Eukaryotic and Prokaryotic Cells Flashcards
What does cell theory state?
Cells are the fundamental unit of structure, function and organisation in all living organisms
What is a unicellular organism?
Organism composed of a single cell
What is a multicellular organism?
Organism composed of multiple cells
Name a feature of multicellular organisms
After development their cells become differentiated and specialised although this means they cant divide further
What is differentiation?
The process by which cells specialise, becoming adapted for a specific function
What is a tissue?
A group of cells that have a common origin and similar structure and perform a single function
What is an organ?
A group of tissues that have a specific function
What is a system?
A group of tissues and organs that collectively perform a specific function
What does a condenser lens do?
focuses light before it hits a specimen to be viewed. used to vary light intensity
What is the eyepiece lens?
The lens you look down to see the specimen
What is the objective lens?
The set of lenses attached to the nosepiece that rotate so you can choose which magnification you want to view the sample with
What is the coarse focus?
Used to focus the low and medium power objectives
What is the fine focus?
Used to focus the high power objective
What is the stage?
Where the microscope slide is placed
Explain how you would carry out temporary prep
Tissues placed on slide and covered in liquid to prevent it from drying out and then coverslip going on top
Explain how you would carry out permanent prep
Water removed from tissue and replaced with a firmer substance. Cover slip held in place by a resin
What does a stain do?
Helps to identify key cell structures bc they colour the cell
What is magnification?
The extent to which an object is enlarged by a microscope
How do you calculate magnification?
Image size/specimen size
What is resolution?
The ability to distinguish between points that are very close together
How does an electron microscope work?
Electron gun fires electron beam at sample and electromagnets focus the beam onto a fluorescent screen for viewing
What are eukaryotic cells?
A cell with a nucleus and membrane bound organelles in its cytoplasm
What are prokaryotic cells?
Cells with no nucleus and no membrane bound organelles
What is cytosol?
Aqueous solution of chemicals around the organelles
What does the cell surface membrane do?
Contains the organelles and the cytosol
What are organelles?
Structures in the cytoplasm of eukaryotic cells that perform a discrete function and are membrane bound
Describe the structure of the nucleus
Largest organelle
Double membrane - outer layer continuous with the RER
Pores to allow movement of mRNA and ribosomes out and hormones and nutrients in
Contains chromatin/chromosomes
What are chromosomes?
Strands of DNA wound around histone
What is chromatin?
Diffuse network of chromosomes
What is the function of the nucleolus
Site of ribosome synthesis in the nucleus
Makes ribosomes from ribosomal RNA
Describe the structure of the mitochondria
Rod shaped organelles Double membrane Folded inner membrane to form cristae Outer membrane smooth Inside inner membrane is matrix
What are cristae?
The folds of the inner membrane of the mitochondria
What is the matrix?
An aqueous solution of metabolites and enzymes inside the inner membrane of the mitochondria
Explain the structure of a chloroplast
Biconcave structure
Folded inner membrane
Smooth outer membrane
What are thylakoids?
The folded inner membrane of the chloroplasts