Cell structure and studying cells Flashcards
What is the structure and function of the nucleus?
Structure:
Double membrane
Nuclear envelope
DNA packaged in histone proteins
Function:
Control centre of the cell
Contains the genetic information
What is the structure and function of the rough endoplasmic reticulum?
Structure:
Highly folded cisternae
Stubbed with ribosomes
Function:
Protein synthesis
What is the structure and function of the smooth endoplasmic reticulum?
Structure:
Highly folded cisternae
Function:
Lipid synthesis
What is the structure and function of the Golgi apparatus?
Structure:
Membrane flattened sacs folded on top of one another
Functions:
Modified sorts and packages proteins
What is the structure and function of the mitochondria?
Structure: Double membrane Cristae folding of the inner membrane Matrix Self replicating Own DNA
function:
Power house of the cell
Produces ATP via aerobic respiration
What is the structure and function of lysosomes?
Structure:
Phospholipids in a bilayer ( micells)
Function: Contain hydrologic enzymes Compartmentalise enzymes Recycling Phagocytosis
What is the structure and function of chloroplasts?
Structure: Double membrane Stroma Thylakoids (granum) Own loop of DNA Chlorophyll
function:
Photosynthesis
What is the structure and function of cilia and undulipodia?
Structure:
Microtubules
Centrioles
Function:
Moving mucus
Receptors
What is the structure and function of ribosomes?
Structure:
rRNA
Ribosomal proteins
Two separate sub units
Function:
Protein synthesis
Translation
What are the structures and function of centrioles?
Structure:
Bundles of microtubules
Function:
Cell division (mitotic spindle)
Formation of cilia and undulipodia
What is the structure and function of the cytoskeleton?
Structure:
Microfilaments
Proteins
Function:
Support
Mechanical strength
Cell-cell communication
What is the structure and function of the cell wall?
Structure:
Bundles of cellulose
Fungi have chitin cell walls
Function:
Strength and support
Permeable
Prevents cells from bursting
What are the properties of eukaryotic cells?
Discrete membrane bound organelles
Larger ribosomes
Larger cells
Divide by mitosis
What are the properties of prokaryotic cells?
No membrane bound organelles Waxy capsule Cell walls Smaller ribosomes Plasmids Flagella Divide by binary fission Small microorganisms Smaller cells
What are the properties of viruses?
Acellular
Non-living particles
Nucleic acids
Capsid
What are the similarities between prokaryotic and eukaryotic cells?
Plasma membrane
Cytoplasm
DNA / RNA
Ribosomes
How do you prepared cells for cell fractionation?
Cold - reduce enzyme activity
Buffered - prevents pH changing
Isotonic - prevents osmosis in or out of cells
What is homogenisation?
Cells are broken up by a homogeniser and filtered to remove all the large cell components
What are the steps in ultracentrifugation?
- Spun at slow speeds
Organelles are passed to the bottom of he tube by centrifugal force
Faster its spin the greater the centrifugal force
The heavier organelles require less force to push them out
Heavier organelles are removed first
- Supernatant is removed and re centrifuges at a higher speed
- Process repeats until the smallest organelles are removed
Why is ultracentrifugation important?
Enables scientists to study the function of isolated cell components
What is magnification?
How much bigger an image appears compared to the original object
What is resolution?
The ability of an optical instrument to distinguish between 2 points
How do optical microscopes work?
Use light wavelengths but have a lower magnification and resolution
What are the benefits of optical microscopes?
See in colour Can view live specimens Cheap Easy to use Portable
