Cell Structure Flashcards

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

What is cell theory

A

Cell theory states that all living organisms are composed of one or more cells

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

What’s field of view (FOV)

A

The circular area visible down a microscope

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

What’s magnification

A

The number of times larger an image appears compared to the real specimen

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

What’s resolution

A

The ability to DISTINGUISH two distinct objects separately and see detail

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

How does magnification effect field of view

A

Field of view decreases as the magnification increases

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

How can you measure the diameter of the field of view

A

Using a stage micrometer

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

What’s a stage micrometer

A

A specialised microscope slide (1mm with 10 divisions)

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

What’s the magnification formula

A

image size / actual size x magnification (set up like triangle)

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

3 advantages of a light microscope

A

Cheap, easy to use, views living specimens, portable, natural colour

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

2 disadvantages of a light microscope

A

Low mag (x1500), limited res (200nm)

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

Name the 3 types of microscopes

A

Light microscope, transmission electron microscope (TEM), scanning electron microscope (SEM)

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

How does a light microscope work

A

Light passes through the specimen and is focused using the glass lenses

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

How does a TEM microscope work

A

Electrons pass through the specimen and are focused by electro magnets onto a fluorescent screen

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

advantages of TEM

A

High mag (x2000000), high res (0.1nm)

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

Disadvantages of TEM

A

Large, expensive, specialist training, black and white images, dead specimens (vacuumed)

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

Advantages of SEM

A

High mag (x2000000), high res (0.1nm but usually less, 5-20nm), can view in 3D

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

Disadvantages of SEM

A

Large, expensive, black and white images

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

What microscope would be most useful for viewing:
1) living daphnia in pond water
2) internal structure of mitochondrion
3) ribosomes
4) cells from a cervical smear to spot abnormalities
5) influenza virus particles

A

1) LM 2) TEM 3) TEM 4) LM 5) SEM

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

How do you prep a specimen

A

1) FIXATION, to preserve tissue
2) DEHYDRATION, to absorb water
3) EMBED in wax, prevents distortion
4) SECTION, thin slices
5) MOUNT, support tissue on slide
6) STAIN, makes structures visible and increases contrast

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

Why are thin specimen sections required (LM)

A

To allow light to pass through

21
Q

Why are stains used

A

Because most biological specimens are almost transparent, makes structures visible and increases contrast

22
Q

What’s differential staining

A

A stain that stains different structures different colours to aid identification

23
Q

What do you use to measure the actual size of a specimen

A

Eyepiece graticule

24
Q

Steps to set up eyepiece graticule

A

1) POSITION stage micrometer on microscope stage to focus scale (x4 mag)
2) FOCUS the eyepiece graticule until scales align with micrometer
3) COMPARE, scales and work out length of one eyepiece graticule
4) REPEAT, for each objective lens
5) REMOVE stage micrometer and place on the specimen
6) MEASURE length of specimen in eyepiece units using graticule
7) CONVERT measurements to actual length with appropriate calibration

25
Q

Summarise the calibration of the eyepiece graticule for different objective lenses

A

Mag of eyepiece lens. Mag of objective. total mag. eyepiece unit
x10. x4. x40. 25um.
x10. x10. x100. 10um.
x10. x40. x400. 2.5um.

26
Q

List the rules for biological drawings

A

Sharp pencil, smooth continuous lines, no shading, label lines with ruler no arrow heads and no crossing labels, title and scale

27
Q

What’s compartmentalisation

A

The role of membranes in forming organelles

28
Q

What’s diversion of labour

A

Each organelle having a specific function within the cell for efficiency

29
Q

What’s a eukaryotic cells

A

Cells containing a nucleus

30
Q

What’s a prokaryotic cell

A

Cells with no nucleus or membrane bound organelles

31
Q

List all the organelles in an animal cell

A

Intermediate filament, ribosome, rough endoplasmic reticulum (RER), nucleus, nucleolus, chromatin, Golgi apparatus, golgi vesicle, cytoplasm, vacuole (in some), secretory vesicle, smooth endoplasmic reticulum (SER), lysosome, microfilament, centrosome, microtubule, plasma membrane, mitochondia

32
Q

What’s the function of the nucleus

A

Carries genetic information

33
Q

What’s the function of the ribosome

A

Site of protein synthesis

34
Q

What’s the function of a mitochondria

A

Site of aerobic respiration to produce ATP

35
Q

What’s the function of chloroplasts

A

Site of photosynthesis to produce sugars

36
Q

What’s the function of the RER

A

Transports proteins made by the ribosomes on its surface and packages them into vesicles

37
Q

What’s the function of the SER

A

Lipid synthesis

38
Q

What’s the function of the Golgi body

A

Receives proteins from RER, modifies and repackages them

39
Q

What’s the function of the lysosomes

A

Hydrolysis’s unwanted materials inside the cell

40
Q

What’s the function of vesicles

A

Transports materials around the cell

41
Q

What’s the function of the cell surface membrane

A

Partially and selectively permeable barrier

42
Q

What’s the function of the cytoskeleton

A

Supports and maintains cell and allows changes in cell shape

43
Q

What’s the function of a pair of centrioles

A

Forms spindle fibres

44
Q

What’s the function of cilia

A

Uses ATP to move fluids by beating

45
Q

What’s the function of the undulipodium

A

Uses ATP to move the whole cell

46
Q

What’s the function of a cell wall

A

Gives shape and supports the cell

47
Q

What’s the function of the vacuole

A

Makes the cell turgid

48
Q

Describe the production and secretion of proteins

A
  1. A gene is transcribed into mRNA in the nucleus
    2.mRNA leaves the nucleus via a nuclear pore
  2. mRNA assembles with a ribosome that attaches to the RER
  3. the ribosome reads the mRNA code and synthesises and packages the protein which is packaged and transported in a vesicle
  4. Proteins transported in vesicles along microtubules by motor proteins to Golgi (requires ATP)
  5. Golgi modifies and repackages proteins into vesicles
  6. Transported to cell surface membrane (ATP)
  7. Vesicle fuses with membrane
  8. Membrane opens and modified proteins are released for use outside the cell (exocytosis)