Lecture 5: Cellular Structure and Function Flashcards
(19 cards)
Who is Robert Hooke?
First to observe cells in 1665 in cork (cellulae; Latin for “small rooms”)
Who is Anton van Leeuwenhoek?
First to observe alive cells, which he termed “animalcules”.
What did Matthias Schleiden do?
Proved plants “are aggregates of fully individualized, independent, separate beings,namely the cells themselves” (1838).
What did Theodor Schwann do?
Reported that all animal tissues also consist of individual cells (1839).
3 Basic Rules of Cell Theory
- All organisms are composed of one or more cells, and the life processes of metabolism and heredity occur within these cells.
- Cells are the smallest living things, the basic units of organization of all organisms.
- Cells arise only by the division of a previously existing cell.
What is the range of a Eukaryotic Cell?
10-100 μm in diameter
What is the range of a Prokyriotic Cell?
1-10 μm in diameter
Why is cell size limited?
Square Cube Law (As the length and surface area increase linearly, volume increases exponentially) Cells use diffusion and other passive methods of nutrient transport because constant active transport would be too taxing, to do this surface area must be maximized and also limit the volume because it would be too hard to maintain
What is Resolution?
The minimum distance in which two objects can be observed as separate (The number of distinguishable cells on a screen)
What are 4 Simple Structures All Cells Contain?
- Centrally Located Genetic Material
- A cytoplasm
- Ribosomes that Synthesize Protein
- A Plasma Membrane
What is the main difference between Prokaryotic and Eukaryotic Cells?
Eukaryotic cells have organelles while Prokaryotes don’t
What are the two main types of microscopes and why do they exist?
Light Microscopes: They can see from a range of cm- 500nm because past that visible light is too big (wavelength of visible light 700-500nm)
Electron Microscopes: Since electrons are so small they can see much further but are really complicated and have to use computer mapping to generate results (They work kinda like radar, bouncing back electrons to imagine depth)
What are the two domains of Prokaryotic cells?
Bacteria and Archaea
What are the 3 basic structures of Prokaryotic Cells?
Cytoplasm: Carries out the functions of the Prokaryote, contains all the genetic information and Puedo organelles that allow the cell to function
Plasma Membrane: Acts as a semi-permeable membrane that controls what goes in and out of the cytoplasm
Cell Wall: Determines the shape of the cell (It is influenced by the cytoskeleton, can be rod or sphere-shaped)
Some differences between Bacteria and Achaea
- Bacteria have cell walls
- Achaea have monolayer membrane walls that have great thermal stability
- Achaea has DNA machinery closer to Eukaryotic cells
- Some bacteria: jelly-like polysaccharide capsule
- Antibacterials mess with cell wall membranes which only bacteria have
What is a way some Prokaryotes move?
Flagella: Moves ions in and out in opposing directions and this forces both sides to rotate in the same direction and propel the cell
Made of protein fibres
In a Eukaryotic cell, where is the Genetic Information Stored?
In the cell’s nucleus. It is specifically condensed in the nucleus’s chromatin which is further compressed into chromosomes
How do nutrients and information get in and out of a Nucleus?
Through the nuclear pores on the nuclear envelope found on the outside of the nucleus. The envelope helps keep the cytoplasm from the chromatin and the pores are entrances for nutrients and messenger proteins to travel
What does the nucleolus do in a cell?
The nucleolus contains and manufactures ribosomes and rRNA (Ribosomal RNA) which allows for RNA to be translated into functional code that can be used to make proteins.
