IMMS Flashcards
(212 cards)
1
Q
what are peroxisomes
A
catalase containing vesicles, which converts 2H2O2 to 2H2O and O2
- beta oxidation of fatty acids
2
Q
what are the structures found in the mitochondria
A
matrix (where krebs occurs), crista (ETC) and the inner membrane
3
Q
what is the function of mitochondria
A
respiration and energy generation
4
Q
what is the function of ribosomes
A
Site of protein synthesis
5
Q
what is the function of RER
A
synthesis and processing of proteins
6
Q
what is the function of SER
A
lipid synthesis
7
Q
what is the function of the golgi
A
processing and packaging of proteins
8
Q
what is the function of lysosomes
A
contains acid hydrolases for digestion and recycling
9
Q
what is the function of peroxisomes
A
fatty acid and ethanol oxidation - contains catalase
10
Q
what is lipofuscin
A
yellow brown pigment granules which is made from lipids containing residues of lysosomal digestion. (wear and tear pigment from peroxidation of lipids)
11
Q
where are lipids stored
A
they are stored in adipocytes as triglycerides, in cell membranes, in lipoproteins as HDLs and LDLs
12
Q
what are the different ways molecules move across a membrane
A
simple diffusion, facilitated diffusion and active transport
13
Q
what are the different cell junctions
A
Tight junction, adherends junction, desmosome, hemidesmosome and gap junction
14
Q
what is a tight junction
A
seals neighboring cells together in an epithelial sheet and prevents leakage between them
15
Q
what are adherends junctions
A
joins an actin bundle in one cell to one in another cell
16
Q
what is the function of desmosomes
A
they join the intermediate filaments from one cell to those in another
17
Q
what is the function of hemidesmosomes
A
anchors the intermediate filaments in a cell to basal lamina
18
Q
what is the function of gap junctions
A
allows the passage of small water soluble ions and molecules
19
Q
what is the definition of homeostasis
A
maintenance of constant internal environment
20
Q
what is merocrine, apocrine and holocrine secretion
A
merocrine is no part of the cell is lost in secretion. apocrine is that the top of the cell is lost in secretion and holocrine is the whole cell is lost with secretion
21
Q
Based on a 70kg male, what is the water distribution in their fluid compartments
A
total is 42L. intracellular fluid is 28L, ECF is 14L, interstitial fluid is 11L and plasma is 3L
22
Q
what is osmosis
A
the net diffusion of water across a partially permeable membrane from a high to low water potential
23
Q
what is osmolality
A
the total solute concentration of a solution - number of solute particles per Kg, the higher the osmolality the lower the water potential
24
Q
what is osmolarity
A
total solute concentration of a solution the number of solute particles per 1L of solvent (high osmolarity is a lower water potential)
25
what is the osmotic pressure
pressure that must be applied to a solution on side of a membrane to prevent osmotic flow of water across the membrane from a compartment of pure water
26
what is the oncotic pressure
form of osmotic pressure exerted by proteins (albumin)
27
what is the structure of a phospholipid
hydrophilic phosphate head and a hydrophobic hydrocarbon tail. 2 fatty acids and a phosphate group
28
what are the purines
adenine and guanine
29
what are the pyrimidines
cytosine, uracil and thymine
30
what is the general structure of an amino acid
amino group, a side chain and a carboxyl group
31
what are the different forces acting on proteins
hydrophobic interactions, disulphide bridge, hydrogen bond, hydrophilic reactions and ionic bonds
32
what is topoisomerase
required to unwind the supercoils and unwind the double helix
33
what is the function of DNA helicase
breaks the hydrogen bonds between the two strands exposing the nucleotides
34
what is transcription
free mRNA nucleotides line up against complementary bases on the template strand which begins at the promotor region. this forms an antiparallel RNA which leaved the nucleus and attaches to the ribosome
35
what is translation
the mRNA attaches to the ribosome. the tRNA molecules with anticodons bind to the complementary mRNA codon. along with this the tRNA brings an amino acid in, and once two tRNA are bound to their complimentary codons, their amino acids join via a peptide bond. this process is repeated until a stop codon is reached
36
what are the different types of mutations that can occur in DNA
missense, nonsense and silent
37
what are the stages of the cell cycle
interphase, prophase, prometaphase, metaphase, anaphase, telophase, cytokinesis
