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Flashcards in Cell Biology Deck (179)
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1
Q

hierarchy of life (in ascending order)

A

atoms

molecules

organelles

cells

tissues

organs

systems

organisms

population

community

ecosystem

biosphere

2
Q

2 main categories of organisms

A

prokaryotes

eukaryotes

3
Q

prokaryote

A

unicellular organism which lacks membrane-bound nucleus, mitochondria, or other membrane-bound organelles

4
Q

literal definition of “prokaryote”

A

before nucleus

before nut

before kernel

5
Q

eukaryote

A

multicellular organism which contains membrane-bound nucleus, mitochondria, and other membrane-bound organelle

6
Q

literal definition of “eukaryote”

A

good nucleus

true nucleus

good nut

true nut

good kernel

true kernel

7
Q

characteristics of life

functions of life

A

reproduction

nutrition

metabolism

growth

reaction to environment (response)

homeostasis

excretion

8
Q

reproduction

A

creation of new but similar organisms

also known as “gettin’ down to business”

9
Q

nutrition

A

procurement of food to provide energy and materials needed for growth

10
Q

metabolism

A

chemical reactions inside cells to release energy

sum of all reactions that occur in an organism

11
Q

metabolic rate

A

rate at which metabolism occurs

12
Q

requirements for metabolism to occur

A

absorbance of reactants by cell (through plasma membrane)

removal of waste products from cell (through plasma membrane)

13
Q

relationship between surface area and metabolic rate of cell

A

direct relationship

14
Q

reaction to environment

response

A

reaction to stimuli and changes in environment

15
Q

growth

A

physical enlargement of a living thing

16
Q

homeostasis

A

steady state of bodily functions

17
Q

excrement

A

process of getting rid of waste

18
Q

3 principles of cell theory

A

all living things are made of cells

cells are smallest units of life

existing cells come from other cells

19
Q

3 pieces of evidence to support cell theory

A

consistent appearance of all living things to be composed of cells when observed

requirement of cooperation of all organelles for life processes

lack of evidence that proves spontaneous generation or abiogenesis

20
Q

discrepancy

A

exception to general trend

21
Q

3 atypical examples in regards to cell theory

A

striated muscle tissue

giant algae

aseptate fungi

22
Q

discrepancy between striated muscle tissue and cell theory

A

much larger than typical animal cell

able to have many (sometimes up to 100) nuclei

23
Q

discrepancy between giant algae and cell theory

A

much larger than most unicellular organisms (able to grow up to 100nm long with only 1 nucleus)

24
Q

discrepancy between aseptate fungi and cell theory

A

has no septa to divide cell (causes uninterrupted tube-like structure with many nuclei)

25
Q

4 similarities between all cells

A

surrounded by membrane

contains genetic materials which store all instructions needed for cell’s activities

catalyzes chemical reactions by utilizing enzymes produced within cell

has unique energy release system that powers all activities

26
Q

complexity of structure of prokaryotes (and why)

A

complex (in order to carry out every function of life within one cell)

27
Q

number of cells in adult human body

A

10,000,000 cells

28
Q

cooperative group

A

collection of cells which work together in multicellular organisms

has no cells which act as ‘leader’ or ‘supervisor’

29
Q

emergent property

emergent property of a system

A

property of system as a whole (rather than components which make up system)

30
Q

emergence

A

way that complex systems and patterns arise from many small and relatively simple interactions

31
Q

reductionism

A

scientific practice of analyzing and describing a complex phenomenon by studying smaller parts of it

32
Q

predictability of emergent properties through reductionism

A

unpredictable

33
Q

cell differentiation

A

process by which acquires more specialized function and purpose

34
Q

cell potency

A

ability of a eukaryotic cell to differentiate into other cells

35
Q

totipotent cell

A

eukaryotic cell which has ability to differentiate into any other type of cell

36
Q

specialized cell

A

eukaryotic cell which is modified to carry out particular function

37
Q

benefits of cell specialization

A

efficiency

development of ideal structure (for assigned function)

creation of enzymes needed to carry out all chemical reactions associated with assigned function

