Topic 4 Flashcards
(69 cards)
1
Q
parameters for microscopy
A
- magnification
- resolution
- contrast
2
Q
magnification
A
ratio of an objects image sice to real size
3
Q
resolution
A
minimum distance of two distingushable points
4
Q
contrast
A
visable differences in brughtness between parts of a sample
5
Q
what are the different types of microscopy
A
light microscopy
electron microscopy (scanning SEM, transmission TEM)
6
Q
light microscopy has limit to
A
resolution
7
Q
cellular components shared between all cells
A
- plasma/ cell membrane
- cytosol
- DNA
- ribosomes
8
Q
prokaryotic cells
A
- no nucleus
- dna in an unbound region called nucleoid
- no membrane bound organelles
- generally smaller than eukaryotic
9
Q
eukaryotic cells
A
- dna in nucleus that is bounded by a double membrane
- membrane bound organelles
- cytoplasm in the region between plasma membrane and nucleus
- generally larger
10
Q
cellular size ratios
A
- practical limits to size of cells due to metabolic requirements
- surface area to volume ratio is critical
- as a cell increases in siz its vollume grows proportionally more than surface area
11
Q
plasma membrane
A
selective barriier that allows sufficient passage of oxygen, nutruents, and waste
- phospholipid bilayer
12
Q
we need a large surface area for cellular function due to
A
plasma membrane components
13
Q
organelles
A
membranes separate cell into compartments
14
Q
present in animal, not in plant
A
- lysosome
- flagellum
- intermediate filament
- centrosome
15
Q
present in plant, not animal
A
- central vacuole
- chroloplast
- plasmodesmata
- cell wall
16
Q
nucleus
A
most visable organelle
- contains dna in a eukaryotic cell
- dna is organized into units called chromosomes
17
Q
nuclear envolope
A
encloses the nucleus, separating nucleus from cytoplasm
- double membrane, each membrane has a phosholipid bilayer
- pores regulate the entry and exit of molecules from the nucleus - pore complex
18
Q
pore complex
A
pores that regulate the entry and exsit of molecules from the nucleus
19
Q
nucleolus
A
located within the nucleus
- site of ribosomal RNA (rRNA) synthesis
- ribosomes (protein and rRNA) assembled in nucleolus then they are exported
20
Q
ribosomes
A
make proteins via translation
- made of ribosomal RNA and protein
- cells with high protein synthesis have large numbers of ribosomes
21
Q
where do ribosomes carry out protein synthesis
A
- in the cytosol (free ribosomes)
- on the endoplasmic reticulum or in the nuclear envelope (bound ribosomes)
22
Q
endomembrane system
A
regulates protein traffic and performs metabolic functions in the cell
23
Q
endomembrane system includes
A
- nuclear envelope
- endoplasmic reticulum
- golgi apparatus
- lysosomes
- vacuoles
- plasma membrane
components are either continious or connected by vesicles
24
Q
endoplasmic reticulum
A
- continous with nuclear envelope
- smooth: lack ribosomes
- rough: studded w ribosomes
25
smooth ER functions
- syntehsize lipids
- metabolize carbs
- detoxifies drugs and poisons
- stores calcium ions
26
rough ER functions
- bound ribosomes produce proteins
- make and distribute secretory proteins surrounded by membranes- distrubted by transport vesicles
- membrane factory for cell
27
golgi apparatus
- consits of flattened membranous sacs called cisternae
28
golgi function
modifies products of the ER (transported by vesicles) and other molecules
- sorts and packages materials into transport vessicles
29
flow of golgi
- cis face receiving side, closest to ER
- trans face shipping side.
