Cell Structure Flashcards
Name 13 structures found in plant cells
-Mitochondria
-Chloroplast
-Cytoplasm
-Golgi apparatus
-SER
-RER
-Ribosomes
-Nucleus
-Nucleolus
-Nuclear envelope
-Plasma membrane
-Cell wall
-Large vacuole
Name 10 structures found in animal cells
-Mitochondria
-Golgi apparatus
-SER
-RER
-Ribosomes
-Nucleus
-Nucleolus
-Nuclear envelope
-Cell surface membrane
-Lysosome
State 5 roles of intracellular membranes
-Compartmentalisation
-Isolate enzymes/metabolic reactions from each other
-Provides site for attachment of enzymes (mitochondria) & ribosomeds (RER)
-Controls what enters & leaves organelle
-Creates conc gradients/electrochemical gradients
State 3 roles of extracellular membranes
-Controls what enters & leaves cell
-Create conc gradient
-Cell to cell signalling
State the type of membrane a nuclear envelope has
Double
Describe the function of the nucleus
Stores genome (DNA of organism-made of genes) which controls activities of cell
Describe the function of the nuclear envelope
Has pores:
-mRNA can leave
-Hormones can enter
Which types of cells have a nucleolus, nucleus & nuclear envelope?
-Animal
-Plant
-Fungal
Describe the function of the nucleolus
-Contains RNA
-Ribosome synthesis
Describe the function of the cytoplasm
Site for chemical reactions e.g. anaerobic resp
Describe the structure of the rough endoplasmic reticulum and the smooth endoplasmic reticulum
RER:
-Coated w/ ribosomes
-Continued from nuclear envelope
Both:
-Have cristernae (system of membranes & cavities)
Describe the function of the RER
-Large SA for protein synthesis (in ribosomes)
-Folds + modifies proteins
-Packages proteins into transport vesicles
-Intracellular transport
Describe the function of the SER
-Lipid synthesis + transportation
-Metabolism
Which types of cells have a RER, SER and golgi apparatus?
-Animal
-Plant
-Fungal
Describe the structure of the golgi apparatus
Flat (membrane-bound) sacks stacked together -> cristernae
Describe the function of the golgi apparatus
-Modifies (folds) & packages proteins into (secretory) vesicles
-Secretory vesicles enter & leave
-Adds prosthetic group to proteins
-Synthesis of complex lipids
State the function of ribosomes
Protein synthesis
Which type of cells have ribosomes?
-Animal
-Pant
-Fungal
Describe the structure of mitochondria
-Double membrane
-Inner membrane folded into cristae (to increase SA)
a) Describe the function of the mitochondria
b) Which type of cells is it present in?
a) Aerobic resp (ATP synthesis)
b) Animal, plant & fungal
Describe the structure of lysosomes
-Single membrane
-Contains hydrolytic enzymes
-Formed by golgi
Describe the function of lysosomes
-Digest old organelles/foreign matter
-Keep hydrolytic enzymes compartmentalised
Which types of cells have lysosomes?
Animals only
Describe the structure of chloroplast
-Double membrane
-Contain chlorophyll & starch grains
State the function of the chloroplast
Photosynthesis
Which type of cells have chloroplast & a vacuole?
Plants only
Name 5 different membranes and whether they are double or single
-Tonoplast (single)
-Nuclear envelope (double)
-Mitochondrial membranes (double)
-Chloroplast membranes (double)
-Golgi/RER/SER membrane (single)
a) What is the membrane of a vacuole called?
b) Is it double or single?
a) Tonoplast
b) Single
Describe the function of the vacuole
Filled w/ water & solutes for stability + turgidity
a) Describe the structure of cilia & undulipodia.
b) Describe the structure of flagella
a) -Long protrusions from cell surface membrane
-Made of microtubules
b) Whip-like protrusion
Describe the function of…
a) Cilia
b) Flagella
a) Waft substances along
b) Locomotion/cell motility
Describe the structure of a centriole
2 bundles of microtubules (at right angles) arranged in cylinder
Describe the function of the centriole
Forms spindle fibres in cell division
What is the cytoskeleton?
-Network of long chains of proteins
-Made of: microfilaments, microtubules, intermediate filaments
State 4 functions of the cytoskeleton
-Maintain/change cell shape
-Maintain position of organelles
-Enabes cell movement
-Intracellular transport of organelles/molecules/vesicles
Describe the function of microfilaments
-Cell movement
-Contraction (cytokineses)
-Allow cell to maintain/change shape
What is a microfilament?
2 actin chains
Describe the function of a microtubule
-Makes up centrioles, flagella, cilia
-Organelle movement
What are microtubules made of?
Tubulin
What is the function of intermediate filaments?
Hold organelles in place
Describe a method for separating organelles
Cell fractionation
-Break open cells w/ homogeniser -> release organelles
Untracentrifugation
-Solution of organelles spun at v high speed
-Largest organelles fall to bottom
–Whole cells/nucleus/cytoskeleton
–Chloroplast/mitochondria/lysosome
–Fragments of ER/vesicles
–Ribosomes
Identify 5 structures that are always present in prokaryotic cells and 6 structures that are sometimes present
Always:
-Plasma membrane
-Cell wall
-Circular DNA
-Cytoplasm
-Ribosome
Sometimes:
-Pili
-Plasmid DNA
-Slime capsule
-Mesosome
-Infolding of plasma membrane
-Flagellum
Describe the function of pili
-Involved in sexual reproduction
-Attachment to other cells/surfaces
State the function of the slime capsule on a prokaryotic cell
Additional protection
State the function of mesosome in a prokaryotic cell
-Production of ATP
(-Helps form cell wall
-DNA replication)?
State the function of infolded plasma membrane in a prokaryotic cell
Carry out nitrogen fixation
Compare the staining required for each type of microscope
-Light: Coloured stain
-TEM & SEM : Heavy-metal compound
-Laser scanning confocal: No stain (florescent dye sometimes used)
Compare how each type of microscope works
-Light: Light source passes through specimen
-TEM: e^- fired at specimen, pass through
-SEM: e^- fired at specimen, bounce off surface -> 3D image
-Laser scanning confocal: Laser light scans object point by point, computer assembles image
State the pros and cons of using a light microscope
-Pros: Cheap, portable, don’t kill specimen
-Con: Low res & mag
State the pros and cons of using a transmission electron microscope
-Pros: High res & mag
-Cons: Expensive, specimen must be dead, specimen must be chemically fixed (time consuming)
State the pros and cons of using a scanning electron microscope
-Pros: High res & mag, 3D
-Cons: Expensive, specimen must be dead, black & white image
State the pros and cons of using a laser scanning confocal microscope
-Pros: Study whole, live specimens, has depth selectivity
-Cons: Expensive
When studying cell structure using a microscope, the smallest unit of measurement commonly used to describe findings is the nanometre. Explain why
Microscope’s highest resolution is 0.2nm
State the formula used to work out the image size of a specimen when the actual size is known
I=AM
State the difference between magnification and resolution
-M: Ability to see small objects
-R: Ability to distinguish between 2 close objects
What type of ribosomes are present in eukaryotic cells vs prokaryotic cells?
-E: 80s ribosomes
-P: 70s ribosomes
State the maximum magnification & resolution that can be achieved by a…
a) Light microscope
b) TEM
a) Mag: 1500
Res: 0.2 μm
b) Mag: 500,000
Res: 1nm
What are cells found in?
Extracellular fluid/tissue
Order the 3 parts of the cytoskeleton in order of increasing diameter
-Microfilaments
-Intermediate filaments
-Microtubules
