Cell Biology

Question 1

What is a Cell?

Answer 1

1. The basic structural and functional unit of cellular organisms is called cell.
2. It is capable of independent existence and performing the essential functions of life.
3. Robert Hooke 1665
4. Anton van Leeuwenhoek 1674

Question 2

What are the types of cells?

Answer 2

Prokaryote Cell- A unicellular organism that lacks a membrane bound nucleus, mitochondria, or any other membrane bound organelle
1. Archaea 2. Bacteria

Eukaryote Cell- have nucleus enclosed within membranes and also contain other membrane bound organelles such as Mitochondria and Golgi Apparatus. Maybe part of multicellular organisms.

Question 3

What is Cell Biology?

Answer 3

Cell biology focuses on the structure and function of a cell, from the most general properties shared by all cells, to the unique, highly intricate functions particular to specialized cells. Focusing on the cell permits a detailed understanding of the tissues and organisms that cells compose. Some organisms have only one cell, while others are organized into cooperative groups with huge numbers of cells. Can be divided into subtopics

1. Study of Cell metabolism
2. Cell communication
3. Cell cycle
4. Cell composition

Cell culture, microscopy, Cell fractionation techniques
Interrelated- Cancer Biology

Question 4

Modern interpretation of cell theory:

Answer 4

The cell represents the elementary unit of construction and function in living organisms.
All cells come from the division of pre-existing cells.
Energy flow – metabolism and biochemistry – happens within cells.
Cells contain genetic information in the form of DNA passed on from cell to cell during division.
In the organisms of similar species, all cells are fundamentally the same.
All living organisms consist of one or more cells.
Some cells – unicellular organisms – consist of only one cell.
Other living entities are multicellular, containing multiple cells.
The living organism’s activities depend upon the combined actions of individual, independent cells.

Question 5

Cell Membrane

Answer 5

Surrounded by a structure called the cell membrane — which, much like the walls of a house, serves as a clear boundary between the cell’s internal and external environments. The cell membrane is sometimes also referred to as the plasma membrane.
Cell membranes are based on a framework of fat-based molecules called phospholipids, which physically prevent water-loving, or hydrophilic, substances from entering or escaping the cell. These membranes are also studded with proteins that serve various functions. Some of these proteins act as gatekeepers, determining what substances can and cannot cross the membrane. Others function as markers, identifying the cell as part of the same organism or as foreign. Still others work like fasteners, binding cells together so they can function as a unit. Yet other membrane proteins serve as communicators, sending and receiving signals from neighboring cells and the environment — whether friendly or alarming

Question 6

Techniques to study Cell Biology

Answer 6

Many techniques commonly used to study cell biology are:
Cell culture: Utilizes rapidly growing cells on media which allows for a large amount of a specific cell type and an efficient way to study cells.
Fluorescence microscopy: Fluorescent markers such as GFP, are used to label a specific component of the cell. Afterwards, a certain light wavelength is used to excite the fluorescent marker which can then be visualized.
Phase-contrast microscopy: Uses the optical aspect of light to represent the solid, liquid, and gas phase changes as brightness differences.
Confocal microscopy: Combines fluorescence microscopy with imaging by focusing light and snap shooting instances to form a 3-D image.
Transmission electron microscopy: Involves metal staining and the passing of electrons through the cells, which will be deflected upon interaction with metal. This ultimately forms an image of the components being studies.
Cytometry: The cells are placed in the machine which uses a beam to scatter the cells based on different aspects and can therefore separate them based on size and content. Cells may also be tagged with GFP-florescence and can be separated that way as well.
Cell fractionation: This process requires breaking up the cell using high temperature or sonification followed by centrifugation to separate the parts of the cell allowing for them to be studied separately.