cells Flashcards
1
Q
name all the organelles in an animal cell
A
cell membrane
cytoplasm
nucleus
nucleolus
nuclear envelope + pores
lysosome + lysozymes
ribosomes
mitochondria
golgi apparatus + vesicles
rough endoplasmic reticulum
smooth endoplasmic reticulum
2
Q
name all the organelles in a plant cell
A
cell membrane
cytoplasm
nucleus
nucleolus
nuclear envelope + pores
lysosome + lysozymes
ribosomes
mitochondria
golgi apparatus + vesicles
rough endoplasmic reticulum
smooth endoplasmic reticulum
chloroplasts
vacuole
cell wall
3
Q
what is the function of the rough endoplasmic reticulum
A
folds and processes proteins that have been made by ribosomes
4
Q
what is the function of the SER
A
synthesises and processes lipids
5
Q
what is the function of the vacuole
A
maintains cell pressure and keeps the cell rigid, isolates unwanted chemicals in the cell
6
Q
what is the function of the golgi apparatus
A
processes and packages lipids and proteins and make lysosomes
7
Q
what is the function of the golgi vescicle
A
stores lipids and proteins made by G.A and transports them out of the cell
8
Q
what is the function of the lysosomes
A
type of golgi vescicle which contains digestive enzymes called lysozymes and digest invading cells
9
Q
features of algal cells
A
similar to plant cells
can be unicellular
have chloroplasts and cellulose cell walls
chloroplasts differ in size and shape
10
Q
features of fungal cells
A
uni or multicellular
chitin cell walls
no chloroplasts
11
Q
role of organelles in production, transport and release of proteins
A
nucleolus makes ribosomes
ribosomes make proteins
RER- folds and processes proteins
golgi A processes + packages
golgi V stores and transports out of cell
12
Q
which type of cells don’t have chloroplasts
A
animal cell
fungal cell
13
Q
which cells don’t have a cell wall
A
animal
14
Q
which cells don’t have a vacuole
A
animal
15
Q
what is the cell wall of a fungal cell made of
A
chitin
16
Q
what are the folds of the inner mitochondrial membrane called
A
cristae
17
Q
what are the 3 substructures of mitochondria
A
outer membrane
inner membrane
matrix
18
Q
what are the 4 substructures found in chloroplasts
A
outer membrane
inner membrane
grana/ stacked thylakoids
stroma
19
Q
what are the similarities and differences between mitochondria and chloroplasts
A
both have a double membrane
starch grains vs none
pigments vs no pigments
stroma vs matrix
grana vs cristae
20
Q
why are viruses acellular and non living
A
they have no cell membrane and no mitochondria
21
Q
what is the cell wall of a prokaryote made from
A
murein ( a glycoprotein )
22
Q
what is cell fractionation
A
separating cell components
23
Q
what is the process of homogenisation
A
cells are broken up and release organelles
24
Q
what is the process of filtration
A
filtering the homogenate using a gauze to remove large debris
25
what is the process of ultracentrifugation
homogenate fragments separated by centrifugal force in a centrifuge, heaviest organelles forma pellet at the bottom with the lowest speed, the rest form a supernatent and process is repeated
26
what are the conditions needed for homogenisation
ice cold- prevent enzymes from working
isotonic- no osmosis for the same water potential
pH buffer-stops pH from fluctuating
27
what happens during prophase
chromosomes condense
nuclear membrane and nucleolus break down
centrioles move to poles
spindle fibres develop
28
what happens during metaphase
chromatids line up in middle of cell
spindle fibres attach to chromatids at the centromere
29
what happens during G1 of the cell cycle
cell grows larger as new proteins and organelles are duplicated
30
what happens during S in the cell cycle
DNA replicates to divide by mitosis
chromosomes are copied
31
what happens during G2 of the cell cycle
cell continues to grow and synthesise enzymes
spindle proteins for mitosis
32
what are the organelles in a bacterial cell
plasmid dna
slime capsule
cell membrane
ribosomes
cytoplasm
chromosome dna
cell wall (murein)
33
what is the function of plasmid dna
carry genes to transfer between bacteria
34
function of the slime capsule
protection
35
what is murein an example of
a glycoprotein
36
what is the function of chromosome dna
contain genes to allow replication of bacteria
37
what is the structure of a virus- organelles
capsid
enzymes
attachment proteins
genetic material
lips envelope
matrix
38
what is the function of attachment proteins
bind to receptors on host cells
39
what is the function of capsid
protect genetic material
40
what is chitin
the polysaccharide found in fungus cell walls
41
how do viruses work
attach to a host and reproduce by inserting genetic material
42
characteristics of TEMs
use electromagnets
high resolution to see internal structures
only in 2D
only thin specimens
electrons have a short wavelength
43
characteristics of SEMs
scan a beam of electrons
gathered in cathode ray tube
images show surfaces
can be 3D
thick specimens allowed
low resolution
44
magnification equasion
magnification = image size / actual size
45
definition of magnification
how much bigger the image is than the specimen
