second quiz Flashcards
(136 cards)
1
Q
A eukaryotic ribosome consists of a ___ and a ___ subunit
A
large and a small
2
Q
What are ribosomes made of
A
ribosomal RNA and proteins
3
Q
Where are ribosomal subunits assembled
A
Nucleolus
4
Q
What happens in the Nucleolus
A
ribosomal RNA synthesis takes place and ribosomal subunits are assembled and exit through the nuclear pores
5
Q
where are ribosomes found
A
some are freely suspended in cytosol, some are attached to membranes
6
Q
proteins made on free ribosomes go where?
A
some remain in the cytosol, pass into the nucleus, or become parts of mitochondria, chloroplasts, cytoskeleton or other cytoplasmic structures.
7
Q
what is the endomembrane system
A
series of membranes in cytoplasm dividing cells into compartments where different cellular functions occur
8
Q
what are vesicles
A
small membrane bound sacs that transfer substances between parts of system
9
Q
what organelles/cell parts are part of endomembrane system (6)
A
nuclear envelop, endoplasmic reticulum, golgi complex, lysosomes, vesicles and plasma membrane
10
Q
What are the smooth parts of the ER called
A
cisterna
11
Q
what is the space between cisterna called in the ER
A
ER lumen
12
Q
why is it called the Rough ER
A
ribosomes attached to surface of cisterna
13
Q
Why do the proteins made on the ribosomes that are attached to the rough ER go into the ER lumen
A
to fold into their final form. Also chemical modifications like addition of carbohydrates to produce glycoproteins
14
Q
How are the proteins that are modified in the Rough ER delivered to other regions of the cell ( e.g. golgi complex)
A
From vesicles that pinch off from ER
15
Q
Why is it called smooth ER
A
No ribosomes attached to Cisterna
16
Q
function of Smooth ER?
A
synthesize lipids that become part of cell membrane
17
Q
function of smooth ER in liver?
A
converts drugs, poisons, and toxic by products into substances that can be tolerated or easily removed from the body
18
Q
What is the golgi appartus made of and what are they
A
golgi bodies, flattened sacs of interconnected membranes
19
Q
What are the different networks and network compartment names
A
Cis-, medial-, trans golgi network and trans-golgi network compartments
20
Q
Where do proteins that are made in the ER enter in the golgi complex
A
Cis face
21
Q
What happens to the transport vesicles that deliver proteins to the cis face
A
They fuse with the membrane
22
Q
Where do modified proteins exit in the golgi complex and how do they exit
A
they exit fromthe trans face and in vesicles that bud off from the membrane
23
Q
what are the functions of the golgi body (4)
A
collects, packages, and distributes molecules using vesicles synthesized at one location in the cell and utilized at another location
sugar production and addition to proteins and lipids to form glycoproteins and glycolipids
final protein folding
stores secreted material
24
Q
Proteins to be secreted from the cell are transported in what? And what is the action called
A
secretory vesicles and exocytosis
25
what happens to the vesicle during the end of exocytosis
it fuses with the plasma membrane and becomes a part of the plasma membrane
26
what are lysosomes
membrane bounded digestive vesicles
27
where do lysosomes come from
golgi apparatus, trans-golgi network
28
lysosomes are found in (animals/plants), choose one
animals, not plants
29
What is the function of lysosomes
enzymes in it catalyze breakdown of macromolecules and the subunits are recycled int he cell
30
what is phagocytosis
to destroy cell or foreign matter that the cell has engulfed (soluable and insoluable substances) [to eat=phago]
31
what is autophagy
to digest worn out or damaged organelles [eat self]
32
what is pinocytosis
to destroy soluable foreign material (to drink)
33
what is the pH of the lysosome and the pH of the cytosol
pH of lysosome is 5, cytosol is 7.2
34
what are coat proteins and their function
they bind to vesicles to ensure the vesicle is going to where it needs to go and release to the compartment it should release in
35
what are peroxisomes and what is its function
variety of enzyme bearing, membrane enclosed vesicles. The enzymes are involved in oxidation of fatty acids
36
what is the byproduct of oxidation of fatty acids and what enzyme renders it harmless
hydrogen peroxide and catalase (in peroxisomes)
37
What organelles have their own DNA
Chloroplast, mitochondria, nucleus
38
How many bilayers does the mitochondria have
2, inner and outer membrane
39
What are the folds called that the inner is partitioned into in mitochondria
cristae
40
what is the innermost compartment of the mitochondria called and what does it contain
Matrix, contains DNA, ribosomes and other components
41
Where is Cellular respiration occur, what is cellular respiration
it occurs in cristae and matrix of mitochondria and it is the breaking down of energy rich food molecules and the energy is captured as ATP
42
Is mitochondria aerobic or anaerobic. Does this mean cellular respiration require oxygen or not?
