HT IMMS Flashcards
1
Q
what does the nucleus contain
A
chromatin:
-euchromatin= loosely coiled, expressed
-heterochromatin= tight coils, repressed
nucleus: RNA synthesis
2
Q
where is the main site of ATP synthesis?
A
mitochondria
3
Q
what is SER involved in
A
membrane lipid synthesis & protein storage
phase 1 detoxification
4
Q
what is RER involved in
A
protein synthesis, has many ribosomes
5
Q
what is the structure and function of the Golgi apparatus
A
3 parts:
cis- receives protein and lipid vesicles
medial- modifies these by adding sugars
trans- releases modified vesicles
6
Q
what are lysosomes involved in?
A
protein degradation and cell autolysis
- low pH inside cell (5)
this is maintained by H+ and K+ ATPases
7
Q
what are peroxisomes involved in
A
peroxisome = type of vesicle
-beta oxidation of fatty acids
-produces reactive oxygen species e.g hydrogen peroxide H2O2
-removes H from lipid, alcohol, toxic substances
8
Q
what is the structure and function of microtubules
A
25nm
motor protein arranged in alpha and beta structure.
function= mitosis + structural component of cilia
9
Q
what is the structure and function of intermediate filaments
A
10nm
no motor proteins
function= maintain cell structural integrity + cell 2 cell contact
10
Q
what is the structure and function of microfilaments
A
5-7nm
myosin motor proteins
function= maintains cell shape + mobility
11
Q
3 storage products in cells
A
-lipofuscin
-lipids
-glycoprotein
12
Q
lipofuscin
A
wear and tear pigment- brown
indicates cells are old and have undergone oxidative lipid degradation
13
Q
lipids
A
stored in adipocytes (adipose tissue)
pale, white
14
Q
glycoproteins
A
glucose reserve
found in skeletal muscle + liver
15
Q
5 main functions of cell membrane
A
-semi permeable
-maintains structural integrity of cell
-separates intracellular and extracellular (boundary)
-contains receptors for self/foreign identification
-links adjacent cells
16
Q
membrane proteins: receptors
A
outside binding triggers intracellular response:
- enzyme linked/ ion channel response
-G-coupled response (most common)
extracellular binding, activates pathway internally
17
Q
membrane receptor proteins: channel proteins
A
-ligand gated, depends on ligand binding to open
-voltage gated, imp. 4 impulse transmission
-mechanical gated, open when stretched
18
Q
cell to cell junctions (4 main +2)
A
-tight junctions
-adherens
-demosomes
-gap junctions
-hemidemosome= intermediate filament to extracellular matrix
-focal adhesion= 2 extracellular matrix
19
Q
tight junctions
A
-no passage
-cells sealed like a sheet
e.g GI tract, blood brain barrier
20
Q
adherens
A
-binds adjacent actin bundles of cells in extracellular matrix/cytoskeleton
21
Q
desmosomes
A
-adjacent intermediate filaments joined together
22
Q
gap junctions
A
-allows adjacent passage of ions and molecules from cell to cell
key in myocardium contraction- allows contraction as a synctrum
23
Q
how do molecules move in diffusion & osmosis
A
down a conc. gradient/water gradient
24
Q
what is used in facilitated diffusion
A
protein
25
what is direct active transport
directly using energy to move molecules
e.g Na and K pumps
26
what is indirect transport
co-transport
e.g na moving against conc. gradient & glucose moving down conc. gradient
27
what is exocytosis
expelling of vesicles from cell surface membrane- substances are too big to diffuse out
28
what is endocytosis
intake molecules in phagosomes vacuoles
29
what are the 3 types of endocytosis
phagocytosis- eating/engulfing full cells
pinocytosis- drinking/engulfing dissolved solutes
receptor mediated- engulfing of ligand receptor complex
30
define homeostasis
maintenance of constant internal conditions at a normal range
31
what does autocrine communication act on
the same cell/itself , secretion into ECF
32
what does paracrine communication act on
neighbouring/nearby cell via secretion into ECF e.g Ach @ neuromuscular junction
33
what does endocrine communication act on
on distant (target) cell
secretion into BLOOD
e.g ADH
34
deviation away from the normal causes
negative feedback loop
35
amplification of a signal