46
definition of resolution
how detailed the image is/ how well a microscope distinguishes between 2 close points
47
features of optical microscopes
use light
maximum resolution of around 0.2 um (can’t view organelles smaller than 0.2um)
maximum magnification is around x 1500
48
what happens during anaphase
centrioles divide and seperate chromosomes
spindle fibres contract and pull them to opposite poles
49
what happens during telophase
chromatids reach opposite poles, uncoil and extend back into chromosomes
new nuclear envelope forms 2 nuclei
cytoplasm divides, spindle fibres disappear
50
what happens during cytokinesis
cell divides into 2 genetically identical daughter cells
51
what is a prokaryote
unicellular with no membrane bound organelles
52
what organelles can only be found in SOME bacterial cells
flagellum
slime capsule
plasmids
53
how are bacterial ribosomes different to eukaryotic ribosomes
bacterial ribosomes are smaller - 70S
54
name 3 components of ALL viruses
capsid
attachment proteins
genetic material
55
what is the approximate size of a virus
0.1um
56
what is binary fission
process of bacterial cell division
57
describe the binary fission process
-circular dna and plasmids replicate
-cell lengthens, circular dna is pulled to poles
-new cell membrane grows between 2 dna molecules and pinches in
-new cell wall forms
-cytoplasm splits
2 daughter cells with a copy of circular dna
58
mitotic index
number of cells in mitosis / total cells
59
what are cell membranes needed for
keep conditions inside cell separate from conditions outside
act as a barrier between organelles and cytoplasm
60
what is the phospholipid bilayer
fluid- constantly moving
61
what is the function of the glycoprotein
found on the outside of the cell membrane
made of protein attached to a carbohydrate
help hormone signalling
62
what is the function of cholesterol in the fluid mosaic
fits between phospholipids and help them pack tightly
makes membranes more rigid
maintain animal cell shape
63
what is the function of the extrinsic proteins
only found on the outside of membrane
mechanical support
receptors for hormones
allows cell to recognise other cells
64
name the 2 integral proteins
channel and carrier
65
what is the function of the channel protein
form proves to facilitate movement of chargers particles
66
what is the function of carrier proteins
facilitate diffusion of different molecules that are larger to enter the intracellular space
67
how do carrier proteins allow molecules to pass through
a large molecule attaches to the binding side of the carrier protein
carrier protein changes shape
releases molecule to the intracellular space
68
what is the function of aquaporins
water can flow more rapidly in or out of cells compared to simple diffusion across plasma membrane
69
what is the definition of diffusion
net movement of particles from an area of higher concentration to lower concentration down a concentration gradient
70
what is simple diffusion
small simple molecules diffuse directly through a cell membrane (non polar molecules)
71
how does temperature affect the rate of simple diffusion
higher temperature= more kinetic energy to move faster through the membrane, increasing rate of reaction
72
how does size of concentration gradient affect rate of simple diffusion
steeper concentration gradient increases the rate of reaction
73
how does surface area affect the rate of reaction of simple diffusion
increased surface area= increased rate of reaction as there is more area for diffusion to occur across
74
how does having a thin membrane affect the rate of simple diffusion
short diffusion distance= pass through membrane earlier and faster= increased rate of reaction
75
applicable to an experiment- how does stirring affect rate of simple diffusion
more kinetic energy= increased rate of diffusion
76
why can’t large molecules pass through simple diffusion
larger molecules such as amino acids or glucose would diffuse slowly through the phospholipid bilayer as they are too large
77
what are the factors that affect facilitated diffusion
simple diffusion factors
amount of channel proteins or carrier proteins
78
how does amount of channel/ carrier proteins affect rate of facilitated diffusion
faster rate of diffusion as more charged particles can diffuse
79
what is the definition of osmosis
the net movement of water molecules form an area to higher to lower water potential through a partially permeable membrane until equilibrium
80
what is the definition of water potential
likelihood of water molecules diffusing out of/ into a solution
81
what is water potential measured in
kilopascals- negative scale
82
isotonic
2 solutions with the same water potential, no net movement of water
83
hypertonic
lower water potential than inside the cell, water moves out of the cell and shrivels up/ becomes flaccid
84
hypotonic
higher water potential than inside the cell, water moves into the cell and bursts/ becomes turgid
85
why won’t plant cells burst in hypertonic solutions
has a cellulose cell wall which is strong and rigid
86