flows for cis to trans
30
lysosome
- membranous sacs of hydrolytic enzymes that can digest molecules
- works best in acidic
- break down amterial
-PHAGOCYTOSIS engulfing smaller particles
31
lysosome responsible for
cellular recycling
- autophagy- acidic enzymes RECYCLE cells own organelles and macromolecules
32
vacuoles
large vesicles derived from the ER and golgi apparatus
33
food vacuoles
formed by phagocytosis (engulfing smaller particles)
34
contractile vacuoles
found in many freshwater protisist, pump excess water out of cells
35
central vacuole
found in many mature plant cells, hold organic compounds and water
36
mitochandria chem
sites of cellular respiration
- uses O2 to generate ATP
37
chloroplasts chem
found in plants and algae
- site of photosynthesis
- converts solar enegry to chem energy
38
mito and chloro similarites
- enveloped by double membrane
- contain free ribosomes and circular dna molecules
- grow and reporduce independently in cells
LEAD TO ENDOSYMBIONT THEORY
39
ENDOSYMBIONT theory
early ancestor of eukaryotes englufed an oxygen using nonphotosyntehtic cell
- engulfed cell formed relationship with host cell
- evolved into mitochandria
- then it took up photosyntehtic prokayote which evolved into chloroplast
40
mito function
- found in all eurkayotic cells
- dynamic organelle
- smooth outer membrane, folded inside membrane CRISTAE
41
what is cristae, function
inner layer of mitochandria, creates a large surface area for enzymes that synthesize ATP
42
inner layer of mito creates what
intermembrane space and mitochandrial matrix
43
mitochandrial matrix does what
some metabolic steps of cellular respiration are catalyzed in the matrix
- contains mitochandrial DNA and ribosomes
44
the chloroplast is one group of plant organelles called
plastids
45
chroloplast contains what
green pigment called chlorphyll
- includes enzymes and other molecules that function in photosythesis
46
chloropplast structure includes
thylakoids: double membrane sacs
- granum: stacks of thylakoids
- stroma: internal fluid, contains DNA and ribosomes
47
perosisome
oxidative organelles
- not part of endomembrane system
- contain enzymes which produce hydrogen peroxide then convert to water
- break down fatty acids and reactive oxygen species
48
cytoskeleton
- network of fibers that organizes the cells structure and activities
- anchors organelles
- dynamic: constantly reassembling
- throughout cytoplasm
49
what does the cytoplasm do
helps support the cell and maintain its shape
- interacts with motor proteins to produce cell mobilityu
- organelles and vvesicles can travel along tracks provided by the cytoskeleton
50
components of cytoskeleton
- microtubules (thickest part)
- microfilaments (also called actin, thinniest)
- intermediate filament (fibers with diameters in a middle range)
51
microtubules
- hollow rods made of tubin dimers
- largest
52
microtubule function
- shaping cell, withstand compression
- guiding movement of organeeles
- separating chromosomes during cell division (centrosome/centrioles)
- cell mobility (cilia, falgella)
53
microfilaments
- solid twisted double chain of actin filaments
- support cells shape
54
function of microfilaments
- withstand tension (pulled or stretches)
- cellular mobility and contraction
- celluar extensions allow for crawling
- cytoplasmic streaming in plants
55
intermediate filaments
- in the middle
- more permanent cytoskeleton fixtures
- made up of various sub units
56
function of intermediate filaments
- support cell shape, withstand tension
- anchor organelles
- formation of nuclear lamina
57
extracellular components of cells
- most cells synthesize and secrete materials that are external to plasma membrane
- these extracellular materials and structures are involved in many cellular functions
58
cell wall
an extracellular structure that distingushes plant cells from animal cells
59
function of cell wall
- protects plant cell
- maintain shape, helps resist force of gravity
- prevents excessive uptake of water
60
what is the cell wall composed of
cellulose fibers embedded in other polysaccarides and proteins
61
cell wall layers
- middle lamella: thin layer between primary walls of adjecent cells
- primary cell wall: relatively thing and flexable
- secondary cell wall: added between the plasma membrane and primary cell wall
62
extracellular matrix
- animal lack cell walls but are covered by an elaborative extracellular matrix (ECM)
63
the ECM is made up of
glycloproteins such as collagen, proteoglycans and fibronectin
64
ECM binds to what
receptor proteins called integrins
- integrins are attaached to cytoskeleton
65
neighbouring cells need to do what
adhere, interact and communicate through direct physical contact
66
plasmodesmata
PLANTS
are channels that perforate plant cell walls
- cytosol can pass between cells
- joins most of plant into one licing continuum
67
tight junctions
animal
- membrane of neighbouring cells are pressed toegther
- prevents leakage of extracellular fluid
68
desmosomes (anchoring junctions)
animal
- fasten cells together into strong sheets
69
gap junctions (communicating junctions)
animal
- provide cytoplasmic channels between adjecent cells