38
what happens in prophase
the nuclear envelope breaks down, chromosomes condense and become visible
39
what happens in prometaphase
spindle fibers form
40
what happens in metaphase
chromosomes line up along the central line and each sister chromatid attaches to the spindle fibers from opposite poles
41
what happens in anaphase
spindle fibers contract and sister chromatids pulled towards opposite poles
42
what happens in telophase
the nuclear envelope reforms and cleavage begins, the spindle fibers breaks down
43
what happens in cytokinesis
this is the last stage of mitosis where the cell splits resulting in two identical daughter cells in mitosis, and 4 non identical haploid cells in meiosis
44
what happens in meiosis
there are 4 non identical gametes produced. there is genetic variability through splitting and crossing over
45
what is nondisjunction
caused by a failure of homologous chromosomes to separate properly
46
what is a numerical chromosomal defect
when there are a different number of chromosomes in each cell, i.e trisomy 21
47
what is a structural chromosomal defect
parts of an individual chromosome missing, duplicated or transferred to another chromosome or turned upside down
48
What is gonadal mosaicism
mutation where more than one set of genetic information is present, specifically within the gamete cells. all or part of the prenatal germline is affected by the mutation
49
what is a karyotype
the number and visual appearance of the chromosomes in the nucleus of an organism or species
50
what is multifactorial genetics
where both genetic and environmental factors produce a trait of condition
51
what are different patterns or inheritance
autosomal dominant and recessive, sex linked, lyonization
52
what is lyonization
X inactivation, process by which females have one X chromosome inactivated
53
what is penetrance
proportion of individuals carrying a particular variant allele or a gene and the expression of the associated trait
54
what is variable expression
when one genotype can produce a range of different phenotypes - one individual may be more severely affected by another
55
what is sex limitation
genes may be present in both sexes but only expressed in one and remains turned off in another
56
what are some examples of a genetic disease
downs syndrome, cystic fibrosis, huntingtins, edwards syndrome (trisomy 18) and patau syndrome (trisomy 13)
57
what are some examples of multifactorial disease
spinal bifida, cleft lip/palate, diabetes, schizophrenia
58
what are some examples of environmental disease
poor diet, infection, drug related illness, trauma related illness
59
what is produced during glycolysis
2NADH, 2ATP and 2 pyruvate
60
what is the regulatory enzyme of glycolysis
phosphofructokinase - rate limiting
61
what happens to pyruvate after glycolysis
goes to the link reaction in aerobic conditions and becomes acetyl-coA. in anaerobic conditions they it goes into the lactate cycle
62
where does krebs reaction occur
happens in the matrix of the mitochondria
63
what occurs in the krebs cycle
Acetly-coA - citrate - isocitrate - alpha ketoglutarate, succinyl coA, succinate, fumarate, malate, oxaloacetate
can I keep selling socks for money officer
64
what is produced in the krebs cycle
1 pyruvate in and one ATP, 3 NADH and 1 FADH2 out, as well as 2CO2
65
what is the rate limiting step of krebs cycle
isocitrate dehydrogenase
66
where does oxidative phosphorylation occurs
in the mitochondrial matrix
67
what happens during oxidative phosphorylation
electron from NADH or FADH2 is donated to complex I (or II in the case of FADH2). this is transported from complex to complex (as well as cytochrome c). this then goes to the final electron acceptor (O2). the energy from the electron pumps hydrogen ions into the intermembrane space. this causes a hydrogen gradient. hydrogen is then moved back through the ATP synthase - gradient energy is used to make ATP
68
what happens during fatty acid beta oxidation
this is where fatty acids are broken down to make ATP. first fatty acids are converted into acyl COA in the cytoplasm. (NOT ACETLY COA). the carnitine shuffle transports the acyl coA across the mitochondrial membrane and the oxidation occurs
69
how are ketones made
ketones are made in the liver from two acetyl - coA molecules
70
what are the main ketones to know
acetone, acetoacetate and beta hydroxybutyrate
71
what happens between weeks 1 and 8 of fertilization
week 1 - fertilisation and blastocyst formation
week 2 - bilaminar disc and implantation
week 3 - trilaminar disc and gastrulation
