2.1 Biological Molecules Flashcards

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1
Q

what is resolution

A

The ability of an optical instrument to see or produce an image that shows fine detail and has ability to distinguish between 2 objects

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2
Q

Whats is magnification

A

The ability of an optical instrument to produce an image bigger than the original objects

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3
Q

what are the 2 types of microscopes

A

Optical
electron

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4
Q

advantages of optical microscope

A

Cheap
easy to use
portable
able to study whole living organisms

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5
Q

disadvantages of optical microscope

A

Poor resolution
low magnification due to the long wavelength of light

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6
Q

advantage & disadvantage of electron microscope

A

Advantages- high magnification and resolution.
Disadvantages-Expensive, specimen has to be dead, not portable

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7
Q

2 types of e-microscpes

A

TEM
SEM

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8
Q

How does TEM work

A
  • extremely thin specimens are stained and placed in vacuum
  • Electron guns produce a beam of electrons that pass through specimen
  • Some parts of specimens absorb more electrons making them denser and making them appear darker
  • Created 2d images
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9
Q

How does SEM work

A
  • Specimen doesn’t need to be thin as electrons don’t pass through it as electrons beamed on the surface cause secondary electrons to bounce of surface + scatter and are focused on a screen
  • 3d image formed
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10
Q

Max resolutions of all microscopes
(micrometers)

A

Light- 0.2
SEM- 0.003 - 0.001
TEM- 0.0005

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11
Q

Max magnifications of all microscopes

A

Lights - x1500
SEM - less than x1,000,000
TEM - More than x1,000,000

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12
Q

Units of measurements

A

Metre - m - 1
Millimetre - mm - 10 x -3
Micrometre - ym - 10 x -6
Nanometre - nm - 10 x -9
Picometre - pm - 10 x -12

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13
Q

Equation triangle

A

Image = Actual x Magnification
Actual = Image / Magnification
Magnification = Image / Actual

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14
Q

why do optical microscopes have low resolution & magnification

A
  • Optical microscopes have the same wavelength as visible light (400-700nm)
  • For this reason it can’t produce an image of object with a smaller wavelength than light
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15
Q

Rules for scientific drawings

A
  1. Include a title
  2. State magnification
  3. Use a sharp pencil for drawings and labels
  4. Use white, unlined paper
  5. Use as much paper as possible for the drawing
  6. Draw smooth, continuous lines
  7. Do not shade
  8. Draw clearly defined structures
  9. Ensure proportions are correct
  10. Label lines must be parallel to the top of the page and drawn with a ruler. They must not cross or have arrow heads.
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16
Q

Define organeles

A

Membrane bound compartment within the cell each providing distinct environments and therefore conditions for different cellular reactions

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17
Q

animal cell organelles that can be seen by light microscope

A

Cell Surface Membrane
Cytoplasm
Nucleus
Mitochondria
Centriole
Cytoplasmic Granules

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18
Q

plant cell organelles that can be seen by light microscope

A

Cell Wall
Cell surface membrane
Cytoplasm
Nucleus
Vacuole
Tonoplast
Mitochondria
Starch grains
Chloroplast

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19
Q

Animal Cell organelles that can be seen using electron microscope

A

Cell Surface membrane
Rough endoplasmic Reticulum (RER)
Nucleolus
Nucleus
Smooth Endoplasmic Reticulum (SER)
lysosome
Ribosome
Nuclear envelope with pores
Golgi apparatus
Cytoplasm
Mitochondria

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20
Q

Plant cell organelles that can be seen using electron microscope

A

Cell Surface membrane
Chloroplast
Rough endoplasmic Reticulum (RER)
Plasmodesmata
Nucleolus
Nucleus
Smooth Endoplasmic Reticulum (SER)
Ribosome
Nuclear envelope with pores
Golgi apparatus
Cytoplasm
Mitochondria
Vacuole
Cell Wall

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21
Q

Structure of Nucleus
(5)

A
  1. Nucleur envelope- surrounds the nucleus ad acts like a double membrane
  2. Nucleur Pores- Are hles in the nucleus that allows things to enter + leave
  3. Nucleur Plasm- A granular jelly like material
  4. Nucleolus- Small spheres where RNA + Ribbosommes are made inside
  5. Chromosomes- Are protein bound to nucleus and are linear DNA
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22
Q

Function Of nucleus

A
  1. Site of DNA replication and transcription
  2. Contains genetic code for each cell
  3. Site of ribbosommes synthesis
23
Q

Flagella structure

A

Has whip like structure

24
Q

Flagella Function

A

Mobility

25
Q

Cilia structure
(2)

A
  • Small hair like projections found on the surface membrane of animal cells
  • Contains microtubles
26
Q

Cilia Function

A

-Microtubles allow cilia to move
-The movement is used to move substances along cell

27
Q

Centrioles structure

A

Small hollow cyclinders of microtubles arranged at right angles

28
Q

Centrioles Function

A

Involved in production of spindle fibres and seperation of chromosomes during cell division

