Cell Biology Exam 3

Front 1

Features of MPF

Back 1

Regulates transition in M phase

Front 2

Stages of Mitosis

Back 2

Metaphase

Anaphase

Front 3

During prometaphase, the microtubules of the spindle elongate and shrink depending on whether or not the microtubule is too short or too long. What motor protein helps pull the chromosome towards the center on the long side of the spindle and what is the long microtubule doing?

Back 3

Dynein a motor protein that pulls the chromosome towards the poles (-), as the long side of the microtubule depolymerizes.

Front 4

Which of the following features would you expect to find in a sample taken from a patient with ataxiatelangiectasia (Loss of ATM protein function)?

Back 4

Reduced transcription of P2
1

Front 5

During the phase of mitosis, when bi-polar myosin motor proteins begin moving along actin filaments, what is a visual cue for this event?

Back 5

Cleavage furrow formation

Front 6

Which of the following proteins, that is degraded during mitosis, actually appears during S phase of the cell cycle? (As a hint, consider what each of these proteins actually does.)

Back 6

Cohesin

Front 7

(A = True / B = False) The action of the sarcomere in muscle contraction may be an evolutionary predecessor to the contractile ring of cytokinesis.

Back 7

False

Front 8

(Human Perspective) Which of the following diseases is caused by meiotic nondisjunction of the [HIDDEN] chromosome in a [HIDDEN] zygote ([HIDDEN])?

Back 8

Klinfelter syndrome= male with an extra X chromo. Ex: (XXY)

Front 9

How does the cell leave [HIDDEN] phase of the cell cycle

Back 9

APC marks cyclin B for destruction

Front 10

Suppose a cell in M phase is suddenly loaded with cyclin [HIDDEN], what response might the cell display

Back 10

Hidden= Cyclin E, Answer= activation of DNA synthesis

Front 11

For CDK4 to be active which cyclin must be [HIDDEN]?

Back 11

Cyclin D

Front 12

If a cell is deficient in the spindle assembly checkpoint what would you expect the outcome to be?

Back 12

a higher occurrence of mitotic non-disjunction

Front 13

(A = True / B = False) If a cell is flooded with CDK2, then it is anticipated the cell will enter [HIDDEN] phase of the cell cycle.

Back 13

False

Front 14

The energy for contractile ring activity is derived from what?

Back 14

GTP hydrolysis

Front 15

Which cyclin is elevated to push the cell into G2 phase

Back 15

Cyclin A

Front 16

All of the following are motor proteins involved in mitosis EXCEPT

Back 16

seperin

Front 17

What are [HIDDEN] microtubules

Back 17

Hidden= Astral, Answer= Radiate outward from centrosome to outside of spindle

spindle

Front 18

What type of signaling is best described as: a cell releases a signal to the local environment that is detected by other cells.

Back 18

Paracrine

Front 19

What are receptor tyrosine kinases capable of binding to

Back 19

Adapter, scaffold, signaling molecule, effectors

Front 20

As a portion of the protein content of a cell, how many receptors will a cell express? (Compare to actin)

Back 20

A lot less

Front 21

(A = True / B = False) For a given signal (e.g. acetylcholine) it is reasonable to expect that different cells that can detect the specific signal will respond in different ways. In other words, a specific signal / receptor pair can have different effects in different cell types.

Back 21

True

Front 22

Generally, what distinguishes G-Protein Coupled Receptors (GPCR) from Receptor Tyrosine Kinases (RTK

Back 22

GPCRS act through a secondary mediating protein, RTKS directly activate downstream elements

Front 23

For GTP binding protein switches, how are they activated

Back 23

The alpha subunit trades GDP for GTP

Front 24

Which of the following is a known secondary messenger?

Back 24

Cyclic AMP (cAMP)Inositol triphosphate (IP3)Diacylglycerol (DAG)Ca++

Front 25

What enzyme does PIP3 activate in the insulin pathway

Back 25

activates PDK1

Front 26

After a G-protein is activated by a receptor what is the next thing that happens to the G-protein

Back 26

none of the above

Front 27

How are G-proteins inactivated?

Back 27

The alpha subunit hydrolyzes the GTP to GDP

Front 28

(A = True / B = False) In a G-protein, the [HDDEN] have no signal transduction capability; they exist to conceal the subunit.

Back 28

False

Front 29

The photon detection of the vision system occurs by

Back 29

a G-Protein Coupled Receptor System

Front 30

Which of the following statements about Receptor Tyrosine Kinase Systems (RTKs) is/are true

Back 30

RTK’s possess inherent enzymatic activity

Front 31

(A = True / B = False) On recognizing a signal, RTKs dimerize and cross-phorphorylatethe opposite dimer via [HIDDEN].

Back 31

True

Front 32

Which of the following is not a typical method of RTK activity

Back 32

Binding to and activating a G-protein by phosphorylating GDP

Front 33

Activation of the insulin RTK results in the creation of which second messenger that activates Protein Kinase B, that results in protein translation of glucose uptake molecules and glycogen synthesis

Back 33

Ip3

Front 34

Unlike normal cells, cancers [HIDDEN]:

Back 34

Hidden= grow by, Answer= growing into piles called foci

Front 35

What is cancer?

Back 35

all of the above

Front 36

What distinguishes a benign tumor from a [HIDDEN] tumor?

Back 36

Benign tumors are constrained by the basement membrane

Front 37

What is the most common cancer type?

Back 37

Lung/Bronchus carcinoma

Front 38

What are cancers of connective tissue called?

Back 38

Sarcoma

Front 39

If a liver cancer migrates to the lung the mass in the lung would be termed:

Back 39

Metastasi
s

Front 40

A cell that fails at the G1>> S check point (sometimes called the “R” point) is likely to:

Back 40

undergo apoptosis

Front 41

(A = True / B = False) Apoptosis, unlike necrosis, is consider a [HIDDEN] form of cell death as it [HIDDEN] spilling cellular contents to the surrounding environment.

Back 41

True

Front 42

A cancer cell is likely to evolve to [HIDDEN], which of the following

Back 42

Hidden= up regulate, Answer= Telomerase

Front 43

What commonly mutated cancer protein is also a G-protein?

Back 43

Ras

Front 44

The process of developing blood vessels is termed:

Back 44

angiogenesis

Front 45

(A = True / B = False) All cancers evolve only from inherited genes, termed predisposition.

Back 45

False

Front 46

Cancer cells activate unusual signaling pathways that result in the cell signaling itself. This is termed

Back 46

Autocrine

Front 47

Why do cancers evolve the ability to create blood vessels?

Back 47

In order to overcome the diffusion limits of oxygen and nutrients

Front 48

What chemotherapeutic would be used to affect the [HIDDEN]?

Back 48

Taxol

Front 49

What is the role of the enzyme telomerase

Back 49

Repairs the ends of the chromosomes