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Flashcards in Cellular Deck (30)
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1
Q

Why is there different sections in the cell for reactions?

A

Many of the intra-cellular reactions are incompatible

2
Q

What is one way that the cell separates the various reactions?

A

compartmentalization in membrane bound organelles

3
Q

Since most proteins are hydrophobic, how do the cross the membranes?

A

Vesicle transporters
Membrane Translocation proteins
Pore - nuclear pores

4
Q

What are the two main protein trafficking pathways?

A

Secretory Pathway

Default Cyctosolic Pathway

5
Q

What are the potential final destinations of proteins from the secretory pathway?

A

Outside the Cell
Cell Membrane
Lysosomes

6
Q

What are the potential final destinations of the proteins from Default Cyctocolic Pathway?

A

Cyctosol
Nucleus
Mitochondria
Perioxsomes

7
Q

If a protein is of the secretory pathway, what will it pass through?

A

Rough Endoplasmic Reticulum and Golgi Apparatus

8
Q

Where can proteins be synthesised?

A

Cytosol
Mitrochondria
Rough Endoplasmic Reticulum

9
Q

What determines if a protein is transferred to the RER and where is it located on the protein?

A

Signal Peptide on the N-terminal of the peptide chain (16-20 amino acids)

10
Q

What binds to the Signal Sequence on the peptide chain to allow it to be recognised by the proteins on the membrane of the RER?

A

Signal Recognition Particle

11
Q

When the Signal Recognition Particle is stimulated it opens a channel to allow enter for the Peptide with the Signal Peptide?

A

Translocoon

12
Q

What cleaves the Signal Peptide?

A

Signal Peptidase

13
Q

What are the three parts of the Golgi Apparatus?

A

Cis Cisternae, Medial &s Trans Cisternae, Trans Golgi Network

14
Q

As the peptide chain passes through the Golgi Apparatus it fuses with vesicles and passes through getting further post-transnational modification. What is this called?

A

Cis Maturation Model

15
Q

What post transnational modification occurs in the Golgi apparatus?

A

Phosphorylation - alters protein activity
Acetlyisation - alters Histone/ Gene activity
Ubiqutatition - degradation
Farnelysation - Targets proteins to the cell membrane and Ras Activity

16
Q

What is added to keep a protein stuck in the cell membrane?

A

Stop Translocation

17
Q

From the default cytosolic pathway, what is added to send the protein to the nucleus?

A

Nucleus Localisation Signal

18
Q

What does nuclear bound proteins enter into the nucleus via?

A

Importin via Importin receptors

19
Q

What Junction disorder leads to Vonwinkel Syndrome?

A

GAP junctions

20
Q

What type of junction is involved in cell to ECM conenction?

A

Focal Adhesion

21
Q

What determines the tertiary structure of proteins?

A

Interactions of the side chain functional groups. including:

  • disulfide bonds
  • hydrogen bonds
  • salt bridges
22
Q

What is the quaternary structure of proteins?

A

Mutliple sub unit proteins (groups of peptide chains) come together to form a larger molecule through covalent and non-covalent bonds.

23
Q

What factors leave mitochondrial DNA most susceptible to mutations?

A

Highly oxidative reactions taking place inside it

Lack of histones around the DNA

24
Q

What is it called when thyamine undergoes dimerisation?

A

Cylobutulythiamine

25
Q

What is homologous DNA repair?

A

This is where there has been a double stranded break and the DNA is repaired by using a sister chromotid to make the complimentary strand from - which will return to the damaged chromotid and will then be used to fix the other damaged strand

26
Q

What can non homologous DNA repair lead to?

A

Translocation of chromosomes

27
Q

What is the term used when more than one condon can be used to code for the same amino acid?
why is this important?

A

Degeneracy

it allows for some mutations to take place

28
Q

What is the amino acid acceptation to degeneracy? and what does it do?

A

Methionine is non-degeneracy.

codes for starting point of protein synthesis

29
Q

When there is a single amino acid change which leads to a similar protein, what is this called?

A

Conservative amino acid substitute

30
Q

What does the ribosome scan for in order to carry out translation of the mRNA?

A

Kozak sequence. this informs it that the next AUG (methionine) is where to start translation