3.2.1 Cells - structure, methods to study cells Flashcards
1
Q
what are differences between eukaryotes and prokaryotes?
A
eukaryotes are larger
eukaryotes have a true nucleus, prokaryotes don’t
eukaryotes have membrane bound organelle
2
Q
cell surface membrane structure
A
found in all cells
phospholipid bilayer - molecules embedded within and attached on the outside (proteins, carbohydrates and cholesterol)
3
Q
cell surface membrane function
A
controls the entrance and exit of molecules
4
Q
nucleus structure
A
nuclear envelope - double membrane
nuclear pores
nucleoplasm - granular, jelly like material
chromosomes - protein bound, linear DNA
nucleolus - smaller sphere in the nucleoplasm which is the site of rRNA production and ribosome synthesis
5
Q
nucleus function
A
site of DNA replication and transcription
contains the genetic code for each cell
6
Q
mitochondria structure
A
double membrane
an inner membrane called the cristae
the fluid center called the mitochondrial matrix
contains 70S ribosomes and circular DNA
7
Q
mitochondria function
A
site of aerobic respiration and ATP production
8
Q
chloroplast function
A
site of photosynthesis
9
Q
chloroplast structure
A
surrounded by a double membrane
contains thylakoids (folded membranes embedded with pigment)
the fluid filled stroma contains enzymes for photosynthesis
found in plants
contains 70s ribosomes and circular DNA
10
Q
golgi apparatus and vesicles structure
A
folded membranes making cisternae
secretory vesicles pinch off from the cisternae
11
Q
golgi apparatus and vesicles function
A
transport, modify and store proteins and lipids produced by the RER and SER
12
Q
lysosomes structure
A
bags of digestive enzymes - can contain 50 different enzymes
13
Q
lysosomes function
A
hydrolyse pathogens in phagosomes
completely break down dead cells
exocytosis - release enzymes outside the cell to destroy material
digest worn out organelles for reuse of materials
14
Q
ribosome structure
A
small granules made up of two sub units of proteins and rRNA
80S - large ribosome found in eukaryotic cells
70S - smaller ribosomes found in prokaryotic cells, mitochondria and chloroplasts
15
Q
ribosome function
A
the site of protein synthesis
16
Q
RER function
A
protein synthesis
17
Q
RER structure
A
have folded membranes called cisternae
have ribosomes on the cisternae
18
Q
SER function
A
synthesises and stores lipids and carbohydrates
19
Q
SER structure
A
have folded membranes called cisternae
20
Q
cell wall structure
A
in plants and fungal cells
plants - made of microfibrils of the cellulose polymer
fungi - made of chitin
21
Q
cell wall function
A
provides structural strength to the cell
22
Q
vacuole structure
A
filled with fluid surrounded by a single membrane called a tonoplast
23
Q
vacuole function
A
makes cells turgid and therefore provides support
temporary store of sugars and amino acids
the pigments are responsible for coloured petals which attract pollinators
24
Q
what does a capsule do?
A
provides protection from other cells and helps bacteria stick together
25
what are the 3 main adaptations of specialised cells?
large surface area
high number of mitochondria
lots of RER and golgi
26
what are the key differences between prokaryotic and eukaryotic cells?
the cells are much smaller
no membrane bound organelles i.e. mitochondria
smaller ribosomes - 70S
a cell wall made of murein - unlike plant cell wall made of cellulose
27
what type of ribosomes do bacterial cells contain?
smaller ribosomes that are 70S rather than 80S
28
what are prokaryotic cell walls made from?
do not contain cellulose or chitin
made of a glycoprotein called murein
29
what are the three additional features that bacteria can also contain?
plasmids - rings of DNA containing genes linked to survival such as antibiotic resistance
capsule - provides protection from other cells and helps bacteria agglutinate (stick together)
flagella - used for locomotion
30
what type of microscope is an optical microscope?
light microscope
31
what type of microscope is a scanning or transmission microscope?
electron microscope
32
how is an image created in a light microscope?
a beam of light is condensed to form an image
33
what type of lens is used to condense the beam of light in a light microscope?
a glass lens
34
why does a light microscope have a poorer resolution?
due to having a longer wavelength
35
can light microscopes view living samples?
