Cell Structure Flashcards
What is the structure of mitochondria
Spherical rod shaped branched 2-5 micrometers long and surrounded by double membrane with inner membrane folded to form cristae and small circular pieces of dna found in matrix and ribosomes
What is the function of mitochondria
Site of ATP production during aerobic respiration and visible with a light microscope
What is the structure and function of chloroplasts
Found in plant cells and is surrounded by double membrane and inner membrane continuous with stacks of flattened memb. sacs called thylakoid and contains loops or dna or starch graisn and the function is that it is the site of photosynthesis
What is the structure and function RER
Phospholipid bilayer forms cisternae and covered with ribosomes on surface. MEMBRANE CONTINIOUS W/ NUCLEAR ENVOLOPE
Proteins actively pass through memb. into cisternae and transported into G.A for modification and packaging
What is the structure and function of SER
System of memb. containing fluid filled cavities which are continous w/ nuclear memb. but no ribosomes on the surface
Involved in production processing and storagfe of lipids carbohydarates and steroids
What is the structure and function of the G.A
Contains flattened memb. sacs similar to RER
Modifides and packages proteins before packaging them into the G.A and then transports porteins and lipids into their desired destination
What is the structure of Lysosomes
Specalist form of vesicles which contain hydrolyic enzymes
Breaks down waste materials
What is the structure of nucelus
Nucelus is surrounded by a double membrane called the nucelar envolope - (contains dna organised and wound into linear chromsonoes and seperates contents of nucelus from rest of the cell) and there inside the nucelus called the nucelous - (contains rna where chromosones unwind themselves)
What are the differences about prokaryotes which eukaryotes don’t have
Much smaller than eukaryotes
Cytoplasm which lacks memb. bound organekkes
Smaller ribosomes
Contains: plasmids - single circular piec3e of dna not assoicated with histone proteins
flagellum - enables cell movement
ce3ll wall made of peptidoglycan
What are the similarities between Prokaryotes and Eukaryotes
Both have cytoplasm
DNA and RNA
Plasma Memb.
What is the defenition of magnification
Tells you how much bigger the image produced by a microscope is than the real life image you are viewing
What is the defenition of resolution
Ability to distinguish between object which are close together
What are the 3 different types of microscopes
Laser - Scanning Confocal
Optical
Electron
What are the features of optical microscopes
Uses light to form an image which limits the resolution of optimical resoluton
What is the max resolution of optical microscopes
0.2 MICROMETERES
200 NANOMETERS
What is the max magnification of light microscopes
1500x
What is an electron microscope
Uses electrons to form an images which increases the resolution and gives a more detailled image
What is the max resolution of electron microscopes
0.2NM/ 0.0002MICROMETERS
What are the 2 types of electron microscopes
Transmission EM-more than 1,000,000x, 0.2
Scanning EM-2nm less than 500,000x
What are the adv. and disadv. of TEM
They Transmit through species
They give higher resolution
Allow internal structures to be seen
HOWEVER
They can only be used to observe thin specimen/sections of objects observed
They do not produce colour on images
Only used to overserve live specimen
What is SEM and what are the features
Bounce of surface of specimen
Advantages:
They produce 3D Images
which can be seen by specimen
Disadvantages:
They give lower resolution images
Cannot be used to observe live specimens
What are the features and adv. and disav. of Laser Scanning Confocal Microscopes
Clles stained with fluorescent dye and laser veam reflected by fluorescent dye
Advantages:
Can be used with living cells
Gives High resolution
Disadvantages:
Slow process
It has potential to cause photodamage to cells
State the steps for how proteins are produced?
- The DNA from nucleus is copied into a molecule called mRNA via transcrption
- mRNA strand leaves nucleus through nuclear pores and attaches to a ribosome on RER
- Ribosome reads genetic insturvtions contained within mRNA and uses code to **Synthesise a protein ** which is called translation
- Protein passes into **RER ** to be folded and Processed
- The processed proteins are the transported into the Golgi Apparatus in Transport Vesicles which fuse w/ G.A releasing the proteins
- The G.A modifies the proteins prepearing them for Secretion
- Modified proteins packaged into *Secretory Veislces *then leave G.A in Secretory vesicles moving along cytoskeleton
- Vesicles *fuse w/ plasma memb. * releasing proteins via exocytosis
What is the importance of cytoskeleton
Strengthening and support–> provides cell w/ mechanical strength forming scaffolding helping maintain shape
Intracelluar Movement –> cytoskeleton aids transport** * within cells **forming tracks** along which organelles can move
**Celluar movement –> enables cell movement via *cillia and flagella
What is the structure and function of centrioles
Consist of small hollow cylindrical proteins called microtubules
Function is that is seperates chromosones during cell replication
Explain the role of membrane in RER
Holds ribosomes in place
Seperate Proteins from Cytoplasm
How to measure size/diameter of nucelus
Use Eyepiece Graticule
Calibrate Eyepiece Graticule using stage micrometer
Calculate diamater of Nucleus in EPU
Repeat this several times to calculate a mean
Use CALIBRATED EPU TO CALCULATE MEAN
How does cytoskeleton move organelles
Via MICROTUBULES
