Brainscape's Knowledge GenomeTM

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


See full index

Nutrition Semester 1 > BMS1060: Cell division/death and connective tissue > Flashcards

BMS1060: Cell division/death and connective tissue Flashcards

1
Q

What are the different phases of the cell cycle?

A

M phase - mitosis and cytokinesis

Interphase:
G1 phase - cell growth
S phase - DNA replication - chromatin proteins produced
G2 phase - cell growth

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

Name the stages of the M phase.

A

Prophase
prometaphase
Metaphase
Anaphase
Telophase

Cytokinesis

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

What is cohesin?

A

Cohesin is a protein complex that holds sister chromatids together. It is in the form of a ring - encircling the sister chromatids.

Cohesus disintegrates during metaphase to allow sister chromatids to separate and move to opposite poles of the cell in anaphase.

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

What occurs in prophase?

A

Replicated chromosomes condense. Mitotic spindles assemble between the two centrosomes (outside nucleus).

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

What occurs in prometaphase?

A

Breakdown of nuclear envelope. Chromosomes attach to spindle microtubules via kinetochores.

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

What occurs in metaphase?

A

Chromosomes line up along the equator of the spindle. Kinetochore microtubules attach sister chromosomes to opposite poles of spindle.

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

What occurs in anaphase?

A

Sister chromatids synchronously separate to from two daughter chromosomes - each pulled towards the spindle poles it faces.

Kinetochore microtubules get shorter, and the spindle poles also move apart.
Contributes to chromosome segregation.

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

What occurs in telophase?

A

Two sets of daughter chromosomes arrive at the poles of the spindle and decondense.
New nuclear envelope reassembles around each set.
Division of cytoplasm begins.

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

What occurs in cytokinesis?

A

Cytoplasm is divided by a contractile ring of actin and myosin filaments - producing 2 daughter cells (1 nucleus, 1 centrosome, share of all organelles)

DNA decondenses and cells return to resting interphase G1.

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

What is included in the actin cytoskeleton? What does it do? What happens to it during mitosis?

A

Actin cytoskeleton -> Actin filaments, accessory and regulatory proteins.

Can produce protrusive and contractile forces - defining cell shape.

During mitosis, actin cytoskeleton is dismantled and rearranged.
At end of mitosis, actin rearranges - important in separating centrosomes in cytokinesis.

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

Describe the structure of the spindle

A

Array of microtubules

Kinetochore microtubules attached to sister chromatids via kinetochores.

+ ends of kinetochore binds to large numbers of microtubules.

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

The cell cycle is based on a series of _____ whcih initiate specific cell-cycle events.

What are the 3 major regulatory transitions they are involved with?

A

swtiches (on/off)

1) G1/S transition
2) G2/M transition
3) Metaphase/Anaphase transition

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

What do Kinases do?

A

They catalze phosphorylation (ATP -> ADP + Pi)

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

What are the main enzymes involved in the cell-cycle control system?

What binds to them to activate them?
What binds to them to inhibit them?

A

Cyclin-depenent kinases

Cyclins

Cdk inhibitor proteins

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

When does cyclin-dependent kinase activity increase in the cell cycle?

A

At the G2/M transition -> increases phosphorylation of proteins that control events in early mitosis

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

There are cyclic changes in concentration of _______ throughout the cell cycle, which result in different levels of ________ of cyclin-dependent kinases - causing the different _____ of the cell cycle.

A

Cyclin

Activation

Stages

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

How is meiosis different to mitosis?

A

There are 2 successive rounds of chromosome separation (separating homologous pairs, then sister chromatids) in meiosis while only 1 round (separating chromatids) in mitosis.

Meoisis produces 4 haploid (1 copy of each chromosome) cells, while mitosis produced 2 diploid (2 copies) cells.

Meoisis has DNA cross-over to from recombinant DNA - increasing genetic diversity - while mitosis doesn’t.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are bivalent chromosomes?

What is the chiasma?

A

Chromosomes from male and females parents which line up to form exchange points (crossing over).