38
Q

tissue

A

group of cells which differentiate in same way to perform same function

39
Q

gene expression

A

way in which a gene is used within a particular cell

dictates cell differentiation

40
Q

stem cell

A

eukaryotic cell at early stages of embryonic development

capable of dividing many times to produce large amounts of tissue

able to differentiate into any type of cell (totipotent)

41
Q

2 key properties of stem cells

A

ability to divide again and again to produce copious quantities of new cells

totipotency

42
Q

3 main types of stem cells

A

embryonic stem cells

cord blood stem cells

adult stem cells

43
Q

embryonic stem cell

A

stem cell which originates from a fertilized human egg (approximately 4 to 5 days post-fertilization)

totipotent

44
Q

therapeutic uses of embryonic stem cells

A

tissue regeneration

treatment and healing of diseases

(possibly in future) growth of replacement organs

45
Q

non-therapeutic uses of embryonic stem cells

A

large-scale production of striated muscle fibers (or meat) for human consumption

46
Q

cord blood stem cell

A

stem cell which originates from blood that remains in placenta and attached umbilical cord following childbirth

easily obtainable and stored

has limited capacity to differentiate into different types of cells (pluripotent)

47
Q

adult stem cell

somatic stem cell

A

stem cell which originates from some adult tissues

extremely difficult to obtain (located in only 3 known locations extremely deep in tissues)

48
Q

in vitro fertilization

A

process of fertilization where an egg is combined with sperm outside the body

49
Q

cell division

A

process by which parent cell divides into 2 or more daughter cells

50
Q

products from cell division of specialized cells

A

2 or more daughter cells of same specialization

51
Q

products from cell division of stem cells

A

2 or more daughter stem cells

52
Q

importance of surface area of cell for metabolism

A

substances cannot enter as quickly as required and waste would accumulate in cell (because waste would be produced faster than it could be expelled) if surface area were too small

53
Q

importance of surface area of cell on production and loss of heat

A

cell may overheat (because metabolism produces heat faster than lost over cell’s surface) if surface area were too small

54
Q

microscopy

A

technical field of using microscopes to view objects and areas of objects that cannot be seen with the naked eye

55
Q

microscope

A

instrument used to see objects that are too small to be seen by naked eye

56
Q

important parameters of microscopy

A

magnification

resolution

contrast

57
Q

(microscopy)

magnification

A

ratio of image size to real size

58
Q

(microscopy)

resolution

A

clarity of image

minimum distance of 2 distinguishable points

59
Q

(microscopy)

contrast

A

visible differences in parts of a sample

60
Q

2 main types of microscopes

A

light microscope

electron microscope

61
Q

light microscope

optical microscope

A

microscope that commonly uses visible light and a system of lenses to magnify images of small objects

62
Q

maximum magnification of most light microscopes

maximum magnification of most optical microscopes

A

approximately 1,000 times the actual size of sample

63
Q

electron microscope

A

microscope that uses beam of accelerated electrons as source of illumination

64
Q

2 types of electron microscopes

A

scanning electron microscope

transmission electron microscope

65
Q

scanning electron microscope

A

electron microscope which focuses beam of electrons onto surface of specimen

66
Q

transmission electron microscope

A

electron microscope which focuses beam of electrons through specimen

67
Q

(cell structure)

plasma membrane

A

biological membrane that separates interior of all cells from extracellular matrix

composed of phospholipid bilayers, membrane proteins, and cholesterol

found in every type of cell

68
Q

(cell structure)

cytosol

cytoplasmic matrix

A

everything inside of cell except for nucleus

found in every type of cell

69
Q

(cell structure)

cytoplasm

A

all the liquidy stuff inside cell

found in every type of cell

70
Q

(cell structure)

mitochondrion

A

double-membrane-bound organelle which produces most of cell’s supply of energy (in form of ATP)

found in eukaryotes

71
Q

2 parts within mitochondrion

A

intermembrane space

mitochondrial matrix

72
Q

(cell structure)

cytoskeleton

A

complex and dynamic network of interlinking protein filaments that extends from cell nucleus to cell membrane

provide structure and support to shape of cytoplasm

found in eukaryotes

73
Q

(cell structure)