week 4 - folding of the embryo
week 5-8 - most organs are developing and becoming a fetus
72
what is gastrulation
forming of the trilaminar disc
73
what are the three layers formed during gastrulation
ectoderm, mesoderm and endoderm
74
what does the ectoderm form
the epidermis of the skin, the CNS, the PNS, the hair nails and eyes
75
what does the endoderm form
forms the GI tract, the thyroid, parathyroid, liver and respiratory tract
76
what does the mesoderm form
connective tissue in between muscle, bones, cartilage, urogenital system and blood vessels
77
what happens during neurulation
the notochord is derived from the mesoderm through release of chemical messengers which affects the overlying ectoderm. this causes in folding which creates the neural tube and the central canal
78
what are the three structures in the cytoskeleton
microtubules, intermediate filaments and microfilaments
79
what is the size and function of microtubules
they are 25nm long. they are a tubulin motor protein and their function is for mitosis as well as a component of cilia
80
what is the size and function of intermediate filaments
10nm. their function is cell integrity and cell to cell contact
81
what is the size and function of microfilaments
5-7nm. they are myosin motor proteins and their function is cell shape and motility
82
what are the different receptor types
enzyme linked, ion linked and G coupled
83
what are the different types of channel protein
ligand gated, voltage gated and mechanical gated
84
what is a focal adhesion
it is tethers the actin filaments in a cell to the extracellular matrix
85
what is direct active transport
when you directly use energy to move a substance though a cell membrane
86
what is indirect active transport
when you co transport a molecule with another - one down its concentration gradient and the other up its concentration gradient
87
what are the three different types of hormones
peptide, steroid and amino acid derived
88
describe a peptide hormone
they are made from amino acids and are water soluble so travel directly in the blood. they bind to cell surface membranes of a target cell and act quickly. they can be premade and stored in vesicles.
89
give an example of a peptide hormone
ADH and insulin
90
describe steroid hormones
they are made from cholesterol and are lipid soluble. therefore they need a carrier protein to travel in the blood (usually albumin). they diffuse directly through cell membranes and have a slower course of action. it can not be premade
91
give an example of a steroid hormone
oestrogen and testosterone
92
describe an amino acid derived hormone
this is a hormone made directly from an amino acid and has the same properties as a peptide hormone
93
give an example of a peptide hormone
adrenaline
94
what is the main intracellular ion
potassium
95
what is the main extracellular ion
sodium
96
what is sensible water loss
this is measurable water loss for example urine
97
what is insensible water loss
this is water loss that isnt measurable for example sweat or breathing
98
what activates the RAA system
when there is low blood pressure, detected by the juxtaglomerular cells in afferent arterioles. also stimulated by low NaCl detected by macula densa cells of the distal convoluted tubule
99
what cells secrete renin
the juxtaglomerular cells
100
describe what happens in the RAA system
Renin converts angiotensinogen to angiotensin 1 . this is then converted to angiotensin 2 by ACE. angiotensin 2 acts on the adrenal glands to produce aldosterone, as well as increasing ADH release and acting as a vasoconstrictor
101
where is ACE released from
the lungs
102
where is angiotensinogen made
the liver
103
what is the action of ADH
it acts on the AP - II receptor on the collecting ducts to increase the permeability and increases water retention. this increases ECF and therefore BP
104
where is ADH released from
the pituitary gland
105
what is the effect of aldosterone
it increases sodium resorption in the ascending limb of the loop of Henle. Water then follows the sodium, increasing ECF and therefore BP
106
what is ANP and what is its action
it is atrial natriuretic peptide. It is released from the atria when it is enlarged and acts as an antagonist to aldosterone
107
what is hypernatremia
it is too much sodium. it is caused by dehydration, increased aldosterone and kidney failure
108
what is hyponatremia
it is excess water, not enough sodium. its symptoms are nausea, vomiting, headache, confusion
109
what is hyperkalemia
it is too much potassium caused by kidney failure. it causes nerve and muscle issues
