Studying Cells Flashcards
What is the function of the nucleus?
- contains genetic material
- DNA replication
- production of mRNA
- production of rRNA
Describe the structure of the nucleus.
- nuclear envelope and pores
- chromatin
- nucleolus
What is the function of the mitochondria.
- site of aerobic respiration
- ATP production
Function of rough endoplasmic reticulum.
- encrusted in ribosomes
- site of protein synthesis
- transports and stores proteins within the cell
Function of Golgi apparatus.
- modifies + packages proteins
- produces vesicles
Function of lysosomes.
- digestive enzymes
- digest organelles
Function of cell surface membrane.
- phospholipid bilayer
- controls what enters and exits cell
- can be folded in to increase surface area
Function of chloroplasts.
- contain thylakoids
- stacked into granum
- site of photosynthesis
Function of capsule.
- protects cell from immune systems
- aids bacteria sticking together
Function of plasmid.
- circular DNA
- contains antibiotic resistant genes
Function of cell wall.
- provides rigid shape
- stops osmotic lysis
Role of organelles in production, transport and release of proteins in a eukaryotic cell.
- DNA is code
- ribosomes on RER produce protein
- mitochondria produce ATP
- Golgi package/modify
- vesicles transport
- vesicles fuse with cell-surface-membrane
Function of smooth endoplasmic reticulum.
- site of lipid synthesis
Function of flagellum.
- allows movement
Contrast eukaryotic and prokaryotic.
comparisons =
- nucleotide structure identical
- joined by phosphodiester bonds
contrasts =
- eukaryotic DNA is longer, prokaryotic shorter
- eukaryotic DNA contain introns, prokaryotic DNA doesn’t
- eukaryotic linear, prokaryotic circular
- eukaryotic histone, prokaryotic no histone
Advantages of using TEM rather than SEM..
- higher resolution
- higher magnification
- allows internal details to be seen
Advantage of using SEM rather than a TEM…
- thin sections do not need to be prepared
- shows surface of specimen
- can have 3D images
What is the function of the ribosomes?
- site of protein synthesis
Advantages and disadvantaged of using a TEM.
advantages =
- small objects can be seen
- TEM has high resolution
- electron wavelength shorter
disadvantages =
- cannot look at living cells
- must be in a vacuum
- must cut section
Explain why the solution was =
isotonic
ice cold
buffered
- prevents osmosis
- reduce enzyme activity
- maintain constant pH
Describe cell fractionation and centrifugation.
- homogenise cells to break cell surface membrane and release organelles
- filter to remove debris
keep solution isotonic, ice cold and buffered - creates supernatant
- centrifuge at higher speeds for lightest organelles
