cells Flashcards
(102 cards)
1
Q
cell theory (3)
A
- living organisms made of cells
- are smallest unit of life
- come from pre-existing cells
2
Q
how do light microscopes magnify images
A
lenses bend light; magnification dependent on lenses
3
Q
how many m is 1 um
A
1 x 10^-6m; 1000um= 1mm
4
Q
fluorescent stain
A
synthetic dyes used to bind cellular compounds to resolve specific structures
5
Q
immunofluorescence stain
A
uses antibodies linked to fluorescent probes, specifically targeting a cellular component
6
Q
scanning electron microscope (4)
A
- surface detail
- 3D
- lower magnification
- coats specimen in dense metal (gold)
7
Q
transmission electron microscope (4)
A
- electron beam through specimen on photofilm
- 3D difficult
- great detail
- small fov
8
Q
cyrogenic electron microscopy
A
freezing samples b4 viewing, generates image of comparable standard to x-ray crystallography
9
Q
what does cyrogenic electron microscopy allow for
A
determination of molecular structures @near atomic resolution
10
Q
freeze fracture**
A
frozen specimen cracked along plain, internal cellular structures can then be studied
11
Q
advantages of light microscopes (6)
A
- living specimens (movement)
- cheaper
- portable
- simple prep
- colours
- large fov
12
Q
advantages of electron microscopes (2)
A
- better resolution
- increased magnification
13
Q
magnification formula**
A
drawing size/actual size (dont forget units)
14
Q
examples of the functions of life unicellular organisms carry out (7)
A
- metabolism
- response to stimuli
- homeostasis
- growth
- reproduction
- nutrition
- excretion
15
Q
what do all cells have (3)
A
- plasma membrane
- DNA containing region
- cytoplasm
16
Q
what dont prokaryotes (some bacteria) have
A
membrane bound nucleus
17
Q
what does the cell membrane consist of
A
phospholipid bilayer; hydrophilic head, hydrophobic tail
18
Q
why do cells stay small in size
A
maintain high SA:V ratio so materials transfer in and out more efficiently + distributed more efficiently
19
Q
what factors does SA:V ratio affect (3)
A
- rate of heat production
- waste production
- resource consumption
20
Q
what is a function of SA
A
rate of exchange of materials + energy
21
Q
draw a prokaryote cell + label rn- e. coli
A
22
Q
how big are prokaryote cells
A
<5 um, smallest known cell
23
Q
2 groups of prokaryote cells, what do they differ in
A
archea (extremophiles), bacteria, differ in amino acids used to initiate protein synthesis
24
Q
what do most prokaryote cells have
A
cell wall surrounding plasma membrane
25
what do many prokaryote cells have
flagella- used for movements, pili (used to attach to surfaces)
26
what kind of ribosomes are in the cytoplasm of prokaryote cells
70S
27
what might circular DNA concentrated in nucleoid region have
plasmids
28
how do prokaryote cells divide
binary fission
29
what does the nucleoid contain for prokaryote cells
"naked" Dna which has instructions for proteins (building blocks)
30
how many proteins (histones) support DNA in prokaryote cells
little to none
31
be able to draw and label eukaryotic cell- liver
32
eukaryotic nucleus
contains DNA w proteins (histones), which has instructions for generating proteins (building blocks)
33
eukaryotic nucelar envelope
double membrane w pores (proteins) allowing flow of materials in + out of nucleus
34
eukaryotic endomembrane system (ER, golgi, vesicles)
organelles where lipid + new polypeptide (protein) chains are modified into final proteins
35
eukaryotic lysosomes
vesicle that buds from golgi membranes, organelle of intracellular digestion
36
eukaryotic peroxisomes
sacs of enzymes breaking down fatty acids, alcohol, amino acids
37
eukaryotic mitochondria + chloroplasts
double layered membranes, contain own DNA, mitochondria DNA inherited from mothers for humans)
38
eukaryotic mitochondria function
synthesize ATP
39
eukaryotic central vacuole
fluid filled storage sac w aa, sugars, ions, water, toxic waste. large in plants; small in animals
40
eukaryotic microtubles
for cell shape, motion, growth, structure of cells, flagella
41
eukaryotic microfillaments
cell shape + movement @ surface
42
eukaryotic cell wall
- provide structure + support of plants + fungi
- plants-cellulose
- fungi- chitin
43
eukaryotic cell movement cilia
many motile structures that projects from surface of cells
44
eukaryotic atypical cell structure- striated muscle
multinucleated due to fusion of cells
45
eukaryotic cell movement flagella
flagella- not as profuse as cilia but same function
46
eukaryotic cell movement pseudopods
"false feet" temporary lobe bulging from cells
47
eukaryotic atypical cell structure- sieve tube cell
in phloem + may lack nuclei + organelles
48
eukaryotic atypical cell structure- fungal hyphae
cells usually separated by septa, but some arent + have continuous cytoplasm
49
eukaryotic atypical cell structure- red blood cell
lack nucleus + cant replicate
50
DNA differences between pro + eu
pro- naked DNA eu- DNA + histones
51
mitochondria differences between pro + eu
pro- none eu- yes
52
ribosomes differences between pro + eu
pro- 70s (small) eu- 80s
53
what allows eukaryotic cells to compartmentalize their functions
internal membranes
54
what kind of properties do multicellular organisms show
emergent
55
when do multicellular organisms show emergent properties