aerobic, requires oxygen
43
What are the ovals inside the chloroplasts called, and what is it called if its stacked
thylakoids, stacked thylakoids are called grana
44
Why do we think the mitochondria was a prokaryotic cell
It has DNA, ribosomes, and molecular machinery resemble the equivalent structures in bacteria
45
what is the endosymbiotic theory
An ancient eukaryotic cell consumed a aerobic prokaryotic cell and that is the modern animal eukaryotic cell. A eukaryotic cell consumed a photosynthetic prokaryotic cell and thats a modern plant cell
46
which came first according to endosymbiotic theory, the animal cell or plant cell?
animal cell
47
what is the cytoskeleton
interconnected system of protein fibers and tubes that extends throughout the cytoplasm
48
what are the main functions in cytoskeleton
maintains a cells characteristic shape, and internal organization, and functions in movement
49
In animal and plant cells, what are the 3 protein polymers found in cytoskeleton. Name them from largest to smallest
microtubule, intermediate filaments, microfilaments
50
What is the diameter of microtubules
25nm in diameter
51
What are microtubules made of
alpha and beta tubulin dimers
52
how many tubulin dimers (aka protein filaments) make up the wall of microtubules
13 protein filaments
53
how are they organized, what characteristic does it give, and to which end are tubulin added
organized head (+ end) to tail (- end) and give polarity, also dimers are added to the + end
54
What does it mean "microtubules are dynamic structures"
That means they can change their length by addition or removal of tubulin dimers
55
what is it called when you add tubulin dimer? what if its removed?
polymerization and depolymerization
56
microtubles radiate (outwards/inwards) from the ____ to anchor many organelles in position
outwards, centrosome(call center)
57
what are centrioles
two short barrel shaped structures at the midpoint of the cell center
58
What do vesicles move on between interior of cell and plasma membrane
tracks provided by microtubules
59
what do microtubules do during cell division
separate and move chromsomes
60
What are the 3 motor proteins and what protein polymer do they push or pull against
dyneins and kinesins push or pull against microtubules
| myosins push and pull against microfilaments
61
What is the difference between dyneins and kinesins
dyneins carry cargo from the edge of the cell towards the cell body
kinesins carry cargo from cell body towards the edge of the cell
62
how are the two ends of a kinesin or dynein molecules differ
one end is fixed to a cell structure such as vesicle or to a microtubule or microfilament
and the other is "walking" along another microtubule or microfilament by making an attachment, forcefully swiveling and releasing.
63
Why is it called "intermediate filaments"
the size is between microtubules and microfilaments
64
what are intermediate filaments made of
intermediate filament proteins
65
do intermediate filaments work in bundles/interlinked networks, or alone
they can work in bundles/networks or alone
66
do intermediate filaments work with microtubules or microfilaments
they can work with either OR both at the same time
67
what are the functions are intermediate filaments
provide structural support ins many cells and tissues, and are tissue specific in their protein composition,
focuses on "cell infrastructure"
68
what are the microfilaments subunits
actin subunit
69
how large are microfilaments
7nm in diameter
70
how large are intermediate filaments
8-12nm in diameter
71
do microfilaments have polarity?
yes, positive and negative end
72
what are the functions of microfilaments (3)
components of contractile elements in muscle fibers.
involved in cytoplasmic streaming which transport nutrients, proteins, and organelles in animal and plant cells , and is responsible for amoeboid movement.
divide the cytoplasm when animal cells divide
73
how are flagella and cilia different
cilia are shorter than flagella
74
how are flagella and cilia the same
they are both elongated, moving structures that extend from cell's surface
75
where do flagella and cilia arise from
centrioles
76
centrioles remain at the innermost end of the flagellum/cilium development is complete as the ____ ___ of the structure
basal body
77
what is the 9+2 complex
circle of nine double microtubules and a pair of single microtubles in the middle
78
how do dynein motor proteins produce movement
dynein motor proteins slide microtubules of the 9+2 slides over each other to produce movement
79
how does the flagella and cilia differ movement
flagella is an s-shape wave (harmonic) and the cilia is a power stroke followed by recovery stroke (free stroke from swimming)
80
what are some structures that are only found in plant cells and not animal cells (3)
chloroplasts, largte central vacuole and plant cell walls
81
where does chloroplasts also occur in
algal protsists
82
where do cell walls also appear in
algal protists and fungi
83
what are the 3 plastids we need to know and what are their colors
Chloroplasts (yellow-green) amyloplasts (colorless) and chromoplasts (yellow, red)
84
what do amyloplasts do
store starch
85
what do plastids contain and what are their functions
contain DNA genomes and molecular machinery for gene expression and protein synthesis on ribosomes or on their genomes
86
How many bilayers does chloroplasts have
2
87
what is the inner compartment of the chloroplasts called
stroma
88
what are the flattened-closed sacs in chloroplasts called, and what are they called if theyre stacked
thylakoids, grana
89
what is the green pigment in thylakoid membranes called and what does it do
chlorophyll absorbs light energy and converts it to chemical energy
90