yes
36
does a light microscope have a lover magnification than an electron microscope?
yes
37
what colour images are produced from a light microscope?
coloured not black and white
38
how is an image created in an electron microscope?
a beam of electrons is condensed to create the image
39
what is used to condense the beam in an electron microscope?
electromagnets
40
why does an electron microscope have a higher resolving power?
they have a shorter wavelength
41
does an electron microscope have a higher magnification then a light microscope?
yes
42
what colour images do electron microscopes produce?
black and white
43
what does the sample have to be like in an electron microscope?
must be in a vacuum and therefore non-living
44
why do light microscopes have poor resolution?
due to the long wavelength of light
45
what are not visible in a light microscope?
small organelle
46
why must samples be in a vacuum in an electron microscope?
the electrons are absorbed by air
47
what is the equation for magnification?
image divided by the actual
48
what should you always measure the image size in when calculating magnification?
millimeters
49
how do you convert from millimeter to micrometer (um)?
times by 1000
50
how do you convert from micrometer (um) to nanometer (nm)?
times by 1000
51
what can the eyepiece graticule be used to measure?
to measure the size of objects you are viewing under the microscope.
52
what do you have to do with the eyepiece every time you change the objective lens?
calibrate the eyepiece to work out what the distance is between each division at that magnification.
53
what is used to calibrate the eyepiece graticule?
A stage micrometer
54
what is stage micrometer?
This is a glass slide with a scale on it which you place on the stage.
The scale on the stage micrometer is typically 2mm long and
the sub-divisions are 10µm apart
55
what are the steps for studying cells using calibration?
Step 1 - Line up the stage micrometer and eyepiece graticule whilst looking through the eyepiece.
Step 2 – Count how many divisions on the eyepiece graticule fit into one division on the micrometer scale.
Step 3 – Each division on the micrometer is 10µm, so this can be used to calculate what one division on the eyepiece graticule is at that current magnification
56
what are cell fractionation and ultracentrifugation used to break down?
Cell fractionation and ultracentrifugation are used to break down
cells and remove organelles so that they can be studied.
57
how are cells separated in cell fractionation?
is done using a homogeniser (blender)
58
what must the solution be during homogenisation?
cold
isotonic
buffered
59
why must the solution be cold during homogenisation?
cells must be kept in a solution that is cold to reduce enzyme activity to prevent the breakdown of cell components.
60
why must the solution be isotonic during homogenisation?
to prevent any movement of water by osmosis which could result in organelles shrivelling or bursting.
61
why must the solution be buffered during homogenisation?
to resist pH changes
this is to prevent damage to organelles and enzymes.
62
why must the solution be filtered after being broken up?
Once the cell has been broken open the solution must be filtered to remove larger pieces of debris.
63
what is the homogenate solution ready for after being filtered?
ready to be centrifuged
the solution is placed into a centrifuge which spins at high speed to separate organelles depending on their density due to the centrifugal force
64
what does the supernatant contain after one spin?
supernatant after the first spin at low speed- pellet
contains the nuclei
65
what does the supernatant contain after the second spin?
supernatant after the second spin at medium speed pellet contains mitochondria and chloroplasts (if a plant cell)
66
what does the supernatant contain after the third spin?
supernatant after the third spin at high speed- pellet
contains lysosomes and SER/RER.
67
what does the supernatant contain after the fourth spin?
supernatant after the fourth spin at very high speed- the
pellet contains ribosomes
68
What is cell fractionation?
A method used to break down cells and remove organelles for study
69
What equipment is used for homogenisation?
Homogeniser (blender)
70
Why must the solution be cold during homogenisation?
To reduce enzyme activity and prevent breakdown of cell components
71
What is the purpose of using an isotonic solution in cell fractionation?
To prevent movement of water by osmosis, avoiding organelle shrivelling or bursting
72
What does it mean for a solution to be buffered?
It resists pH changes to prevent damage to organelles and enzymes
73
What is the first step after breaking open the cell?
Filter the solution to remove larger pieces of debris
74
What is the purpose of centrifugation in cell fractionation?
To separate organelles based on their density
75
What is the supernatant after the first spin at low speed?
It contains the nuclei
76
What organelles are found in the pellet after the second spin at medium speed?
Mitochondria and chloroplasts (if a plant cell)
77
What is separated in the pellet after the third spin at high speed?
Lysosomes and SER/RER
78
What is contained in the pellet after the fourth spin at very high speed?
Ribosomes
79
Fill in the blank: The process of breaking down cells to study organelles is called _______.
[cell fractionation]
80
True or False: The homogenate solution is immediately ready for centrifugation after homogenisation.
False
81
What is a stage micrometer?
A glass slide with a scale used to calibrate the eyepiece graticule
82
What is the typical length of the scale on a stage micrometer?
2mm long
83
What is the distance between sub-divisions on a stage micrometer?
10um
84
Step 1 in calibrating the eyepiece graticule involves _______.
lining up the stage micrometer and eyepiece graticule
85
In Step 2 of calibration, what do you count?
how many divisions on the eyepiece graticule fit into one division on the micrometer scale
86
If 20 divisions of the eyepiece graticule fit into 10 divisions of the micrometer, how many divisions fit into one division of the micrometer?
2 divisions
87
How do you calculate the size of one division on the eyepiece graticule?
10um / 2 = 5um
88
What is the length of the nucleus measured in divisions?
13 divisions long
89
What is the actual length of the nucleus in micrometers?
65um
90
Fill in the blank: Each division on the micrometer is _______.
10um
91
True or False: The eyepiece graticule is calibrated to measure the size of cells or organelles.
True
92
What is the formula to calculate image size in microscopy?
Image size = Actual size x Magnification
## Footnote
This is often used to determine the dimensions of microscopic structures.
93
How can you calculate the magnification of an image?
Magnification = Image size / Actual size
## Footnote
All units must be the same for accurate calculations.
94
What must be done to the units when calculating magnification?
All units must be the same
## Footnote
For example, converting mm to µm or vice versa may be necessary.
95
How do you convert millimetres to micrometres?
Multiply by 1000
## Footnote
1 mm = 1000 µm.
96
What is an eyepiece graticule?
A scale on a glass disc inside optical microscopes
## Footnote
It is used to measure the size of objects viewed under the microscope.
97
What must be done to the eyepiece graticule when changing objective lenses?
Calibrate the eyepiece
## Footnote
This recalibration is necessary to measure distances accurately at different magnifications.
98
Fill in the blank: The formula for magnification can also be expressed as _______.
Magnification = Image size / Actual size
99
True or False: The eyepiece graticule can be used without calibration when changing magnification.
False
## Footnote
Calibration is required each time the objective lens is changed.
100
What happens to the distance between divisions on the eyepiece graticule when magnification changes?
It changes and requires recalibration
## Footnote
Different objective lenses provide different levels of magnification, affecting the scale.
101
List the units in order from largest to smallest: metre, millimetre, micrometre, nanometre.
* Metre (m)
* Millimetre (mm)
* Micrometre (µm)
* Nanometre (nm)
102
What is the resolution limitation of light microscopes?
Poor resolution due to the long wavelength of light
103
What type of samples can be examined using an optical microscope?
Living samples
104
What type of image is obtained from an optical microscope?
Coloured image
105
Why must samples be in a vacuum for electron microscopes?
Electrons are absorbed by air
106
What type of specimens can be examined using electron microscopes?
Non-living specimens
107
What is a key characteristic of images produced by electron microscopes?
Black and white images
108
What is the purpose of staining specimens in Transmission Electron Microscopes (TEM)?
To enhance visibility
109
Describe the image produced by a Transmission Electron Microscope (TEM).
2D image showing detailed internal structure of cells
110
What is the main difference between Transmission Electron Microscopes (TEM) and Scanning Electron Microscopes (SEM)?
TEM requires thin specimens; SEM does not
111
How does a Scanning Electron Microscope (SEM) produce images?
Electrons are beamed onto the surface and scattered
112
What type of image does a Scanning Electron Microscope (SEM) produce?
3D image
113
Fill in the blank: Light microscopes can examine _______ samples.
living
114
Fill in the blank: In a Transmission Electron Microscope, a beam of _______ passes through the specimen.
electrons
115
True or False: Electron microscopes can be used to view living specimens.