110
what is hypokalemia
it is not enough potassium, caused by diarrhoea and increased aldosterone. it causes weakness and heart problems
111
what is hypercalcemia
it is too much calcium. caused by increased vitamin D and skeletal metastasis. it causes bone and muscle weakness as well as calcification
112
what is hypocalcemia
it is too little calcium. it is caused by decreased vitamin D, decreased PTH and GI malabsorption. it causes muscle twitch/spasms
113
what is a nucleoside
it is a nucleotide without the phosphate group
114
what are the 4 structures of a protein
1. amino acid sequence
2. H bonds between amino acids forming alpha helix or beta sheet
3. 3D folding - ionic and disulphide bonds
4. more than 1 polypeptide chain
115
what is the structure of haemoglobin. how is it different in the foetus
it has two alpha and two beta subunits. in the foetus is has two alpha and two gamma which increases the affinity to oxygen
116
what happens in sickle cell anemia
where there is two alpha and two mutated beta chains. there is a mutation at the 11p locus which causes a GAG to become a GTG, which means a valine is coded for rather than a glutamic acid
117
what are the bases in RNA
adenine, uracil, guanine and cytosine
118
what direction does DNA polymerase run in
it joins the free nucleotides together in a 5-3' direction
119
what are formed on the antisense strand of DNA during DNA replication
Okazaki fragments
120
what happens in G1, S and G2 phases of interphase
G1 - organelles replicate
S - DNA replicates
G2 - preparation for mitosis
121
what are the two checkpoints in interphase and what are they checking
G1 checkpoint checks for DNA damage or mutations before replication
G2 checkpoint checks for DNA damage or mutations after replication
122
what is the sequence of sperm formation from most immature to most mature
spermatogonia - primary spermatocyte - 2 X secondary spermatocyte - 4 X spermatids
these then differentiate into spermatozoa
123
when does spermatogenesis begin
it begins at puberty and is consistent after that
124
when does oogenesis begin
it begins at birth/in utero and is then suspended until ovulation
125
is the formation of oocytes even or uneven
uneven cytoplasm division
126
what is the pathway of oocyte generation from most immature to most mature
oogonia - primary oocyte - secondary oocyte (plus 1 polar body) - ootid (plus 3 polar bodies) - ovum
127
what is penetrance
the percentage of people with the expected phenotype from their genotype
128
what is anticipation
it is when the trinucleotide repeats of the mutated sequence increases over generations. symptoms show earlier and they are more severe
129
what is autozygosity
the same mutation found on both sides of the family
130
what is hemizygous
where the genes are carried on an unpaired chromosome (i.e the Y chromosome)
131
what are mandelian forms of inheritance
autosomal dominant, autosomal recessive, X linked and Y linked
132
what is a non traditional form of inherited disease
mitochondrial inheritance
133
In a pedigree chart what does_ mean:
- box
- circle
- unshaded
- shaded
- line through symbol
- two lines to two symbols
- diamond
- diamond sb
- triangle with a line through it
- triangle
- two lines between a circle and square
Male, Female, Unaffected, Affected, Deceased, Twins, Unborn sex unknown, Still born sex unknown, Termination, Ongoing pregnancy, Consanguinity
134
what are some examples of chromosomal abnormalities
Turners syndrome - X monosomy
Downs syndrome - Trisomy 21
Edwards syndrome - Trisomy 18
135
how much energy released from carbohydrates
4 kcal/g
136
how much energy release from protein
4 kcal/g
137
how much energy is released from alcohol
7kcal/g
138
how much energy is released from fat
9kcal/g
139
how many grams of alcohol is the same as a unit
8
140
what is the absorptive state
when youre eating
141
where are fat, carbohydrates and proteins stored
fat - adipocytes, ito cells and triglycerides
carbs - liver and skeletal muscle as glycogen stores
protein - muscle and liver
142
what is the first step of glycolysis and what is the enzyme that catalyzes it
it is glucose to glucose 6 phosphate
| Hexokinase (in liver its glucokinase)
143
what is glucose 6 phosphate converted to in glycolysis (second step)
fructose 6 phosphate
| done by enzyme phosphoglucoisomerase
144
what is fructose 6 phosphate converted to in glycolysis (3rd step)
fructose 1 6 bisphosphate
| done by phosphofructokinase 1
145
what is fructose 1 6 bisphosphate converted to in glycolysis
4th step
into dihydroxyacetone phosphate or G3P.