when individual components in environment come tgt, creating distinct, collective + interactive properties + functions
56
can emergent properties manifest themselves
no, unless organisms are looked @ in its entirety
57
fluid mosaic model
fluid- motion + interaction of parts
mosaic- mix of many components
58
what are cell membranes made up of
phospholipid bilayer, glycolipids (sugar fats), sterols proteins
59
amphipathic
hydrophilic head polar w phosphate molecule, hydrophobic tail- 2 non-polar hydrocarbon chain
60
phospholipid bilayer
hydrophobic groups (non-polar) dont wanna be exposed to water (polar) + will spontaneously form bilayer
61
hydrocarbon chains forming core of bilayer
hydrophobic, have low permeability to large + enlarged substances (large compounds + hydrophilic particles like ions + polar molecules cant cross bilayer)
62
which organelle compositions are very similar to the cell membrane + what happens bc of this
nuclear envelope, ER, golgi, so sections of each of membranes can be exchange w/o overall charge
63
cholesterol
(sterol in animal cells) wedged between phospholipids to restrain movement (fluidity) of phospholipids + permeability to some solutes
64
can proteins move along cell membrane
yes unless theyre large, may be attached to cytoskeleton for support
65
integral proteins
embedded proteins, partially/ spanning membrane (usually involves transport)
66
extrinsic/periphera proteins
on membrane surface or just inside membrane (phosphate end of phospholipid)
67
transport proteins
allow water soluble material through, passive transport I.e. channel protein
68
pump proteins
active transport of solutes
69
receptor proteins
bind extracellular substances to trigger changes in cell activity e.g. hormone binding sites
70
recognition proteins
found on surface, contain carbohydrate chains (glycoproteins)/ lipids (glycolipids) to identify a cell (cell fingerprint); white blood cells attack non-recognizable cells
71
electron transport proteins
pass electron from carrier to carrier
72
enzyme proteins
catalyze chemical reactions along membrane (ATP synthase)
73
draw a cell membrane rn and label
74
diffusion, give example
molecules net movement is from high to low concentration areas using kinetic energy (molecules move independent of other types of molecules)
ex: oxygen moves into cells, carbon dioxide moves out of cells
75
when does diffusion stop
dynamic equilibrium
76
factors affecting rate of diffusion (4)
- concentration gradient
- temp.
- size of molecules
- pressure difference
77
facilitated diffusion, give example
like regular diffusion, but uses channel/ carrier protein, moving solutes across membrane, no energy
ex: integral ibuprofens containing hydrophilic pore via which lens my cross from 1 side of membrane to other (carrier protein is slow)
78
what are channel proteins selective abt
ions, may be gated to regulate passage of ions in response to certain stimuli (neuron)
79
osmosis
diffusion of water molecules from H->L through selectively permeable membrane; water molecules pass through biological membrane very quick
80
hypotonic solution
turgid in plants, low solute concentration; high water concentration
81
hypertonic solution
plasmolyzed in plants, high solute concentration; low water concentration
82
Isotonic solution, give example
flaccid in plants, solutions w same concentrations of both solute + water, dynamic movement still occurring
ex: saline solution is used to bathe organs for organ transport to maintain osmolarity
83
active transport
uses membrane proteins, which use ATP energy to move molecules against concentration gradient, proteins change shape as molecules bind on one side to release it on other side, pumps or movements of cell membrane
84
eukaryotic vs prokaryotic nucleus
pro- lacks membrane enclosed nucleus
eu- have nuclear envelope
85
cytoskeleton
internal support + maintains shape of cell
85
endoplasmic reticulum
transports materials throughout cell, provide sites for chemical reactions
86
ribosomes
site of protein synthesis
87
nucleus
contain genetic info DNA needed for directing cell function + reproduction
88
nucleolus
makes ribosomes
89
golgi apparatus
stores, packs, modifies cellular materials for transport
90
cell membrane
encloses cell cytoplasm, regulates exchange of materials between cell + its environment
91
vacuole
cellular materials stored
92
cytoplasm
everything in cell but nucleus
93
nuclear membrane
separates DNA material inside nucleus from cytoplasm of cell
94
what is the most abundant substance in cytoplasm
water
95
bulk transport
movement of large molecules in membrane bound sac (vesicle) across membrane
96
endocytosis
inward sinking of cell membrane, pinches off + brings substances into cell, forming vesicle
97
phagocytosis
endocytosis of particles that are solid and large
98
pinocytosis
when liquids re taken up by membrane folding
99
exocytosis
process where vesicle fuses w cell membrane to expel bulk, replaces losses of cell membrane
100
are viruses living
no
101
what might membrane proteins embedded within phospholipid bilayer act as
points of transport for large + charged substances; makes lipid bilayer selective barrier bc membrane proteins can coordinate transport of hydrophilic materials according to need
