does water contribute? How many litres is the?
60%
42L
What percentage of the water in our bodies is intracellular? How many L?
40%
28L
What percent of water in the body is extracellular? How many L?
20%
14L
What are the 2 division of the ECF?
Plasma
Interstitial
How many litres of fluid are found in the plasma of the ECF?
3L
How many litres of fluid are found in the interstitium?
11L
What is/are the predominant electrolyte(s) in the ECF?
Na
Chloride
Bicarbonate
What is the predominant electrolyte in the ICF?
K
What is the transcellular fluid?
(ECF) Makes up CSF, digestive fluid, mucus etc
What are the main osmotically active substances in the ECF?
Sodium
Chloride
Glucose
Urea
What is the main osmotically active substance in the ICF?
K
What are the 3 methods of fluid intake
Drinks
Diet
IV
What are the 2 types of water loss?
Sensible and insensible
State the sensible loss of fluid?
Urine - kidneys
State the insensible losses?
Vomiting
Breathing
Sweating
Faeces
What are the 3 regulating hormones of water homeostatis?
ADH
Aldosterone
Atrial Natriuretic Peptide
How is osmolality of the ECF increased?
Increased solutes
Decreased water
Where are osmoreceptors located?
Hypothalamus
What hormone is released in response to an increase in osmolality?
ADH
What hormone is released when renal blood flow is decreased?
Aldosterone
What is the action of aldosterone?
Increased Na reab
K secretion
Also stimulates ADH
State the causes of dehydration?
Decreased in take - drink
Increased lose - urine/sweat
Decreased ADH
Hyponatraemia is a consequence of what?
Dehydration
Define hydrostatic pressure
Pressure diff between capillary blood and interstitial fluid
Hydrostatic pressure decreased from arterial end to venule end
In which direction does hydrostatic pressure cause water and solute to move?
From cap to interstitium
Define oncotic pressure
The osmotic pressure cause by the difference in protein concentration between the capillary blood and interstitial fluid
In which direction does oncotic pressure cause water and solute to move?
From interstitium to plasma
Define odema
XS water intracellular tissue
Define osmolality/osmolarity
The amount/conc of a solute in a solution/the measure of the no. of dissolved particles per unit of fluid
Give the units for osmolality
m(Os)mol/Kg
Give the units for osmolarity
mmol/L
Define osmosis
The spontaneous net movement of water through a semi-permeable membrane to a region of higher solute concentration
Define oncotic pressure
Form of osmotic pressure exerted by proteins, tends to cause water to move from interstitium to plasma
What are the 4 different types of odema
Inflammatory
Venous
Lymphatic
Hypoalbuminaemic
Give 2 examples of positive feedback mechanisms
Clotting cascade
Oxytocin release
Give examples of negative feedback
Temp regulation
BP reg
BM reg
Metabolic regulation
Define osmotic pressure
The pressure exerted on water by the movement of solute
What happens in inflammatory oedema?
Leaky capillaries
What happens in venous oedema?
Increase end pressure
What happens in lymphatic oedema?
Decreased lymphatic drainage
What happens in hypoalbumaenic oedema?
Low albumin in capillary, decrease in oncotic pressure less water moves back to cap
State the causes of hypernatriaemia
Increased Na - diet/mineralcorticoids-aldosterone
Decreased water - low intake, high output
What is meant by a negative gibbs free energy (delta G)
Reaction is spontaneous
In which direction is DNA synthesised?
5’ to 3’ direction
State the stop codons RNA
UAG, UGA, UAA
State the start codon
AUG