False
116
What is the primary method used to study the internal structure of cells?
Microscopes, cell fractionation, ultracentrifugation
## Footnote
These methods allow for the visualization and analysis of cellular components.
117
What are the three key types of microscopes?
Optical microscopes, transmission electron microscopes, scanning electron microscopes
## Footnote
Each type has unique features and applications in studying cells.
118
Define magnification in the context of microscopy.
How many times larger the image is compared to the object.
119
Define resolution in microscopy.
The minimum distance between two objects in which they can still be viewed as separate.
120
What determines the resolution in an optical microscope?
The wavelength of light.
121
What determines the resolution in an electron microscope?
The wavelength of the beam of electrons.
122
What is a key characteristic of an optical microscope?
Uses a beam of light to create the image.
123
What is a key characteristic of an electron microscope?
Uses a beam of electrons to create the image.
124
What is the resolution comparison between optical and electron microscopes?
Optical microscopes have poorer resolution; electron microscopes have higher resolving power.
125
What is the typical magnification capability of an optical microscope?
Lower magnification.
126
What is the typical magnification capability of an electron microscope?
Higher magnification.
127
What type of images do optical microscopes produce?
Black and white images.
128
What type of images do electron microscopes produce?
Coloured images.
129
Can living samples be viewed with an optical microscope?
Yes.
130
Can living samples be viewed with an electron microscope?
No, the sample must be in a vacuum and therefore non-living.
131
What is a plasmid?
Rings of DNA containing genes linked to survival such as antibiotic resistance
## Footnote
Plasmids are often used in genetic modification.
132
What role does a capsule play in bacteria?
Provides protection from other cells and helps bacteria agglutinate
## Footnote
Agglutination refers to the sticking together of bacterial cells.
133
What are flagella used for in bacteria?
Locomotion
134
What are viruses characterized as?
Non-living and acellular
135
What are the components of viruses?
Genetic material, a capsid, and attachment proteins
136
What additional feature does HIV have?
A lipid envelope with attachment proteins
## Footnote
This envelope helps HIV identify which host cells to enter.
137
List the key differences between prokaryotic cells and eukaryotic cells
* Prokaryotic cells are much smaller
* Prokaryotic cells have no membrane-bound organelles
* Prokaryotic cells have smaller ribosomes
* Prokaryotic cells have no nucleus
* Prokaryotic cells have a cell wall made of murein
138
What type of cell wall do eukaryotic cells have?
Made of cellulose or chitin
139
True or False: Prokaryotic cells have a nucleus.
False
140
Fill in the blank: Prokaryotic cells have _____ ribosomes.
smaller
141
What are prokaryotic cells?
Cells that are much smaller, lack membrane-bound organelles, and have no nucleus
## Footnote
Prokaryotic cells include bacteria and archaea.
142
List key differences between prokaryotic cells and eukaryotic cells.
* Smaller size
* No membrane-bound organelles
* Smaller ribosomes
* No nucleus
143
What is murein?
A glycoprotein that makes up the cell wall of prokaryotic cells
## Footnote
Murein is also known as peptidoglycan.
144
What type of ribosomes do prokaryotic cells contain?
70S ribosomes
## Footnote
Eukaryotic cells contain 80S ribosomes.
145
Where is the DNA located in prokaryotic cells?
In the cytoplasm as a single circular molecule
## Footnote
The DNA in prokaryotic cells is not associated with histone proteins.
146
What is the composition of prokaryotic cell walls?
Made of murein (peptidoglycan)
## Footnote
They do not contain cellulose or chitin.
147
Fill in the blank: Prokaryotic cells do not have a _______.
nucleus
148
True or False: Prokaryotic cells have membrane-bound organelles.
False
149
What is the function of fimbrae in prokaryotic cells?
Attachment to surfaces
## Footnote
Fimbrae are hair-like structures that help bacteria adhere to host tissues.
150
What is the primary function of the plasma membrane in prokaryotic cells?
Regulates the movement of substances in and out of the cell
151
Fill in the blank: Bacterial cells are key examples of _______ cells.
prokaryotic
152
What is the structure of the cell wall in plant cells?