Chiasma = point of crossing-over

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

Name the 5 stapes of meiotic prophase

A

Leptotene
Zygotene
Pachytene
Diplotene
Diakenesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is histology?

A

The study of tissue and cells - by cutting,
staining and examining under a microscope.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is used to stain samples in histology?

A

H&E

Haematoxylin - basic dye that binds to acidic components (DNA and RNA)

Eosin - acidic dye that binds to basic components (proteins in cytoplasm).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are two types of epithelial tissue?

A

Epithelia - layers of cells covering internal and external surfaces

Glands - structures that produce secretions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are the functions of epithelial tissues?

A
  1. Provide protection
  2. Control permeability
  3. Provide sensation
  4. Absorb nutrients
  5. Secretion
  6. Transport (e.g. ciliated epithelia)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are the characteristics of epithelial tissue?

A

POLARITY- basal and apical surfaces

SPECIALISED CONTACTS - cell junctions, closely packed cells

ATTACHMENT - via basal lamina to underlying connective tissue.

AVASCULARITY - no blood vessel -> diffusion

REGENERATION - replacing lost cells via cell division from stem cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What do apical and basal surfaces come in contact with?

A

Apical - outside environment/internal cavity

Basal - basement membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What benefit comes from epithelial tissues havin specialised contacts? Give examples of these contacts.

A

Increases strength and impermeability - makes cells hard to pull apart.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is the function of the Basal lamina and Reticular lamina? (both part of the basement membrane)

A

Basal Lamina - selective filter

Reticular Lamina - gives basement membrane its strength

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

How do you classify Epithelial tissue?

A

Number of cell layers:
- simple (one)
- stratified (many)

Cell shape:
- Squamous (flat)
- Cuboidal (cube)
- Columnar (column)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is the function and location of the simple and stratified SQUAMOUS epithelium?

A

SIMPLE SQUAMOUS
- diffusion and filtration
- lung alveoli and capilaries

STRATIFIED SQUAMOUS
- protection
- lining esophagus, mouth and vagina. Kertinized type (contain keratin) in skin epidermis etc.

30
Q

What is the function and location of the simple and stratified CUBOIDAL epithelium?

A

SIMPLE CUBOIDAL
- secretion and absorption
- kidney tubules, ducts and secretory portions of small glands

STRATIFIED CUBOIDAL (generally two layers)
- secretion
- lumen of glands (e.g sweat glands)

31
Q

What is the function and location of the simple and stratified COLMNAR epithelium?

A

SIMPLE COLUMNAR
- absorption, secretion and movement (ciliated types)
- digestive tract, ducts of some glands, ciliated respiratory tract and uterous

STRATIFIED COLUMNAR (basal cells cuboidal and superficial cells columnar)
- protection and secreition
- large ducts of glands and urethra

32
Q

What are the two extra unusual classes of epithelial tissue?

A

PSEUDOSTRATIFIED COLUMNAR EPITHELIUM
- seems stratified columnal, but actuallt simple.
- secretes and moves (usually mucus)
- male reproductive tract and respiratory system

TRANSITIONAL EPITHELIUM
- suface cells dome shaped/flat. Basal cells cuboidal/columnar
- stretches to permit distension of bladder
- lines urinary bladder

33
Q

What do glands have a lot of?

A

ER, golgi apparatus and secretory granules.

34
Q

How are glands classified?

A

ENDOCRINE (hormones enter blood/lymphatic fluid) VS EXOCRINE (hormones secreted on skin or in body cavities/ducts)

Unicellular / multicelluar

35
Q

Describe the goblet cell - what kind of gland is it? Where is it found? What does it secrete?

A

Unicellular Exocrine Gland

Found in linings of digestive and respiritory tracts.

Secretes mucin which dissolves in water to form mucus.
Mucus protects (from microorganisms, digestive enzymes, dust particles etc) and lubricates sufraces.

36
Q

Describe multicellular exocrine glands.

A

Composed of duct and secretory unit.

Formed by invagintion of epithelium.

Connective tissue provides support and nutrients to glands.

