Brainscape's Knowledge GenomeTM

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


See full index

Cells > Organelles and Cytoskeleton > Flashcards

Organelles and Cytoskeleton Flashcards

1
Q

What is chromatin?

A

Combined structure of proteins and DNA

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

What is the role of nuclear pores?

A

Allows mRNA strands to exit the nucleus and proteins to enter the nucleus

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

What type of RNA does the nucleolus produce?

A

Ribosomal RNA

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

What are synthesised at the nucleolus?

A

Ribosomes

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

What is the structure of the Golgi apparatus?

A

A single membrane consisting of cisternae

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

What is added to lysosomal enzymes by the golgi, why?

A

Mannose-6-phosphate

Keeps them sequestered

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

What is the role of the Golgi body?

A

Modifies proteins before packaging them into vesicles to leave the cell

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

What are the two faces of the golgi apparatus, what do they do?

A

Cis-face where vesicles are received from the ER

Trans-face where vesicles are send out after modification.

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

What is the structure of a mitochondria?

A

Oval shaped organelle, with a double membrane, the inner membrane is folded into cristae creating an internal matrix.

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

What is the function of the mitochondria double membrane?

A

Energy from the electron transport chain can be used to pump H+ into the intermembrane space so its chemiosmosis can drive ATP synthase to produce ATP.

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

What does the lysosome consist of?

A

Contains lyososymes which are digestive enzymes to degrade cellular waste

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

What enzymes are lysosymes?

A

Acid hydrolases

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

Why dont lysosymes digest cellular material?

A

Acidic nature - enzymes would be inactive in neutral pH.

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

How is the acidic pH maintained in lysosomes?

A

Proton pump that pumps H+ into the lysosymes.

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

Where are proteosomes present?

A

Nucleus and the cytoplasm

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

What is the role of proteosomes?

A

Breaks down proteins through proteolysis

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

How do proteosomes break down proteins?

A

Proteases are located in the central pore.

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

What identifies a protein for breakdown?

A

Ubiquitin

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

What metabolism are peroxisomes involved with?

A

Breakdown of very long chain fatty acids

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

What roles do peroxisomes have other than VLCFA?

A

Breakdown of D(enantiomer)-amino acids

Reduction of reactive oxygen species, specifically hydrogen peroxide

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

What are vesicles?

A

Small organelles containing a liquid or substance encased in a phospholipid bilayer

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

What are the important roles of vesicles?

A

Transporting substances across the cell, via MT pathways and driven by motor proteins

Transporting substances into and out of cells by endo and exocytosis

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

What is the structure of the RER?

A

Surrounds the nuclear membrane

Series of long fluid filled sacks that are dotted with ribosomes. It has many folds called cisternae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the role of the RER?

A

Protein synthesis and modification

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

What are the roles of the SER?

A

Lipid synthesis it also produces steroid hormones, and assists detoxification.

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

What is the fluid in the cytoplasm?

A

Cytosol

27
Q

What are the three main roles of the cytoskeleton?

A

Movement: Cell motility

Cellular organisation: Moving organelles around a cell, vesicle transport for secretion.

Structure: Mechanical strength

28
Q

What are the three major protein filaments of the cytoskeleton?

A

Microfilaments
Intermediate filaments
Microtubules

29
Q

What is the diameter of microfilaments?

A

5-7nm

30
Q

What is the diameter of intermediate filaments?

A

10-12nm

31
Q

What is the diameter of microtubules?

A

25nm

32
Q

What is the most notable microfilament?

A

Actin

33
Q

Where are actin microfilaments concentrated?

A

Just below the cell membrane

34
Q

What is meant by microfilament polarity, what is different at each end?

A

A plus end where growth and shrinkage are fast and a minus end where they are slow

35
Q

How do actin filaments determine cell shape and movement?

A

Depolymerising and polymerising at the ends

36
Q

How does actin determine cell movement (muscle in particular)?

A

Actin binding site forms a cross-bridge with the myosin head that leads to a power-stroke.

37
Q

What proteins make microtubules?

A

Alpha and beta tubulin

38
Q

Where do microtubules originate from?

A

Microtubule organising centre (MTOC).

39
Q

What are the roles of microtubules?

A

Positions organelles, aids cell division and intracellular transport

40
Q

What does the MTOC contain?

A

Two cylindrical shaped centrioles

41
Q

Where do centrioles move in cell division?

A

To poles

42
Q

Which end of the microtubule is embedded in the MTOC?

A
  • end
43
Q

Which end of the microtubule grows/shrinks faster?

A

+ end

44
Q

What molecules favour growth and shrinkage of MT?

A

GTP favours growth, GDP favours shrinking

45
Q

What is the name of proteins that move along MT?

A

Motor proteins

46
Q

What do motor proteins require to move along MT?

A

ATP

47
Q

What are the two key motor proteins and what direction does each one move cargo?

A

Kinesin moves from the MTOC to the plus end, dynein moves from the plus end to the minus end.

48
Q

What is the role of MAPs?

A

Microtubule associated proteins (MAPs) bind the stabilise longer microtubules to encourage growth at the plus end.

49
Q

What is the main role of intermediate filaments?

A

Maintain mechanical strength and structure

50
Q

What are key examples of intermediate filaments?

A

Neurofilament, keratin and nuclear laminin proteins.

51
Q

What holds keratin filments in place (2)?

A

Disulfide bond crosslinks as a result of many cysteine residues

Hemidesmosomes (basal lamina to cell)

52
Q

What are the three main types of cell junction?

A

Anchoring
Occluding (tight)
Gap

53
Q

What filaments underpin anchoring junctions?

A

Intermediate filaments

54
Q

What are the three subcategories of anchoring junctions?

A

Desmosomes (cell to cell)

Hemidesmosome ( cell to basal lamina)

Adherens (cell to cell)

55
Q

What intermediate filaments underpin anchoring junctions in epithelia?

A

Keratin

56
Q

What intermediate filaments underpin anchoring junctions in cardiac cells?

A

Desmin

57
Q

What are adherens, why are they different to desmosomes?

A

Cell to cell adhering junction

Connect actin filaments not intermediate

58
Q

What is the role of tight junctions?

A

Dynamic seal that adjusts intercellular permeability acting as a barrier to harmful contents

59
Q

What are the tight junction proteins?

A

Claudin and occludin

60
Q

Describe the structure of a gap junction

A

6 transmembrane connexin proteins makes up a connexon complex

61
Q

What is the function of gap junctions?

A

Couple cells chemically and electrically

62
Q

What are several junctions that are important in tight epithelia?

A

Junctional complex
Zonula occludens
Zonula adherens
Macula adherns

63
Q

Site for activation of sugars for oxidation

A

Cytoplasm

Cells (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions