cell structure (cells) Flashcards

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1
Q

label a b c

A
  • A: cytoplasm
  • B: cell wall
  • C: cell (surface) membrane or plasma membrane
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2
Q

name the cell part labelled as D and describe its function within the cell

A
  • vacuole
  • maintains pressure inside the cell
  • or keeps the cell rigid/turgid
  • or stores food reserves
  • or stores waste products
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3
Q

both plant cells and prokaryotic cells contain cell walls, describe the difference between the composition of a plant cell wall and a prokaryotic cell wall (2)

A
  • prokaryotic cell walls are made up of peptidoglycan (murein)
  • plant cell walls are made up of cellulose
  • or plant cell walls a polymer of beta-glucose
  • plant cell walls contain hydrogen bonds between (individual) cellulose molecules
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4
Q

describe the function of the nucleus in non-dividing cells (4)

A
  • contains chromosomes/DNA/genes or contains genetic material
  • contains coded information for protein synthesis
  • contains sequences of bases in DNA
  • site of transcription of genes or site of production of mRNA
  • protects the DNA from degradation (by enzymes)
  • contains a nucleolus
  • makes ribosomes or makes ribosomal subunits
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5
Q

name the parts labelled A, C, D, and E

A
  • A: (secretory) vesicle
  • C: nuclear envelope/membrane
  • D: rough endoplasmic reticulum
  • E: cell (surface) membrane or plasma membrane
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6
Q

name the organelle labelled B in the diagram above and explain its function within the animal cell (2)

A
  • smooth endoplasmic reticulum
  • synthesis/storage of lipids/carbohydrates
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7
Q

name one organelle shown in the diagram above that you may also find in a prokaryotic cell

A
  • ribosomes
  • cell membrane
  • vesicles
  • cytoplasm
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8
Q

describe the role of organelles in the synthesis, transport, and release of proteins from these cells (4)

A
  • DNA in the nucleus contains the code (for proteins)
  • ribosomes produce proteins
  • mitochondria produce ATP (for protein synthesis)
  • Golgi apparatus packages/modifies proteins
  • vesicles transport proteins
  • vesicles fuse with cell (surface) membrane
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9
Q

complete the table by placing a tick in the boxes to show which cell types contain each component in their cell walls

A
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10
Q

which cell type contains murein in its cell wall

A

prokaryotes

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11
Q

which cell type contains cellulose in its cell wall

A

plants

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12
Q

which cell type contains chitin in its cell wall

A

fungi

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13
Q

what component do prokaryotes contain in their cell walls

A

murein

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14
Q

what component do plants contain in their cell walls

A

cellulose

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15
Q

what component do fungi contain in their cell walls

A

chitin

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16
Q

name structures A, B, C, and D

A
  • A: cell (surface) membrane OR plasma membrane
  • B: capsule
  • C: cell wall
  • D: flagellum
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17
Q

name the main biological component found in structure A

A

phospholipids

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18
Q

name one organelle that you would also find inside a chloroplast

A

ribosomes

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19
Q

compare the similarities and the differences between prokaryotic and eukaryotic cells (4)

A

similarities
- both contain cytoplasm
- both contain a cell (surface) membrane or a plasma membrane
- both contain ribosomes
differences
- eukaryotic cells contain membrane-bound organelles (e.g. mitochondria), prokaryotes do not
- eukaryotic cells (mostly) contain 80S ribosomes, prokaryotic cells (only) contain (smaller) 70S ribosomes
- eukaryotic cells contain a nucleus, prokaryotic cells do not
- some eukaryotic cells contain a cellulose/chitin cell wall, prokaryotic cells contain a murein/peptidoglycan cell wall

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20
Q

name the parts of the chloroplast labelled A, B, and C

A
  • A: granum/thylakoid/grana
  • B: stroma
  • C: lamella
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21
Q

describe the function of chloroplasts inside palisade cells (2)

