IMMS2 Flashcards
(193 cards)
1
Q
What is DNA?
A
Deoxyribonucleic acid
2
Q
What is RNA?
A
Ribose nucleic acid
3
Q
What is structural difference between RNA and DNA? (2)
A
DNA- deoxyribose sugar
RNA- ribose sugar
DNA double stranded
RNA single strand
4
Q
What is function DNA?
A
Store genetic info
AT CG
5
Q
What is function RNA?
A
Transfer genetic info
AU CG
6
Q
What are 3 bases in DNA called?
A
Triplet
7
Q
What are 3 bases in RNA called?
A
Codon
AU CG
8
Q
State process semi conservative DNA replication?
A
1) Topoisomerase unwinds supercoil
2) Helicase breaks H bonds- expose bases
3) Single strand bases- bid exposed bases avoid re-annealing to other strand
4) Free nucleotides bind complimentary to exposed template bases on DNA strands
5) DNA polymerase- catalyse phosphodiester bonds between free nucleotides
Read 3’-5’- antiparallel
Synthesise 5’-3’- antiparallel
6) DNA Ligase joins okazaki fragments- phosphodiester bonds
9
Q
How is DNA configured?
A
Antiparallel configuration
10
Q
Function of SSBs?
A
Bind to exposed bases to avoid reannealing to other strand
11
Q
What are enzymes in DNA replication? (5)
Function?
A
1) Topoisomerase- unwind supoercoil
2) DNA helicase- break H bonds- expose bases
3) SSB’s- bind exposed bases prevent re-annealing
4) DNA polymerase- form phosphodiester bonds between free nucleotides
5) DNA ligase- form ozaki fragments on lagging strand by phosphodiester bonds
12
Q
Where does transcription occur?
A
Nucleus
13
Q
Outline process of transcription?
A
1) Initiation
Topoisomerase- unwinds supercoil
DNA Helicase- break H bonds
SSB’s- prevent reannealing
2) Production
Free mRNA nucleotides bind
Initiated by TATA box sequence (promotor region)
AUG (Methionine)- start codon
RNA polymerase travels 5’ to 3’ from promotor to stop codon
Pre-mRNA released
3) Splicing
Remove introns- now able translated
14
Q
Function of transcription and translation?
A
Synthesise new proteins
15
Q
What are introns?
A
Non-conding codons
16
Q
What are exons?
A
Coding
Exons expressed
17
Q
What is start codon for RNA polymerase?
A
AUG (Methionine)
18
Q
Where does translation occur?
A
Cytoplasm
19
Q
Outline process translation?
A
1) mRNA moves out nuclear pore, enter cytoplasm
2) mRNA bind small ribosomal small unit- recognised by start codon- AUG
3) tRNA- large ribosomal unit- carry aa to mRNA
4) tRNA binds complimentary to mRNA codons using anticodons- form H bonds temporarily
5) Ribosome move along mRNA
6) Once ‘read’ tRNA molecules detach- leave aa
7) Adjacent aa form peptide bonds
8) Polypeptide chain released at mRNA stop codon
9) Sent to golgi
20
Q
What bonds from between amino acids?
A
Peptide bonds
21
Q
How many chromosomes?
A
46 total
44 autosomal, 2 sex
mean 22 autosomal pairs
1 sex pair
22
Q
Where is DNA found? (2)
A
Nucleus
Maternal mitochondria
23
Q
Draw cell cycle
A
24
Q
What parts of cell cycle make interphase?
A
G1
S
G2
25
What occurs during G1 phase?
Preparation
Organelles replicate
DNA doesn't
26
What occurs S phase?
DNA replication
27
In what phase does DNA replication occur?
Synthesis
28
What occurs in G2 phase?
Preparation mitosis
29
What checkpoints are there?
G1 checkpoint- check DNA damage pre-DNA replication
- if damage tumour suppressing genes
activated (p53) activate p21- autolysis to
prevent tumour growth
G2 checkpoint- check DNA damage before mitosis
- remove damaged bases through
glycolyase enzymes
30
Outline cell cycle
G1- organelles replicate, DNA doesn't (prep)
G1 checkpoint- check DNA damage pre DNA replication
- if damage act p53- act p21- cell autolysis
S phase- DNA replication
G2- prepare mitosis
G2 checkpoint- check DNA damage pre-mitosis
- damaged bases removed by glycolyase
Mitosis- PPMAT (C)
G0- NO replication, fully differentiated
31
What phase are cells fully differentiated?