factors that affect osmosis
temperature
surface area
water potential gradient
humidity
more aquaporins
thin membrane
87
how does surface area affect osmosis
larger exchange surface, more aquaporins and faster rate of osmosis
88
how does water potential gradient affect osmosis
steep= faster osmosis as there is a bigger difference in water potential
89
features found in a cell specialised for absorption
aquaporins/ integral proteins
surface area
active transport
90
how does a large number of aquaporins affect rate of absorption
larger number means a faster rate of osmosis/ facilitated diffusion and faster absorption of substances
91
how does surface area affect the rate of absorption
folded membrane leads to larger SA and faster rate of absorption
92
how does integral proteins affect rate of absorption
large number allows a faster rate of diffusion and absorption of large molecules via facilitated diffusion, increasing absorption
93
how does active transport affect the rate of absorption
more mitochondria in cells to release ATP for active transport so rate of absorption increases
94
definition of active transport
movement of molecules/ ions in or out of a cell from an area of lower to higher concentration against a concentration gradient using proteins and atp
95
differences between AT and simple diffusion
AT lower-higher. SD higher-lower
AT against conc gradient. SD passive
AT uses energy. SD doesn’t use energy
AT carrier proteins. SD no integral proteins
96
process of active transport including integral protein
molecule being transported binds to carrier protein
atp binds to protein and is hydrolysed into adp and pi, energy changes shape
molecule travels through newly opened channel
phosphate ion is released and recombines with atp
carrier protein returns to original shape
97
factors affecting rate of active transport
number of mitochondria- atp production +respiration
98
when is active transport used
digestion
phloem loading
absorb mineral ions from soil
reabsorbtion of useful molecules
99
what is co transport
cells can transport 2 substances at the same time through the same carrier protein
100
what is a pathogen
a microorganism which can cause infectious diseases
101
how are pathogens detected
foreign entigens on pathogen surface
102
what is an antigen
protein on the cell surface that generates an immune system response when detected by the body
103
chemical barriers the body defends itself by
tears- lysozymes
mucus
stomach acid
104
physical barriers
skin
hair- nose
cilia- trachea
scabs- made by platelets to prevent pathogens from entering through wounds
105
what are the 2 types of immune response
specific
non specific
106
what is a specific immune response
a slower response which directly targets pathogen, immune system recognises pathogen and coordinates response
107
what is a non specific immune response
immediate response which happens regardless of pathogen type e.g phagocytosis
108
what is a phagocyte
macrofage/ white blood cell which digests and engulfs a pathogen
109
what is phagocytosis
process which phagocyte engulfs and digests a pathogen
110
what are the steps of phagocytosis
antigens on surface of pathogen are recognised by phagocyte
cytoplasm engulfs pathogen
pathogen > phagosome
phagosome fuses with lysosome > phagolysosome
lysozymes hydrolise/ digests pathogen
phagocyte presents antigen on its surface >antigen presenting cell , to activate other cells
111
what do the role of antibodies in stimulating phagocytosis
bind to a complimentary antigen on the pathogen
agglutinate pathogens to engulf many at the same time with many phagocytes
112
why do phagocytes become antigen presenting cells
present antigens on surface to activate t- cells for a cell mediated response
113
what are the 2 cells involved in a cell mediated response
T- helper cells
cytotoxic T-cells
114
when are t cells activated
when an antigen binds to receptor proteins on surface
115
what is the role of T-helper cells
release chemical signals that activate and stimulate phagocytes + CT cells
116
what is the role of cytotoxic T-cells
kill abnormal and foreign cells as they produce perforan to create a hole in the cell membrane of the infected cell and granzymes enter to digest contents
117
what are the cells involved in humoral response
B-cells
118
when are B-cells produced
final stage of immune response
119
features of a B-cell
covered in antibodies that bind to antigens
activated by cells divide into plasma cells via clonal selection
120
which cells can produce memory cells
B + T cells
121
what are plasma cells
identical to their B-cells
rapidly reproduce antibodies specific to antigen
122
where are lymphocytes produced
bonemarrow
123
where do b cells mature
thymus gland
124
what are the 2 types of white blood cell
phagocyte
lymphocyte
125
where are antigens found
cell surface
126
what is a memory lymphocyte
stay in blood after primary infection and produce more antibodies at a faster rate
127
which type of white blood cell makes antitoxins
lymphocytes
128
what is found in a vaccine
dead/ inactive/ weakened form of pathogens
129