3 components of cytoskeleton

A

microtubules

intermediate filaments

actin filaments (microfilaments)

74
Q

(cell structure)

microtubule

A

cytoskeletal structural components composed of polymers of tubulin

found in eukaryotic cells

75
Q

(cell structure)

intermediate filament

A

cytoskeletal structural component composed of family of related proteins sharing common structural and sequence features

found in eukaryotes

76
Q

(cell structure)

microfilament

actin filament

A

cytoskeletal structural component that is primarily composed of polymers of actin

found in eukaryotes

77
Q

(cell structure)

motor protein

A

protein which moves throughout cytoplasm of cell

converts energy into mechanical work through hydrolysis of ATP

responsible for most active transport of proteins and vescicles in cell

found in animal cells

78
Q

(cell structure)

nucleus

A

membrane-bound organelle which contains all of cell’s genome (except for small fraction of mitochondrial DNA)

found in most eukaryotes

79
Q

(cell structure)

nucleolus

A

largest structure in nucleus of cell

found in eukaryotes

80
Q

examples of cells without nuclei (enucleated cells)

A

prokaryotes

mammalian red blood cells

81
Q

(cell structure)

nuclear envelope

A

double-membrane-bound organelle which surrounds nucleus

protects nucleus of cell

has many nuclear pores that allow materials to move between cytosol and nucleus

found in eukaryotes

82
Q

(cell structure)

nuclear pore

A

part of large complex of proteins (nuclear pore complex) which spans across nuclear envelope

allows transport of molecules across nuclear envelope (including RNA and ribosomal proteins)

found in eukaryotes

83
Q

(cell structure)

chromatin

A

complex of DNA and protein located in nucleus of cells

found in eukaryotic cells

84
Q

(cell structure)

endoplasmic reticulum

A

type of organelle that forms interconnected network of cisternae

adjacent to nucleus in most cells

found in eukaryotes

85
Q

cisternae

A

flattened membrane disk or sac of endoplasmic reticulum and Golgi apparatus

86
Q

(cell structure)

smooth endoplasmic reticulum

A

membrane-bound organelle responsible for synthesis of lipids and steroid hormones, detoxification of harmful metabolic byproducts, and storage and metabolism of calcium ions within cell

composed of cisternae

scarce in most cells

found in eukaryotes

87
Q

(cell structure)

rough endoplasmic reticulum

A

membrane-bound organelle responsible for production of proteins

composed of cisternae

covered by ribosomes

found in eukaryotes

88
Q

structural difference between smooth endoplasmic reticulum and rough endoplasmic reticulum

A

surface of smooth endoplasmic reticulum does not contain ribosomes

surface rough endoplasmic reticulum contains ribosomes

89
Q

(cell structure)

Golgi apparatus

Golgi complex

A

membrane-bound organelle responsible for secretion and intracellular transport

composed of cisternae

attached to vesicles and folded membranes within cytoplasm

found in eukaryotes

90
Q

2 main networks of Golgi apparatus

A

cis Golgi network

trans Golgi network

91
Q

cis Golgi network

A

“receiving” side of Golgi apparatus

92
Q

trans Golgi network

A

“shipping” side of Golgi apparatus

93
Q

structural difference between endoplasmic reticulum and Golgi apparatus

A

endoplasmic reticulum has elongated cisternae (sometimes) with attached ribosomes

