Bio I - 5 Flashcards
What is cell biology?
The study of cells and their structure, function, and behavior. This is also called cytology. 
True or false: all living organisms are made of cells
True
What is a cell?
The cell is the basic structural and functional unit of all living organisms
True or false: cells do not vary in size and proportion.
False
How big is a bacterial cell?
A few micrometers in length.
How big is a frog egg?
1 mm diameter
True or false: not all cells are equal in their requirements.
True
Some cells are specialized for producing certain substances such as:
Hormones
Starch
Fat
Certain pigments
When was the microscope invented and who invented it?
17th century.
Some say it was Hans Lippershay (also invented the telescope)
Others say it was Hans and Zacharias Janssen
What is a Light Microscope?
Visible light passes through a specimen and then through glass lenses, which magnify the image.
What does the quality of an image depend on?
Magnification - the ratio of an objects size to its real size.
Resolution - the measure of the clarity of the image, or the minimum distance if two distinguishable points.
Contrast - visible differences in parts of the sample.
Who discovered the cell?
Robert Hooke
Who discovered LIVING cells?
Antoni Van Leeuwenhoek (discovered Protozoa) later saw bacteria for the first time.
Who discovered the cell nucleus?
Robert Brown.
Who proposed the cell theory?
Schleiden and Schwann
Who discovered the mitochondria?
Rudolf Albert von Kolliker
Who discovered the Golgi apparatus?
Camillo Golgi
Who discovered the electron microscope and when?
Palade, Porter, and Sjostrand.
1952
What is a fluorescence microscope?
Detects fluorescent dyes used for staining cells. Dyed objects show up in color on a dark background.
What is a scanning electron microscope?
Specimen coated with thin layer of metal. Scanned by beam of electrons. Magnetic coils act as lenses. Creating 3D images.
What is transmission electron microscope?
Uses beam of electrons with a short wavelength. Used to visualize inside of cell such as organelles.
What is cell fractionation?
It’s a process that takes cells apart and separates the major organelles from one another.
What is ultracentrifuges?
They fractionate cells into their component parts.
What do prokaryotic cells consist of?
Bacteria and archaea.
What are different types of eukaryotic cells?
Protists, fungi, animals, and plants.
What are the two domains of prokaryotes?
Bacteria and archaea
How do prokaryotes reproduce?
Binary fission
How much time at least does a prokaryotic cell divide in?
20 minutes
What do prokaryotes have that help them adapt to their environment?
They have flagella which help them move and they have a capsule to help them adhere.
What types of bacteria are there?
Cocci - spherical
Bacilli - rods
Spirilla - spirals
Do prokaryotes have a nucleus?
No
They have a nucleoid which contains circular chromosome
True or false: Prokaryotes have membrane enclosed organelles.
False
They do not
How are prokaryotic cells classified?
- no nucleus
- no membrane enclosed organelles
- DNA is in an inbound region called the nucleoid
- cytoplasm is bound by the plasma membrane
What are eukaryotic cells characterized as?
- DNA is in a nucleus that is bounded by a membranous nuclear envelope
- membrane-bound organelles
- cytoplasm is the region between the plasma membrane and nucleus
True or false: eukaryotic cells are generally much larger than prokaryotic cells.
True
How to eukaryotic cells reproduce?
Through mitosis and can involve meiosis
What are the 3 main parts of the eukaryotic cell?
Plasma membrane
Cytoplasm
Nucleus
What is the plasma membrane?
Separating the cells internal environment from the cells external environment. It is a semipermeable membrane.
What is the cytoplasm?
Cyt = cell
Plasm = molded
All of the cellular contents between the plasma membrane and the nucleus. There are two compartments- cytosol and organelles
What is the nucleus?
It is the organelle which houses most of the cells DNA
What is the plasma membrane?
It is a selective barrier that allows sufficient passage of oxygen, nutrients, and waste to service the volume of every cell.
What is the general form of a plasma membrane?
A double layer of phospholipids
What happens when the surface area of a cell increases by a factor of n^2?
The volume increases by a volume of n^3
True or false: small cells have a greater surface area relative to volume
True
What is the cytoskeleton?
A network of fibers extending through the cytoplasm
What does the cytoplasm do?
It organizes the cells structures and activities, anchoring many organelles.
What is the cytoskeleton composed of?
Microtubules
Microfilaments
Intermediate filaments
List the 3 diff types of cytoskeleton in order from thickest to thinnest.
Microtubules - thickest
Intermediate filaments - middle
Microfilaments - thinnest
What are the diff types of intercellular junctions?
Plasmodesmata (plant)
Tight junctions
Desmosomes
Gap junctions
What is a tight junction?
Membranes of neighboring cells are pressed together, preventing leakage of extra cellular fluid
What are desmosomes?
They fasten cells together into strong sheets
What are gap junctions?
They provide cytoplasmic channels between adjacent cells
