Cells Flashcards
1665 - Cells discovered by ____________
Robert Hooke
1670s - they described single-celled organisms
• Referred to them as “animacules”
Marcello Malpighi and Nehemiah Grew
1809 – __________ said “No body can have life if its constituent parts are not cellular tissue.”
Jean Baptiste de Lamarck
1824 – ___________ concluded that all plant and animal and plant tissues are made of cells
• Reinforced Lamarck’s statement
Rene J.H. Dutrochet
1831 - He discovered the nucleus
Robert Brown
_________ discovered the nucleolus shortly after Brown’s discovery.
Matthias Schleiden
1838 - __________ formulated the Cell Theory
Schleiden and Theodor Schwan
Cell Theory states that all living organisms are composed of cells and cells form a unifying structural basis of organization. True or false?
True
1858 - He argued there is no spontaneous generation of cells.
Rudolf Virchow
• 1862 - experimentally disproved spontaneous generation
• 1871 - concluded that natural alcoholic fermentation always involves the activity of yeast.
Louis Pasteur
1897 – He accidentally discovered that fermentation could occur without living yeast cells
• Extracts from cell contained the necessary enzymes
Eduard Buchner
Increase magnification as light passes through a series of transparent lenses made of glass or calcium fluoride crystals
Light Microscope
Light passes through thinly sliced material. In general, it can distinguish organelles 2 micrometers or larger in diameter. Can magnify up to 1500x
Compound Microscope
Also known as stereomicroscopes. Allow three-dimensional viewing of opaque objects and can magnify up to 30x
Dissecting Microscopes
Use a beam of electrons produced when high-voltage electricity is passed through a wire. Includes transmission and scanning electron microscopes.
Electron Microscope
Up to 200,000x magnification, but material must be sliced extremely thin
Transmission Electron Microscope
Up to 10,000x magnification. Surface detail can be observed on thick objects.
Scanning Electron Microscope
-Uses a probe that tunnels electrons upon a sample. It produces a map of sample surface. Even atoms can become discernible. First picture of DNA segment showing helical structure
Scanning Tunneling Microscope
Cells lack a nucleus. For ex., bacteria
Prokaryotic
Cells contain a nucleus.
• Unicellular eukaryotes, fungi, plants, and animals
• Organelles - Membrane-bound bodies found within eukaryotic cells
Eukaryotic
It surrounds protoplasm
Cell wall
It consists of all living cell components
Protoplasm
It consists of all cellular components between the plasma membrane and the nucleus.
Cytoplasm
Fluid within cytoplasm containing organelles
Cytosol
Persistent structures of various shapes and sizes with specialized functions. Most, but not all, are bound by membranes.
Organelles
Cells of higher plants generally vary in length between ___ and ___ micrometers
10 and 100 micrometers
Increase in surface area of a spherical cell is equal to the square of its increase in diameter, but its increase in volume is equal to the cube of its increase in diameter. True or false?
True
Smaller cells have relatively large surface to volume ratios enabling slower and less efficient cellular communication. True or false?
False, it enables faster and more efficient cellular communication.
Main structural component of cell walls is what?
Cellulose
Holds cellulose fibrils together
Hemicellulose
Gives stiffness (like in fruit jellies) in cell wall
Pectin
Are proteins with associated sugars
Glycoprotein
It is first produced when new cell walls are formed. Shared by two adjacent cells
Middle lamella
Flexible ________________ are laid down on either side of the middle lamella. Consists of a fine network of cellulose, hemicellulose, pectin, and glycoproteins
Primary Cell Wall
These are produced inside primary walls.
Secondary walls
Derived from primary walls by thickening and inclusion of lignin
Secondary wall