G0
32
What are tumour suppressor genes?
Damage to DNA- act p53 act p21- cell autolysis
33
Outline stages mitosis?
Prophase
Prometaphase
Metaphase
Anaphase
Telophase
Cytokenesis
34
What occurs during prophase?
Nuc envelope breakdown
Centrioles move polar ends
Chromosomes condense- change chromatin to chromosomes
35
What occurs during prometaphase?
Centromeres binds to spindle
36
What occurs in metaphase?
Chromosomes line up on equatorial plate
37
What occurs anaphse?
V shaped
Sister chromatids pulled polar cell ends
38
What occurs in telophase?
Chromosomes to chromatin
2 nuclear envelopes reform
39
What occurs in cytokenisis?
Division cytoplasm
2 genetically identical daughter cells
40
What is function mitosis?
Form 2 genetically identical daughter cells
41
Is cytokenesis part of mitosis?
Yes
42
Outline stages of meiosis?
M1- mitosis 1- genetic info become haploid
- 2n to n
- still 2 sister chromatids
- prophase 1- crossing over
- metaphase 1- independent segregation
M2- genetic info remains haploid
- 1 chromatid chromosomes
43
How is genetic diversity achieved in meiosis?
Prophase 1- crossing over
Metaphase 1- independent segregation
44
What is function meiosis? Produce?
Reduce number chromosomes in parent cell by half
Produces four gamete cells
Needed sexual reproduction
45
What is process of sperm development?
Spermatogenesis
46
What is process of developing egg?
Oogenesis
47
When does spermatogenesis begin?
Puberty
48
Even or unequal cell division in spermatogenesis?
Even
49
Outline process spermatogenesis?
1) Spermatogonia becomes 1 degree spermatocyte
2) M1- 1 primary spermatocyte to 2 secondary spermatocytes
- 2n to n
3) M2- 2 secondary spermatocyte to 4 spermatids
4) Differentiate into mature sperm- spermatazoa
50
What are spermatids?
Immature sperm
51
What does spermatogenesis produce?
4 haploid daughter cells
Genetically different
52
What is mature sperm referred to?
Spermatazoa
53
When does oogenesis occur?
Begins at birth
Suspended until ovulation
54
Even or uneven cytoplasmic division in oogenesis?
Uneven
55
In oogenesis when does miosis 2 occur?
Fertilisation
56
Outline process oogenesis?
1) Oogonia matures primary oocyte
2) M1- from oocyte forms secondary oocyte and polar body
3) M2- from secondary oocyte form ootid and 3 polar bodies
4) Ootid mature into ovum
(only one made)
57
What is M2 division in oogonesis? When occur?
From secondary oocyte to ootid and 3 polar bodies
Only complete at fertilisation
58
What are 2 meiotic pathologies?
1) non-dysjunction
2) gonadal mosaicism
59
What is non-dysjuntion? Give 2 examples
Failure seperate in meiosis 1- chromosomes
meiosis 2- sister chromatids
Trisomy- downs
Monosomy- Turners
60
What is gonadal mosaicism? Example and risk factor?
One healthy parent has mutated germ line
Increase chance age
Duchenne
61
How can parent be healthy but child not?
Gonadal mosaicism
62
Define polymorphism?
Non pathogenic variation at a locus from wild type
63
What is wild type allele?
Normal
64
Define consinguinity?
2 relatives union
65
Define penetrance?
%ppl with expected phenotype from their genotype
66
Define variable expression?
Some ppl express genotype differently
67
Define anticipation? Example
Trinucleotide repeats become bigger over time
Symptoms earlier and more severe
Over 17- CAG huntingtons
68
What repeat causes huntingtons?
CAG
Autosomal dominant
69
Define congenital disease?
At birth
70
Define late onset?
Manifest after birth- later in birth
71
Define autozygosity?
Same mutation from both sides of family
72
Define hemizygous?
Genes carried on an unpaired chromosome
Eg. men hemizygous for genes on Y
73
Define lyonisation?
1 female X randomly inactivated
Prevent 2 genes
Normal
Men doesn't occur
74
Define imprinting?
1 allele suppressed of 2 inherited
75
Define sex limitation? Example
Gene defect effect 1 sex only
E.g BRCA1
76
What are types mendelian traditional disease?
Autosomal dominant
Autosomal recessive
X linked
Y linked
77
Explain autosomal dominant
Carriers?
Transmission between sexes?
How many gen effected?
Example?
Affect AA/Aa- only need 1 pathogenic allele
No carriers
Equal transmission (think m-m pot)
Multiple gen effected
Huntingtons
78
Explain autosomal recessive
Carriers?
Transmission between sexes?
How many gen effected?
Example?
Affects aa- need 2 pathogenic allele
Carriers Aa
Equal transmission
Skip generation due carriers
Cystic fibrosis- middle aged cauc
79
Explain X linked?
No male to male transmission as man never passes X chromo
Female carriers give to affected men
Male 1X therefore always affected if passed it
80
Explain Y linked?
Only males
Dad to all sons
81
What is most common auto recessive disease in male cauc?
What is carrier freq?
What is incidence?
What is defect?
CF
Carrier freq- 1/25
Incidence- 1/2500
F508 defect
82
What is non-traditional disease? Explain?
Mitochondrial- only maternal DNA
- transmission mother to child
83
Define mutations?
Spontaneous DNA base seq change
84
What do genes code for?
AA
85
What do AA code for?
Proteins
86
State meaning symbols
Unaffected clear
Affected shaded
Square male
Circle female
87
Meaning symbol?
Dead male
88
Meaning of symbol?
Twins
89
Meaning of symbol?
Identical twins
90
Meaning of symbol?
Unborn, sex unknown
91
Meaning symbol?
Still birth, sex unknown
92
Meaning symbol?
Termination
93
What is this symbol?
Ongoing pregnancy
94
What does this symbol represent?
Consanguinity- reproductive union 2 relatives
95
What disease type is this?
Autosomal dominant
because
multiple gen effected
m to male transmission
m and f equally
96
What disease type is this?
Autosomal recessive
because
skip generation
more likely manifest consanguinity
m and f equal
97
What is risk factor for autosomal recessive disease?
Consanguinity
98
What disease type is this?
X linked- this dominant
No male to male transmission
99
What is this disease type?
Y linked- from father to all sons
100
Name 5 types mutations?
1) Deletion- remove base
2) Duplication- repeat bases
3) Inversion- DNA segment reversed
- paracentric- outside centromere
pericentric- include centromere
4) Translocation- exchange with nonhomolog chromo
5) Substitution- mis-sense- codes new aa eg. HBA-HBS
- nonsense- cause premature stop codon
101
List 3 stop codons? What mutation an issue?
UAA, UAG, UGA
non-sense- cause premature stop
102
What is in frame deletion?
What is out frame deletion?
Deletion in frame- functional protein
Deletion out frame- disrupt whole protein
103
What is mis-sense mutation? eg
Code new aa
HBA-HBS
104
What is polymorphism mutation?
Non pathogenic- variations
105
What is gene pathogenic mutation?
Affect gene products (proteins)
106
What is whole chromosome mutations? (2 Types)
Numerical- 23 plus minus
Structural- translocations, deletions etc
107
Define karyotype?
Show numerical chromosome configuration
108
Define ideogram?
Show distinct banding of chromosome
109
Draw and label chromosome
Petite arm- p22.3
Q- long arm 36.3q
110
What issues causes following diseases?
Turners
Downs
Edwards
Pataus
Kleinefelders
Turners- X monosomy
Downs- Trisomy 21 (extra chromo)
Edwards- Trisomy 18
Pataus- Trisomy 13
Kleinefelders- XXY trisomy
111
What is centromere arm referred to?
11.1 Increase as go away centromere
22.3- petite
36.3- q
112
Definition of metabolism?
What is metabolic rate?
All intracellular reactions occur in body
Rate this occurs at
113
Energy values?
Carb
Protein
Alcohol
Fat
1 unit alcohol how many grams/ml
Carb- 4 kcal/g
Protein- 4 kcal/g
Alcohol- 7 kcal/g
Fat- 9 kcal/g
1 unit alcohol- 8g/10ml
114
Define absorptive state?
Body wants store macromolecules for post absorptive state
115
What lvls insulin and glucagon in absorptive state?
High insulin, low glucagon
Insulin used storage
116
Where is fat stored?