A
  • absorb/trap light
  • for photosynthesis
  • produces carbohydrates/sugars/proteins/lipids
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22
Q

name the parts of the mitochondrion labelled X and Y

A
  • X: cristae or inner membrane
  • Y: matrix
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23
Q

a theory exists hypothesising that mitochondria evolved from prokaryotic cells, give one piece of evidence that would support this theory (1)

A

mitochondria contain circular DNA like prokaryotes do

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24
Q

which cell shows an animal cell, why (2)

A
  • cell 3
  • no cell wall or only contains a cell (surface) membrane
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25
Q

which cell shows a plant cell, why (2)

A
  • cell 2
  • has a cell wall, but no capsule
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26
Q

name two structures found in plant cells that are not found in animal cells

A
  • chloroplasts/plastids
  • cell wall
  • vacuole
  • starch grains or amyloplasts
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27
Q

describe the similarities and differences between a plant cell and a prokaryotic cell (4)

A

similarities
- both contain a cell wall
- both contain a cytoplasm
- both contain a cell membrane
- both contain ribosomes
differences
- plant cells contain membrane-bound organelles (e.g. chloroplasts), prokaryotes do not
- plant cells (mostly) contain 80S ribosomes, prokaryotes (only) contain 70S ribosomes
- plant cells contain a nucleus, prokaryotes do not
- plant cell walls are made up of cellulose, prokaryote cell walls are made up of murein/peptidoglycan

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28
Q
A
  • A: nuclear envelope/membrane
  • B: lysosome/vesicle
  • C: cell (surface) membrane or plasma membrane
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29
Q

identify the animal cell structures being described in the statements below:
- organelle that modifies and packages proteins
- organelle containing 70S ribosomes
- organelle where protein synthesis takes place

A
  • golgi apparatus or rough endoplasmic reticulum
  • mitochondria
  • ribosomes
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30
Q

name two components you would expect to see in a plant cell that cannot be identified in the animal cell above (2)

A
  • cell wall
  • vacuole
  • chloroplasts
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31
Q

describe the roles of the cell surface membrane within animal and plant cells (4)

A

acting as a selectively permeable barrier:
- acts as a barrier between the cytoplasm and the external environment
- selects substances that can enter or leave the cell
protection:
- protects the organelles from damage/pathogens
- or keeps the cell contents inside the membrane
- or membrane surrounds the organelles
communication with other cells:
- cell signalling or contains receptors for cell signalling
- cell recognition or contains cell surface antigens
- cell-to-cell adhesion
metabolism:
- site for enzymes or site for catalysing reactions
shape and stability:
- anchoring the cytoskeleton
- forms hydrogen bonds with water for stability
- can change shape (e.g. phagocytes)
- or is flexible (e.g. phagocytes)

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32
Q
A
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33
Q
  • identify the organelle shown in the electron micrograph
  • name structures A and B shown in the diagram above
A
  • chloroplast
  • A: granum/grana/thylakoid(s)
  • B: stroma
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34
Q

(mitochondria)
the organelle shown above contains its own DNA, describe the structure of this DNA

A
  • circular DNA
  • short DNA
  • not associated with histones
  • does not contain introns
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35
Q

describe the functions of components A and B in this eukaryotic cell (2)

A
  • component A (smooth endoplasmic reticulum): transports/processes lipids/carbohydrates
  • component B (mitochondrion): (site of aerobic) respiration or produces ATP or releases energy
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36
Q

describe structure of rough endosplasmic reticulum (2)

A
  • made up of flattened sacs/cisternae
  • covered with ribosomes
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37
Q

give two features from the diagram above that provide evidence the cell is eukaryotic

A
  • contains nucleus
  • contains mitochondria
  • contains RER
  • contains SER
  • contains golgi apparatus
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38
Q

proteins are synthesised during translation at the ribosomes, explain what happens to proteins following this process until they are secreted from the cell (3)

