2.1 cell structure Flashcards
What is the maximum resolution of an optical microscope
200 nm
What is the maximum useful magnification of an optical microscope
x1500
What is the resolution of an electron microscope
0.2 nm
What is the maximum useful magnification in an electron microscope
x1,500,000
Describe a transmission electron microscope
- can see internal structures of a cell
- higher resolution than SEM’s
- can only be used for thin specimens
- cannot observe live specimens
Describe a scanning electron microscope
- produce a 3D image
- can be used on thick specimens
- lower resolution
- cannot observe live specimens
Describe a laser scanning confocal microscope
- must be stained with fluorscent dye
- high resolution (3D image)
- can cause photodamage to the cells
- slow process
Equation for magnifcation
magnification = image / actual
What things must you do when doing a biological drawing
- magnification
- no shading
- title
- label lines (no arrow heads)
Structure of nucleus
- nuclear envelope has many pores to allow mRNA
- double membrane bound
What type of DNA does an eukaroytic cell have
linear DNA
What type of DNA does a prokaroytic cell have
circular DNA
Structure to function of the mitochondria
- inner membrane folded called cisternae to increased SA:V for increased aerobic respiration
- creates its own DNA which is needed for replication
- inner fluid called the matrix which contains enzymes need to produce ATP
Structure to function of the chloroplast
- thylakoids are the individual stack and the granum is the stack as a whole
- lamella join the granum together
- produces own DNA for replication
Structure to function of the rough endoplasmic reticulum
- surface covered in ribosomes for protein synthesis
- continuous to the nuclear envelope so easy transport of mRNA
Structure to function of the smooth endoplasmic reticulum
- no ribosomes on the surface due to its function of storing lipids, carbohydrates and steroids
Structure to function of the golgi apparatus
- flattened sacs of membranes that modify and packages proteins
- produces secretory vesicles for transport of proteins
Structure to function of the lysosomes
- membrane bound due to it contain hydrolytic enzymes
Function of the centrioles
- organises the spindle fibres during cell division
Function of the microvilli
- increase the surface area of the cell for faster rate of exchange of substances
Function of the cilia/flagella
movement
Process of protein production
- DNA from the nucleus is copied into mRNA via transcription
- the mRNA strand leaves the nucleus via the nuclear envelope and attaches to a ribosome on the RER
- the ribosome reads the genetic information by translation to synthesise a protein
- this passes through the lumen of the RER to be processed and folded these processed proteins are transported to the golgi body
- this modifies and packages the proteins these leave in secretory vesicles
- these vesicles fuse with the cell surface membrane by the process of exocytosis
What is the role of the cytoskeleton
- strengthing and support to maintain the shape of the cell and keeps cells in position
- intracellular movement (within the cell) it aids transport by forming tracks which cells can move along
- change cell shape
- cellular movement via flagella and cilia
Differences between prokaryotes and eukaroytes
- 80s ribosomes = eukaroytes 70s = prokaroytes
- linear DNA = eukaroytes circular DNA = prokaroytes
- nucleus = eukaroytes no nucleus = prokaroytes
- celluose/lignin = eukaroytes peptidoglycan = prokaroytes
