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1.Which is the shortest phase of cell cycle?.
2.which phases are variable?

1. Mitosis
2. G1 and G0

1

Checkpoints control transition between phase of cell cycle. Is regulated by:

Cyclins
Cycle - dependent kinases (CDK)
Tumor suppressor

2

What is G and what is S in cll cycle

Gap
Synthesis

3

M phase includes

1. mitosis (Prophase, Metaphase, Anaphase, Telophase)
2. cytokinesis (cytoplasm splits in 2)

4

Which cell cycle regulator is CONSTITUTIVE AND INACTIVE

Cyclin dependent kinases (cdk)

5

Which cell cycle regulators are phase specific?
Role?

Cyclins....activate cyclin dependent kinases (CDKs)

6

Phases of cell cycle:
What is interphase?

1. G1 (and G0)
2. S phase
3. G2
4. M phases

Interphase: G1-S-G2

7

1. Tumor suppressors in cell cycle regulation (mechanism)
2. If mutated:

1.P53 induce p21 which HYPOphosphorylates Rb --> binds to and inactivate E2F --> Inhibit G1 to S progression
3. Unrestrained cell cycle division (eg Li-fraumeni)

8

Which cell type is affected by chemotherapy

Labile

9

Cell types according their proliferative ability: (and definition)

1. Permanent - remain in G0, regenerate from stem cells
2. Stable (quiescent) - enter G1 from G0 when stimulated
3. Labile: never go to G0, divide rapidly with shirt G1. Most affected by chemotherapy

10

Cell type that is also called QUIESCENT

Stable

11

Permanent cell examples

Neurons, skeletal and cardiac muscle, red blood cells

12

Stable (quiescent) cells examples

Hepatocytes, lymphocytes

13

Labile cells examples

Bone marrow, gut epithelium, skin, hair follicles, germ cells

14

Smooth vs rough
Endoplasmic reticulum according their structure:

Smooth endoplasmic reticulum LACKS SURFACE RIBOSOMES

15

Cell type with short G1

Labile

16

Smooth endoplasmic reticulum role:

1. Steroids synthesis
2. Detoxification of drugs and poisons

17

Cells rich in smooth endoplasmic reticulum:

1. Liver hepatocytes
2. Steroid hormones-producing cells of the adrenal cortex
3. Steroid hormones-producing cells of the gonads

18

Cells rich in rough endoplasmic reticulum

1. Mucus-secreting goblet cells of the small intestine
2. Antibody-secreting plasma cells

19

Rough endoplasmic reticulum role:

1. Synthesis of secretory (exporter) proteins
2. N-linked oligosaccharides addition to many proteins

20

What are Nissl bodies and what is their function

Nissl bodies are rough endoplasmic reticulum in neurons
Synthesize peptide neurotransmitters for secretion

21

Free ribosomes (structure and function):

Unattached to any membrane
Site of synthesis of cytosolic and organelle proteins

22

Proteasome stracture and function

Barrel-shaped protein complex that degrades damaged or UBIQUITIN-tagged proteins

23

Ubiquitin - Proteasome system defects:

It have been implicated in some cases of PARKINSON disease + Alzheimer
Genes (parkinin, PINK1, DJ-2)

24

Peroxisome structure

Membrane enclosed organelle

25

What is Golgi apparatus?

Is the distribution center for proteins and lipids from the endoplasmic reticulum to the vesicles and plasma membrane

26

Peroxisome function:

Catolism of:
1. Very-long-chain fatty acids
2. Branched chain fatty acids
3. Amino acids
4. ethanol

27

Golgi apparatus function:

1. Modifies N-oligosaccharides on ASPARAGINE
2. Adds O-oligosaccharides on SERINE and THREONINE
3. Adds MANNOSE-6-PHOSPHATE to proteins from trafficking to lysosomes

28

Endosomes?

Sorting centers for materials from OUTSIDE the cell or from the GOLGI sending it to lysosomes for destruction or back to membrane/Golgi for further use

29

I-cell disease (inclusion cell disease also referred to as:

Mucolipidosis II