central vacuole can take up how much volume in a plant cell (percent)
90 percent
91
what is the membrane called that surrounds a central vacuole
tonoplasts
92
what is tonoplasts
the membrane surrounding the central vacuole
93
what is the function of the central vacuole (8)
store salts, organic acids, sugars, storage proteins, pigments, waste product (in some cells), enzymes (to breakdown macromolecules) and molecules for chemical defense
94
what is the function of cell wall
support individual cells, contain the pressure produced in the central vacuole and protect cells against invading bacteria and fungi
95
from outside to inside, what is the order of the cellulose fibers/ layers of cell wall
middle lamela, primary cell wall, secondary cell wall
96
describe the primary cell wall
soft and flexible
97
what does secondary cell wall consist of
cellulose fibers and carbohydrates
98
what reinforces the secondary cell wall in woody plants
lignin
99
middle lamella is made of what
pectin (polysaccharides)
100
what is the plasmodesmata
penetrates primary and secondary cell wall to allow communication and movement of ions and small molecules into the plant's cytosol
101
what are the 3 specialized structures in animal cells
cell adhesion molecules, cell junctions, extracellular matrix
102
what are cell adhesion molecules made of
glycoproteins
103
where do cell adhesions begin (birth) and end
they start between cells in embryonic development and stays in the plasma membrane
104
what is the function of the cell adhesion molecules
bind cells together
105
how are cancer cells related to cell adhesion molecules
cancer cells lose these cells which allow them to break loose and maove
106
what do bacteria and viruses target
cell adhesion molecules
107
what are anchoring junctions
buttonlike spots or belts that weld adjacent cells together
108
what are desmosomes
anchoring junctions with intermediate filaments that anchor the junction in under cytoplasm
109
what protein does adheren junction use and where
microfilaments and cytoskeletal component
110
Anchoring junction is mainly used where
where there are stretching and shear and other mech forces
111
tight junctions do what
seal the space between adjacent cells in cell layers, that cover internal organs, outer surface of body or layers that line internal cavities and ducts
112
how are tight functions made
formed by direct fusion of proteins on the outer surface of plasma membrane of adjacent cells
113
what are gap junctions functions. Where in the body is it most important
direct channels that allow communication of animal cells and allow ions/small molecules to pass from one cell to another. Heart muscle tissue
114
what do gap junctions look like
hollow pipelines
115
what does the ECM contain
proteins and polysaccharides secreted by the cells themselves
116
ECM forms what
skin, bones, tendons, and many highly specialized extracellular strucutres
117
what is the main component of ECM
glycoprotein/collagen
118
whats fibronectin
bind to receptor proteins in the plasma membrane which bind to microfilaments of the cytoskeleton for communication
119
what does proteoglycans do
change consistency of matrix which surrounds the collagen fibers. In bone, its mineral crystal dense and hard but also elastic
120
what is the fluid mosaic model
proposes that the phospholipid molecuels and proteins move around and exchange places like glaciers
121
whats the difference between integral protein and peripheral proteins
integral proteins are embedded in phospholipid bilayer while peripheral are on the surface held by noncovalent bonds
122
purpose of membrane proteins (4)
transport, recognition, receptors, cell adhesion
123
how does unsaturated fatty chain help membrane in low temps
help keep membrane fluid at low temp
124
how does cholesterol help at high and low temps of membrane
low temps prevent membrane from stiffening, at high temps helps membrane stabilize and decrease fluidity
125
how does amount of double bonds and cholesterol change in lower temp
both increase
126
describe frye and edidin experiment
cultured two separate cells (human and mice) and added human/mice antibodies on their respective cell. Dyed human antibodies red and mice green, mixed the cell (chimera) and showed that proteins move after 40 mins
127
the membrane is selectively permeable, what molecules can go through it? whats blocked?
hydrophobic molecules (easily), small polar molecules (but slowly). Ions and molecules are blocked
128
what are the 3 types of passive transport and what is passive transport
use energy from concentration gradient. Simple/facilitated/osmosis
129
What are the two types of active transport and what's the difference
primary- use ATP
| secondary- use energy in forms other than atp
130
what kind of things can go through simple diffusion
nonpolar inorganic gases (o2 n2 and co2) and organic molecules . Also depends on molecular size and lipid solubility
131
What is important to know about facilitated diffusion
are transport proteins and are SPECIFIC
132
What kind of molecules are transported in facilitated diffusion (4)
water, amino acids, sugars, and ions. In general polar and charged molecules
133
How are channel proteins and gated channels different
channel proteins are always open while gated has to switch from open, close and intermediate
134
whats the difference between aquaporins and ion channels
aquaporins are for water an ion channels are for ions (na+ k+, ca2+ cl-) and are gated
135
whats the function of carrier protein
transport ions and solutes across the membrane, but also physically binds molecules and release them to the other side
136
what are essential characteristics of carrier proteins
undergo conformational change
specific
passive
can be saturated if there are too many solute molecules
