3 cell structure Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

how do you calculate magnification?

A

size of image/size of real object

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

how do you calculate the size of the object under a microscope?

A

size of image/magnification

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

what is resolution for a microscope?

A

the minimum distance apart 2 objects can be in order for them to be visible as 2 different items

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

what does cell fractionation do?

A

breaks up cells so it’s different organelles are separated out

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

before cell fractionation can begin, what does the tissue need to be placed in?

A

a cold buffered solution

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

why is the solution that the tissue has to put in before cell fractionation cold and buffered?

A

cold- to reduce enzyme activity that might break down the organelles
buffered- so the pH doesn’t change and alter organelles/enzymes

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

what are the 2 steps of cell fractionation?

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

what happens during homogenation?

A
  1. cells are broken up by a homogeniser (blender) which releases the organelles
  2. the remaining fluid (homogenate) is filtered to remove complete cells/debris
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is magnification?

A

how many times bigger the image is compared to the object

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

explain ultracentrifugation

A
  1. filtered homogenate is spun in a centrifuge at a low speed- forcing the heaviest organelles to the bottom of the tube
  2. fluid at the top of the tube is removed and transferred into another tube and spun at a faster speed in the centrifuge- forcing the next heaviest organelles to the bottom of the tube
  3. continued at higher speeds each time
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

rank these 3 organelles in order of weight, heaviest first:
mitochondria, nucleus, lysosome

A

nucleus, mitochondria, lysosome

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

what is the layer of heaviest organelles called at the bottom of the tube after ultracentrifugation?

A

pellet

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

what are the two types of electron microscope?

A

transmission electron microscope
scanning electron microscope

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

compare a light microscope and an electron microscope (4)

A

LIGHT: can view living samples
ELECTRON: sample must be in a vacuum so cannot be living
LIGHT: lower magnification
ELECTRON: higher magnification
LIGHT: colour images
ELECTRON: black and white images
LIGHT: poorer resolution as light has a longer wavelength
ELECTRON: higher resolution as electrons have a short wavelength

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

what is not visible in a light microscope?

A

small organelles such as parts of the mitochondria

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

what is the difference between a TEM and SEM?

A

TEM: extremely thin specimens are stained and placed in a vacuum where an electron gun produces a beam of electrons that pass through producing a 2D image
SEM: specimens do not need to be thin as electrons do not pass through- electrons beamed onto the surface and scattered creating a 3D image

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

what 11 organelles are in eukaryotic cells?

A
  1. cell surface membrane
  2. nucleus
  3. mitochondria
  4. ribosomes
  5. lysosomes
  6. rough endoplasmic reticulum
  7. smooth endoplasmic reticulum
  8. golgi body and vesicles
  9. chloroplasts
  10. cell wall
  11. cell vacuole
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is the structure of the nucleus?

A

nuclear envelope (double membrane)
nuclear pores
nucleolus
chromosomes

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

what is the function of the nucleus?

A
  • site of DNA replication and transcription
  • contains the genetic material of the cell
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what is the structure of the RER?

A
  • folded membranes called cisternae
  • ribosomes on outer surface
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what is the function of the RER?

A

site of protein synthesis

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

what is the structure of the SER?

A

folded membranes called cisternae

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

what is the function of SER?

A

synthesise, store and transport carbs and lipids

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

what is the structure of the golgi apparatus?

A
  • folded membranes making cisternae
  • vesicles
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

what is the function of the golgi apparatus?

A
  • modify proteins into glycoproteins
  • produce secretory enzymes
  • transport and modify lipids
  • form lysosomes
  • “label” molecules
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

what are lysosomes?

A

bags of digestive enzymes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

what is the function of a lysosome?

A
  • hydrolyse phagocytic cells
  • exocytosis- release enzyme
  • digest worn out organelles
28
Q

what is the structure of mitochondria?

A
  • double membrane
  • cristae
  • matrix
  • circular DNA, ribosomes in matrix
29
Q

what is the function of mitochondria?