Adipocytes
ITO cells
Triglyceride
117
Where is carb stored? (2)
Liver and skeletal muscle
Glycogen stores
118
Where is protein stored? (2)
Muscle
Liver
119
What are lvls insulin and glucagon in postabsorptive state?
Low insulin, high glucagon
Glucagon break macromolecule stores
120
What chemical process occurs in postabsorptive state?
Glycogenolysis- glucose reserves used for energy
121
What does glucagon utilise first?
Glucose stores liver and skeletal muscle
Fat stores
Muscle stores
122
Draw glycolysis?
123
Explain each stage glycolysis?
124
What is hexokinase called in liver?
Glucokinase
125
What is rate limiting enzyme in glycolysis?
Phosphofructokinase-1
PFK1
126
TIP 3-2 is mutation therefore enzyme mutase
TIP 3-2 is mutation therefore enzyme mutase
127
What is net yield glycolysis?
2 pyruvate
2 NADH
2 ATP
128
What regulatory steps glycolysis? (2)
1) G6P controls hexokinase action (eqbm)
Higher conc G6P less hexokinase action mean more glucose
2) PFK1- MAIN
Affected- AMP- high AMP high PFK1
- ATP- high ATP low PFK
129
What is rate limiting step in glycolysis?
Fructose-6-phosphate to fructose-1,6-bisphosphate
130
What 2 steps produce ATP in glycolysis?
1-3 bisphosphoglycerate to 3 phosphoglycerate
(2ADP-2ATP)
Phosphoenylpyruvate to pyruvate
(2ADP-2ATP)
131
High or low insulin increase rate glycolysis?
Insulin increase rate glycolysis
Effects PFK
132
Pneumonic
Gross Guys Feed Fat Dorky Girls Balls 4P
133
Does glycolysis require oxygen?
No- anaerobic
134
What does anaerobic respiration produce?
Lactate
NAD+ mean glycolysis continue
135
What respiration is TCA/Krebs involved in?
Aerobic resp
136
What links glycolysis and krebs?
Pyruvate converted acetyl coA
Acetyl coA enters Krebs
137
Draw krebs/TCA cycle?
138
What is main rate limiting enzyme in Krebs?
Isocitrate dehydrogenase
139
What is main rate limiting step in Krebs?
Isocitrate to alpha ketoglutarate
140
What are 3 rate limiting enzymes in Krebs?
1) Citrate synthase- allosteric inh- ATP and NADH
- comp inh- succinyl coA
2) Isocitrate dehydrogenase- MAIN
- demand oxp quicker
3) Alpha ketoglutarate dehydrogenase- conc. products
141
Function of Krebs?
Produce NADH and FADH2 for oxidative phosphorylation
142
Net product Krebs cycle?
2C
3 NADH
1 FADH
1 ATP/GTP
143
Net product Krebs cycle?
2C
3 NADH
1 FADH
1 ATP/GTP
144
How many times can glucose molecules support krebs?
2
145
Where else can acetyl coA enter from?
Beta oxidation of FA
146
What is another source alpha ketoglutarate?
Oxidative deamination of glutamate
Reverse transamination of glutamate and pyruvate
147
What inhibits krebs/tca cycle?
NH3- ammonia
can cross BBB react akg
deplete oxaloacetate
148
Outline oxidative phosphorylation?
1) NADH to complex 1
FADH2 to complex 2
2) Deposit H+ and e-
NAD and FADH2 reoxidised returned resp pathway
3) H+ and e- enter electron chain complex
complex 4 is end of etc
O2 is terminal e- acceptor
4) Energy from electron transport chain pumps H+ across mitochondrial matrix into intermembrane space
5) H+ return through ATPase channels and combine with O2 at complex 4
H+ + O2 = 4e- get 2H20
6) As H+ return through ATPase channels causes ADP combine phosphate from ATP
ADP + Pi= ATP
149
What is terminal e- acceptor in oxidative phosphorylation?
O2
150
Where does glycolysis occur?
Cytoplasm
151
Where does Krebs occur?
Mitochondrial matrix
152
Where does oxidative phosphorylation occur?
Across mitochondrial membrane
153
What equation occurs at complex 4 in oxidative phosphorylation?
H+ + O2 = 4e- get 2H20
154
How much ATP per glucose?