what are anti toxins
neutralise a toxin by bacteria
130
why are antibodies specific to one antigen
complimentary shape
131
what is the structure of an hiv virus
capsid
reverse transcriptase enzyme
attachment proteins
lipid envelope
matrix
genetic material/ RNA
132
how is hiv different to regular virus cells
has a-
matrix
enzyme - reverse transcriptase
rna
133
how is hiv different to regular virus cells
has a-
matrix
enzyme - reverse transcriptase
rna
134
what does hiv destroy
CD4+ T cells/ t helper cells
135
what do t helper cells do
activate b cells which produce plasma cells to make antibodies
136
what do antibodies do
destroy pathogens
137
why are you more likely to develop secondary infection with hiv virus
antibodies can’t be created to produce antibodies to immobilise and destroy pathogens
138
what sit eh process of hiv replication in easy steps
hiv binds to t cell
rna is injected
rna converted into dna
viral dna enters nucleus and joins dna
cell produces viral proteins
new virus leaves cell
139
what do cytotoxic t cells do
destroy abnormal cells by releasing perforin to put a hole in the cell membrane of the infected cell and granzymes enter cell and digest contents
140
what do suppressor t cells do
prevent innume system from being over active, slows down CT and helper T cells
141
what are the steps of cellular response
•pathogen destroyed by phagocytosis
•phagocyte displays pathogen antigens and becomes an APC
•t helper cell binds to antigen with a complimentary receptor and is activated
•t helper cells divide by mitosis to form genetically identical clones
142
what are the clones that a t cell turns into when going through mitosis
t memory cell
stimulate b cells
stimulate phagocytosis
activate CT cells
143
process of phagocytosis
phagocyte detects foreign antigen on pathogen surface
phagocytes cytoplasm engulfs pathogen
pathogen in a phagosome
lysosome fuses with phagosome and forms a phagolysosome
lysozymes hydrolise pathogen
phagocyte displays pathogen on outside of cell and becomes an APC
T cells activated
144
antibody structure
2 light chain polypeptides
2 heavy chain polypeptides
binding sites which are complimentary
veritable region
constant region
145
humoral response
antigens taken up by b cells
antigens displayed on b cell surface
activated t helper cell attached to antigens and activates b cells
activated b cell clones by mitosis- plasma cells or b memory cells
146
what are vaccinations contain
dead, attenuated, purified pathogens
147
what is the primary infection process
antigens enter body for 1st time
slow reaction due to lack of b cells
symptoms show
t and b cells produce memory cells
148
what is the secondary infection process
same pathogen enters body
faster immune response
memory b cells activated and divide into plasma cells
149
immunity definition
capacity to recognise the intrusion. of foreign antigens
150
what are the 2 types of immunity
passive and active
151
what is passive immunity
antibodies given to a person
don’t make their own antibodies
152
what is active immunity
makes their own antibodies after exposure to pathogen
longer lasting
153
what are the 2 factors of immunity
artificial
natural
154
what does attenuated and purified mean
weakened
inactive
155
what is the process of vaccination
vaccine- with dead/ purified/ attenuated pathogens- given to a person
makes complimentary antibodies
plasma b cells create memory b cells
small response
secondary infection of antigen- rapid production of antibodies
156
what is antigenic variability
pathogen may mutate frequently, immune system won’t have antibodies to destroy pathogen
157
what is the role of a suppressor t cell
prevent immune system from being over active, slows down t and ct cells
158
what is the role of a suppressor t cell
prevent immune system from being over active, slows down t and ct cells
159
what are b cells
cells activated by chemical signals and differentiate into plasma cells to produce antibodies
160
what is the special adaptation of plasma cells
have. a large nucleus to code for proteins and RER
161
process of producing monoclonal antibodies
mouse is exposed to pathogen
b cells in mouse produce antibodies- exctranced from spleen
b cells are mixed with cells that divide outside of body (cancer cells)
detergent added to cells to break down cell membrane of both cell types
cells fuse together- hybridoma cells
hybridoma cells separated + cultured to form clones
clones tested for antibody required
any clone porduciny antibody is grown on large scale
antibodies extracted - monoclonal antibodies
162
what is a monoclonal antibody
collection of antibodies that are specific to one antibody- come from a clone of a single b cell
163
what are the 2 types of t cell
t helper cell
cytotoxic t cell
164
what happens during clonal selection
t cells release a chemical signal to activate b cells and they divide into plasma cells
165
what is an antibody
protein found in body that bind to antigens and stimulate immune response
166
what are the uses of the eliza test
medical diagnosis- pregnancy tests
targeting drugs to specific cells
167