A
  • proteins folded in the rough endoplasmic reticulum
  • proteins are packaged into or transported in vesicles
  • proteins are modified in the Golgi apparatus/body/complex
  • exocytosis
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39
Q

describe the function of a sperm cell (1)

A
  • delivers genetic information to the female gamete
  • or fertilises the female gamete
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40
Q

explain how root hair cells are specialised for their function (2)

A
  • large surface area for absorption of water and ions
  • thin permeable cell wall for absorption of water and ions
  • cytoplasm contains lots of mitochondria to provide energy for active transport
41
Q

in multicellular organisms, specialised cells become organised to form the body structure, describe how cells are organised in multicellular organisms (5)

A

differentiation and specialisation:
- cells differentiate or cells become specialised
- (e.g. epithelium, cartilage, muscle) or (e.g. heart, lungs, liver) or (e.g. digestive system, respiratory system)
organisation:
- groups of cells form tissues
- groups of tissues form organs
- groups of organs form organ systems
- groups of cells/tissues/organs/organ systems interact or carry out the same function

42
Q

define the term tissue (2)

A
  • a group/collection of cells
  • cells are specialised
  • to perform a function or to work together
43
Q

describe the role of phloem tissue (1)

A

transports sugars/sucrose or amino acids around the plant

44
Q

describe the role of xylem tissue (1)

A

transports water and (mineral) ions around the plant

45
Q
  • fungal cells are similar to plant cells except there are no what in fungal cells
  • and cell wall is made of what
A
  • chloroplasts
  • cell wall is made from chitin instead of cellulose
46
Q

what are the two most fundamental groups of cells

A
  • eukaryotic
  • prokaryotic
47
Q

components of a phospholipid (3)

A
  • a lipid molecule
  • two fatty acid chains
  • a phosphate-containing group
48
Q

what type of molecule are cell-surface membranes made up of

A

phospholipid

49
Q

which of the following is found in the nucleoplasm

A
50
Q

ribosomal RNA joins with proteins to form

A

ribosomal subunit

51
Q

ribosomal RNA joins with what to form ribosomal subunit

A

proteins

52
Q

ribosomal subunits exist via pores in the

A

nuclear envelope

53
Q

ribosomal subunts exit via what in the nuclear envelope

A

pores

54
Q

ribosomal subunits are formed in the

A

nucleolus

55
Q

mitochondria are responsible for making

A

adenosine triphosphate (ATP)

56
Q

the area surrounded by the cristae folds in the mitochondria is called the

A

mitochondrial matrix

57
Q

in addition to cholesterol, what else do cell-surface membranes have embedded in them

A

proteins

58
Q

what do cell-surface membranes have embedded in them

A
  • cholesterol
  • proteins
59
Q

the features of mitochondria are (3)

A
  • oval-shaped
  • double membrane organelles
  • have their own ribosomes and DNA
60
Q

nuclear envelope is a double-membrane structure that has pores that control the passage of ions, molecules and RNA between the nucleoplasm and

A

cytoplasm

61
Q
A
62
Q
  • golgi vesicles store and transport what
  • from what
  • to what
A

modified proteins and lipids from the golgi apparatus to target cells

63
Q

lysosomes are a special type of

A

golgi vesicle

64
Q

lysosmes contain enzymes called

A

lysozymes

65
Q

the endoplasmic reticulum (ER) is a series of interconnected membranous sacs and

A

tubules

66
Q

the endoplasmic reticulum (ER) is a series of interconnected membranous sacs and tubules responsible for

A

modifying proteins and synthesising lipids

67
Q

smooth er is the site of

A

lipid synthesis and processing

68
Q

rough ER site of

A

protein folding and processing

69
Q

what are ribosomes in the endosplasmic reticulum the site of

A

protein production

70
Q

the Golgi apparatus is a series of flattened membranous sacs responsible for sorting, tagging and

