Cell Structure:2.1 Flashcards
What is the function of the nucleolous
Idensely packed DNA. Darker colour
What is the function of the ribosomes?
Site of protein synthesis
Where are ribosomes found in the cell ?
Some are found in the endoplasmic reticulum and the others and free floating in the cytoplasm
What is the function of the nucleus ?
The nucleus contains the DNA of the cells, which contains the information for producing proteins
What is the function of the nuclear envelope
Separates the nucleus from the rest of the cell
- allows substances in and out such as MRNA
What is the function of the nuclear pores?
They allow relatively large molecules ato exist and enter such as mRNA and ribosomes.
What is the nucleolus?
It contains densely packed chromatins. Darker in colour
What is meant by a eukaryotic cell ?
There are membrane bound organelles
Role of the rough endoplasmic reticulum?
transports proteins that are synthesised in the Ribosomes.
Role of the smooth endoplasmic reticulum?
Lipid and hormone syntheisis
What is the Golgi apparatus?
Modifies and packages proteins into vesicles
What is the mitochondria?
The site of ATP production during aerobic respiration.
What is the structure of chloroplast?
Chloroplasts contain two fluid separated membranes and the inner membrane is folded into a network of flattened sacs called Thylakoids that are stacked into Grana (one Granum, two Grana). The Thylakoids contain Chlorophyll in which the process of Photosynthesis occurs.
What are the functions of chloroplast?
The site of photosynthesis
What is the function of lysosomes ?
contain digestive ( hydrolytic)enzymes used to break down materials
Formula for magnification
Magnification = image size/ actual size
What is the difference between magnification and resolution?
magnification is the number of times larger the image is compared to the object. resolution is the degree to which it is possible to distinguish between two objects that are very close together. it allows the viewer to see detail.
What are the similarities between prokaryotic and eukaryotic cells?
- they both have cytoplasm, a cell membrane and ribosomes.
What is the difference between the way DNA is packaged in a eukaryotic cell than a prokaryotic cell ?
- eukaryotic cells DNA is in the nucleus whereas in a prokaryotic cell the DNA is free in the cytoplasm(plasmid)
What is the difference between prokaryotic and eukaryotic cells ?
- prokaryotic cells are smaller ( 0.1-5um) where are eukaryotic cells are (10-100um)
- prokaryotic have smaller ribosomes 70s rather than 80s
- prokaryotic have a less developed cytoskeleton
- eukaryotic cell walls are made from cellulose or chitin in fungi whereas prokaryotic have a peptidoglycan cell wall
- prokaryotic have a flagella, waxy protective capsule and pilli which eukaryotic cells don’t have
How do organelles work together in the production and secretion of proteins?
- the gene that has coded instructions for a protein in the nucleus is transcribed into MRNA.
- the MRNA leaves the nucleus through the nuclear pore and is transported to the rough ER where it is translated into a amino acid sequence with the aid of ribosomes, which read the instructions to assemble the protein and enzymes
- the molecules are ‘pinched off’ into vesticles and travel towards the Golgi apparatus
- at the Golgi apparatus the molecules are modified and packaged then are pinched off in vesticles to the plasma membrane.
- vesticles fuse to the plasma membrane which opens to release the protein molecule
Light microscopes
- allows to view whole cells and organelle
-magnification= up to x1500
Resolution= 50-200nm
Scanning electron microscopes
-magnification= up to 100,000
-resolution=0.2nm
- view cell surfaces
Transmission electron
- view great detail of cells
- resolution=0.05-1
-magnification= up to 500,000
Laser scanning microscope
-look at objects at a certain depth within a cell
Centriole
- form spindle fines in mitosis
- only in animals
Cell wall
- provides tensile strength
- insoluable
-inert
Vesicles
- membrane bound organelles used to transport substances
Chloroplast
- site of photosynthesis
Role of the cytoskeleton
- whole cell supper
- movement of flagella and cilla
- moving organelles (like vesicles)
-movement of chromosomes
Role of plasma membrane in prokaryotic
- moves substance in and out of the cell
Role of cytoplasm in prokaryotes cells
-site of chemical reactions