positive feedback (not loop)
e.g to amplify blood clotting at site of wound
36
Peptide hormones
-made from a.as, 3-20
-water soluble (dissolve in blood)
-travels through blood & binds to receptor on cell surface membrane
-fast acting
-premade and stored in vesicles
e.gs ADH insulin
37
steroid hormones
-made from lipid cholesterol
-lipid soluble
-move via transport proteins in blood e.g albumin
-diffuse through cell surface membrane
-slow acting
-not premade/stored
e.gs oestrogen, testosterone
38
roughly how many litres of water in a 70 kilo male
42
39
how many litres of water make up ICF in an average adult male
28 (2/3) intracellular ion = K+
40
how many litres of water make up ECF in an average adult male
14 (1/3) intracellular ion= Na+
41
what 2 parts make up ECF
interstitial fluid-11L , outside blood vessels
plasma fluid- 3L inside blood vessels
42
what is sensible water loss
measurable loss
e.g urine, vomit etc
43
what is insensible water loss
immeasurable loss
e.g sweat, breath
44
what does RAAS stand for
Renin angiotensin aldosterone system- mechanism to maintain BP
45
what activates the RAAS (2) and where
activated by a dec. in BP
-detected by juxtaglomerular cells in the afferent arteriole of the kidney
OR
dec. in NaCl
-detected by macula densa cells in distal convoluted tubule
46
during RAAS where is renin released from
juxtaglomerular cells in afferent arteriole
47
what does renin do in the RAAS
cleaves angiotensinogen (liver, inactive) to form angiotensin 1 (active)
48
what converts angiotensin 1 to angiotensin 2
ACE (angiotensin converting enzyme)
-from lung
49
what 3 things does angiotensin II activate
-ADH
-aldosterone
-sympathetic NS
50
where is ADH released from
produced in hypothalamus
released from posterior pituitary
51
what does ADH do in the kidneys
-acts on AP 2 proteins in collecting ducts
increase collecting duct permeability
- more H20 retention
-more ECF
-higher BP
52
where is aldosterone released from
suprarenal cortex of adrenal glands - zona glomerulosa
53
what does aldosterone do in the kidneys
Increases absorption of Na+ in ascending limb of loop if henle- therefore more excretion of K+
H20 follows Na+ ions
-more ECF
-higher BP
54
what antagonist is there to aldosterone
ANP (atrial naturetic peptide)
released by dilated atria when high BP
therefore dec. BP
55
what can excess H20 in ECF cause
oedema
56
define osmolaRity
conc of sub/LITRE of solution
57
define osmolaLity
conc. of sub/ KG of solution
58
define osmotic pressure
pressure exerted by a pure solvent on solution needed to prevent inward osmosis, from solvent to solution
59
define oncotic pressure
albumin pressure om capillary walls keeping fluid in
60
define hydrostatic pressure
pressure from fluid wanting to move out of capillary
61
excess of sodium
HYPERnatremia
causes:
-dehydration
-inc in aldosterone
-failing kidneys
sypmtoms= oedema, high BP
62
sodium deficit
HYPOnatremia
causes:
-excess H20
-dec in aldosterone
symptoms= low BP, over hydrated intracellularly
63
excess potassium
HYPERkalemia
causes:
-kidney failure
-dec. in aldosterone
-alkadosis
symptoms= nerve + muscle issues
64
potassium deficit
HYPOkalemia
causes:
-diarrhoea
-acidosis
-inc. in aldosterone
symptoms= weakness, heart problems
65
excess calcium
HYPERcalcemia
66
calcium deficit
HYPOcalcemia
67
carbohydrate molecule types
mono, oligo, polysaccharide
68
what bonds are in carbohydrates
glycosidic
69
are triglycerides soluble in H20
no, they are hydrophobic
70
what is the main energy source in the body
lipids, via fatty acid oxidation
71
how many naturally occurring a.as are there
20
(8 essential)
72
what is an enzyme
functional tertiary globular protein
73
HbA structure
normal haemoglobin
2 alpha chains
2 beta chains
74
fetal haemoglobin, HbF, structure
2 alpha chains
2 gamma chains- higher O2 affinity
75
sickle HbS structure
2 alpha chains
2 mutated beta chains
76
what is the function of DNA
to store genetic info
77
what is the function of RNA
to transfer genetic info
78
what enzyme unwinds supercoiled DNA
topoisomerase
79
which enzyme breaks the H bonds between nucleotides in DNA