Golgi apparatus has curved cisternae with no attached ribosomes and many vescicles nearby

94
Q

(cell structure)

lysosome

A

single-membrane-bound organelle formed from vesicles near Golgi apparatus

contain digestive enzymes which can be used to break down ingested food (found in vesicles), organelles, or even entire cells

found in eukaryotes

95
Q

autophagy

A

process by which cell eats itself

96
Q

(cell structure)

peroxisome

A

double-membrane-bound organelle responsible for catabolism of particular fatty acids, amino acids, and polyamines

produces hydrogen peroxide

found in eukaryotes

97
Q

(cell structure)

centrosome

A

membrane-bound organelle that serves as the main microtubule-organizing center of the animal cell and regulator of cell-cycle progression

composed of two centrioles arranged at right angles to each other

found in animal cells

98
Q

(cell structure)

centriole

A

cylindrical organelle responsible for helping with development of spindle fibers (used in cell division)

composed mainly of a protein called tubulin

located near nucleus of cell

found in eukaryotes

99
Q

(cell structure)

cell wall

A

tough structural layer surrounding cell membrane

found in prokaryotes and plant cells

100
Q

(cell structure)

vacuole

A

membrane-bound organelle which are filled with water containing inorganic and organic molecules

may contain solids which have been engulfed

derived from endoplasmic reticulum and Golgi apparatus

found in every type of cell

101
Q

(cell structure)

central vacuole

A

membrane-bound organelles which hold organic compounds and water

found in plant cells

102
Q

(cell structure)

contractile vacuole

A

membrane-bound organelle which pumps excess water out of cell

found in freshwater plants

103
Q

(cell structure)

plastid

A

type of organelle in cytoplasm of cell which contains pigment or food

found in plant cells

104
Q

(cell structure)

chloroplast

A

plastid that conducts photosynthesis

contains chlorophyll

found in plant cells

105
Q

photosynthesis

A

conversion of light into energy

106
Q

(cell structure)

granum

A

stack of thylakoids within chloroplast

found in plant cells

107
Q

(cell structure)

thylakoid

A

membranous sac within chloroplast

located in granum within chloroplast

found in plant cells

108
Q

(cell structure)

stroma

A

internal fluid of chloroplast

109
Q

(cell structure)

capsule

A

polysaccharide layer that lies outside cell wall

found in prokaryotes

110
Q

(cell structure)

pili

A

long hair-like appendage found on surface of cell

found in prokaryotes

111
Q

(cell structure)

fimbriae

A

short hair-like appendage on surface of cell

found in prokaryotes

112
Q

(cell structure)

flagellum

A

lash-like appendage that protrudes from cell body

assists with locomotion and sensory

found in every type of cell (mainly prokaryotes)

113
Q

(cell structure)

cilium

A

slender organelle which protrudes from surface of cell

assists with sensory

found in eukaryotes

114
Q

(cell structure)

nucleoid

nucleoid region

A

irregularly shaped region within cell that contains all or most genetic material (genophore)

found in prokaryotes

115
Q

(cell structure)

vescicle

A

structure within or outside a cell used to transport particles

consists of liquid or cytoplasm enclosed in phospholipid bilayer

found in every type of cell

116
Q

(cell structure)

ribosome

A

organelle which serves as site of biological protein synthesis

links together amino acids in order specified by messenger RNA (mRNA) molecules

located on surface of rough endoplasmic reticulum within eukaryotes

found in every type of cell

117
Q

(cell structure)

nuclear lamina

A

fibrillar network inside nucleus of most cells

maintains shape of nucleus

found in eukaryotes

118
Q

(cell structure)

extracellular matrix

A

three-dimensional network of extracellular glycoproteins (such as collagen, proteoglycans, and fibronectin)

binds to receptor proteins in plasma membrane (integrin)

found around every type of cell (mainly animal cells)

