Flashcards in Unit 3.1.3 - Cells and Plasma Membranes Deck (88)
What is the difference between a prokaryotic cell and a eukaryotic?
Eukaryotic cells are big complex cells where as prokaryotic cells are usually single celled organisms
Name three organelles you wouldn't find in a prokaryotic cell and the main reason why?
Nucleus, mitochondria and ER because they are too large and wouldn't fit it
Label the diagram of a eukaryotic cells?
See flash card 8
Label the diagram of a nucleus?
See flash card 9
Label the diagram of a mitochondria?
See flash card 10
What is the function of a nucleus?
Controls the cell activity
What is the function of the nucleolus?
What is the function of mitochondria?
Produce energy by aerobic respiration
What is the function of smooth ER?
Makes and transports lipids
What is the function of rough ER?
Makes and transports proteins
What is the function of Golgi apparatus?
What is a vesicle?
A sack of protein that is used to transport the protein
What is the function of a ribosome?
To make protein
What is the function of the plasma membrane?
Control which substances enter and leave the cell
What is the function of the cytoplasm?
Where chemical reactions take place
What is the function of lysosomes?
Destroys (digests) dead organelles
What are microvilli?
Folds in the plasma membrane
Name two adaptations of an epithelium cell which makes it suitable for its function an why?
Microvilli - increase surface are for food absorption
Lots of mitochondria - to provide energy for the active transport of food molecules against the concentration gradient
What is the difference between magnification and resolution?
Magnification - how much bigger the image is than the specimen
Resolution - how detailed the image is
How do you calculate magnification?
Length of image / Length of specimen
How do you convert mm into µm?
What are the three types of microscopes?
1.) light microscope
2.) scanning electron microscope (SEM)
3.) transmission electron microscope (TEM)
How do transmission electron microscopes work?
They use electromagnets to focus a beam of electrons through a specimen, denser parts of specimen absorb more electrons which make them look darker on the image
How do scanning electron microscopes work?
They scan a beam of electrons across a specimen, this knocks of electrons from the specimen which are gathered in a cathode ray tube to form an image
Why cant you use either electron microscope on a living specimen?
You have to dehydrate the specimen and use heavy metals to stain it so you can see it under the microscope which kills any living cells
What are two advantages of a light microscope?
1.) can see living cells
2.) can see actual colour
What are two disadvantages of a light microscope?
1.) low magnification
2.) poor resolution
What are two advantages of a TEM?
1.) high magnification
2.) good resolution
What are three disadvantages of a TEM?
1.) can only be used on thin specimens
2.) can't be used on living specimens
3.) must be in a vacuum