| enzyme is aldolase
146
can G3P and DHP be converted into each other in glycolysis
yes, it is catalysed by triose phosphate isomerase
147
what does G3P get converted to in glycolysis
| 5th step
to 1 3 bisphosphoglycerate
| catalysed by G3P dehydrogenase
148
what is 1 3 bisphosphoglycerate converted into in glycolysis
6th step
3 phopsphoglycerate
| catalysed by phosphoglycerate kinase
149
what is 3 phosphoglycerate converted to in glycolysis
| 7th step
2 phosphyglycerate
| catalysed by phosphoglycerate mutase
150
what does 2 phosphoglycerate get converted to in glycolysis
| 8th step
to phosphoenolpyruvate
| catalysed by mutase
151
what does phosphoenolpyruvate get converted to in glycolysis
last step
to pyruvate by pyruvate kinase
152
what is the secondary regulatory enzyme of glycolysis
hexokinase - it is controlled by the amount of glucose 6 phosphate
153
what are the two steps in glycolysis that produce ATP
1 3 bisphosphoglycerate to 3 phosphoglycerate
| phosphoenolpyruvate to pyruvate
154
what is are the substrates made in the krebs cycle, from first to last starting with acetyl coA
acetyl coA, citrate, isocitrate, alpha ketoglutarate, succinyl coA, succinate, fumarate, malate, oxaloacetate (cycle starts again)
155
what are the enzymes in krebs, in order of use from start (citrate synthase)
citrate synthase, aconitase, isocitrate dehydrogenase, alpha ketoglutarate dehydrogenase, succinyl coA synthetase, succinate dehydrogenase, fumarase, mutate dehydrogenase
156
when is carbon dioxide given off in the krebs cycle
isocitrate to alpha ketoglutarate
| alpha ketoglutarate to succinyl coA
157
what step(s) in krebs is FADH2 given off at
from conversion of succinate to fumarate
158
what step(s) is NADH produced in krebs
between malate to oxaloacetate,
isocitrate to alpha ketoglutarate,
alpha ketoglutarate to succinyl coA
159
what are the regulation steps in the krebs cycle
citrate synthase - inhibited by ATP and NADH
isocitrate synthase - this is the most regulatory one. the more oxidative phosphorylation the faster krebs will go
AKG dehydrogenase - affected by succinyl coA and NADH
160
what are the two ways acetyl coA can enter into the krebs cycle
from the link reaction, or from beta oxidation of fatty acids
161
what occurs in beta oxidation of fatty acids
the fatty acids are converted to acyl adenylate in the cytoplasm (ATP-ADP). this is then converted into acyl coA by acyl coA synthase.
this is then shuttles into the mitochondrial matrix by the carnitine shuttle. it will then undergo a series of hydrolysis and oxidation reactions to form acetyl coA
162
how much of the bodies ATP is made though beta oxidation of fatty acids
60%
163
what is the rate limiting step of beta oxidation
the carnitine shuttle
164
what is the factor determining if acyl coA can use the carnitine shuttle
it needs to have 12 or more carbons in its fatty acid tail
165
what happens to excess acetly coA in beta oxidation
it will be turned into ketones
166
what does the body use as its buffering system
bicarbonate
167
how does haemoglobin act as a buffer in the body
it mops up excess hydrogen, it can transport NO for vasodilation
168
what happens during metabolic acidosis
there is low pH, low HOC3-
| compensation is deep hyperventilation to increase carbon dioxide excretion
169
what happens during metabolic alkalosis
increased pH, increased HCO3-
compensation is hypoventilation and renal excretion of HCO3-
increase CO2 retention
170
what happens in respiratory acidosis
there is a decreased pH, increased co2
| compensation is increased renal HCO3- retention
171
what happens in respiratory alkalosis
increased pH, decreased CO2
| compensation is increased renal excretion of HCO3-
172
how can you tell the difference between metabolic and respiratory alkalosis/acidosis
in metabolic the CO2 and HCO3- move in the same direction, where as in respiratory they move in opposite directions
173
what are the antioxidant vitamins
E and C
174
what is ROS function in the respiratory burst
phagocytes engulphs the material into a phagolysosome. the pathogen is then destroyed using ROS, myeloperoxidase and OH+
175
what is the equation for the anion gap
([NA+]+[K+]) - ([Cl-]+[HCO3-])
176
what enzyme causes the DNA double helix to unzip
Helicase
177
why can sickle cell anemia be treated with hydroxyurea
because it increases the synthesis of HbF (foetal Hb)
178
why does the HbS cause sickling
Deoxygentaed HbS polymerises and binds to the cell cytoskeleton which distorts the normal cell shape into the classic sickle shape
179
what is sickle cell anemia caused by
Sickle cell anaemia is an autosomal recessive inherited condition which substitutes valine for the normal glutamine in the beta globin chain.