29
Q

Cytoskeleton Structure

A

Network of protein structures within cytoplasm consisting of microfilaments, microtubles and intermediate fibres

30
Q

Cytoskeleton Functions

A
  • Provide mechanical strength to cells to help maintain shape + stability
  • Microfillaments are responsible for cell movement
  • Microtubules are responsible for creating a scaffold like structure
  • Intermediate fibres provide mechanical strength
31
Q

Golgi apparatus Structure

A

They are fluid-filled Flatened and curved sacs with vesicles surrounding the edges

32
Q

Golgi apparatus Function

A
  • Produces lysosomes
  • Processes + packages proteins and lipids
  • Secrets carbohydrates
33
Q

Structure Of lysosomes

A
  • small bags / vesicles around golgi apparatus
  • contain digestive enzymes
34
Q

Function of Lysosomes

A
  • Hydrolyse phagocytic cells
  • Can break engulf old cell organelles
  • Break down dead cells
  • Keep powerful hyrolytic enzymes seperate from rest of cell
35
Q

Structure of Mitochondria

A
  • Oval Shaped
  • Have double membrane. The inner one is folded to form projections called Cristae
  • The inside contains the matrix which has all the enzymes involved in respiration ( its a fluid in the centre )
36
Q

Function of Mitochondria

A
  • Site where ATP energy is produced
  • Site of aerobic respiration
37
Q

Structure of Ribosomes

A
  • Small Spherical organelles
  • Made from RNA + proteins
  • Some remain free in cytoplasm while some are attached to endoplasmic rectilum
38
Q

Function of Ribosomes

A

Site of protein synthesis

39
Q

Structure of Chloroplast

A
  • Surrounded by double membrane or envelope
  • Contain stacks of flattened membrane sacs called thylakoid
  • each stack/pile of thylakoid is called a granum
  • Inside the thylakoid there is chlorophyll
  • Contains fluid filled stroma which contains enzymes for photosynthesis
  • Contain loop of DNA + Starch grains
40
Q

Function of Chloroplast

A

Site of photosynthesis

41
Q

Cell wall structure

A

Plants: Made of microfibrils of cellulose polymer
Fungi: Made of chitin, a nitrogen containing polysaccharide

42
Q

Cell wall function

A

Provides Structural Strength

43
Q

Plasma Membrane Structure

A
  • Found in all cells
  • Forms cell surface membrane
  • Made of phospholipid bilayer which contains molecules embedded within and attached on the outside ( Proteins, Carbohydrates, Cholesterol )
44
Q

Plasma Membrane Function

A
  • Controls what enters + leaves the molecules
  • Contains receptors which allow it to respond to chemical hormones
45
Q

Structure of RER

A
  • System of membrane bound Sacs
  • Coated with ribosomes
46
Q

Function of RER

A
  • Folds + processes proteins mde fro amino acids
  • Folds + processes proteins made at ribosome
47
Q

SER structure

A
  • System of membrane bound sacs containing fluid filled cavities ( cisternae ) that re continous with the nucleur membrane
  • Contain no ribosomes
48
Q

SER Function

A

Produces + Processes lipids

49
Q

Vesicle Structure

A

A small fluid filled sac in the cytoplasm surrounded by a membrane

50
Q

Vesicle Function

A

Transport substances in + out of the cell

51
Q

Simmilarites between prokaryotic and Eukaryotic

A

Both have :
- Plasma Membrane
- Cytoplasm
- Have ribsomes
- DNA & RNA

52
Q

Prokaryote only

A
  • Smaller
  • Less developed Cytoskeleton with no centrioles
  • No nucleus
  • No Membrane bound organelles e.g mitochondria , ER
  • Cell wall is made of peptidoglycan
  • Smaller ribosmes ( EU= 80s , PR = 70s )
  • ahve naked DNA that isn’t bounded but floats freely in cytoplasm as loop not linear
53
Q

Some prokaryotic features + uses

A
  1. Capsule= Protective waxy/slimy layer to cell to retain moisture
  2. Plasmids= Small loops of DNA as well as main Loop
  3. Flagella= Long whip like structure enabling movement. The structures of these flagella differ to eukaryotic ones
  4. Pili- Small hair like projections that allow it to attach on to other cells + allows passage of plamid DNA from one cell to another
54
Q

steps to protein production

A

1) Proteins are synthesised on ribosomes bound to ER
2) They are then passed into the cisternae & are packaged into transport vesicles
3) Vesicles containing newly synthesised proteins move towards golgi apparatus via transport function of cytoskeleton
4) The vesicles fuse with the cis face of the G.A & the proteins enter. The proteins are structurally modified before leaving G.A in vesicles from it’s trans face
5) Secretory vesicles carry proteins that are to be released from the cell
6) The vesicles move towards & fuse with the cell surface membrane releasing their contents by exocytosis
7) some vesicles form lysosomes (these contain enzymes for use in cell)