119
Q

functions of extracellular matrix

A

support

adhesion

movement

regulation

120
Q

(cell structure)

endomembrane system

A

components which are continuous with or connected to plasma membrane (via transfer by vescicles)

121
Q

components of endomembrane system

A

nuclear envelope

endoplasmic reticulum

Golgi apparatus

lysosomes

vacuoles

plasma membranes

122
Q

(cell structure)

phospholipid bilayer

A

main component of polar cell membrane

made of two layers of amphipathic phospholipid molecules

semi-permeable

found in every type of cell

123
Q

hydrophilic substance

A

substance which is attracted to water

124
Q

hydrophobic substance

A

substance which is not attracted to water

125
Q

amphipathic substance

A

substance with hydrophilic portion and hydrophobic portion

126
Q

phospholipid

A

amphipathic lipid which contains 2 hydrocarbon chains attached to 1 phosphate group by a glycerol molecule

127
Q

structure of phospholipid

A

1 polar phosphate group (hydrophilic “head”)

2 nonpolar hydrocarbon chains (hydrophobic “tails”)

128
Q

phosphate group

hydrophilic “head”

A

polar ends of phospholipid molecules

face outwards on both sides of plasma membrane

attached to 2 hydrocarbon chains

129
Q

hydrocarbon chain

hydrophobic “tail”

A

nonpolar end of phospholipid molecules

face inwards on both sides of plasma membrane

attached to phosphate group

130
Q

effect of double bonds in hydrocarbon chains of phospholipids

A

makes phospholipids to sit further away from each other (causes semi-fluid state of plasma membranes)

131
Q

(cell structure)

membrane protein

A

proteins found in or on surface of plasma membrane

found in every type of cell

132
Q

functions of membrane protein

A

transport channels for passive transport of materials into or out of cell

enzymatic activity

cell-to-cell communication (signal transduction)

cell-to-cell recognition

cell-to-cell adhesions (tight junctions)

attachment to cytoskeleton and extracellular matrix

133
Q

types of membrane proteins

A

integral membrane protein

peripheral membrane protein

134
Q

integral membrane protein

integral protein

A

protein embedded in between hydrocarbon tails of plasma membrane

hydrophobic on exterior

sometimes hydrophilic on interior (depending on function)

has specific orientation (positioned specifically for needs of cell)

135
Q

peripheral membrane protein

peripheral protein

A

protein which sits on surface of plasma membrane

hydrophilic exterior (prevents it from embedding in plasma membrane)

has specific orientation (positioned specifically for needs of cell)

136
Q

deciding factor of protein content of plasma membrane

A

function of plasma membrane (more active membranes require higher protein content)

137
Q

(cell structure)

cholesterol

A

lipid (neither fat nor oil)

steroid (gives it 4-ring structure)

mostly hydrophobic (except for hydroxyl group at one end of molecule)

found in animal cell membranes

138
Q

location of cholesterol in plasma membrane

A

between phospholipids

139
Q

functions of cholesterol in plasma membrane

A

stabilize fluidity of plasma membrane (regardless of temperature or other factors)

help plasma membrane curve to form vesicles

140
Q

3 plasma membrane models

A

Gorter and Grendel model

Davson and Danielli model (sandwich model)

Singer and Nicolson model (fluid mosaic model)

141
Q

(plasma membrane model)

Gorter and Grendel model

A

proposed in 1920

described plasma membrane as a bilayer

claimed that membranes also contained proteins (without specifying their location)

succeeded by Davson and Danielli model (sandwich model)

142
Q

(plasma membrane models)

Davson and Danielli model

sandwich model

A

proposed in 1935

described phospholipid bilayer that lies between 2 layers of globular proteins (like sandwich)

had many discrepancies

succeeded by Singer and Nicholson model (fluid mosaic model)

143
Q

problems with Davson and Danielli model

A

freeze-etched electron micrographs (caused fractures along lines of weakness through membrane)

structure of membrane proteins (variance in shape and size)