Made of microfibrils of the cellulose polymer
## Footnote
Cellulose provides structural support to the cell
153
What is the structure of the cell wall in fungal cells?
Made of chitin, a nitrogen-containing polysaccharide
## Footnote
Chitin provides structural strength in fungal cells
154
What is the primary function of the cell wall?
Provides structural strength to the cell
155
What is the tonoplast?
The single membrane surrounding the cell vacuole
156
What is the main function of the cell vacuole?
Makes cells turgid and provides support, temporary store of sugars and amino acids, and contains pigments for attracting pollinators
157
Fill in the blank: The cell vacuole is filled with fluid surrounded by a _______.
tonoplast
158
What components are found in the primary cell wall?
* Pectin
* Cellulose
* Hemicellulose
* Soluble Protein
159
True or False: The cell vacuole is only responsible for storing pigments.
False
## Footnote
The vacuole also stores sugars and amino acids and helps maintain turgidity
160
What are ribosomes made up of?
Two sub-units of protein and rRNA
161
What is the size of the large ribosome found in eukaryotic cells?
80S (25nm)
162
What is the size of the smaller ribosome found in prokaryotic cells, mitochondria, and chloroplasts?
70S
163
What is the primary function of ribosomes?
The site of protein synthesis
164
What does RER stand for?
Rough Endoplasmic Reticulum
165
What is the function of the Rough Endoplasmic Reticulum?
Protein synthesis
166
What does SER stand for?
Smooth Endoplasmic Reticulum
167
What is the function of the Smooth Endoplasmic Reticulum?
Synthesizes and stores lipids and carbohydrates
168
What structural feature do both Rough and Smooth ER have?
Folded membranes called cisternae
169
What distinguishes Rough ER from Smooth ER?
Rough ER has ribosomes on the cisternae
170
Fill in the blank: Ribosomes are composed of _______ and rRNA.
[protein]
171
What is the structure of the Golgi apparatus?
Folded membranes making cisternae
## Footnote
Cisternae are the flattened membrane-bound compartments that make up the Golgi apparatus.
172
What are secretory vesicles?
Vesicles that pinch off from the cisternae of the Golgi apparatus
## Footnote
Secretory vesicles transport materials to the cell surface for exocytosis.
173
What is the function of the Golgi apparatus?
Add carbohydrates to proteins, produce secretory enzymes, secrete carbohydrates, transport, modify and store lipids, form lysosomes
## Footnote
The Golgi apparatus is crucial for processing and packaging macromolecules.
174
What is exocytosis?
The process by which vesicles fuse with the plasma membrane to release their contents outside the cell
## Footnote
This mechanism is essential for the secretion of hormones and neurotransmitters.
175
What is hydrolysis?
The chemical process of breaking down compounds by adding water
## Footnote
Hydrolysis is vital for digestion and cellular metabolism.
176
What are lysosomes?
Bags of digestive enzymes that can contain 50 different enzymes
## Footnote
Lysosomes play a key role in breaking down waste materials and cellular debris.
177
What is autolysis?
The process by which dead cells are completely broken down
## Footnote
Autolysis is a form of self-digestion that occurs in dying cells.
178
What is the role of lysosomes in phagocytosis?
Hydrolyse pathogens in phagosomes and digest worn-out organelles
## Footnote
This process helps in immune response and cellular recycling.
179
Fill in the blank: The Golgi apparatus produces _______ that transport materials to the cell surface.
secretory vesicles
180
True or False: The Golgi apparatus is involved in labeling molecules to reach their destination.
True
181
What are the components involved in the Golgi apparatus' transport system?
Cisternae, transport vesicles, and secretory vesicles
## Footnote
These components work together to modify, package, and transport proteins and lipids.
182
What does the rough endoplasmic reticulum produce?
Secretory enzymes
## Footnote
The rough ER is studded with ribosomes, which synthesize proteins.
183
What is the cis face of the Golgi apparatus?
The side that receives vesicles from the rough endoplasmic reticulum
## Footnote
The cis face is involved in the initial processing of proteins.
184
What is the trans face of the Golgi apparatus?
The side that ships vesicles to the plasma membrane
## Footnote
The trans face is responsible for exporting finished products.