DNA helicase
80
what keeps DNA strands separate during complementary base pairing
single strand bases
81
are DNA strands parallel or antiparallel
antiparallel- run opposite ways
3,5
5,3
82
which enzyme catalyses phospho-diester bonds between free nucleotides
DNA polymerase
83
what direction does DNA polymerase read and synthesise a DNA strand
read- 3,5
synthesise- 5,3
84
which enzyme joins ozaki fragments via phosphodiester bonds
DNA ligase
85
what is the promoter region where free mRNA nucleotides start binding from
TATA box sequence
start codon always= AUG
86
define splicing
removal of non coding regions (introns) in pre mRNA
- extrons only are expressed
87
what happens in the G1 phase of the cell cycle
-organelles replicate
-DNA doesn't yet
G1 checkpoint- for damage to DNA
-tumour receptor cells
88
what happens during the S phase of the cell cycle
DNA replicates
89
what happens in the G2 phase of the cell cycle
prep. for mitosis
G2 checkpoint- to check DNA damage before mitosis
90
what does it mean when a cell enters the G0 phase
a cell is fully differentiated and will not continue to replicate
91
list the stages of mitosis
prophase
pre metaphase
metaphase
anaphase
telophase
cytokinesis
92
prophase
-nuclear envelope breaks
-centrioles (made of tubulin) move to polar ends of cell, form mitotic spindle
-chromosomes condense, become visible
93
prometaphase
centromeres bind to spindle
94
metaphase
chromosomes line up on equatorial plane of cell
95
anaphase
v shaped chromatids
-sister chromatids pulled to polar ends of cell
96
telophase
chromosomes turn back to chromatin- no longer visible
nuclear envelopes reform around chromatin
97
cytokinesis
division of cytoplasm- produces 2 genetically identical daughter cells
98
what happens during meiosis I
becomes haploid
99
when does crossing over occur in meiosis
prophase 1
100
when does independent segregation occur in meiosis
metaphase 1
101
what happens during meiosis 2
sister chromatids split
102
when does spermatogenesis occur
begins at puberty
103
when does spermatogenesis occur
begins at puberty
104
when does oogenesis begin
at birth, then suspended til ovulation begins
- uneven cytoplasm division, meiosis 2 only occurs after fertilisation
105
what is non disjunction
failure of chromosomes to separate
downs, turners
106
what is gonadal mosaicism
parent has mutated germline, therefore mutation will be present in only some gametes
107
define polymorphism
non pathogenic variation at locus of normal allele
108
define consanguinity
unity of two relatives
109
define penetrance
% of people with expected phenotype from their genotype
110
define variable expression
same genotype expressed differently
111
define anticipation
wider trinucleotide repeats of mutated sequence over generations
symptoms= earlier + more severe
112
define line onset
manifestation of disease later on in life, not a birth
113
define autozygosity
same mutation from both sides of the family
114
define hemizygous
genes come on unpaired chromosomes
115
define haploinsufficeny
mutation where diploid organism only has 1 functional copy of gene, single gene does not produce enough gene product for wild type phenotype, resulting in disease
116
define lyonisation
1 female x gene randomly inactivated
117
define imprinting
1 allele expressed of the 2 inherited
118
define sex limitation
gene defect affects 1 sex only
e.g breast cancer
119
which genotypes are affected in autosomal dominant diseases
AA, Aa
-no carriers since 1 allele means it will be expressed
-M + F affected equally
e.g Huntington's
120
which genotypes are affected by autosomal recessive disease
aa
-Aa is a carrier, therefore can skip generations
-m + f equally affected
e.g cystic fibrosis
121
x-linked mutations
female carriers
men always affected as only 1 X
if mutated, gene is expressed
122
y- linked mutations
only affects males
-father will pass mutation onto all sons
123
what causes CF
F508 defect
124
which parent do children inherit mitochondria from
only from mother- only f have mitochondrial DNA, therefore any mutations in this DNA always come from mother.
