The Dynamic Cell - Block 6

Front 1

When was the first cell born?

Back 1

3 billion years ago.

Front 2

When were the first eukaryotic cells formed?

Back 2

2 billion years ago.

Front 3

When did the first multicellular organism form?

Back 3

800 million years ago.

Front 4

How are cells stained, and what state must the cell be in for this to happen?

Back 4

The cell must dead, stained with chemicals.

Front 5

How does the phase of light change through a cell?

Back 5

Wavelength shortens, creating a contrast which can then be picked up by the microscope.

Front 6

What are the advantages and disadvantages of immunostaining?

Back 6

Look at specific proteins.
Look at multiple proteins.
Cell must be dead/fixed.

Front 7

What are the benefits of GFP tagging?

Back 7

Cells can be kept alive and observed in situ.

Front 8

What are the 5 types of light microscopy?

Back 8

Bright field microscopy
Phase contrast/DIC microscopy
Fluorescence microscopy
Immunostaining

Front 9

What is the another, powerful version of microscopy?

Back 9

Electron microscopy.

Front 10

What are the two types of electron microscopy?

Back 10

Transmission EM
Scanning EM

Front 11

What are the three approaches to studying cells?

Back 11

Genetic
Biochemical
Cytological

Front 12

What is the microscopic technique that can be used to observe proteins in situ?

Back 12

Green Fluorescent Protein

Front 13

How do molecules get tagged to be seen in fluorescent microscopy?

Back 13

With immunostaining.

Front 14

What is aneuploidy?

Back 14

Chromosome loss or gain.

Front 15

What are the differences between homologous chromosomes and sister chromatids?

Back 15

Two sister chromatids make up one homologous chromosome.

Front 16

How are quiescent cells stimulated to reproduce in the human body?

Back 16

When mitogens or growth factors are introduced.

Front 17

In what situations are mitogens/growth factors introduced?

Back 17

After tissue damage or in an embryo.

Front 18

What are 2 examples of cells that are continually replaced in the body?

Back 18

Skin and Blood cells.

Front 19

What are the three characteristic features of stem cells?

Back 19

Can divide without limit.
Are not terminally differentiated.
At least one daughter cell stays a stem cell.

Front 20

What is a multipotent hematopoeitic stem cell?

Back 20

Can differentiate into all types of blood cells.

Front 21

WHat is the special thing about embryonic stem cells?

Back 21

They are pluripotent, and so can differentiate into any type of cell.

Front 22

Where have embryonic stem cells been taken from?

Back 22

Teratomas
Embryos

Front 23

How are induced pluripotent stem cells made?

Back 23

Nucleus from somatic cell implanted into denucleated nucleus, embryo forms, iPS harvested.

Front 24

What are the two types of cell death?

Back 24

Necrosis and apoptosis.

Front 25

What are the conditions associated with apoptosis?

Back 25

Cell shrinkage.
Cytoskeleton collapse.
Nuclear envelope disassembly.
DNA fragmentation.

Front 26

What group of proteins initiate apoptosis?

Back 26

Capsase protease.

Front 27

What are the two types of caspase proteins?

Back 27

Initiator and effector caspases (initiates... initiates the effector caspases)

Front 28

How are initiator caspases activated?

Back 28

Through external or internal death signals.

Front 29

Why does apoptosis occur?

Back 29

Metamorphosis
Excess brain cells are made, some need to die
Defective cells killed (with virus or bacteria)

Front 30

What is the main function of the intermediate filaments?

Back 30

Used to enhance cell strength.

Front 31

What are 4 examples of IMF?

Back 31

Laminins
Keratin
Desmin
Neurofilament

Front 32

What cytoskeletal structures are used in cell motility?

Back 32

Actin and microtubules.

Front 33

What are the proteins that allow actin polymerisation from a preexisting strand?

Back 33

ARP complexes

Front 34

What are the 3 types of motor protein?

Back 34

Myosin
Kinesin
Dynein

Front 35

In which direction does myosin move?

Back 35

Plus and minus.

Front 36

What is the arrangement of dynein amongst the microtubules that produces flagellation?

Back 36

9 complexes (dynein and microtubules) in a ring
2 complexes in centre.

Front 37

Where are dynein molecules that produce flagellation usually found?

Back 37

Cilia, flagella.

Front 38

Which way do kinesin molecules move?

Back 38

Most move to plus end, few to minus.

Front 39

What is the role of the microtubule network in nuclear division?

Back 39

Form the mitotic spindle.

Front 40

What is the role of actin in nuclear division?

Back 40

Forms a rings, which then closes and pinches off, causing cytokinesis.

Front 41

What is the use of chemotaxis?

Back 41

Chemotaxis allows cells to make their flagella point in a specific direction. Without stimulus, tumbling happens.

Front 42

What are 4 examples of secondary messengers?

Back 42

cAMP
Ca2+
Phosphatidyl inositol phosphates
Nitric Oxide

Front 43

What do amoebas do when starving?

Back 43

Group together to form a seemingly multicellular organism.

Front 44

How do cells arrange themselves once mixed?

Back 44

Noncommunicating cells move into distinct groups.
Communicating cells form layers based on what they're usual arrangement is.

Front 45

What is the niche principle related to stem cells?

Back 45

As more stem cells grow, some cells are pushed out of their niche. This forces them to differentiate.

Front 46

What are the processes that occur in asymmetric cell division?

Back 46

Establish cell polarity
Localise cell fate determinant
Align the mitotic spindle accordingly.

Front 47

What is the only domain of life without a known pathogen?

Back 47

Archaebacteria

Front 48

What are the 4 ways a virus can enter a cell?

Back 48

Membrane Fusion (no vesicle formed)
Endocytosis (Protein coat causes vesicle to open)
Non-enveloped endocytosis (move out of vesicle by destroying membrane)
Non-enveloped endocytosis (moves out of vesicle by moving through membrane)

Front 49

Give an example of each of these viruses.

Back 49

Membrane fusion: HIV
Endocytosis: Flu
Non-enveloped endocytosis (move out of vesicle by destroying membrane): Polio
Non-enveloped endocytosis (moves out of vesicle by moving through membrane): Adenovirus

Front 50

Give an example of a virus that inject molecules into a host cell, and what is the use of this?

Back 50

Salmonella, stimulates phagocytosis.

Front 51

What cytoskeletal structure does herpes simplex use to move around a cell?

Back 51

Microtubules.

Front 52

Give an example of a pathogen that uses both actin and microtubules.

Back 52

Vaccinia virus (pox virus)

Front 53

What are the two characteristic features of a cancer cell?

Back 53

Divide uncontrollably and invade and colonise other tissues.

Front 54

Do cancer cells require mitogens?

Back 54

No.

Front 55

Do cancer cells have a limited number of divisions like normal cells?

Back 55

No.

Front 56

Are cancer cells likely to undergo apoptosis or undergo terminal differentiation?

Back 56

No.

Front 57

Why are cancer cells able to survive in foreign environments?

Back 57

Normally cells die without specific mitogens. Without need of mitogens, cancer cells can grow anywhere.

Front 58

Can cancer cells escape from foreign tissues?

Back 58

Yes.

Front 59

How do cancer cells arise?

Back 59

Multiple hits from expressed oncogenes or suppresed protooncogenes.

Front 60

What are the 6 characteristics of cancer cells.

Back 60

Divide without signal
Divide without limit
Don't undergo apoptosis
Don't undergo terminal differentiation
Escape from original tissue
Survive and divide in foreign environment.