185
Fill in the blank: The plasma membrane is involved in _______ to release enzymes outside of the cell.
exocytosis
186
What is the function of receptors in lysosomes?
Facilitate the recognition and binding of substrates
## Footnote
Receptors ensure that lysosomes target the correct materials for digestion.
187
What is the structure of mitochondria?
Double membrane, inner membrane called cristae, mitochondrial matrix
## Footnote
Mitochondria also contain 70S ribosomes and circular DNA.
188
What is the primary function of mitochondria?
Site of aerobic respiration and ATP production
## Footnote
ATP synthase particles are involved in the process.
189
What are the components of the mitochondrial structure?
Intermembrane space, matrix, cristae, ribosome, granules
## Footnote
Mitochondria have both an inner and outer membrane.
190
What is the structure of chloroplasts?
Surrounded by a double membrane, contains thylakoids and stroma
## Footnote
Thylakoids are folded membranes embedded with pigment.
191
What is the primary function of chloroplasts?
Site of photosynthesis
## Footnote
Chloroplasts contain enzymes for photosynthesis in the stroma.
192
What components are found in chloroplasts?
Thylakoids, stroma, granum, plastoglobule, ribosome
## Footnote
Chloroplasts also contain 70S ribosomes and circular DNA.
193
Fill in the blank: Mitochondria contain _______ and circular DNA.
70S ribosomes
194
True or False: Chloroplasts are found in animal cells.
False
## Footnote
Chloroplasts are found in plant cells.
195
What is the fluid-filled space within chloroplasts called?
Stroma
196
What is the significance of cristae in mitochondria?
Increases surface area for ATP production
197
Fill in the blank: The _______ is the site of aerobic respiration in mitochondria.
matrix
198
What is the function of thylakoids in chloroplasts?
Site of the light-dependent reactions of photosynthesis
199
What are the two membranes surrounding chloroplasts called?
Outer membrane and inner membrane
200
What is the structure that controls the entrance and exit of molecules in cells?
Phospholipid bilayer
## Footnote
The phospholipid bilayer is found in all cells and consists of molecules embedded within and attached on the outside, including proteins, carbohydrates, and cholesterol.
201
What are the two types of proteins associated with the phospholipid bilayer?
* Peripheral protein
* Integral protein
## Footnote
Integral proteins include globular proteins and alpha-helix proteins, while peripheral proteins are associated on the surface.
202
Fill in the blank: The _______ is a jelly-like material found within the nucleus.
Nucleoplasm
203
What are the main functions of the nucleus?
* Site of DNA replication
* Site of transcription (making mRNA)
* Contains the genetic code for each cell
## Footnote
The nucleus is essential for genetic information processing and storage.
204
True or False: The nuclear envelope consists of a single membrane.
False
## Footnote
The nuclear envelope is a double membrane structure.
205
What are the structures found within the nucleus?
* Nuclear Envelope
* Nuclear Pores
* Nucleoplasm
* Chromosomes
* Nucleolus
## Footnote
Each of these structures plays a specific role in the function and organization of the nucleus.
206
What is the role of the nucleolus?
Site of RNA production and ribosome synthesis
## Footnote
The nucleolus is a smaller sphere located within the nucleoplasm.
207
Fill in the blank: The _______ are protein-bound, linear DNA structures found in the nucleus.
Chromosomes
208
What are the components of the cell-surface membrane?
* Phospholipid bilayer
* Proteins
* Carbohydrates
* Cholesterol
## Footnote
These components work together to maintain the integrity and functionality of the cell membrane.
209
What type of protein is a protein channel classified as?
Transport protein
210
What is the difference between heterochromatin and euchromatin?
* Heterochromatin: densely packed, inactive DNA
* Euchromatin: loosely packed, active DNA
## Footnote
This distinction is important for understanding gene expression and DNA accessibility.
211
What are the hydrophilic and hydrophobic parts of a phospholipid molecule?
* Hydrophilic heads
* Hydrophobic tails
212
What is the function of the cell-surface membrane?
Controls the movement of substances in and out of the cell
## Footnote
The cell-surface membrane is selectively permeable.
213
What organelle is responsible for energy production in eukaryotic cells?
Mitochondria
## Footnote
Mitochondria are often referred to as the powerhouse of the cell.
