Topic 1.2: Ultrastructure of Cells Flashcards Preview

HL Biology > Topic 1.2: Ultrastructure of Cells > Flashcards

Flashcards in Topic 1.2: Ultrastructure of Cells Deck (116):
1

Define prokaryotes

are organisms whose cells lack a nucleus

2

What are organisms whose cells lack a nucleus called?

prokaryotes

3

Define archaebacteria

bacteria found in extreme environments like high temperatures, salt concentrations or pH

4

Define eubacteria

traditional bacteria including most known pathogenic forms

5

What are found in extreme environments like high temperatures, salt concentrations or pH called?

archaebacteria

6

What are traditional bacteria including most known pathogenic forms called?

eubacteria

7

Define cytoplasm

internal fluid component of the cell

8

Define nucleoid

region of the cytoplasm where the DNA is located (DNA strand is circular and called a genophore)

9

Define plasmids

autonomous circular DNA molecules that may be transferred between bacteria (horizontal gene transfer)

10

Define ribosomes

complexes of RNA and protein that are responsible for polypeptide synthesis (prokaryote ribosome = 70S)

11

Define cell membrane

Semi-permeable and selective barrier surrounding the cell

12

Define cell wall

rigid outer covering made of peptidoglycan; maintains shape and prevents bursting (lysis)

13

Define slime capsule

a thick polysaccharide layer used for protection against dessication (drying out) and phagocytosis

14

Define flagella

Long, slender projections containing a motor protein that enables movement (singular: flagellum)

15

Define pili

Hair-like extensions that enable adherence to surfaces (attachment pili) or mediate bacterial conjugation (sex pili)

16

What is the internal fluid component of the cell called?

cytoplasm

17

What is the region of the cytoplasm where the DNA is located (DNA strand is circular and called a genophore) called?

nucleoid

18

What is the autonomous circular DNA molecules that may be transferred between bacteria (horizontal gene transfer) called?

plasmids

19

What are complexes of RNA and protein that are responsible for polypeptide synthesis (prokaryote ribosome = 70S) called?

ribosomes

20

What is the Semi-permeable and selective barrier surrounding the cell called?

cell membrane

21

What is the rigid outer covering made of peptidoglycan; maintains shape and prevents bursting (lysis) called?

cell wall

22

What is a thick polysaccharide layer used for protection against dessication (drying out) and phagocytosis called?

slime capsule

23

What are Long, slender projections containing a motor protein that enables movement (singular: flagellum) called?

flagella

24

What are Hair-like extensions that enable adherence to surfaces (attachment pili) or mediate bacterial conjugation (sex pili) called?

pili

25

Define binary fission

a form of asexual reproduction used by prokaryotic cells

26

What is a form of asexual reproduction used by prokaryotic cells?

binary fission

27

What are the 3 steps to binary fission?

The circular DNA is copied in response to a replication signal

The two DNA loops attach to the membrane

The membrane elongates and pinches off (cytokinesis), forming two cells

28

What is the first step to binary fission?

The circular DNA is copied in response to a replication signal

29

After The circular DNA is copied in response to a replication signal What is the next step to binary fission?

The two DNA loops attach to the membrane

30

After The two DNA loops attach to the membrane What is the next step to binary fission?

The membrane elongates and pinches off (cytokinesis), forming two cells

31

Define eukaryotes

organisms whose cells contain a nucleus

32

What are organisms whose cells contain a nucleus?

eukaryotes

33

What are the two types of bacteria?

archaebacteria and eubacteria

34

What are the four kingdoms of eukaryotes?

protista, fungi, plantae, animalia

35

What makes a eukaryote a protista?

unicellular organisms; or multicellular organisms without specialised tissue

36

What makes a eukaryote a fungi?

have a cell wall made of chitin and obtain nutrition via heterotrophic absorption

37

What makes a eukaryote a plantae?

have a cell wall made of cellulose and obtain nutrition autotrophically (via photosynthesis)

38

What makes a eukaryote a animalia?

no cell wall and obtain nutrition via heterotrophic ingestion

39

What kingdom of eukaryotes are unicellular organisms; or multicellular organisms without specialised tissue?

protista

40

What kingdom of eukaryotes have a cell wall made of chitin and obtain nutrition via heterotrophic absorption?

fungi

41

What kingdom of eukaryotes have a cell wall made of cellulose and obtain nutrition autotrophically (via photosynthesis)?

plantae

42

What kingdom of eukaryotes have no cell wall and obtain nutrition via heterotrophic ingestion?

animalia

43

What is the structure of ribosomes?

Two subunits made of RNA and protein; larger in eukaryotes (80S) than prokaryotes (70S)

44

What is the function of ribosomes?

Site of polypeptide synthesis (this process is called translation)

45

What is the structure of cytoskeleton?

A filamentous scaffolding within the cytoplasm (fluid portion of the cytoplasm is the cytosol)

46

What is the function of cytoskeleton?

Provides internal structure and mediates intracellular transport (less developed in prokaryotes)

47

What is the structure of plasma membrane?

Phospholipid bilayer embedded with proteins (not an organelle per se, but a vital structure)

48

What is the function of plasma membrane?

Sem-permeable and selective barrier surrounding the cell

49

What is the structure of nucleus?

Double membrane structure with pores; contains an inner region called a nucleolus

50

What is the function of nucleus?

Stores genetic material (DNA) as chromatin; nucleolus is site of ribosome assembly

51

What is the structure of endoplasmic reticulum?

A membrane network that may be bare (smooth ER) or studded with ribosomes (rough ER)

52

What is the function of endoplasmic reticulum?

Transports materials between organelles (smooth ER = lipids ; rough ER = proteins)

53

What is the structure of golgi apparatus?

An assembly of vesicles and folded membranes located near the cell membrane

54

What is the function of golgi apparatus?

Involved in the sorting, storing, modification and export of secretory products

55

What is the structure of mitochondria?

Double membrane structure, inner membrane highly folded into internal cristae

56

What is the function of mitochondria?

Site of aerobic respiration (ATP production)

57

What is the structure of peroxisome?

Membranous sac containing a variety of catabolic enzymes

58

What is the function of peroxisome?

Catalyses breakdown of toxic substances (e.g. H2O2) and other metabolites

59

What is the structure of centrosome?

Microtubule organising centre (contains paired centrioles in animal cells but not plant cells)

60

What is the function of centrosome?

Radiating microtubules form spindle fibres and contribute to cell division (mitosis / meiosis)

61

What is the structure of chloroplasts?

Double membrane structure with internal stacks of membranous discs (thylakoids)

62

What is the function of chloroplast?

Site of photosynthesis – manufactured organic molecules are stored in various plastids

63

What is the structure of vacuole?

Fluid-filled internal cavity surrounded by a membrane (tonoplast)

64

What is the function of vacuole?

Maintains hydrostatic pressure (animal cells may have small, temporary vacuoles)

65

What is the structure of cell wall?

External outer covering made of cellulose (not an organelle per se, but a vital structure)

66

What is the function of cell wall?

Provides support and mechanical strength; prevents excess water uptake

67

What is the structure of lysosome?

Membranous sacs filled with hydrolytic enzymes

68

What is the function of lysosome?

Breakdown / hydrolysis of macromolecules (presence in plant cells is subject to debate)

69

What structure is Two subunits made of RNA and protein; larger in eukaryotes (80S) than prokaryotes (70S)?

ribosomes

70

What structure has the function of Site of polypeptide synthesis (this process is called translation)?

ribosomes

71

What structure is A filamentous scaffolding within the cytoplasm (fluid portion of the cytoplasm is the cytosol)?

cytoskeleton

72

What structure has the function of Provides internal structure and mediates intracellular transport (less developed in prokaryotes)?

cytoskeleton

73

What structure is Phospholipid bilayer embedded with proteins (not an organelle per se, but a vital structure)?

plasma membrane

74

What structure has the function of Sem-permeable and selective barrier surrounding the cell?

plasma membrane

75

What structure is Double membrane structure with pores; contains an inner region called a nucleolus?

nucleus

76

What structure has the function of Stores genetic material (DNA) as chromatin; nucleolus is site of ribosome assembly?

nucleus

77

What structure is A membrane network that may be bare (smooth ER) or studded with ribosomes (rough ER)?

endoplasmic reticulum

78

What structure has the function of Transports materials between organelles (smooth ER = lipids ; rough ER = proteins)?

endoplasmic reticulum

79

What structure is An assembly of vesicles and folded membranes located near the cell membrane?

golgi apparatus

80

What structure has the function of Involved in the sorting, storing, modification and export of secretory products?

golgi apparatus

81

What structure is Double membrane structure, inner membrane highly folded into internal cristae?

mitochondria

82

What structure has the function of Site of aerobic respiration (ATP production)?