Classified by mode of secretion.

37
Q

What are the 3 modes of secretion of exocrine glands?

A

MEROCRINE GLANDS - secrete by exocytosis

APOCRINE GLANDS - a portion of plasma membrane buds off cell containing secretion.

HOLOCRINE GLANDS - entire cell disintegrates to secrete product.

38
Q

Why is cell death important?

Any cons?

A

It maintains tissue homeostasis and eliminates harmful cells.

Homeostasis -> Balance between cell growth, division and death

Cons:
- Killing wrong cells (e.g. neurodegeneration)
- Failing to kill cells generated in excess (cancer)

39
Q

What are the 2 main types of cell death?

Briefly describe them

A

Necrosis and Apoptosis

NECROSIS - accidental cell death
Cells swell and burst. Contents released -> inflammation.

APOPTOSIS - Programmed cell death.
Cells engulfed and digested.
Energy (ATP) dependent.

40
Q

What are the 3 other types of cell death?

A

AUTHOPHAGY - degradation of unneccesary/dysfunctional cellular components.

FERROPTOSIS - triggered by accumulation of lethal ROS in cells.

NECROPTOSIC - form of necrosis - triggered by viral loads.

41
Q

What is the role of apoptosis?

A

For tissue structure (e.g. hands and feet development)

When structure is no longer needed (tadpole -> frog)

Quality control - eliminating abnormal cells

Destroying cells that are threats to an organism.

42
Q

Describe the process of Apoptosis

A
  1. Stimulus - > cell shrinks, chromatin condenses.
  2. Membrane starts blebbing. Organelles disintegrate.
  3. Nucleus and organelles collapse. Membrane continues to bleb.
  4. Apoptotic bodies form.
  5. Macrophages phagocytose apoptotic bodies.
43
Q

What are Caspases?

A

Proteases that cleave specific proteins at specific AA sequences. (Particuarly at aspartic acids).

Not all caspases are involved in Apoptosis (11 different caspases)

44
Q

What are the two major classes of apoptic caspases?

A

Initiator and Executioner caspases

(initiator caspases trigger executioner caspases)

45
Q

Briefly describe the mechanism of Initiator caspases.

A

Inactive initiator caspase monomers –Apoptotic signal–> Activated initiator caspase –(cleavage)–> mature active initiator caspase

46
Q

What is a dimer?

A

A chemical compounds consisting of two or more protein monomers

47
Q

Executioner caspases:
- what activates them? How?
- what does activation of one E-caspase lead to?

A

Activated through cleavage by initiator caspases.

Once activated, they cause widespread cleavage of proteins - killing cells and preparing them for engulfment and digestion.

This process is irreversible.

48
Q

What are the two activation pathways for initiator caspase?

A

Extrinsic - signal from outside of cell

Intrinsic - signal from inside the cell

Each uses its own initator caspases.

49
Q

What type of receptors are found in the extrinsic pathway for initiator caspase?

A

Death receptors

Signal proteins from outside to cell bind to these to trigger the apoptotic process.

50
Q

What induces the intrinsic pathway for initiator caspase?

A

Cytochrome C (mitochondrial protein released from intermembrane space into cyctosol).

This initiated adaptor protein, which recruits caspase monomers an apoptosome.

51
Q

What is osteoporosis?

A

A progressice systematic skeletal disease characterized by LOW BONE MASS and MICRO ARCHITECTUAL DETERIATION of bone tissues, leading to increased BONE FRAGILITY and susceptibility of fractures.

52
Q

What is the difference between Osteoclasts and Osteoblasts?

A

Osteoclasts - create resorption cavities - breakdown bones.

Osteoblasts - make bone matrix which is then mineralised - build up bones.

53
Q

How does bone density differ according to age? What can be done to reduce bone density loss?

A

Increase calcium, protein and vitamin D intake. Increase excercise. Decrease alcohol and smoking.

54
Q

The body has mechanisms to keep Ca levels balanced and stable called ________ ___________. If this fails this can lead to __________ or __________.

