Cells Flashcards
(19 cards)
Can you describe the structure of eukaryotic cells, including the: * Lysosomes * Ribosomes * Rough endoplasmic reticulum and smooth endoplasmic reticulum
Hydrolytic Enzymes in acidic solution within vesicle.
Digest damaged organneles and DNA
Phagocytosis/apoptosis.
2 subunits, small and large
rRNA + protein
Translation of proteins
80 s ribosomes in eukaryotes.
Found in Cytoplasm/RER
RER: Continuous with nucleus
Cisternae connected by lamellae.
Synthesised and transports proteins and glycoproteins to golgi.
SER: lipids to golgi
throughout the cell.
Can you describe the structure of eukaryotic cells, including the: * Nucleus * Mitochondria * Golgi apparatus and Golgi vesicles
Contains DNA to determine cell function
Double membrane, the nuclear envelope, continuous with RER.
Nuclear pores let RNA and subunits out.
Chromatin within nucleoplasm
Nucleolus where ribosomal subunits are made.
Largest Organelle.
Site of aerobic respiration, ATP produced
Double Membrane
Inner membrane highly folded, cristae
High surface area for ATP synthase attached to cristae.
Matrix, proteins/lipids, mitochondrial DNA for enzyme synthesis and self replication.
Mitochondria adapted for high energy output may have more cristae.
Cisternae
Sorts, modifies, processes proteins
May be used to form lysosomes.
Well developed in secretory cells.
Can you describe the structure of eukaryotic cells, including the: * Chloroplasts * Cell wall * Cell vacuole
Double membrane envelope: inner/outer
Grana- stack of thylakoid discs w/photosynthetic pigments
Stroma- Calvin cycle, enzymes required to move sugars
Starch grains- energy storage
DNA and ribosomes in stroma : enzyme synthesis and self- replication.
Can you explain the adaptations of eukaryotic plant cells?
Cellulose: Many H bonds within microfibrils.
High tensile strength, withstand turgor pressure.
Lignin also increases strength, matrix formed with cellulose.
Structure and support to plant
Permeable cellulose (cuticle above membrane)
Source of fibre when feeding
Large permanent vacuole
Tonoplasts: membrane
Solution of salts/sugars called cell sap
Large area of cytoplasm occupied.
Maintain cell rigidity
Can isolate unwanted chemicals.
What is cell differentiation and what are its advantages?
Specialisation: switching on and off certain evens to allow specific proteins to be synthesised.
Gene products allow cell to carry out a specific function with specific adaptations.
Can include different shapes of cells/organelles.
Increasing efficiency of organism.
Explain the role of each part of a prokaryotic cell
Flagellum: rotates for movement
Capsule: retain moisture sticky to adhere to surfaces.
Mesosomes: ATP Synthesis
Pili: attach to other bacteria
How are cells are arranged into tissues? Give some examples of tissues
issue: Group of specialised cells with the same function (simple) group of different specialised cells to carry out an overarching function is a compound tissue.
Cardiac tissue, nervous, connective, epithelial.
How are organs arranged into organ systems? Give some examples of organ systems.
Group of organs working together to form a system to control a larger function in the body.
Nervous, respiratory, digestive, excretory, reproductive ,circulatory
Can you explain whether viruses are living or not and why?
Not alive very small and require host cell machinery to replicate.
How are tissues are arranged into organs? Give some examples of organs.
roup of tissues working to perform a certain function.
Heart, lungs
Can you explain how prokaryotic cells differ from eukaryotic cells?
Prokaryotes: Circular DNA, no histones, plasmids, no membrane bound organelles, no true nucleus, 70 s ribosomes, mesosomes for ATP synthesis, murrain cell wall, flagella, some have capsule.
Can you explain the difference between magnification and resolution?
Magnification: No x larger than real life
Resolution: Ability to distinguish between 2 points close together and see detail.
Can you describe the principles of cell fractionation and ultracentrifugation in separating cell components?
Homogenisation, filter, differential centrifugation, remove pellet, Differential centrifugation at faster speed on supernatant, repeat.
Nuclei —> mitochondria/chloroplasts —> membranes —> ribosomes
Before cell fractionation, the tissue is placed in what type of solution?
Ice cold isotonic buffer solution:
Ice cold: reduce enzyme action
Isotonic: no osmosis, no bursting or crenation
Buffer: no denaturation
Can you describe how a light microscope works and explain the limitations of it
Light focused with glass lenses
Viewed with eye
Specimens can be dead or alive
Staining often required to make features visible
Limited to 1500 x
No smaller structures such as ribosomes visible
Resolution limited by wavelength of light.
Quick no skill required.
can you describe how a transmission electron microscope works and explain the limitations of it:
Electron pass through thin specimen
Denser parts absorb more electrons so appear darker
High resolution
Dear thin vacuum specimens
Artefacts present from complex staining process with heavy metals.
Higher resolution than SEM
Cross section taken
X500k mag
Time consuming Skill required
Can you describe how a scanning electron microscope works and explain the of limitations it:
Not sliced
Electrons bounce off surface of specimens
3D images produced and colourised, no cross section
Can you explain how you would use an eyepiece graticule to measure cells:
Fit graticule onto eyepiece
Place stage micrometer on stage
Calculate length of 1 division one article using accurate scale of stage micrometer.
How did the scientific community distinguish between artefacts and cell organelles?
Repeat, analyse with known structure images, compare with optical images.