mitochondria

83

What structure is Membranous sac containing a variety of catabolic enzymes?

peroxisome

84

What structure has the function of Catalyses breakdown of toxic substances (e.g. H2O2) and other metabolites
?

peroxisome

85

What structure is Microtubule organising centre (contains paired centrioles in animal cells but not plant cells)?

centrosome

86

What structure has the function of Radiating microtubules form spindle fibres and contribute to cell division (mitosis / meiosis)?

centrosome

87

What structure is Double membrane structure with internal stacks of membranous discs (thylakoids)?

chloroplast

88

What structure has the function of Site of photosynthesis – manufactured organic molecules are stored in various plastids?

chloroplast

89

What structure is Fluid-filled internal cavity surrounded by a membrane (tonoplast)?

vacuole

90

What structure has the function of Maintains hydrostatic pressure (animal cells may have small, temporary vacuoles)
?

vacuole

91

What structure is External outer covering made of cellulose (not an organelle per se, but a vital structure)?

cell wall

92

What structure has the function of Provides support and mechanical strength; prevents excess water uptake?

cell wall

93

What structure is Membranous sacs filled with hydrolytic enzymes?

lysosome

94

What structure has the function of Breakdown / hydrolysis of macromolecules (presence in plant cells is subject to debate)
?

lysosome

95

How do electron microscopes work?

Electron microscopes use electron beams focused by electromagnets to magnify and resolve microscopic specimens

96

What type of microscopes use electron beams focused by electromagnets to magnify and resolve microscopic specimens?

electron microscopes

97

What does a Transmission electron microscopes (TEM) do?

generate high resolution cross-sections of objects

98

What type of electron microscope generate high resolution cross-sections of objects?

Transmission electron microscopes (TEM)

99

What does a Scanning electron microscopes (SEM) do?

display enhanced depth to map the surface of objects in 3D

100

What type of electron microscope display enhanced depth to map the surface of objects in 3D?

Scanning electron microscopes (SEM)

101

What are the two advantages electron microscopes have over light microscopes?

They have a much higher range of magnification (can detect smaller structures)
They have a much higher resolution (can provide clearer and more detailed images)

102

What is one disadvantage of electron microscopes?

they cannot display living specimens in natural colours

103

Define micrograph

a photo or digital image taken through a microscope to show a magnified image of a specimen

104

What is a photo or digital image taken through a microscope to show a magnified image of a specimen?

micrograph

105

What are the 3 differences between prokaryotes and eukaryotes when it comes to DNA?

Prokaryotes: DNA is naked, DNA is circular, usually no introns

Eukaryotes: DNA bound to protein, DNA is linear, usually has introns

106

What are the 3 differences between prokaryotes and eukaryotes when it comes to organelles?

Prokaryotes: no nucleus, no membrane-bound, 70S ribosomes

Eukaryotes: has a nucleus, membrane-bound, 80S ribosomes

107

What are the 2 differences between prokaryotes and eukaryotes when it comes to reproduction?

Prokaryotes: binary fission, single chromosome (haploid)

Eukaryotes: mitosis and meiosis, chromosomes paired (diploid or more)

108

What is the difference between prokaryotes and eukaryotes when it comes to average size?

Prokaryotes: smaller (1-5 micrometers)

Eukaryotes: larger (10-100 micrometers)

109

What is the difference between plant and animal cells when it comes to plastids?

Plant: have plastids (chloroplasts)

Animal: do not have plastids

110

What is the difference between plant and animal cells when it comes to cell wall?

Plant: have a cell wall (made of cellulose)

Animal: do not have a cell wall

111

What is the difference between plant and animal cells when it comes to vacuoles?

Plant: have a large, central vacuole

Animal: have small, temporary vacuoles (if any)

112

What is the difference between plant and animal cells when it comes to plasmodesmata?

Plant: may have plasmodesmata

Animal: do not have plasmodesmata

113

What is the difference between plant and animal cells when it comes to centrioles?

Plant: do not have centrioles

Animal: have paired centrioles within centrosomes

114

What is the difference between plant and animal cells when it comes to cholesterol?

Plant: do not have cholesterol in cell membrane

Animal: have cholesterol in the cell membrane

115

What is the difference between plant and animal cells when it comes to storing glucose?

Plant: store excess glucose a starch

Animal: store excess glucose as glycogen

116

What is the difference between plant and animal cells when it comes to shape?

Plant: generally have a fixed, regular shape

Animal: generally have an amorphouse shape

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