Chapter 2- Cell Structure Flashcards
Function of smooth ER?
- lipid + carbohydrate synthesis
- storage
Function of lysosome?
- contains hydrolytic enzymes
- break down organelles, pathogens, cells
Function of ribosome?
Protein synthesis
Features of plant cells that are not features of animal cells?
- vacuole
- chloroplast
- cell wall
Features of animal cell that are not present in plant cells?
- centrioles
- lysosomes
Role of cytoskeleton?
- maintains shape
- holds organelles in place
- movement of chromosomes in cell
- provides strength
how do organelles work together to produce and release protein molecules from cells?
- nucleus contains gene for protein. This is site of transcription
- Ribosome on RER site of protein synthesis
- vesicle transports protein to Golgi apparatus
- this modifies and repackages proteins
- another vesiclescontaining proteins fuse with CSM
Function of mitochondria?
Involved in aerobic respiration and produces ATP
Detail of organelle could not be seen clearly with light microscope. Why?
- too small
- resolution not high enough
advantages of staining specimens?
- increases contrast
- allows organelles to be identified
Types of extra cellular proteins secreted?
- hormones
- enzymes
- glycoproteins
State stages during secretion of protein that require energy
- transporting vesicle to CSM
- exocytosis
Role of Golgi apparatus?
- receives ribosomes from RER in vesicles
- modifies and repackages proteins in vesicles
- makes lysosomes
- lipid synthesis
Features in prokaryotic cells but not in eukaryotic cells?
- circular DNA
- plasmids
- 70s ribosomes
Added water to slide with blood. Cell burst
Added water to slide with epidermal cell. Did not burst.
Why?
- cell cytoplasm has lower water potential than water
- water moves into both cells down water potential gradient
- water moves into cell by osmosis
- CSM of blood cannot withstand pressure and bursts
- epidermal cell has cell wall that can withstand pressure and becomes turgid
How to prevent cell bursting when looking under microscope?
Use solution with similar water potential
What is magnification?
The no. of times larger the image is to the object
What is resolution?
The ability to distinguish between two points and see detail
How do images taken with SEM turn out?
- 3D images
- can see surface
Function of nuclear pores?
Allow molecules to move in and out of nucleus
Describe how the ultrastructure of neutrophil is specialised to enable the engulf and digestion of foreign cells
- many lysosomes
- many ribosomes
- many mitochondria
- many receptors on CSM
Function of chloroplasts?
Site of photosynthesis
Name structures associated with the cytoskeleton which bring about cell movement
- microtubules
- microfilaments
- flagella
- cilia
Processes inside cells that require cytoskeleton for movement?
- cytokinesis
- movement of chromosomes
Suggest why 2 mitochondria look different?
- cut in diff planes
- mitochondria still growing
How are vesicles moved from one organelle to another?
- move along microfilaments and microtubules
- using ATP
Why nuclear envelope has pores?
- allow movement of molecules in and out of nucleus
- e.g. mRNA out of nucleus
Advantages of staining (image included)
- increases contrasts
- organelle X can now be seen
Intermediate fibres?
- gives mechanical strength
- maintains integrity of cell
Microfilaments?
- contractile fibres
- made from actin
- responsible for cel movement
- e.g. cell contraction in cytokinesis
Microtubules?
- globular tubulin proteins polymerise to form tubes
- form scaffold like structures
- determines shape of cell
- e.g. spindle fibres
Empty magnification?
-magnification increased without increase in resolution so no more detail visible
Role of vacuole?
Storage
What are the organelles like in eukaryotic cells?
Membrane bound AND non membrane bound
What does mitochondria contain?
Circular DNA
Diameter of eukaryotic cell?
20-40 micrometers
Diameter of prokaryotic cell?
0.5-5 micrometers
How big are the ribosomes in eukaryotic cells?
- 80s
- 22nm
How big are the ribosomes in prokaryotic cells?
- 70s
- 18nm
Does lysosome have an envelope?
No
How many membranes does chloroplast have?
2
Organelle extracted and kept in sucrose solution. Purpose of sucrose solution?
Prevents organelle from changing shape
How images with transmission electron miscroscope are?
- 2D
- internal details visible
Roles of the cytoskeleton?
- make up spindle fibres
- provide strength
- determine shape
- movement of organelles
- hold organelles in place