30-34
155
What occurs to Fatty Acids in beta oxidation?
Where is initial reaction?
Cytoplasm
FA converted acyl adenylate in cytoplasm
Acyl adenylate converted acyl coA by acyl coA synthase
1)FA
2) Acyl adenylate
3) Acyl coA
156
Outline process beta oxidation
1) In cytoplasm FA converted acyl adenylate
2) Acyl adenylate converted acyl coA
3) Acyl coA (12C+) shuffled into mitochondrial matrix via cartinine shuttle
4) Undergo series reactions in mitochondria
Oxidation and hydrolysis
5) Produce acetyl coA
6) Acetyl coA enter krebs
157
What is rate limiting step in fatty acid beta oxidation?
Cartinine shuffle
158
Function of beta oxidation?
Oxidation FA to obtain energy
159
What is source of acetyl coA in krebs?
Fatty acid beta oxidation
160
What occurs to acetyl coA formed as result of FA beta oxidation?
1) Krebs cycle
2) Excess- ketogenesis
161
What produces most bodies ATP?
FA beta oxidation
162
What occurs when excess acetyl coA (not all used in TCA)?
Ketogenesis
163
Explain what ketones are? how formed?
Acetyl coA converted acetate, acetoacetate- ketones
Inactive, storage
164
What occurs to ketones when need acetyl coA?
Ketones reversed back to acetyl coA for TCA
165
When does diabetic ketoacidosis occur?
High ketone concentration in blood
Low blood glucose
High acidity due to ketones being weak acid
Affects Hb affinity
166
What can brain use as fuel of glucose reserves out?
Ketones
167
Can liver use ketones for fuel?
No- doesn't have enzyme convert ketone to acetyl coA
168
What is most important buffering system?
169
What enzyme catalyses H2CO3 to H+ + HCO3-?
Carbonic anhydrase
170
What is body pH?
7.35-7.45
171
How is CO2 excreted/enter?
How is H+ excreted?
How is HCO3- recycled?
CO2- ventilation (resp)
H+ is renally excreted (kid)
HCO3- renally (kid)
172
What is equation for carbonic anhydrase method?
173
What is function Hb? (4)
Equations
1) Transport O2 Hb + O2 = HbO2
2) CO2 transport to lungs
3) Act as buffer- mup up H+ Hb + H+ = HbH
4) NO transport around body for vasodilation
174
What is equation for formation oxyhaemoglobin?
175
What is equation for carbaminohaemoglobin?
176
What values for acidosis and alkalosis?
177
What types acidosis and alkalosis?
Metabolic and respiratory
178
What will arterial blood gas read metabolic acidosis?
Compensation?
Low pH
Low HCO3-
Comp- deep hyperventilating
Decrease CO2 (clear acidic gas)
179
What would arterial blood gas read metabolic alkalosis?
Compensation
High pH
High HCO3-
Comp- hypoventilate (increase CO2- acidic)
renal HCO3- excretion
180
What would arterial blood gas read respiratory acidosis?
Compensation
Low pH
High CO2
Comp- increase renal HCO3- retention
- increase HCO3-
181
What would arterial blood gas read respiratory alkalosis?
Compensation
High pH
Low CO2
Comp- increase renal excretion of HCO3-
- decrease HCO3-
182
Respiratory and metabolic acronym
ROME
Respiratory opposite- pH and CO2 opposite things
Metabolic equal- pH and HCo3- move equally
ROME
183
Is HCO3- metabolic or repiratory?
Metabolic
184
Can you have mixed acidosis/alkalosis?
Yes
185
What is anion gap?
Main anions
Main cation
Anions takeaway cations
Anions- Na+ K+
Cations- Cl- HCO3-
186
What is normal range of anion gap?
10-16
187
What is function of ROS?
Key in respiratory burst
Immunological defensive mechanism
Phagocytes release ROS to hydrolyse foreign materials
188
Give example ROS?
ClO-
Destroy bacterial cell membrane and wall
189
Outline reduction oxygen into water?
190
Is H2O a radical?
No- decomposed in chains reaction
191
What is fenton reaction?
What is haber weiss reaction?
192
What is unintended consequence of ROS?
What are diseases associated?
Damage own cells
Parkinsons
Diabetes
Renal failure
193
How is body protected from ROS? (2)
Antioxidant vitamins E C
Cellular compartments
