Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Cells molecules and genes > Cytology 3-4 mitochrondria and lecture 3(cytoskeleton) and 4(nucleus) > Flashcards

Cytology 3-4 mitochrondria and lecture 3(cytoskeleton) and 4(nucleus) Flashcards

You may prefer our related Brainscape-certified flashcards:
Organic Chemistry 101 flashcards
0
Q

Which stain used to detect mitochondria and which colour is positive?

A

Mitotracker - pink

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
1
Q

Importance of granules in mitochrondria

A

Maintain low levels of Calcium and Mg ions.

Store these ions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What makes mitochondria semi-independent? (5)

A 
Replicate by fission or fusion with other mitochondria - form larger mitochrondria 
MtRNA, DNA - protein synthesis
Mito-ribosomes
Mt DNA - circular similar to plasmids
RNA polymerase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Composition of outer mitochondrial membrane? (4)

A

50% lipids - main phosphotidylcholine
Porins - channel proteins
Similar to ER membrane
Enzymes - (lipid synthesis, fatty acid metabolism)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Inner membrane composition?

A

20% lipids
Cristae or tubular (in cells specialised for steroid hormone synthesis)
3 transport proteins
Enzymes for ETC and ATP synthase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Where are tubular inner membrane mito found?

A

Cells syn of steroid hormones. Eg adrenal glands, gonads.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is an inclusion?

A

Not metabolically active cytoplasmic component.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Give 5 examples of inclusions

A

Glycogen - hydrolysed to glucose.
Lipid droplets of fat - triglycerides - energy store, insulation, protection.
Cholesterol - component in lipid and steroid hormone synthesis.
Lipofuscins - dead residual body from lysosomal digestion. Increase with age. Common in stationary cells. E.g. Cardiac, skeletal, neurons.
Plectin - adhesion of 3 structural proteins. Micro, intermediate filaments and microtubules. Found at cell to cell junctions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Actin and microtubules tread-milling req.

A

Actin - atp, mg2+, k+

Microtubules - gtp, mg2+

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How are mito proteins formed in the cytosol?

A

Specific Terminus C AA sequence.
Followed by heat shock protein 70.
Translocation into mitochondria via TOM - ITM
Heat shock protein 70 cleaves AA positive terminus C sequence,

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

At what inclination does actin bind to myosin?

A

45 degrees

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Function of actin binding protein?

A

Accelerate/decelerate polymerisation of actin filaments.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What type of myosin do non muscle cells contain?

A

Myosin I

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Nucleus quick points (4)

A

DNA, Double bilayer membrane, nucleolus (protein synthesis), continuous with ER

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Nucleus irregular in….

A

Leukocytes, plasma cells, spermatozoa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Observing nucleus…..(4)

A

Display different shapes,
Not present in all cells eg rbs, platelets
Not present during whole cell cycle (nucleolus)
Multiple nucleus present eg syncytia, plasmodia, dome cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Ratio of nucleus to cytosol

A

Vn / Vcytoplasm - Vn

= k

If k not constant - pathology

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Nucleolus

A 
No membrane, basophilic, granular and fibrillar layer.
Breakdown during pro-metaphase. 
rRNA transcription
Synthesis of ribosomal sub units. 
Surrounded by nuclear chromatin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Inner nuclear membrane?

A

Unique proteins - nuclear lamina - filaments -> lamin proteins A B C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

2 types of chromatin in NUCLEUS

A

Euchromatin - dark, active

Heterochromatin - compacted, not active, electron dense

20
Q

Nuclear lamina size

A

25nm

21
Q

Cell cycle, lamin phosphorylation

A

Prophase, lamin phosphorylation, breakdown NE

Telophase, lamin dephosphorylation, reform NE

22
Q

Nuclear lamina (4)

A

Intermediate filaments beneath NE,
Provides shape and stability, link between DNA + envelop.
Regulates chromatin compartment - therefore gene expresson reg.

Therefore mutation of proteins effects gene expression

23
Q

3 laminopathy

A

Muscular laminopathy - muscle weaken, die - skeletal muscle, heart, conduction of heart
Lipodystrophies - loss of fat from facial area. Decrease in leptin ( hormone which regulates satiety - controls lipid met)
Progeria laminopathy (premature ageing) - patients die within 20 years of birth. Due to abnormal lamin A - accumulation into nucleus therefore effect lamina formation - therefore effect gene expression

24
Q

What is a npc?