A

site of aerobic respiration and ATP production

30
Q

what type of ribosomes are found in eukaryotic cells?

A

80s

31
Q

what type of ribosomes are found in prokaryotic cells?

A

70s

32
Q

what are ribosomes made up of?

A

a large and a small sub unit made up of rRNA and proteins

33
Q

what is the function of a ribosome?

A

site of protein synthesis

34
Q

what is the vacuole made up of?

A

fluid filled sac with a single membrane called tonoplast

35
Q

what is the function of a vacuole?

A
  • makes cells turgid
  • stores sugars and amino acids for food store
  • pigments colour petals
36
Q

what is the structure of a chloroplast?

A
  • double membrane
  • grana (stacks of thylakoids)
  • lamellae
  • stroma (contains enzymes)
37
Q

what is the function of a chloroplast?

A

site of photosynthesis

38
Q

what are cell walls in plants made up of?

A

microfibrils of cellulose

39
Q

what are cell walls in fungi made of?

A

chitin

40
Q

what is the function of a cell walls?

A

strengthen cell and prevents cell from bursting

41
Q

what is the cell wall made up of in bacterial cells?

A

murein

42
Q

what is a capsule on a prokaryotic cell?

A

capsule of slime that coats and protects the cell

43
Q

contrast prokaryotic and eukaryotic cells

A

PRO: no nucleus
EUK: nucleus present
PRO: circular DNA
EUK: linear DNA
PRO: no membrane bound organelles
EUK: membrane bound organelles
PRO: cell wall made of murein
EUK: cell wall made of cellulose or chitin
PRO: DNA not associated with proteins
EUK: DNA associated with histones

44
Q

what is the structure of a virus?

A
  • genetic material
  • attachment proteins
  • capsid
  • matrix
  • lipid envelope (on HIV)
45
Q

how do viruses replicate?

A

inside of cells

46
Q

how do viruses attach to host cells?

A

through attachment proteins

47
Q

how do eukaryotic cells replicate?

A

mitosis and meiosis

48
Q

how do prokaryotic cells replicate?

A

binary fission

49
Q

how do viruses replicate?

A

inside a host cell- invading the cell by injecting their nucleus acid in cell to replicate virus particles

50
Q

what are the stages of the cell cycle?

A

G1 (interphase)
S (interphase)
G2 (interphase)
mitosis

51
Q

what is G1 phase?

A

the cell increases in size

52
Q

what is the S phase?

A

where semi conservative DNA replication takes place

53
Q

what is G2 phase?

A

organelle growth

54
Q

what is mitosis?

A

division of a cell resulting in 2 identical daughter cells

55
Q

what happens during interphase?

A

replication of DNA
2 copies joined at centromere

56
Q

what happens during prophase?

A

chromosomes condense and become visible

57
Q

what happens during metaphase?

A

chromatids joined by the centromere arrange themselves in the equator of the cell

58
Q

what happens during anaphase?

A

the centromeres divide into 2 and spindle fibres pull the chromatids apart.
chromatids move to opposite poles of the cell

59
Q

what pulls the chromatids apart?

A

spindle fibres at opposite poles of the cell

60
Q

what happens during telophase?

A

chromosomes reach their poles and become longer and thinner
spindle fibres disintegrate

61
Q

what happens during cytokinesis?

A

cytoplasm splits

62
Q

what is a tissue?

A

a collection of similar cells that group together perform a specific function

63
Q

explain binary fission

A
  1. circular DNA replicates and both copies attach to cell membrane
  2. plasmids also replicate
  3. cell membrane begins to grow and DNA molecules pinch inwards- dividing the cytoplasm
  4. a new cell wall forms between two molecules producing two identical daughter cells
64
Q

how is cancer treated?

A

by disrupting the cell cycle by:
- preventing DNA from replicating
- inhibiting the metaphase stage of mitosis by interfering with spindle formation

65
Q

what is a pro and con of the treatment of cancer?

A

con: disrupt the cell cycle of normal cells
pro: more effective against rapidly dividing cells