214
Fill in the blank: The organelle responsible for photosynthesis is the _______.
[Chloroplast]
## Footnote
Chloroplasts contain chlorophyll, which captures light energy.
215
What is the primary function of the nucleus?
Contains genetic material and controls cell activities
## Footnote
The nucleus is surrounded by a nuclear envelope.
216
List the two types of endoplasmic reticulum.
* Rough endoplasmic reticulum
* Smooth endoplasmic reticulum
## Footnote
Rough ER is involved in protein synthesis, while smooth ER is involved in lipid synthesis.
217
True or False: Ribosomes are involved in protein synthesis.
True
## Footnote
Ribosomes can be found free in the cytoplasm or attached to the rough endoplasmic reticulum.
218
What is the function of lysosomes?
Digestive organelles that break down waste materials and cellular debris
## Footnote
Lysosomes contain hydrolytic enzymes.
219
What structure provides support and protection to plant cells?
Cell wall
## Footnote
The cell wall is primarily made of cellulose.
220
Fill in the blank: The _______ is a large organelle that stores materials and helps maintain turgor pressure in plant cells.
[Vacuole]
## Footnote
Vacuoles can also store nutrients and waste products.
221
What is the role of the Golgi apparatus?
Modifies, sorts, and packages proteins and lipids for secretion or delivery to other organelles
## Footnote
The Golgi apparatus works closely with the endoplasmic reticulum.
222
What are plasmodesmata?
Channels that allow communication and transport between plant cells
## Footnote
Plasmodesmata connect the cytoplasm of adjacent plant cells.
223
What is the tonoplast?
Membrane surrounding the vacuole in plant cells
## Footnote
The tonoplast regulates the movement of ions and molecules in and out of the vacuole.
224
Name the membrane system involved in the synthesis of lipids.
Smooth endoplasmic reticulum
## Footnote
Smooth ER lacks ribosomes, making it smooth in appearance.
225
What organelle is involved in the packaging and transport of proteins?
Golgi apparatus
## Footnote
The Golgi apparatus receives proteins from the rough endoplasmic reticulum.
226
True or False: Peroxisomes are involved in lipid metabolism and the detoxification of harmful substances.
True
## Footnote
Peroxisomes contain enzymes that break down fatty acids and detoxify hydrogen peroxide.
227
What is the function of thylakoid membranes?
Site of the light-dependent reactions of photosynthesis
## Footnote
Thylakoids are found within chloroplasts.
228
Fill in the blank: The _______ is a dense region within the nucleus where ribosomal RNA is produced.
[Nucleolus]
## Footnote
The nucleolus is crucial for ribosome assembly.
229
What are the two types of cells you must learn about?
Eukaryotic and prokaryotic cells
230
Which type of cell is larger and contains DNA in a nucleus?
Eukaryotic cells
231
What type of organisms are made up of eukaryotic cells?
Animals, plants, and fungi
232
What is the basic unit of life that can perform all life processes?
Cell
233
What are organisms made up of that contain a range of organs?
Organ systems
234
What are organs made up of?
Tissues
235
What are specialised cells with similar structures and functions organized into?
Tissues
236
Fill in the blank: Eukaryotic cells are part of complex _______ organisms.
multicellular
237
What is the function of the cell membrane?
It protects the cell and controls what enters and leaves.
238
What is the main function of the mitochondrion?
Energy production
239
True or False: The nucleus contains the DNA in prokaryotic cells.
False
240
What is the function of ribosomes?
Protein synthesis
241
Fill in the blank: The _______ is responsible for processing and packaging proteins.
Golgi apparatus
242
List three components found in an animal cell.
* Cell membrane
* Cytoplasm
* Nucleus
243
What is the role of the vacuole in eukaryotic cells?
Storage of substances
244
What type of endoplasmic reticulum is involved in protein synthesis?
Rough Endoplasmic Reticulum
245
Fill in the blank: The _______ helps in the detoxification of drugs and poisons.
Smooth Endoplasmic Reticulum
246
What is a lysosome's primary function?
Digestion of waste materials
247
What is the term for the jelly-like substance inside the cell?
Cytoplasm
248
What structure is responsible for organizing microtubules in the cell?
Centrosome