A

packaging lipids and proteins

71
Q

plant cells each have a large central

A

vacole

72
Q

the vacole plays a key role in regulating the cells

A

water concentration in changing environmental conditions

73
Q

the eukaryotic membrane is a bilayer formed from two layers of

A

phosoholipids

74
Q

phospholipid molecules have heads which face out of the bilayer which are

A

hydrophilic

75
Q

phospholipid molecules have tails which face into the bilayer which are

A

hydrophobic

76
Q

the bilayer also has many proteins embedded in it, these proteins may be

A
  • integral
  • extrinsic
77
Q

the bilayer also has many proteins embedded in it, these proteins may be integral, meaning

A

that they cross the entire bilayer

78
Q

the bilayer also has many proteins embedded in it, these proteins may be extrinsic, meaning

A

that they are located on only one side of the bilayer

79
Q

proteins in the bilayer have many functions including acting as

A

ion channels or receptors that respond to external signals

80
Q

cholesterol in the bilayer acts as a

A

buffer for membrane fluidity

81
Q

cholesterol in the bilayer acting as a buffer for membrane fluidity means that

A
  • at high temperatures, cholesterol prevents fluidity from rising too high
  • at low temperatures, cholesterol prevents the membrane from becoming solid
82
Q

prokayotic DNA is

A
  • circular
  • found free in the cytoplasm
83
Q

eukaryotic DNA is

A
  • linear
  • found in the nucleus
84
Q

prokayotic ribosomes are smaller than

A

eukaryotic ribosomes

85
Q

prokaryotes do not have any

A

membrane bound organelles

86
Q

bacteria cell walls are formed of

A

peptidoglycan (murein)

87
Q

plant cell walls are formed of

A

cellulose

88
Q

fungal cell walls are formed of

A

chitin

89
Q

prokayotes divide by

A

binary fission

90
Q

eukaryotes divide by

A

mitosis

91
Q

describe the steps you might take to isolate mitochondria from a cell culture in the laboratory

A

lyse the cells
- the cells in the sample are broken open using a blender, homogenisation
- the cells must be kept under very specific conditions:
- ice cold: reduces the activity of the
enzymes
- isotonic solution: there is no water potential for osmosis to occur, which could cause the organelles to shrink or burst
- buffered solution: this keeps the
pH at a constant level to prevent damage to protein structure
filtration
- the homogenised sample is filtered through a
gauze
- filtration separates the
larger components from the smaller
organelles
ultracentrifugation
- the filtered samples are spun at a low speed in a
centrifuge
- it is important that each tube is
balanced with a tube directly opposite
- heavier components are forced to the bottom of the tube
- lighter components rise to the top
repeat
- the supernatant from the first round of centrifugation is centrifuged again
- the pellet this time will be the nuclei from the cells (this is the first pellet)
- the process is repeated and the mitochondria will be isolated in the third pellet

92
Q

having isolated the mitochondria, why would TEM be favourable to SEM to image an orgelle and identitfy the double membrane structure

A

higher resolution:
- transmission electron microscopy can achieve a higher resolution than scanning electrons microscopy which would be needed to identify the two separate membranes
can see internal structures:
- electrons pass through the sample in TEM rather than being scattered off the sample in SEM
- this means that TEM can visualise structures within the cell.
geater magnification:
- mitochondra are between 0.5 - 10 micrometers in size and so it requires very high magnification to visualise their internal consituents

93
Q

name the two organelles, besides the nucleus, that contain their own DNA

A
  • mitochondria
  • chloroplast
94
Q

role of mitrochondria

A

site of aerobic respiration

95
Q

what does the SER do

A

synthesis/storage of lipids/carbohydrates

96
Q

organelle that modifies and packages proteins

A
  • golgi apparatus (or RER)
97
Q

organelle containing 70S ribosomes

A

mitochondria

98
Q

organelle where protein synthesis takes place

A

ribosomes