144
Q

(plasma membrane models)

Singer and Nicholson model

fluid mosaic model

A

proposed in 1972

described plasma membrane as 2-dimensional liquid that restricts lateral diffusion of membrane components

explained concept of integral and peripheral proteins

most-accepted model of plasma membrane to date

145
Q

shape of vesicles

A

spherical

146
Q

function of vesicles

A

facilitation of exocytosis or endocytosis

147
Q

causes of vesicle movement

A

transportation of contents of vesicle

transportation of proteins in vesicle membrane

148
Q

endocytosis

A

process by which a cell uses its plasma membrane to engulf substances

149
Q

2 types of endocytosis

A

phagocytosis

pinocytosis

150
Q

phagocytosis

A

process by which a cell uses its plasma membrane to engulf large particles (≥ 0.5 μm)

type of endocytosis

151
Q

pinocytosis

A

process by which a cell uses its plasma membrane to engulf small particles suspended in extracellular fluid

type of endocytosis

152
Q

exocytosis

A

process by which a cell uses its plasma membrane to remove substances

153
Q

2 types of exocytosis

A

secretion

expulsion

154
Q

secretion

A

process by which a cell uses its plasma membrane to remove useful substances (not waste products)

type of exocytosis

155
Q

expulsion

A

process by which a cell uses its plasma membrane to remove waste products (not useful substances)

type of exocytosis

156
Q

2 methods of particle movement across plasma membrane

A

passive transport

active transport

157
Q

passive transport

A

movement of ions and other atomic or molecular substances across plasma membrane without need of energy input

158
Q

3 types of passive transport

A

simple diffusion

facilitated diffusion

osmosis

159
Q

diffusion

A

net movement of anything from region of higher concentration to region of lower concentration

160
Q

simple diffusion

A

spreading out of particles from region of higher concentration to a region of lower concentration across plasma membrane

involves particles passing between phospholipids

type of passive transport

161
Q

particles which are able to undergo simple diffusion

A

small, nonpolar, uncharged, and hydrophobic molecules

162
Q

facilitated diffusion

A

spreading out of particles from region of higher concentration to a region of lower concentration across plasma membrane

involves particles passing through protein channels

type of passive transport

163
Q

particles which are able to undergo facilitated diffusion

A

polar and hydrophilic molecules

large ions

164
Q

protein channel

A

protein that allows transport of specific substances across plasma membrane

165
Q

osmosis

A

diffusion of water from region of higher concentration to a region of lower concentration across plasma membrane

involves water molecules passing between phospholipids

type of passive transport

166
Q

tonicity

A

ability of surrounding solution to cause cell to gain or lose water

167
Q

isotonic solution

A

solution in which concentration is same inside and outside of cell

involves no net water movement across plasma membrane

168
Q

hypertonic solution

A

solution in which concentration is less inside than outside of cell

involves cell losing water

169
Q

hypotonic solution

A

solution in which concentration is greater inside than outside of cell

involves cell gaining water

170
Q

natural tonicity of animal cells

A

isotonic

171
Q

state of hypertonic animal cell

A

shriveled

172
Q

state of hypotonic animal cell

A

lysed

173
Q

natural tonicity of walled cells

A

hypotonic

174
Q

state of isotonic walled cell

A

flaccid

limp

175
Q

state of hypertonic walled cell

A

plasmolyzed

176
Q

aquaporin

A

integral membrane proteins that serve as channels in transfer of water and small solutes across plasma membrane

177
Q

cells with aquaporins

A

cells which need to move large amounts of water

178
Q

active transport

A

spreading out of particles from region of lower concentration to a region of higher concentration across plasma membrane

involves particles passing through globular pump proteins

requires energy (in form of ATP)

179
Q

endosymbiotic theory

A

evolutionary theory which states that an early ancestor of eukaryotic cells engulfed a nonphotosynthetic prokaryotic cell