Vitamin __ plays a vital role in calcium absorbtion.

A

Calcium homeostasis

Hypercalcium or hypocalcum

Vitamin D

55
Q

What is used to measure bone density? What are the levels we need to know?

What should blood pH level be at?

What do you use to measure vitamin D? What does deficiency lead to?

A

Above -1 = normal
-1 to -2.5 = Osteoperia
Below -2.5 = Osteoporosis

normal blood pH = 7.4

Vitamin D is measured using 25 OHD status.
Dificiency -> Rickets in children, osteoporosis or osteomalacia in adults

56
Q

Give some examples of connective tissue diseases.

A
  • Perivascular collagen deposition / collagen vascular disease
  • Autoimmune diseases

Exact causes remains obsucre. Different diseases associatd with specific antibodies

57
Q

Describe smooth muscle
- what types of cells are formed?
- how many nuclei?
- striated?
- voluntary?
- how fast are contractions?

A
  • Fusiform cells (long, interlocking, spindle-like)
  • 1 Nucelus per cell
  • Non-striated
  • Slow, wave-like contractions
58
Q

Describe cardiac muscle
- what types of cells are formed?
- how many nuclei?
- striated?
- voluntary?
- how fast are contractions?

A
  • Branching cells
  • 1/2 nuclei per cell
  • Striated
  • Involuntary
  • Medium speed contractions
59
Q

Describe skeletal muscle
- what types of cells are formed?
- how many nuclei?
- striated?
- voluntary?
- how fast are contractions?

A
  • Long cyndrical cells
  • Many nuclei per cell
  • Striated
  • Voluntary
  • Rapid contractions
60
Q

What are the ‘muscular’ terminologies for cell membrane, cytoplasm and muscle cells?

A

Cell membrane = Sarcolemma
Cytoplasm = Sarcoplasm
Muscle cells = Fibres

61
Q

What is the difference between fast and slow twitch muscle fibres?

A

FAST:
- high force
- low endurance
- fast myosin ATPase
- uses O2 - high capillary density
- high mitochondria density

SLOW:
- low force
- high endurance
- slower myosin ATPase
- anaerobic respiration - high glycolytic capacty

62
Q

What are the functions of muscle?

A

Movement
Heat production
Maintenance of posture and balance
Protects bones and internal organs

63
Q

Label the sections of this muscle fibre

A
64
Q

What does a smooth muscle contraction look like?

A
65
Q

What type of microscopy can be used to view cell junctions?

A

Freeze fracture electron microscopy

66
Q

What are the 3 classifying groups of cell junctions?

A

Occluding or Tight junctions

Anchoring Junctions

Communicating Junctions

67
Q

What do occluding/tight junctions do?

What makes these junctions’tight’ or ‘leaky’?

What proteins are they formed by?

A

They seal epithelial cells tightly together to prevent molecules leaking from one side to the other.

‘tight’ (e.g. blood-brain barrier) or ‘leaky’ (kidney tubules) depending on number of junctions.

Formed by Claudin or Occludin proteins.

68
Q

What do anchoring junctions do?

What are some examples?

A
  • They mechanically attach cells to their neighbouring cells or extracellular matrix.
  • They provide the tissue with strength.
  • They help to form glands.

Examples:
CELL TO CELL Adherens junctions and desmosomes
CELL TO EXTRACELLULAR MATRIX Hemidesmosomes and Focal adhesions

69
Q

What do desmosomes and hemidesmosomes anchor to?

A

Both anchor to intermediate fillaments.

Desmosomes connect cell to cell.
Hemidesmosomes connect cell to extracellular matrix.

70
Q

What do Adheren junctions and Focal adhesians anchor to?

A

They anchor to actin filaments.

Adherens - link cell to cell.
Focal - link cell to extracellular matrix

71
Q

What do communicating junctions do?

A

They mediate the passage of small molecules from one cell to the next.
- ions, vitamins and metabolites but NOT macromolecules (protein, RNA etc)

This allows chemical and electrical transmission between cells.

Nutrition Semester 1 (11 decks)

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