180
Which of the following is defined as ‘A weak attractive interaction between two atoms due fluctuating electrical charges’
Van der Waals force
181
what happens during sickle cell disease capillary occlusion
there is endothelial damage which causes platelets and white cells to aggregate and therefore occlude the capillary
181
what happens during sickle cell disease capillary occlusion
there is endothelial damage which causes platelets and white cells to aggregate and therefore occlude the capillary
182
capillary occlusion in what causes acute pain crisis in sickle cell disease
capillary occlusion in the bone
183
wat enzyme unwinds supercoiled DNA
topoisomerase
184
what happens to HbS during hypoxia
it polymerases
185
what are alpha helixes and beta sheets examples of
secondary structure
186
The process in which mRNA is used to specify the amino acids required for protein formation is known as ...
Translation
187
what is the action of renin
angiotensinogen to angiotensin 1
188
what is an example of insensible fluid loss
water from respiration, sweat
189
What is the site of synthesis of aldosterone?
Adrenal cortex
190
What is the site of synthesis of ADH (antidiuretic hormone)?
Synthesised by the supraoptic and paraventricular nuclei of the hypothalamus.
However it is then stored in the posterior pituitary gland
191
Total body water (TBW) is distributed into three compartments (Intracellular/interstitial/intravascular). How is the TBW distributed by volume? (Assume healthy 70 Kg man)
28L/11L/3L
192
What is the principal site of renin production?
Juxtaglomerular cells
193
You examine a patient and note he has lower leg pitting oedema. You also note that his blood albumin level is low. What is the relationship between albumin and body fluid?
A low albumin causes a decrease in oncotic pressure and water diffuses from the blood into the interstitial fluid
194
A healthy student drinks 2 litres of water in 5 mins. What describes the physiological response?
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.
195
what is a high energy bond
a chemical bond that releases as much or more energy than that released by ATP hydrolysis
196
what is the end product of fatty acid beta oxidation
Acetyl coA
197
what blood measurements are associated with diabetic ketoacidosis
high glucose, high H+, low pCO2 and low pH
198
what are steroid hormones made from
cholesterol
199
what is an anabolic reaction
synthesis of larger molecules from smaller components
200
what is the average amount of protein we require each day
0.8g/kg body mass
201
what is the bodies normal response to an increase in ECF osmolality
release ADH from the posterior pituitary
202
what are the features of urothelium
it can stretch
| it has a layer of umbrella cells on the top of pseudo stratified cells
203
how many kcal are there in 1 unit of alcohol
56 kcal
1g alcohol is 7kcal and 1 unit is 8 grams
204
what will raise basal metabolic rate
increased body weight, hyperthyroidism, low ambient temperature, fever and caffeine
205
what will lower basal metabolic rate
dieting/starvation, low body mass index, high ambient temperature, increasing age and being female
206
when does implantation of a blastocyst occur
7-8 days post fertilisation
207
what will the embryological epiblast become
ectoderm
208
what do paraxial mesodermal cells in an embryo form
somites
209
what is the embryological circulation formed from
lateral plate mesodermal cells
210
what proportion of body water is found in the plasma
7%
211
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