125
deletion mutation
removes base- causes frame shift
126
duplication mutation
repeating base-causes frame shift
127
inversion mutation
DNA segment reversed
paracentric- outside centromere
pericentric- inside centromere
128
translocation mutation
exchange of non homologous chromosomes
129
substitution mutation (2 types)
misense- causes new a.a to be coded for, eg HbA to HbS
nonsense- causes premature stop codon formation
130
which arms of a chromosome are p and q
p= short arm
q= long arm
131
what does a karyotype show
the numerical configuration of chromosomes
132
what does an ideogram show
the distinct boundaries and banding of chromosomes
133
define metabolism
all the intracellular reactions that place within the body
rate that this occurs= metabolic rate
134
metabolic rate values
carb- 4Kcal/g
protein- 4Kcal/g
alcohol- 7Kcal/g
fat- 9Kcal/g
135
how many g/ml are there in 1 unit of alchol
8g/10ml
136
where is fat stored in the body
adipocytes
ito cells
(as triglyceride)
137
where are carbs stored in the body
liver
skeletal muscle
(as glycogen)
138
where is protein stored in the body
muscles
(liver)
139
what does the body want to do in the absorptive state
store macromolecules for post absorptive state
-high insulin
-low glucagon
140
when does ketogenesis occur
when there's excess Acetyl CoA, too much to be used for kreb's
141
what is acetyl CoA converted to in ketogenesis
acetate, acetoacetate, beta-hydroxybutyrate (all inactive ketones)
when need arises- ketones reversed back to acteyl CoA for Kreb's
142
what happens in diabetic ketoacidosis
v. high conc of ketones in blood
- therefore low blood glucose + inc. in acidity
143
can the liver use ketones for fuel
no, doesn't have the enzyme to convert ketones to acetyl CoA
144
can the brain use ketones for fuel
the brain mainly uses glucose for fuel but can adapt to use ketones
145
what are 4 functions of haemoglobin
-O2 transport
-CO2 transport to lungs, as carbamnohaemoglobin
-mops us excess H+, therefore acts as buffer
-nitrate oxide transport around body for vasodilation
146
below what pH does acidosis occur
below 7.35
147
above what pH does alkalosis occur
above 7.45
148
what is the response to acidosis or alkalosis called
compensation
149
what happens in metabolic acidosis
low pH
low conc. of HC03-
compensation= deep hyperventilation, clearing more C02 out the body
150
what happens in metabolic alkalosis
high pH
high HC03-
compensation= hypoventilation- incs. CO2, renal HC03- excretion
151
what happens in respiratory acidosis
pH low
CO2 high
compensation= more renal retention of HC03-
therefore more HC03-, low 02
152
what happens in respiratory alkalosis
pH high
CO2 low
compensation= more renal excretion of HCO3
therefore less HCO3, low O2
153
What is type 1 collagen
skin, tendons etc
-provides structure to skin
Densely packed
90% of total collagen
154
What is type 2 collagen
Provides joint support in elastic cartilage e.g in gut lining
155
What is type 3 collagen
Found in muscles, arteries and organs
156
What is type 4 collagen
Makes up layers of the skin
157
What is type 5 collagen
Found in cornea
Some layers of skin, hair and tissue of placenta