A

Nuclear pore comples

25
Q

Function of NPC

A

Channel which Regulates movement of proteins/rna in/out of nucleus

26
Q

Nuclear pre example no.

A

Somatic - 10-20/um^2
Ooctye 40-50/um^2

Active cell - greater no. of pores

27
Q

6 structural features of a NPC

A 
Luminal anchor,
Luminal ring,
Basket,
Ring,
Filament,
Scaffold
28
Q

Trafficking thru nuclear pores?

A

Importins - specific proteins - contain Nuclear localisation sequence(NLS)
Exportination - less common - nuclear exp. sequence (NES)

29
Q

Active transport of proteins into nucleus and give example.

A

Receptor for import.
Bind to nucleus.
Moved thru pore via cytosol fibrils.
Passage requires : GTP

EXAMPLE: ribosome subunits. Proteins syn in cytoplasm. Contain NLS. Into nucleus-nucleolus. Synthesis of ribosomal subunits. Back into cytoplasm

30
Q

Nucleoplasm and nucleocytoskeleton

A

80-90% proteins, 10% Nucleic acids, 1% lipids

Nucleocytoskeleton : fibrous lamina, fibrillary network

31
Q

3 structural areas of nucleolus

A

Fibrillar centre - light stain - 5 chromosome - contain rRNA gene
Dark straining region
Pars fibrillosa - processing + precursor of rRNA
Pars granulosa - assembling of ribosome subunits - completed jn cytoplasm

32
Q

Time taken for a eukaryotic cell to divide

A

2hr-3days

33
Q

Interphase 3 subphases

A

G1 protein syn, organelle replication
S dna replication
G2 atp syn, cytoplasmic element doubling, form mitotic spindle

34
Q

Which staining to see mitosis and nucleus in detail?

A

Feulgen staining - fluorescent strain - red:chromosomes. Green : filaments.

35
Q

3 types of MT In mitotic spindle

A

Free - located at radial MTOC
Kinetochore - shorten, contract - depolymerisation
Polar - lengthen at positive end and slide

36
Q

Dephosphorylation of lamins causes?

A 
Telephase - NE To reform
Then cytokenesis ( division of cytoplasm ) - contraction of contractile ring (containing actin and myosin)
37
Q

Time taken for MITOSIS

A

G1 8++ hr
S - 7-10hr
G2 - 2-5hr
Ipmat - 2 hour

38
Q

What is the G0 phase

A

Resting phase. No replication.

Eg neurons and cardiac muscle. Permanently in resting phase

39
Q

Cell renewal (3)

A

Static - resting phase - eg neurons, cardiac muscle.
Stable - quiescent - eg remove portion of hepatocytes stimulated to replicate.
Continuos - renewing - epidermis

40
Q

Cell no. Maintainence

A

Proliferation, differentiation, apopsis (programmed cell death)

41
Q

Cell differentiation - 3 types of genes

A

House keeper - constitutive genes
Conditional ( on/off )
Specialised ( expressed in certain types of tissue, function and time specific)

42
Q

Apoptosis definition

A

Programmed cell death. Condensed chromatin therefore inactive therefore no rRNA syn therefore no ribosomes therefore no protein synthesis.

43
Q

Morphological changes in apoptosis

A

Cell shrinkage - modification of PM ( phosphotidylserine translocated from PM to EC face). Mitochrondria destruction -> cytochrome C released - activates enzymes (Caspases) - digest cell substrates -nuclear changes (dna fragmentation).

44
Q

Necrosis

A

Cell death after injury
1 cell swell
2 cell lysis
3 tissue inflammation ( apoptosis no inflammation )

45
Q

CASPASES

A

Activate Dnase -> dna fragmentation

46
Q

Gel electrophoresis of apoptotic cells

A

Normal cell - high molecular weight
Apoptotic cells - dna ladder formed
Necrotic cells - low weight

47
Q

5 types of actin binding protein

A

Actin binding protein - fibrin, fascin (eg microvilli) cross link actin filaments into parallel strands
Actin filament severing - cut into short fragments (eg gelsolin - high ca2+ conc - severing)
Acting capping - tropomodulin - prevent polymerisation
Actin cross linking - cross link actin filaments ( spectrin, actin, protein 4.1, 4.3
Actin motor proteins - hydrolysis of atp - recock myosin head

Cells molecules and genes (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions